CHAPTER S CONCLUSIONS CHAPTER 05 CONCLUSIONS

CHAPTER S CONCLUSIONS

CHAPTER 05

CONCLUSIONS

The shear strength function for the soil found at Pussallawa landslide site can be given by

the following equation.

x = 20+ (a-ua) tan33°+(ua-uw) tan28.46°

The soil water characteristic curve for the same soil has been developed and is shown in

Figure 3.8

The analysis of Kahagalla and Pussallawa landslides show that with the parameters

obtained from lab tests, the slopes should not fail. But, because Kahagalla landslide is

still active, it seems that the laboratory c' and <)>' values do not represent the actual shear

strength parameters of the failure surface. The parameters of the soil available at the

failure surface may have very low shear strength values, or the assumed failure surface

may not approximate the actual failure surface.

The unsaturated analysis shows that the factor of safety of the slope can be increased

considerably by lowering the water table. The analysis of Pussallawa landslide with

parameters obtained from back analysis shows that when the water table is 5m above the

water table, the factor of safety is 1.0 and it increases to 2.02 when the water table is

lowered to 15m below the failure surface.

For Kahagalla landslide, the factor of safety when the water table is 4.8m above the

failure surface is 1.0 when analysed with parameters obtained from back analysis and it is

1.41 when the water table is lowered to 15m below the failure surface. In this landslide

the increase in factor of safety is smaller compared to that in Pussallawa landslide. That is

57

CHAPTER 5 CONCLUSIONS

because the effect of c|)b values. For soil at Pussallawa landslide site, <|>b is 28. 46° while it

is 11.80° for Kahagalla landslide site.

Suggestions For Further Improvements

Before being able to use unsaturated shear strength parameters for slope stability analysis

in Sri Lanka, there are some other areas that need to be developed and further research is

required. The laboratory facilities have to be improved so that standard tests can be done

for unsaturated soils. Instruments are not available in Sri Lanka for insitu measurement of

suction. Instruments are available in other countries for insitu suction measurements. The

parametric study done here is helpful to find out actual factor of safety of slopes if the

insitu suction measurements can be done with depth. When they are known, these actual

suction values can be used in place where suction values calculated from different

assumed percentages of negative hydrostatic pressures have been used in this study.

While practicing unsaturated soil mechanics, one of the main problems that may arise is

maintaining the water table at a constant level. Some of the methods commonly used in

Sri Lanka for this are discussed in Chapter 1. Due to the wetting front that moves

downwards in rainy seasons, the degree of saturation of soil can increase reducing the

shear strength of soil. Therefore, slopes can fail not only due to the changes in the water

table, but also due to the wetting front.

Before being able to use unsaturated soil mechanics in the actual practice of slope

stability analysis, some other areas where research is required are highlighted herein, in

order to facilitate continuation of research in this area so that the knowledge of

unsaturated soil mechanics can be improved and applied to Sri Lankan conditions.

Soil can get saturated both due to infiltration of water and due to rising of the water table.

The effect of variation of the water table on the stability of slopes was considered in this

research. It is also important to study what percentage of precipitation is infiltrated and

how the increase in the degree of saturation due to infiltrated water affects the factor of

58


safety of the slopes. Therefore, another area where research is required is to quantify the

runoff and the amount that infiltrates into the ground in case of a precipitation to an

interested area and establish methods to quantify the maximum degree of saturation both

under precipitation and the effect of rising up of the water table. In literature, some

attempts that have been made to quantify the amount of water infiltrated are encountered.

The amount of water retained by a medium during a precipitation, can be given by the

equation:

R = P- ( Q E + Q R )

where,

R = amount of water retained

P = Precipitation

Q E =the amount of evaporated water

Q R =the amount of runoff

However, in case of intense rain events, which are capable of triggering landslides, the

amount of water evaporated is comparatively low and the above equation can be

modified to

R = P- Q R

Out of the precipitation, only a portion will contribute for saturation of porosity and the

remainder will be run off. The amount of rainwater that infiltrates into the ground will

depend on factors like, the permeability of the surface and subsurface soil, topography of

the area, vegetation cover etc.

The rainfall history (i.e. the rainfall pattern in the days immediately preceding the day

under consideration) also plays a significant role for landslides because this is a causative

factor for saturation of a terrain's porosity and forming a water table that will be

recharged further by subsequent precipitation. A model been developed to find out the

landslide triggering precipitation after studying four rain induced landslides in the central

59


highland of Sri Lanka by Mohottala et al, (1994). According to that, the retention after a

rainstorm that prevailed for n days is given by:

R = a Z £ X ' P. / = i

where;

a = the percentage of precipitation infiltrated into the ground

Pi = rainfall on the i t h day preceding the event

X = a constant which regulates the phenomenon's pattern in time and depends on

permeability of soil (proposed to be takeen as 0.72 per day)

However in this model also, no suggestions have been made to find out factor a,which is

the percentage of precipitation into the round.

Thus, further research can be suggested in the area of modeling quantities of infiltration

and runoff in landslide hazardous areas.

There is also a close relationship between triggering of landslides and the intensity of

rainfall. After investigating 9 landslide prone areas in Southeastern Brazil, Guidizine and

Ivatya (1977), have noted that the landslides are generally due to precipitation event of

intensity greater than 12% of the annual rainfall. Doing a similar study for 20 landslides

that occurred during the period 1986-1989 in the central highland of Sri Lanka,

Mohottala et al, (1994) report that in nearly all the cases, the 24-hour rainfall event which

was believed to be the causative factor for the instability was under 8% of the annual

rainfall. In case of such high intense rainstorms, if important slopes can be kept

unsaturated by some means as proposed in the Chapter 1, the slopes can still be

maintained stable.

60

CHAPTER 6 REFERENCES

REFERENCES

1. Ching, R.K.H., Sweeney D.J., and Fredland D.G., 1994. Increase in factor of

safety due to soil suction for two Hong Kong slopes; Proceedings, Fourth

International Symposium on Landslides, Toronto, pp 617-6 23.

2. Fredland, D.G., Morgenstern N.R., and Widger R.A., 1978. The shear strength of

unsaturated soils. Canadian Geotechnical Journal, 15: 313-321.

3. Fredland, D.G., 1979. Appropriate concepts and technology for unsaturated soils.

Canadian Geotechnical Journal, 16:121-139.

4. Fredland, D.G., 1989. Negative pore water pressures in slope stability.

Proceedings, South American symposium on slope stability, Paipa, Colombia.

5. Fredland, D.G., and Rahardjo H., 1993. Soil mechanics for unsaturated soils, John

Willey & Sons, New York, NY.

6. Fredland, D.G., Xing. A., and Huang S.Y., 1994. Predicting the permeability

function for unsaturated soils using the soil water characteristic curve. Canadian

Geotechnical Journal, 31(4): 533-546.

7. Fredlund, D.G., and Xing, A. 1994. Equations for the soil-water characteristic

curve. Canadian Geotechnical Journal, 31: 521-532.

8. Fredlund, D.G., 1995a. The scope of unsaturated soil mechanics: An overview.

Keynote address, 1 s t international conference on unsaturated soils, Paris France.

Edited by Alonso, E.E. Balkema Publishers, Rotterdam, The Netherlands Vol.3,

pp. 1155-1177.

9. Fredland, D.G., 1995b. The stability of slopes with negative pore water pressures.

Procedings, Ian Boyd Donald Symposium on Modern Developments in

Geomechanics. Monash University, Melburne, Australia, pp. 99-116.

61


10. Fredland, D.G., Xing A., and Barbour S.L., 1996. The relationship of the

unsaturated soil strength function to soil water characteristic curve. Canadian

Geotechnical Journal, 33 (3): 440-448.

11. Fredland, D.G., 1997. From theory to practice of unsaturated soil mechanics,

Procedings, 3 r d Brazilian Symposium on Unsaturated Soils; Rio de Janeiro, Brazil.

12. Gan, J.K.M., Fredland D.G., and Rahardjo H., 1988. Determination of the shear

strength parameters of an unsaturated soil using the direct shear test. Canadian

Geotechnical Journal, 25 (3): 500-510.

13. Guidicini, G., and Iwaya, O.Y., 1977. Tentative correlation between rainfall and

landslides in humid tropical environment. Bulletin of the international Association

of Engineering Geology, No 16, 13-20, Krefeld.

14. Ho, D.Y.F., and Fredland, D.G, 1982. Multi stage triaxial test for unsaturated

soils. ASTM, Geotechnical Testing Journal, 5(1/2): 18-25, 1982.

15. Janbu, N., 1973. " Slope Stability Computations", Embankment Dam

Engineering, Casagrande V., Hirschfield E and Poulous S. (Ed), John Willey,

New York, 47-86.

16. Mallawarachchi, D.P., Rajapakse, L., and Bandara, K.A.G.S., 1994. Remedial

measures for stabilizing landslide at Pussallawa on Kanky Nuwara Eliysa road:

Construction aspects. Proceedings, National symposium on landslides in Sri

Lanka. Colombo: 17-19 March 1994. pp. 317-324.

17. Mohottala, A.W., and Chandrapala, L., 1994. Relationship between rainfall and

Landslides with particular reference to the hilly regions of Sri Lanka. National

Symposium on Landslides in Sri Lanka, Colombo, Sri Lanka.

18. Morgenstern, N.R., and Price, V.E.W., 1965. The analysis of the stability of

general slip surfaces. Geotechniques. 15(1): 79-93.

62


19. Rajarathnam, K., and Bhandari, R.K., 1994. Prediction of rainfall return periods

for the Watawala landslide area. Proceedings, National symposium on landslides

in Sri Lanka, Colombo, Sri Lanka.

20. Rathnajothy, T., and Puswewala, U.G.A., 2001. Matric suction characteristics of

unsaturated residual soils of Sri Lanka. Thesis for the Degree of M. Ena. In

Geotechnical engineering.

21. Sweeny, D.J., 1982. Some insitu soil suction measurements in Hong Kong's

residual soil slopes. Proceedings, 7 t h South East Asian Regional Conference,

Vol.1, pp 91-106.

22. Terzarghi, K., 1936. The shear resistance of saturated soils. Proceedings, 1 s t

International Conference in Soil Mechanics and Foundation Engineering

(Cambridge, MA) Vol. 1, pp. 54-56.

23. Tennakoon, B.L., 1994. Residual soils and colluvium deposits of Sri Lanka, their

investigation, testing and engineering behavior. Proceedings, National symposium

on landslides in Sri Lanka.

24. Wickramasekara, K., and Sinnathamby, R., 1994. Some rain induced landslides of

Sri Lanka and Criteria for earth warning. Proceedings, National symposium on

landslides in Sri Lanka, Colombo, Sri Lanka.

25. Wulfsohn, B.A., Adams, and Fredland D.G. Application of unsaturated soil

mechanics for agricultural conditions. Canadian Agricultural Engineering, 38(3):

173-181, 1996.

63

Appendix A Consolidated Undrained Triaxial Test Results

Consolidated Undrained Triaxial Test Results

300

250

200

« 150

100

50

Stress Path Plot

\ HB"^--.

i i 1 i

i

\ \ i

100 200 300 400

s ' k P a

500 600

Shear Strength Parameters

f = 33

20kPa o

64

APPENDIX A CONSOLIDATED DRAINED T R I A X I A L TEST RESULTS ON UNSATURATED SAMPLES

Sample : Pussallawa

U a = 80kPa U w = 50kPa a 3 =230kPa Dry density = 1725kg/m3 Rate of Strain = 0.001"/min

Vertical displ-. acement(div)

Proving ring reading(div)

Axial strain

(%)

Volume g a u g e reading(ml)

Corrected area(mm 2 )

Deviator s t r e s s (kN/m 2)

0 0.0 0.00 27.80 1991.08 0.00 10 12.0 0.23 27.85 1996.05 10.99 20 11.0 0.45 27.90 2001.04 10.05 30 9.0 0.68 27.90 2005.61 8.20 40 47.0 0.91 27.90 2010.20 42.74 50 78.0 1.13 27.75 2013.46 70.82 60 105.0 1.36 27.50 2015.83 95.22 70 125.0 1.59 27.15 2017.30 113.27 80 143.0 1.81 26.95 2020.14 129.40 90 160.0 2.04 26.55 2021.17 144.71 100 176.0 2.27 26.25 2023.12 159.03 110 191.0 2.49 26.05 2025.99 172.33 120 205.0 2.72 25.70 2027.50 184.83 130 219.0 2.95 25.50 2030.40 197.17 140 232.0 3.18 25.25 2032.85 208.62 150 246.0 3.40 24.95 2034.85 220.99 160 258.0 3.63 24.75 2037.78 231.44 170 271.0 3.86 24.50 2040.27 242.81 180 282.0 4.08 24.25 2042.76 252.35 190 292.0 4.31 24.00 2045.27 260.98 200 302.0 4.54 23.85 2048.73 269.46 210 312.0 4.76 23.65 2051.73 277.98 220 321.0 4.99 23.45 2054.75 285.58 230 330.0 5.22 23.30 2058.25 293.08 240 339.0 5.44 23.15 2061.77 300.56 250 347.0 5.67 22.95 2064.83 307.20 260 355.0 5.90 22.80 2068.39 313.74 270 363.0 6.12 22.70 2072.43 320.19 280 371.0 6.35 22.55 2076.02 326.68 290 379.0 6.58 22.45 2080.10 333.07 300 385.0 6.80 22.30 2083.73 337.75 310 392.0 7.03 22.20 2087.85 343.21 320 399.0 7.26 22.05 2091.51 348.73 330 406.0 7.48 21.95 2095.67 354.14 340 412.0 7.71 21.75 2098.89 358.83 350 418.0 7.94 21.70 2103.57 363.24 360 425.0 8.16 21.60 2107.80 368.58 370 432.0 8.39 21.50 2112.04 373.90 380 439.0 8.62 21.40 2116.30 379.19 390 446.0 8.84 21.30 2120.59 384.46 400 453.0 9.07 21.25 2125.39 389.62 410 460.0 9.30 21.15 2129.72 394.83 420 467.0 9.53 21.10 2134.56 399.93 430 473.0 9.75 21.05 2139.43 404.15

65

APPENDIX A CONSOLIDATED DRAINED T R I A X I A L TEST RESULTS ON UNSATURATED SAMPLES Vertical displ-. Proving ring Axial strain Volume g a u g e Corrected Deviator s t r e s s acement(div) reading(div) (%) reading(ml) area(mm 2 ) (kN/m 2)

440 479.0 9.98 20.90 2143.33 408.53 450 485.0 10.21 20.80 2147.75 412.79 460 490.0 10.43 20.80 2153.19 416.00 470 496.0 10.66 20.75 2158.16 420.12 480 500.0 10.89 20.70 2163.15 422.53 490 504.0 11.11 20.60 2167.66 425.03 500 507.0 11.34 20.50 2172.20 426.66 510 511.0 11.57 20.50 2177.77 428.93 520 514.0 11.79 20.40 2182.36 430.54 530 517.0 12.02 20.40 2187.98 431.94 540 519.0 12.25 20.30 2192.62 432.69 550 522.0 12.47 20.20 2197.28 434.27 560 525.0 12.70 20.20 2202.99 435.64 570 526.0 12.93 20.10 2207.70 435.53 580 527.0 13.15 20.10 2213.47 435.23 590 528.0 13.38 20.05 2218.75 435.01 600 528.0 13.61 20.05 2224.57 433.87 610 528.0 13.83 20.05 2230.42 432.74 620 528.0 14.06 20.05 2236.31 431.60 630 527.0 14.29 20 2241.71 429.74 640 527.0 14.51 20 2247.65 428.61 650 526.0 14.74 20 2253.63 426.66

Stress Vs Strain (Pussallawa)

66


Sample : Pussallawa U a = 115 kPa U w = 50kPa a 3 = 265 kPa Dry density = 1725kg/m3 Rate of Strain = 0.00257min



Axial strain

(%)




0 0.0 0.00 22.80 2005.82 0.00 10 20.0 0.23 22.80 2010.38 18.19 20 18.0 0.45 22.80 2014.96 16.33 30 22.0 0.68 22.80 2019.56 19.91 40 72.0 0.91 22.80 2024.18 65.02 50 118.0 1.13 22.80 2028.83 106.32 60 170.0 1.36 22.80 2033.49 152.82 70 211.0 1.59 22.80 2038.18 189.24 80 242.0 1.81 22.80 2042.89 216.54 90 267.0 2.04 22.80 2047.62 238.36 100 285.0 2.27 22.80 2052.37 253.84 110 302.0 2.49 22.80 2057.14 268.36 120 316.0 2.72 22.80 2061.94 280.15 130 328.0 2.95 22.80 2066.75 290.11 140 340.0 3.18 22.80 2071.60 300.02 150 351.0 3.40 22.80 2076.46 309.00 160 361.0 3.63 22.80 2081.35 317.06 170 369.0 3.86 22.80 2086.26 323.32 180 380.0 4.08 22.80 2091.19 332.17 190 389.0 4.31 22.80 2096.14 339.24 200 397.0 4.54 22.80 2101.12 345.39 210 405.0 4.76 22.80 2106.13 351.52 220 414.0 4.99 22.80 2111.15 358.47 230 422.0 5.22 22.80 2116.21 364.53 240 431.0 5.44 22.80 2121.28 371.41 250 439.0 5.67 22.80 2126.38 377.40 260 447.0 5.90 22.80 2131.51 383.35 270 455.0 6.12 22.80 2136.65 389.27 280 464.0 6.35 22.80 2141.83 396.01 290 470.0 6.58 22.80 2147.03 400.16 300 476.0 6.80 22.80 2152.25 404.29 310 482.0 7.03 22.80 2157.50 408.39 320 488.0 7.26 22.80 2162.78 412.46 330 493.0 7.48 22.80 2168.08 415.67 340 499.0 7.71 22.80 2173.41 419.70 350 504.0 7.94 22.80 2178.76 422.86 360 509.0 8.16 22.80 2184.14 426.00 370 514.0 8.39 22.80 2189.55 429.13 380 519.0 8.62 22.80 2194.98 432.23 390 524.0 8.84 22.80 2200.44 435.31 400 529.0 9.07 22.80 2205.93 438.37 410 534.0 9.30 22.80 2211.45 441.41 420 539.0 9.53 22.80 2216.99 444.43 430 544.0 9.75 22.80 2222.56 447.43

67

APPENDIX A CONSOLIDATED DRAINED T R I A X I A L TEST RESULTS ON UNSATURATED SAMPLES Vertical displ-. acement(div)


Axial strain

(%)




440 549.0 9.98 22.80 2228.16 450.40 450 554.0 10.21 22.80 2233.79 453.36 460 559.0 10.43 22.80 2239.44 456.30 470 564.0 10.66 22.80 2245.13 459.21 480 569.0 10.89 22.80 2250.84 462.11 490 574.0 11.11 22.80 2256.59 464.98 500 579.0 11.34 22.80 2262.36 467.84 510 584.0 11.57 22.80 2268.16 470.67 520 589.0 11.79 22.80 2273.99 473.48 530 594.0 12.02 22.80 2279.85 476.27 540 599.0 12.25 22.80 2285.74 479.04 550 604.0 12.47 22.80 2291.67 481.79 560 608.0 12.70 22.80 2297.62 483.73 570 612.0 12.93 22.80 2303.60 485.65 580 616.0 13.15 22.80 2309.62 487.55 590 620.0 13.38 22.80 2315.67 489.43 600 624.0 13.61 22.80 2321.75 491.30 610 630.0 13.83 22.80 2327.86 494.72 620 634.0 14.06 22.80 2334.00 496.55 630 638.0 14.29 22.80 2340.17 498.37 640 641.0 14.51 22.80 2346.38 499.38 650 644.0 14.74 22.80 2352.62 500.39 660 647.0 14.97 22.80 2358.90 501.38 670 650.0 15.19 22.80 2365.21 502.37 680 653.0 15.42 22.80 2371.55 503.34 690 656.0 15.65 22.80 2377.93 504.29 700 659.0 15.88 22.80 2384.34 505.24 710 662.0 16.10 22.80 2390.78 506.17 720 665.0 16.33 22.80 2397.26 507.09 730 668.0 16.56 22.80 2403.78 507.99 740 670.0 16.78 22.80 2410.33 508.13 750 672.0 17.01 22.80 2416.91 508.26 760 674.0 17.24 22.80 2423.54 508.38 770 676.0 17.46 22.80 2430.20 508.49 780 678.0 17.69 22.80 2436.89 508.59 790 680.0 17.92 22.80 2443.62 508.69 800 682.0 18.14 22.80 2450.39 508.77 810 684.0 18.37 22.80 2457.20 508.85 820 686.0 18.60 22.80 2464.05 508.92 830 688.0 18.82 22.80 2470.93 508.98 840 690.0 19.05 22.80 2477.85 509.04 850 692.0 19.28 22.80 2484.81 509.08 860 694.0 19.50 22.80 2491.82 509.12 870 696.0 19.73 22.80 2498.86 509.15 880 698.0 19.96 22.80 2505.94 509.17 890 700.0 20.18 22.80 2513.06 509.18 900 703.0 20.41 22.80 2520.22 509.91 910 705.0 20.64 22.80 2527.42 509.90 920 707.0 20.86 22.80 2534.66 509.89 930 711.0 21.09 22.80 2541.95 511.30

68


Vertical displ-. Proving ring Axial strain Volume g a u g e Corrected Deviator s t r e s s acement(div) reading(div) (%) reading(ml) area(mm 2 ) (kN/m 2)

940 713.0 21.32 22.80 2549.27 511.27 950 715.0 21.54 22.80 2556.64 511.23 960 717.0 21.77 22.80 2564.05 511.17 970 719.0 22.00 22.80 2571.51 511.11 980 721.0 22.23 22.80 2579.01 511.04 990 723.0 22.45 22.80 2586.55 510.97 1000 725.0 22.68 22.80 2594.14 510.88 1010 727.0 22.91 22.80 2601.77 510.79 1020 729.0 23.13 22.80 2609.44 510.69 1030 730.0 23.36 22.80 2617.16 509.88 1040 731.0 23.59 22.80 2624.93 509.07 1050 732.0 23.81 22.80 2632.74 508.25 1060 733.0 24.04 22.80 2640.61 507.43 1070 734.0 24.27 22.80 2648.51 506.61 1080 734.0 24.49 22.80 2656.47 505.09 1090 734.0 24.72 22.80 2664.47 503.57 1100 734.0 24.95 22.80 2672.52 502.05 1110 733.0 25.17 22.80 2680.62 499.86 1120 733.0 25.40 22.80 2688.77 498.34


a 3 = 265 kPa U a = 115 kPa Uw = 50 kPa

0.00 5.00 10.00 15.00

S t r a i n (%)

20.00 25.00

69


Sample : Pussallawa U a = 150 kPa U w =50kPa a 3 = 300kPa Dry density = 1725kg/m3 Rate of Strain = 0.00257min



Axial strain

(%)




0 0.0 0.00 26.25 1979.02 0.00 10 5.0 0.23 26.25 1983.52 4.61 20 53.0 0.45 26.25 1988.04 48.73 30 102.0 0.68 26.25 1992.58 93.58 40 162.0 0.91 26.20 1996.69 148.31 50 224.0 1.13 26.20 2001.27 204.61 60 270.0 1.36 26.20 2005.87 246.06 70 301.0 1.59 26.20 2010.49 273.68 80 324.0 1.81 26.20 2015.14 293.91 90 347.0 2.04 26.15 2019.35 314.12 100 372.0 2.27 26.15 2024.03 335.97 110 391.0 2.49 26.15 2028.74 352.31 120 404.0 2.72 26.15 2033.47 363.18 130 419.0 2.95 26.15 2038.22 375.78 140 429.0 3.18 26.15 2043.00 383.85 150 442.0 3.40 26.15 2047.79 394.56 160 452.0 3.63 26.15 2052.61 402.54 170 461.0 3.86 26.15 2057.45 409.59 180 469.0 4.08 26.10 2061.85 415.81 190 475.0 4.31 26.10 2066.74 420.13 200 483.0 4.54 26.10 2071.65 426.19 210 489.0 4.76 26.10 2076.58 430.46 220 495.0 4.99 26.10 2081.54 434.71 230 501.0 5.22 26.10 2086.52 438.93 240 506.0 5.44 26.05 2091.05 442.35 250 512.0 5.67 26.05 2096.08 446.52 260 516.0 5.90 26.00 2100.66 449.03 270 522.0 6.12 25.95 2105.25 453.25 280 529.0 6.35 25.90 2109.88 458.33 290 536.0 6.58 25.85 2114.52 463.37 300 542.0 6.80 25.85 2119.66 467.42 310 549.0 7.03 25.85 2124.83 472.31 320 556.0 7.26 25.85 2130.03 477.16 330 561.0 7.48 25.85 2135.25 480.27 340 566.0 7.71 25.85 2140.50 483.37 350 571.0 7.94 25.85 2145.77 486.44 360 576.0 8.16 25.85 2151.07 489.49 370 580.0 8.39 25.85 2156.40 491.67 380 586.0 8.62 25.85 2161.75 495.53 390 592.0 8.84 25.85 2167.13 499.36 400 598.0 9.07 25.85 2172.53 503.17 410 605.0 9.30 25.85 2177.96 507.79 420 611.0 9.53 25.85 2183.42 511.54 430 616.0 9.75 25.85 2188.91 514.43

70



440 623.0 9.98 25.80 2193.93 519.09 450 629.0 10.21 25.80 2199.47 522.77 460 634.0 10.43 25.80 2205.04 525.59 470 639.0 10.66 25.80 2210.63 528.40 480 640.0 10.89 25.80 2216.26 527.88 490 646.0 11.11 25.80 2221.92 531.47 500 652.0 11.34 25.75 2227.09 535.16 510 658.0 11.57 25.75 2232.81 538.71 520 662.0 11.79 25.75 2238.55 540.59 530 666.0 12.02 25.75 2244.32 542.46 540 670.0 12.25 25.75 2250.12 544.31 550 674.0 12.47 25.75 2255.95 546.14 560 678.0 12.70 25.75 2261.81 547.96 570 682.0 12.93 25.75 2267.70 549.76 580 686.0 13.15 25.75 2273.62 551.55 590 690.0 13.38 25.75 2279.57 553.31 600 694.0 13.61 25.75 2285.56 555.06 610 698.0 13.83 25.75 2291.57 556.80 620 701.0 14.06 25.75 2297.62 557.72 630 704.0 14.29 25.70 2303.18 558.75 640 707.0 14.51 25.70 2309.29 559.65 650 710.0 14.74 25.70 2315.43 560.53 660 713.0 14.97 25.65 2321.08 561.53 670 716.0 15.19 25.65 2327.29 562.39 680 719.0 15.42 25.65 2333.53 563.24 690 722.0 15.65 25.65 2339.80 564.07 700 725.0 15.88 25.65 2346.11 564.89 710 728.0 16.10 25.65 2352.45 565.70 720 731.0 16.33 25.65 2358.83 566.50 730 734.0 16.56 25.65 2365.24 567.28 740 737.0 16.78 25.65 2371.68 568.05 750 740.0 17.01 25.65 2378.17 568.81 760 743.0 17.24 25.65 2384.68 569.55 770 746.0 17.46 25.65 2391.23 570.29 780 749.0 17.69 25.65 2397.82 571.01 790 752.0 17.92 25.65 2404.45 571.71 800 755.0 18.14 25.65 2411.11 572.41 810 759.0 18.37 25.65 2417.81 573.85 820 762.0 18.60 25.65 2424.54 574.51 830 765.0 18.82 25.65 2431.32 575.17 840 768.0 19.05 25.65 2438.13 575.81 850 771.0 19.28 25.65 2444.98 576.44 860 774.0 19.50 25.65 2451.87 577.06 870 777.0 19.73 25.65 2458.79 577.66 880 780.0 19.96 25.65 2465.76 578.26 890 783.0 20.18 25.65 2472.77 578.84 900 786.0 20.41 25.65 2479.81 579.40 910 789.0 20.64 25.65 2486.90 579.96 920 791.0 20.86 25.65 2494.03 579.76 930 794.0 21.09 25.65 2501.19 580.30

71




Axial strain

(%)




940 797.0 21.32 25.65 2508.40 580.81 950 799.0 21.54 25.65 2515.65 580.59 960 801.0 21.77 25.65 2522.95 580.36 970 803.0 22.00 25.65 2530.28 580.13 980 805.0 22.23 25.65 2537.66 579.88 990 807.0 22.45 25.65 2545.08 579.63 1000 809.0 22.68 25.65 2552.55 579.36 1010 811.0 22.91 25.65 2560.05 579.09 1020 813.0 23.13 25.65 2567.61 578.81 1030 815.0 23.36 25.65 2575.21 578.52 1040 817.0 23.59 25.65 2582.85 578.23 1050 819.0 23.81 25.65 2590.54 577.92 1060 821.0 24.04 25.65 2598.27 577.61 1070 823.0 24.27 25.65 2606.05 577.29 1080 825.0 24.49 25.65 2613.88 576.96 1090 827.0 24.72 25.65 2621.75 576.62 1100 829.0 24.95 25.65 2629.67 576.27 1110 831.0 25.17 25.65 2637.65 575.92 1120 833.0 25.40 25.65 2645.66 575.55 1130 835.0 25.63 25.65 2653.73 575.18 1140 837.0 25.85 25.65 2661.85 574.80 1150 839.0 26.08 25.65 2670.01 574.41 1160 841.0 26.31 25.65 2678.23 574.02 1170 843.0 26.53 25.65 2686.50 573.61 1180 845.0 26.76 25.65 2694.82 573.20 1190 847.0 26.99 25.65 2703.19 572.77 1200 849.0 27.21 25.65 2711.61 572.34 1210 851.0 27.44 25.65 2720.09 571.90 1220 853.0 27.67 25.65 2728.61 571.46 1230 855.0 27.89 25.65 2737.20 571.00 1240 857.0 28.12 25.65 2745.83 570.54 1250 859.0 28.35 25.65 2754.52 570.06 1260 861.0 28.58 25.65 2763.27 569.58 1270 863.0 28.80 25.65 2772.07 569.09 1280 865.0 29.03 25.65 2780.93 568.59 1290 867.0 29.26 25.65 2789.84 568.09 1300 869.0 29.48 25.65 2798.82 567.57 1310 871.0 29.71 25.65 2807.85 567.05 1320 872.0 29.94 25.65 2816.93 565.87 1330 873.0 30.16 25.65 2826.08 564.68 1340 874.0 30.39 25.65 2835.29 563.50 1350 875.0 30.62 25.65 2844.56 562.30 1360 876.0 30.84 25.65 2853.88 561.10 1370 877.0 31.07 25.65 2863.27 559.90 1380 878.0 31.30 25.65 2872.73 558.70 1390 879.0 31.52 25.65 2882.24 557.49 1400 880.0 31.75 25.65 2891.82 556.27 1410 881.0 31.98 25.65 2901.46 555.05 1420 882.0 32.20 25.65 2911.16 553.83 1430 883.0 32.43 25.65 2920.93 552.61

72




Axial strain

(%)




1440 884.0 32.66 25.65 2930.77 551.37 1450 885.0 32.88 25.65 2940.67 550.14 1460 886.0 33.11 25.65 2950.64 548.90 1470 887.0 33.34 25.65 2960.68 547.66 1480 888.0 33.56 25.65 2970.79 546.41 1490 888.0 33.79 25.65 2980.96 544.54 1500 888.0 34.02 25.65 2991.21 542.68 1510 888.0 34.24 25.65 3001.53 540.81 1520 887.0 34.47 25.65 3011.92 538.34 1530 887.0 34.70 25.65 3022.38 536.48 1540 887.0 34.93 25.65 3032.91 534.61 1550 886.0 35.15 25.65 3043.51 532.15 1560 886.0 35.38 25.65 3054.20 530.29 1570 885.0 35.61 25.65 3064.95 527.83 1580 885.0 35.83 25.65 3075.78 525.97


600.00

0.00 10.00 20.00 30.00

S t r a i n (%)

73


Sample : Pussallawa U a = 200 kPa U w =50kPa a 3 = 350kPa Dry density = 1725kg/m3 Rate of Strain =0.0025" /min



Axial strain

(%)




0 0.0 0.00 33.10 1949.10 0.00 10 11.0 0.23 33.00 1952.64 10.30 20 11.0 0.45 32.95 1956.64 10.28 30 11.0 0.68 32.95 1961.10 10.25 40 115.0 0.91 32.95 1965.59 106.95 50 115.0 1.13 32.95 1970.10 106.71 60 115.0 1.36 32.95 1974.63 106.46 70 154.0 1.59 32.95 1979.18 142.24 80 215.0 1.81 32.95 1983.75 198.12 90 259.0 2.04 32.90 1987.89 238.17 100 311.0 2.27 32.90 1992.50 285.32 110 369.0 2.49 32.90 1997.14 337.75 120 410.0 2.72 32.85 2001.33 374.49 130 442.0 2.95 32.85 2006.01 402.78 140 469.0 3.18 32.85 2010.71 426.38 150 493.0 3.40 32.80 2014.97 447.26 160 512.0 3.63 32.80 2019.71 463.40 170 529.0 3.86 32.75 2024.01 477.77 180 544.0 4.08 32.75 2028.79 490.16 190 560.0 4.31 32.75 2033.60 503.38 200 573.0 4.54 32.70 2037.96 513.97 210 586.0 4.76 32.70 2042.82 524.38 220 597.0 4.99 32.70 2047.69 532.95 230 608.0 5.22 32.65 2052.12 541.60 240 618.0 5.44 32.65 2057.04 549.19 250 619.0 5.67 32.60 2061.51 548.88 260 639.0 5.90 32.60 2066.48 565.26 270 649.0 6.12 32.55 2071.00 572.85 280 659.0 6.35 32.55 2076.01 580.27 290 669.0 6.58 32.55 2081.05 587.65 300 677.0 6.80 32.50 2085.64 593.37 310 683.0 7.03 32.50 2090.73 597.17 320 689.0 7.26 32.50 2095.84 600.95 330 695.0 7.48 32.45 2100.49 604.84 340 701.0 7.71 32.45 2105.66 608.57 350 707.0 7.94 32.40 2110.36 612.41 360 711.0 8.16 32.40 2115.57 614.35 370 717.0 8.39 32.40 2120.81 618.01 380 721.0 8.62 32.40 2126.07 619.92 390 726.0 8.84 32.35 2130.87 622.81 400 730.0 9.07 32.35 2136.18 624.68 410 732.0 9.30 32.35 2141.52 624.83 420 736.0 9.53 32.35 2146.89 626.68 430 739.0 9.75 32.35 2152.29 627.65

74

APPENDIX A CONSOLIDATED DRAINED T R I A X I A L TEST RESULTS ON UNSATURATED SAMPLES Vertical displ-. Proving ring Axial strain Volume g a u g e Corrected Deviator s t r e s s acement(div) reading(div) (%) reading(ml) area(mm 2 ) (kN/m 2)

440 743.0 9.98 32.35 2157.71 629.47 450 747.0 10.21 32.30 2162.66 631.41 460 751.0 10.43 32.30 2168.14 633.18 470 755.0 10.66 32.30 2173.64 634.94 480 759.0 10.89 32.30 2179.17 636.69 490 764.0 11.11 32.30 2184.73 639.25 500 769.0 11.34 32.30 2190.32 641.79 510 774.0 11.57 32.30 2195.94 644.31 520 779.0 11.79 32.25 2201.08 646.96 530 784.0 12.02 32.25 2206.75 649.44 540 789.0 12.25 32.25 2212.45 651.90 550 793.0 12.47 32.20 2217.68 653.66 560 797.0 12.70 32.20 2223.44 655.25 570 800.0 12.93 32.20 2229.23 656.01 580 803.0 13.15 32.20 2235.05 656.76 590 806.0 13.38 32.20 2240.90 657.49 600 810.0 13.61 32.20 2246.78 659.02 610 813.0 13.83 32.20 2252.70 659.73 620 818.0 14.06 32.20 2258.64 662.04 630 820.0 14.29 32.15 2264.10 662.06 640 823.0 14.51 32.15 2270.10 662.72 650 826.0 14.74 32.15 2276.14 663.37 660 828.0 14.97 32.15 2282.21 663.21 670 831.0 15.19 32.15 2288.32 663.84 680 833.0 15.42 32.15 2294.45 663.65 690 836.0 15.65 32.15 2300.62 664.26 700 839.0 15.88 32.10 2306.29 665.00 710 842.0 16.10 32.10 2312.53 665.58 720 845.0 16.33 32.10 2318.79 666.15 730 849.0 16.56 32.10 2325.10 667.49 740 852.0 16.78 32.10 2331.43 668.03 750 856.0 17.01 32.10 2337.80 669.33 760 859.0 17.24 32.10 2344.21 669.84 770 862.0 17.46 32.10 2350.65 670.34 780 867.0 17.69 32.10 2357.13 672.38 790 871.0 17.92 32.10 2363.64 673.62 800 875.0 18.14 32.10 2370.19 674.84 810 878.0 18.37 32.10 2376.77 675.28 820 881.0 18.60 32.05 2382.85 675.86 830 884.0 18.82 32.05 2389.50 676.27 840 889.0 19.05 32.05 2396.20 678.20 850 890.0 19.28 32.05 2402.93 677.06 860 893.0 19.50 32.05 2409.70 677.43 870 895.0 19.73 32.05 2416.51 677.04 880 899.0 19.96 32.05 2423.35 678.14 890 901.0 20.18 32.05 2430.24 677.72 900 903.0 20.41 32.05 2437.16 677.30 910 905.0 20.64 32.05 2444.13 676.86 920 907.0 20.86 32.05 2451.13 676.42 930 909.0 21.09 32.05 2458.18 675.97

75




Axial strain

(%)




940 910.0 21.32 32.05 2465.26 674.77 950 912.0 21.54 32.05 2472.39 674.30 960 916.0 21.77 32.05 2479.56 675.30 970 918.0 22.00 32.05 2486.76 674.81 980 921.0 22.23 32.05 2494.02 675.05 990 924.0 22.45 32.05 2501.31 675.28 1000 927.0 22.68 32.05 2508.65 675.49 1010 930.0 22.91 32.00 2515.45 675.84 1020 933.0 23.13 32.00 2522.87 676.03 1030 937.0 23.36 32.00 2530.33 676.92 1040 945.0 23.59 32.00 2537.84 680.68 1050 947.0 23.81 32.00 2545.40 680.10 1060 949.0 24.04 32.00 2553.00 679.50 1070 952.0 24.27 32.00 2560.64 679.62 1080 954.0 24.49 32.00 2568.33 679.01 1090 956.0 24.72 32.00 2576.07 678.39 1100 958.0 24.95 32.00 2583.85 677.76 1110 961.0 25.17 32.00 2591.68 677.82 1120 964.0 25.40 32.00 2599.56 677.88 1130 967.0 25.63 32.00 2607.49 677.92 1140 969.0 25.85 31.95 2614.86 677.41 1150 971.0 26.08 31.95 2622.89 676.73 1160 973.0 26.31 31.95 2630.96 676.04 1170 975.0 26.53 31.95 2639.08 675.35 1180 977.0 26.76 31.95 2647.25 674.65 1190 979.0 26.99 31.95 2655.47 673.93 1200 982.0 27.21 31.95 2663.75 673.90 1210 985.0 27.44 31.90 2671.46 674.01 1220 989.0 27.67 31.90 2679.83 674.63 1230 991.0 27.89 31.90 2688.26 673.87 1240 993.0 28.12 31.90 2696.74 673.11 1250 994.0 28.35 31.90 2705.28 671.66 1260 996.0 28.58 31.90 2713.87 670.88 1270 996.0 28.80 31.90 2722.51 668.75 1280 997.0 29.03 31.90 2731.21 667.29 1290 999.0 29.26 31.90 2739.97 666.49 1300 999.0 29.48 31.90 2748.78 664.36

1310 997.0 | 29.71 31.90 2757.65 660.89 1320 996.0 29.94 31.90 2766.58 658.10 1330 996.0 30.16 31.90 2775.56 655.97 1340 995.0 30.39 31.90 I 2784.60 653.18

* III.II •

tt

V\ ... .. • • * ... a. j lll.ll • * 111 II . a

i.

Stress Vs S t r a i n ( P u s s a l l a w a )

/ a 3 = 350 kPa / U a = 200kPa j U w = 50kPa

II S.ll 11.11 11.II 11.11 II.II II. Straia. ( x )

ii

76


Sample : Pussallawa

U a = 225 kPa U w = 50kPa a 3 = 375 kPa Dry density = 1725kg/m3 Rate of Strain = 0.00257min

Vertical displ-. Proving ring Axial strain Volume g a u g e Corrected Deviator s t r e s s

acement(div) reading(div) (%) reading(ml) area(mm 2 ) (kN/m 2) 0 0.0 0.00 34.75 2033.96 0.00 10 14.0 0.23 34.75 2038.58 12.55 20 14.0 0.45 34.75 2043.23 12.53 30 72.0 0.68 34.75 2047.89 64.27 40 140.0 0.91 34.75 2052.58 124.68 50 212.0 1.13 34.75 2057.29 188.37 60 281.0 1.36 34.75 2062.02 249.11 70 344.0 1.59 34.75 2066.77 304.26 80 396.0 1.81 34.75 2071.54 349.44 90 443.0 2.04 34.70 2075.88 390.10 100 472.0 2.27 34.70 2080.70 414.68 110 512.0 2.49 34.70 2085.54 448.77 120 542.0 2.72 34.70 2090.40 473.96 130 568.0 2.95 34.70 2095.29 495.54 140 590.0 3.18 34.70 2100.19 513.53 150 610.0 3.40 34.70 2105.13 529.70 160 630.0 3.63 34.70 2110.08 545.78 170 647.0 3.86 34.65 2114.59 559.31 180 665.0 4.08 34.65 2119.59 573.52 190 681.0 4.31 34.65 2124.62 585.93 200 694.0 4.54 34.65 2129.66 595.70 210 707.0 4.76 34.65 2134.73 605.41 220 719.0 4.99 34.65 2139.83 614.22 230 731.0 5.22 34.65 2144.95 622.98 240 742.0 5.44 34.65 2150.09 630.85 250 752.0 5.67 34.65 2155.26 637.81 260 761.0 5.90 34.65 2160.46 643.90 270 770.0 6.12 34.65 2165.68 649.94 280 778.0 6.35 34.65 2170.92 655.11 290 787.0 6.58 34.60 2175.71 661.23 300 794.0 6.80 34.60 2181.01 665.49 310 801.0' 7.03 34.60 2186.33 669.72 320 807.0 7.26 34.60 2191.67 673.09 330 813.0 7.48 34.60 2197.05 676.44 340 820.0 7.71 34.60 2202.44 680.59 350 826.0 7.94 34.60 2207.87 683.88 360 834.0 8.16 34.60 2213.32 688.81 370 840.0 8.39 34.60 2218.80 692.05 380 847.0 8.62 34.60 2224.31 696.09 390 853.0 8.84 34.60 2229.84 699.28 400 860.0 9.07 34.60 2235.40 703.26 410 867.0 9.30 34.60 2240.99 707.22 420 873.0 9.53 34.60 2246.61 710.33 430 879.0 9.75 34.60 2252.26 713.42

77



440 883.0 9.98 34.60 2257.93 714.87 450 887.0 10.21 34.60 2263.63 716.30 460 890.0 10.43 34.60 2269.36 716.91 470 894.0 10.66 34.60 2275.12 718.30 480 900.0 10.89 34.55 2280.41 721.45 490 902.0 11.11 34.55 2286.23 721.21 500 904.0 11.34 34.55 2292.08 720.97 510 905.0 11.57 34.55 2297.96 719.92 520 906.0 11.79 34.55 2303.87 718.86 530 907.0 12.02 34.55 2309.80 717.81 540 909.0 12.25 34.55 2315.77 717.54 550 911.0 12.47 34.55 2321.77 717.26 560 916.0 12.70 34.55 2327.80 719.32 570 921.0 12.93 34.55 2333.87 721.37 580 924.0 13.15 34.55 2339.96 721.84 590 925.0 13.38 34.55 2346.09 720.73 600 929.0 13.61 34.55 2352.25 721.95 610 932.0 13.83 34.55 2358.44 722.38 620 936.0 14.06 34.55 2364.66 723.57 630 940.0 14.29 34.55 2370.92 724.75 640 943.0 14.51 34.55 2377.21 725.14 650 946.0 14.74 34.55 2383.53 725.51 660 948.0 14.97 34.55 2389.89 725.11 670 951.0 15.19 34.55 2396.28 725.47 680 952.0 15.42 34.50 2402.18 724.45 690 953.0 15.65 34.50 2408.64 723.27 700 955.0 15.88 34.50 2415.13 722.84 710 956.0 16.10 34.45 2421.12 721.80 720 958.0 16.33 34.45 2427.69 721.35 730 960.0 16.56 34.45 2434.29 720.90 740 960.0 16.78 34.45 2440.92 718.94 750 960.0 17.01 34.45 2447.59 716.98 760 960.0 17.24 34.45 2454.30 715.02 770 961.0 17.46 34.45 2461.04 713.81 780 962.0 17.69 34.45 2467.82 712.59 790 962.0 17.92 34.45 2474.64 710.62 800 963.0 18.14 34.45 2481.49 709.40 810 964.0 18.37 34.45 2488.39 708.17 820 965.0 18.60 34.45 2495.32 706.93 830 967.0 18.82 34.45 2502.29 706.42 840 969.0 19.05 34.45 2509.30 705.91 850 971.0 19.28 34.45 2516.35 705.38 860 973.0 19.50 34.45 2523.44 704.85 870 975.0 19.73 34.45 2530.57 704.31 880 977.0 19.96 34.45 2537.74 703.76 890 980.0 20.18 34.45 2544.95 703.92 900 981.0 20.41 34.45 2552.20 702.64 910 982.0 20.64 34.45 2559.50 701.35 920 984.0 20.86 34.45 2566.83 700.77 930 985.0 21.09 34.45 2574.21 699.47

78


Vertical d i s p k Proving ring Axial strain Volume g a u g e Corrected Deviator s t r e s s acement(div) reading(div) (%) reading(ml) area(mm 2 ) (kN/m 2)

940 984.0 21.32 34.45 2581.63 696.75 950 984.0 21.54 34.45 2589.09 694.74 960 984.0 21.77 34.45 2596.60 692.73 970 985.0 22.00 34.45 2604.15 691.43 980 985.0 22.23 34.45 2611.74 689.42 990 985.0 22.45 34.45 2619.38 687.41 1000 986.0 22.68 34.45 2627.06 686.09 1010 986.0 22.91 34.45 2634.79 684.08 1020 985.0 23.13 34.45 2642.56 681.38 1030 984.0 23.36 34.45 2650.38 678.68 1040 984.0 23.59 34.45 2658.25 676.67 1050 984.0 23.81 34.45 2666.16 674.66 1060 984.0 24.04 34.45 2674.12 672.65 1070 984.0 24.27 34.45 2682.13 670.64 1080 983.0 24.49 34.45 2690.18 667.96 1090 983.0 24.72 34.45 2698.29 665.95 1100 982.0 24.95 34.45 2706.44 663.27 1110 982.0 25.17 34.45 2714.64 661.26


800.00

0.00 5.00 10.00 15.00 20.00 25.00

Strain (%)

79

APPENDIX A GRAPHICAL ANALYSIS OF-PUSSALLAWA SOIL

Centre of Circle =(g,0), Radius of F r i c t j o n A n g i e

circle = r in Degrees = 33Radian 0.57596 1 of8 r1 218 r2 255.65 r3 290.41 g1 368 g2 405.65 g3 440.41 f1 0 f2 0 f3 0 C1 87900 c1 20.9532C2 99195 c2 41.39549 C3 109622 c3 60.2659

X circle 1 Tangent 1 Circle 2 Tangent 2 Circle 3 Tangent 3 0 #NUM! 20.95 #NUM! 41.40 #NUM! 60.27 5 #NUM! 24.20 #NUM! 44.64 #NUM! 63.51

10 #NUM! 27.45 #NUM! 47.89 #NUM! 66.76 15 #NUM! 30.69 #NUM! 51.14 #NUM! 70.01 20 #NUM! 33.94 #NUM! 54.38 #NUM! 73.25 25 #NUM! 37.19 #NUM! 57.63 #NUM! 76.50 30 #NUM! 40.44 #NUM! 60.88 #NUM! 79.75 35 #NUM! 43.68 #NUM! 64.12 #NUM! 83.00 40 #NUM! 46.93 #NUM! 67.37 #NUM! 86.24 45 #NUM! 50.18 #NUM! 70.62 #NUM! 89.49 50 #NUM! 53.42 #NUM! 73.87 #NUM! 92.74 55 #NUM! 56.67 #NUM! 77.11 #NUM! 95.98 60 #NUM! 59.92 #NUM! 80.36 #NUM! 99.23 65 #NUM! 63.16 #NUM! 83.61 #NUM! 102.48 70 #NUM! 66.41 #NUM! 86.85 #NUM! 105.72 75 #NUM! 69.66 #NUM! 90.10 #NUM! 108.97 80 #NUM! 72.91 #NUM! 93.35 #NUM! 112.22 85 #NUM! 76.15 #NUM! 96.60 #NUM! 115.47 90 #NUM! 79.40 #NUM! 99.84 #NUM! 118.71 95 #NUM! 82.65 #NUM! 103.09 #NUM! 121.96

100 #NUM! 85.89 #NUM! 106.34 #NUM! 125.21 105 #NUM! 89.14 #NUM! 109.58 #NUM! 128.45 110 #NUM! 92.39 #NUM! 112.83 #NUM! 131.70 115 #NUM! 95.64 #NUM! 116.08 #NUM! 134.95 120 #NUM! 98.88 #NUM! 119.32 #NUM! 138.19 125 #NUM! 102.13 #NUM! 122.57 #NUM! 141.44 130 #NUM! 105.38 #NUM! 125.82 #NUM! 144.69 135 #NUM! 108.62 #NUM! 129.07 #NUM! 147.94 140 #NUM! 111.87 #NUM! 132.31 #NUM! 151.18 145 #NUM! 115.12 #NUM! 135.56 #NUM! 154.43 150 0.00 118.36 0.00 138.81 0.00 157.68 155 46.42 121.61 50.31 142.05 53.66 160.92 160 65.27 124.86 70.80 145.30 75.55 164.17 165 79.47 128.11 86.28 148.55 92.13 167.42 170 91.21 131.35 99.13 151.79 105.91 170.67 175 101.37 134.60 110.26 155.04 117.88 173.91 180 110.36 137.85 120.16 158.29 128.55 177.16 185 118.47 141.09 129.11 161.54 138.21 180.41 190 125.86 144.34 137.30 164.78 147.08 183.65 195 132.65 147.59 144.86 168.03 155.28 186.90 200 138.92 150.83 151.87 171.28 162.91 190.15 205 144.76 154.08 158.42 174.52 170.06 193.39 210 150.20 157.33 164.55 177.77 176.77 196.64

80


215 155.29 160.58 170.32 220 160.06 163.82 175.76

225 164.54 167.07 180.89 230 168.76 170.32 185.75 235 172.73 173.56 190.36 240 176.47 176.81 194.72 245 179.99 180.06 198.87 250 183.30 183.31 202.81 255 186.43 186.55 206.55 260 189.37 189.80 210.10 265 192.13 193.05 213.48 270 194.73 196.29 216.69 275 197.17 199.54 219.74 280 199.45 202.79 222.64 285 201.58 206.03 225.39 290 203.57 209.28 228.00 295 205.41 212.53 230.46 300 207.12 215.78 232.80 305 208.70 219.02 235.00 310 210.14 222.27 237.08 315 211.46 225.52 239.04 320 212.65 228.76 240.88 325 213.72 232.01 242.60 330 214.66 235.26 244.20 335 215.49 238.50 245.69 340 216.19 241.75 247.08 345 216.78 245.00 248.35 350 217.26 248.25 249.52 355 217.61 251.49 250.58 360 217.85 254.74 251.54 365 217.98 257.99 252.40 370 217.99 261.23 253.15 375 217.89 264.48 253.81 380 217.67 267.73 254.36 385 217.34 270.98 254.81 390 216.89 274.22 255.17 395 216.32 277.47 255.43 400 215.64 280.72 255.59 405 214.84 283.96 255.65 410 213.92 287.21 255.61 415 212.87 290.46 255.48 420 211.71 293.70 255.25 425 210.42 296.95 254.92 430 209.00 300.20 254.49 435 207.45 303.45 253.96 440 205.77 306.69 253.33 445 203.95 309.94 252.60 450 201.99 313.19 251.77 455 199.89 316.43 250.84 460 197.64 319.68 249.81 465 195.23 322.93 248.67 470 192.67 326.17 247.42

181.02 183.11 199.89 184.27 189.09 203.14

187.51 194.77 206.38 190.76 200.16 209.63 194.01 205.29 212.88 197.25 210.17 216.12 200.50 214.83 219.37 203.75 219.27 222.62 206.99 223.52 225.86 210.24 227.57 229.11 213.49 231.45 232.36 216.74 235.15 235.61 219.98 238.70 238.85 223.23 242.09 242.10 226.48 245.32 245.35 229.72 248.42 248.59 232.97 251.38 251.84 236.22 254.21 255.09 239.46 256.91 258.34 242.71 259.48 261.58 245.96 261.93 264.83 249.21 264.27 268.08 252.45 266.49 271.32 255.70 268.60 274.57 258.95 270.60 277.82 262.19 272.50 281.06 265.44 274.29 284.31 268.69 275.97 287.56 271.94 277.56 290.81 275.18 279.05 294.05 278.43 280.44 297.30 281.68 281.74 300.55 284.92 282.94 303.79 288.17 284.05 307.04 291.42 285.07 310.29 294.66 286.00 313.53 297.91 286.83 316.78 301.16 287.58 320.03 304.41 288.24 323.28 307.65 288.81 326.52 310.90 289.29 329.77 314.15 289.69 333.02 317.39 290.00 336.26 320.64 290.22 339.51 323.89 290.35 342.76 327.13 290.40 346.01 330.38 290.37 349.25 333.63 290.25 352.50 336.88 290.04 355.75 340.12 289.74 358.99 343.37 289.36 362.24 346.62 288.89 365.49

81


3 of 8 475 189.93 329.42 246.06 480 187.03 332.67 244.60 485 183.94 335.92 243.02 490 180.67 339.16 241.33 495 177.19 342.41 239.53 500 173.49 345.66 237.60 505 169.57 348.90 235.56 510 165.41 352.15 233.38 515 160.98 355.40 231.08 520 156.27 358.65 228.65 525 151.24 361.89 226.08 530 145.88 365.14 223.37 535 140.12 368.39 220.51 540 133.94 371.63 217.50 545 127.26 374.88 214.33 550 120.00 378.13 211.00 555 112.05 381.37 207.49 560 103.25 384.62 203.80 565 93.35 387.87 199.91 570 81.98 391.12 195.82 575 68.37 394.36 191.51 580 50.79 397.61 186.97 585 20.86 400.86 182.18 590 #NUM! 404.10 177.12 595 #NUM! 407.35 171.77 600 #NUM! 410.60 166.09 605 #NUM! 160.05 610 153.62 615 146.73 620 139.32 625 131.31 630 122.57 635 112.94 640 102.16 645 89.82 650 75.17 655 56.40 660 25.75 665 #NUM! 670 #NUM! 675 #NUM! 680 685 690 695 700 705 710 715 720 725 730

349.86 288.34 368.73 353.11 287.69 371.98 356.36 286.96 375.23 359.61 286.14 378.48 362.85 285.23 381.72 366.10 284.22 384.97 369.35 283.13 388.22 372.59 281.94 391.46 375.84 280.66 394.71 379.09 279.28 397.96 382.33 277.81 401.20 385.58 276.24 404.45 388.83 274.57 407.70 392.08 272.79 410.95 395.32 270.92 414.19 398.57 268.93 417.44 401.82 266.84 420.69 405.06 264.64 423.93 408.31 262.32 427.18 411.56 259.88 430.43 414.80 257.33 433.68 418.05 254.65 436.92 421.30 251.85 440.17 424.55 248.91 443.42 427.79 245.84 446.66 431.04 242.62 449.91

239.26 235.74 232.06 228.21 224.19 219.97 215.56 210.94 206.10 201.01 195.66 190.03 184.10 177.82 171.17 164.10 156.55 148.45 139.70 130.17 119.69 107.95 94.51 78.50 57.80 21.67

82


4 of 8 735 #NUM! 740 #NUM! 745 #NUM! 750 #NUM! 755 #NUM! 760 #NUM! 765 #NUM! 770 #NUM! 775 #NUM! 780 #NUM! 785 #NUM! 790 #NUM! 795 #NUM! 800 #NUM! 805 #NUM! 810 #NUM! 815 #NUM! 820 #NUM! 825 #NUM! 830 #NUM! 835 #NUM! 840 #NUM! 845 #NUM! 850 #NUM! 855 #NUM! 860 #NUM! 865 #NUM! 870 #NUM! 875 #NUM! 880 #NUM! 885 #NUM! 890 #NUM! 895 #NUM! 900 #NUM! 905 #NUM! 910 #NUM! 915 #NUM! 920 #NUM! 925 #NUM! 930 #NUM! 935 #NUM!

83


5 of 8 340.34 r5 362.76 490.34 95 512.76

0 f 5 0 124602 c4 87.3784 C5 131327 c5 99.54876

Circle 4 Tangent 4 Circle 5 Tangent 5 #NUM! 87.38 #NUM! 99.55 #NUM! 90.63 #NUM! 102.80 #NUM! 93.87 #NUM! 106.04 #NUM! 97.12 #NUM! 109.29 #NUM! 100.37 #NUM! 112.54 #NUM! 103.61 #NUM! 115.78 #NUM! 106.86 #NUM! 119.03 #NUM! 110.11 #NUM! 122.28 #NUM! 113.35 #NUM! 125.53 #NUM! 116.60 #NUM! 128.77 #NUM! 119.85 #NUM! 132.02 #NUM! 123.10 #NUM! 135.27 #NUM! 126.34 #NUM! 138.51 #NUM! 129.59 #NUM! 141.76 #NUM! 132.84 #NUM! 145.01 #NUM! 136.08 #NUM! 148.25 #NUM! 139.33 #NUM! 151.50 #NUM! 142.58 #NUM! 154.75 #NUM! 145.83 #NUM! 158.00 #NUM! 149.07 #NUM! 161.24 #NUM! 152.32 #NUM! 164.49 #NUM! 155.57 #NUM! 167.74 #NUM! 158.81 #NUM! 170.98 #NUM! 162.06 #NUM! 174.23 #NUM! 165.31 #NUM! 177.48 #NUM! 168.55 #NUM! 180.72 #NUM! 171.80 #NUM! 183.97 #NUM! 175.05 #NUM! 187.22 #NUM! 178.30 #NUM! 190.47 #NUM! 181.54 #NUM! 193.71

0.00 184.79 #NUM! 196.96 58.12 188.04 60.02 200.21 81.90 191.28 84.59 203.45 99.93 194.53 103.24 206.70

114.95 197.78 118.79 209.95 128.03 201.02 132.34 213.20 139.72 204.27 144.45 216.44 150.33 207.52 155.46 219.69 160.08 210.77 165.59 222.94 169.13 214.01 174.99 226.18 177.58 217.26 183.78 229.43 185.51 220.51 192.04 232.68 192.98 223.75 199.83 235.92

84

APPENDIX A

6 of 8 200.05 227.00 206.75 230.25 213.13 233.50 219.21 236.74 225.02 239.99 230.57 243.24 235.88 246.48 240.97 249.73 245.86 252.98 250.55 256.22 255.06 259.47 259.39 262.72 263.55 265.97 267.56 269.21 271.42 272.46 275.13 275.71 278.70 278.95 282.14 282.20 285.45 285.45 288.63 288.69 291.70 291.94 294.64 295.19 297.48 298.44 300.20 301.68 302.82 304.93 305.33 308.18 307.75 311.42 310.06 314.67 312.27 317.92 314.39 321.17 316.42 324.41 318.35 327.66 320.20 330.91 321.96 334.15 323.63 337.40 325.21 340.65 326.71 343.89 328.13 347.14 329.47 350.39 330.72 353.64 331.90 356.88 332.99 360.13 334.01 363.38 334.95 366.62 335.81 369.87 336.60 373.12 337.31 376.36 337.94 379.61 338.50 382.86 338.98 386.11 339.40 389.35 339.73 392.60

GRAPHICAL ANALYSIS OF-PUSSALLAWA SOIL

207.20 239.17 214.21 242.42 220.88 245.67 227.25 248.91 233.33 252.16 239.16 255.41 244.74 258.65 250.10 261.90 255.25 265.15 260.20 268.39 264.97 271.64 269.56 274.89 273.98 278.14 278.24 281.38 282.35 284.63 286.31 287.88 290.13 291.12 293.81 294.37 297.37 297.62 300.80 300.87 304.11 304.11 307.31 307.36 310.39 310.61 313.36 313.85 316.22 317.10 318.98 320.35 321.64 323.59 324.19 326.84 326.66 330.09 329.02 333.34 331.30 336.58 333.48 339.83 335.58 343.08 337.59 346.32 339.51 349.57 341.35 352.82 343.11 356.06 344.79 359.31 346.38 362.56 347.90 365.81 349.34 369.05 350.70 372.30 351.98 375.55 353.19 378.79 354.32 382.04 355.38 385.29 356.37 388.54 357.29 391.78 358.13 395.03 358.90 398.28 359.60 401.52 360.23 404.77

85


339.99 395.85 360.78 408.02 340.18 399.09 361.27 411.26 340.30 402.34 361.69 414.51 340.34 405.59 362.04 417.76 340.31 408.84 362.32 421.01 340.20 412.08 362.53 424.25 340.02 415.33 362.67 427.50 339.77 418.58 362.74 430.75 339.45 421.82 362.75 433.99 339.05 425.07 362.68 437.24 338.57 428.32 362.55 440.49 338.02 431.56 362.34 443.73 337.40 434.81 362.07 446.98 336.70 438.06 361.73 450.23 335.92 441.31 361.32 453.48 335.07 444.55 360.84 456.72 334.14 447.80 360.29 459.97 333.13 451.05 359.67 463.22 332.05 454.29 358.97 466.46 330.89 457.54 358.21 469.71 329.64 460.79 357.37 472.96 328.32 464.03 356.47 476.21 326.91 467.28 355.49 479.45 325.42 470.53 354.44 482.70 323.85 473.78 353.31 485.95 322.19 477.02 352.11 489.19 320.44 350.83 318.61 349.48 316.69 348.05 314.67 346.54 312.57 344.95 310.36 343.29 308.07 341.54 305.67 339.71 303.17 337.79 300.57 335.79 297.86 333.70 295.04 331.53 292.10 329.26 289.06 326.90 285.89 324.45 282.60 321.90 279.18 319.25 275.62 316.50 271.93 313.65 268.09 310.69 264.11 307.62 259.96 304.44 255.65 301.14 251.17 297.73 246.51 294.18 241.65 290.51

86


236.59 286.70 231.30 282.76 225.79 278.66 220.02 274.42 213.98 270.02 207.64 265.45 200.98 260.70 193.96 255.77 186.55 250.64 178.69 245.30 170.31 239.74 161.35 233.94 151.70 227.88 141.22 221.54 129.69 214.90 116.83 207.93 102.11 200.60 84.59 192.85 61.92 184.65 21.50 175.92

#NUM! 166.58 #NUM! 156.53 #NUM! 145.62 #NUM! 133.63 #NUM! 120.25 #NUM! 104.94 #NUM! 86.69 #NUM! 62.99 #NUM! 19.23 #NUM! #NUM! #NUM! #NUM! #NUM! #NUM!

#NUM! #NUM'

G r a p h i c a l A n a l y s i s for s o i l at P u s s a l l a w a L a n d s l i d e S i t e

6 0 0 . 0 0 - i — —

5 0 0 . 0 0 -

( o - u a ) ( k P a )

87

APPENDIX B DERIVATION OF FACTOR OFD SAFETY EQATION FOR UNSATURATED SOIL

The shear strength function for unsaturated soil can be written as;

x = c'+ (ovua) tan <]>' + (u a-uw) tan (|>b

Ax

A •

N'

For the slice shown,

Mobilized shear strength T m = tf/F

Where, F is the factor of safety.

Ni = o-Al

Tj = 1/F T f Al = 1/F [c'+Al (ovua)tan ((>' + Al(ua-uw)tan (|)b

Ti= 1/F [Sin Gj]- - [1]

Resolving vertically,

NiCos 0i + TiSin Gi = W( - (X L-X R)

88

Derivation of the Factor of Safety Equation for Unsaturated Soils

APPENDIX B SOIL

DERIVATION O F FACTOR OFD SAFETY EQATION FOR UNSATURATED

Assuming ( X L - X R ) =0 (For Janbu's simplified method)

Nj Cos 9j + 1/F [c'Al + (Ni-uaAl)tan f + Al(ua-uw)tan § b ]Sin 0j = Wf

Nj Cos 9j [1 + 1/F tan ftan 9 (] = Wj - Sin 9i/F[c'Al -uaAltan f + Al(ua-uw)tan 4>b]

If Cos 9j [1+1/F tan ftan 9 f] = M e

Nj = {Wj - l/F[c'Al Sin 9i -uaAltan <))' Sin 9, + Al(ua-uw)tan (|)b Sin 9,]}/ M e [2]

Resolving parallel to the base of the slice,

Ti + ( E L - E R ) C O S 9, = [Wj - ( X L - X R ) ] Sin 9,

Assuming ( X L - X R ) =0 and substituting for Ti

( E L - E R ) C O S 9, = Wf Sin 0| - 1/F [c'Al + (Ni-uaAl)tan cj>' + Al(ua-uw)tan (|)b ]

(EL-ER ) = Wj tan 9i - 1/F [c'Al + (Ni-uaAl)tan f + Al(ua-uw)tan <|>b ]Sec 9, - [3]

In the absence of surface loading,

Z (EL-ER) = 0 [4]

Z ( E L -E R ) = Z Wi tan 9i - 1/F [c'Al + (Ni-uaAl)tan <|>' + Al(ua-uw)tan (|>b ]Sec 9, = 0 [5]

_ Z[ c' Al + (N, - uaM) tan </>'+(ua - uw)Altm<t>h]Sec6i

• ' • F ° = " ~ " " " [ 6 ]

Nj = {Wi - l/F[c'Al Sin 0j -uaAltan f Sin Q, + Al(ua-uw)tan <()b Sin 9J}/ M 9 [2]

Substituting for Nj in [6]

89


c ' A l + CNi - w „ A / ) t a n 0 ' + ( w u - w w ) A / t a n ^

= c'A/,. +[{W. -— (c'Al-uaAl tan f+(ua - uJAl tan <pb) Sin 0} — -uaAl]tan f+(ua-uJAltan<f>b

c 'A l + fN,. - u „ A / ) t a n ^ ' + ( w „ -uJAltan<pb

I A , c'ALSin0itanf WAanf . A I w Al tanf Sin 0,. ., , . A . Ah = c'Al '• '• — + —'• — - {uAl - - s " '-} tan f+(u„ - uJAl tan aT FfMt{0) Mt{0) " FfMt{0)

(ua - uJAl tan <j>bSin 0 tan f [6](a) FfM (0)

Consider

_ c'Al^tanf = c ^ f_L_ _ t a n ^ t a n ^ FfMt{0) 'CosO, FfMt{0)

By def in i t ion, ^ nr, tan 0, tan 0'.. Mt{0) = Cos0[\ + '- —]

Ff M,(0)= ] t a n f l t a n ^ ' Cos0 Ff

M({0) l _ tanc9,tan^' Cos<9 ~ /=}

1 t a n f ? , t a n ^ ' _ 1 1

Ff M,(0) Cos0 M,.(0) Substituting this in [6](b)

c'Al,Sindi tanf r 1 , _ 1 1 „ c A/ . ! '• — = c'Ax,[ ( )]

FfM,(0) Cosei Cos6i M,(<?)

•[6](c)

90

c' A l + f N ; -uaAl)tanf+(ua -uw)Altan<ph

= c'A/,. +[{Wt(c'AlSin0-uaAl tanf Sin 0+{ua - u w)Al tanf Sin 0} waA/]tan<*>' F Mg

+ (ua-uJAltan0h


c'Al +(N: — w„A/)tan</>'+(u -uJAltand>h

' ' " " w M.(<9) M({9) M (0) Mt(0)

Z [ { c , - « 0 + ( « 0 - i . w ) t a n ^ } A x ( . + ^ t a n f ] - 1 1

t o K^tanc?}

Z[ {C'-M„ tan^'+(wa -uJtan^JAx, +^.tant>'] 1

^ 0 =

n ( (9,)

Ketone?, }

I [ {c'Ax, + ( W j -M„Ax,)tan^'+(Mu -wJA^.tan^}/"* Z{^tan0,}

2 _ tanc9tanc '̂. where, ne-Cos 6(\-\ )

91

c, c^Sine.tBnf = t ^ FfM,(0) Mt(0)

Similarly in [6](a),

r ( u _ u ) A / (ua ~ u J A l t a n $ ' S i n ft]tan

<t>b

= (u„-uw)Ax,tan^ " w ' FfMt{9) M({0)

Substituting [6](d) and [6](e) in [6](a),

c'Al, W,tanfh (ua - uw)Axi t a n ^ «flAx,. : t a n y/ -1

By substituting the above result in [6]

4

APPENDIX B PUSSALLAWA SLOPE STABDHTY ANALYSIS WHEN WATER T A B L E IS A T GROUND SURFACE AND SLOPE IS SATURATED

I N P U T S C A L C U L A T I O N - S T A G E 1 2 3 4 5 6 7 8 9 10 11 12 13 1 4 15 16 17 18

Slice Pore Water Pore Air Soil (2 )* (10 )* (11) (9)*(2)

W i d t h Pressure Pressure Type Matric {(4)+(5)} /2 wi Qi

A x i 8i h i h2 Uw U a c' *" Suction q i y hav (kN-per (kN-per tan tan <t>b

(m) (deg) (m) (m) (kN/m2) (kN/m2) (kN/m2) (deg) (deg) (kN/m2) (kN/m2) (kN/m3) (m) m w i d t h ) m w i d t h )

1 1 . 2 0 0 4 . 0 0 0 . 0 0 0 1 . 8 5 0 7 . 8 0 1 2 0 . 0 0 3 3 . 0 0

(kN/m2)

0 . 0 0 1 7 . 2 5 0 . 9 3 1 7 8 . 7 1 0 . 6 5 7 . 8 3 0 4 . 0 0 1 . 8 5 0 3 . 1 5 0 2 3 . 4 5 . 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 2 . 5 0 3 3 7 . 6 7 0 . 6 5

1 4 . 5 6 0 4 . 0 0 3 . 1 5 0 5 . 5 5 0 4 0 . 9 1 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 4 . 3 5 1 0 9 2 . 5 5 0 . 6 5 1 1 . 2 0 0 4 . 0 0 5 . 5 5 0 7 . 3 6 0 5 9 . 6 4 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 6 . 4 6 1 2 4 7 . 1 1 0 . 6 5 1 1 . 2 0 0 4 . 0 0 7 . 3 6 0 8 . 7 6 0 7 4 . 3 6 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 8 . 0 6 1 5 5 7 . 1 9 0 . 6 5 1 4 . 1 8 0 4 . 0 0 8 . 7 6 0 1 1 . 5 0 0 9 3 . 9 8 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 1 0 . 1 3 2 4 7 7 . 8 5 0 . 6 5 9 . 9 2 0 1 1 . 0 0 1 1 . 5 0 0 1 0 . 6 6 0 8 9 . 3 5 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 1 1 . 0 8 1 8 9 6 . 0 1 0 . 6 5 1 0 . 8 9 0 1 3 . 0 0 1 0 . 6 6 0 1 0 . 9 9 0 9 8 . 3 4 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 1 0 . 8 3 2 0 3 3 . 5 0 0 . 6 5 1 1 . 0 0 0 1 6 . 0 0 1 0 . 9 9 0 1 1 . 4 9 0 9 9 . 5 2 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 1 1 . 2 4 2 1 3 2 . 7 9 0 . 6 5 1 1 . 2 0 0 2 0 . 0 0 1 1 . 4 9 0 1 0 . 8 8 0 9 8 . 7 8 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 1 1 . 1 9 2 1 6 0 . 9 4 0 . 6 5 1 1 . 2 0 0 2 4 . 0 0 1 0 . 8 8 0 8 . 6 9 0 9 5 . 6 7 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 9 . 7 9 1 8 9 0 . 4 6 0 . 6 5

8".8"30 j 2 4 . 0 0 8 . 6 9 0 7 . 0 2 0 8 4 . 2 9 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 7 . 8 6 1 1 9 6 . 4 5 0 . 6 5 1 1 . 1 0 0 2 4 . 0 0 7 . 0 2 0 6 . 0 0 0 6 9 . 3 3 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 6 . 5 1 1 2 4 6 . 5 0 0 . 6 5

1 1 . 2 0 2 4 . 0 0 6.66b"1 3 . 7 0 0 5 2 . 7 5 1 2 0 . 0 0 3 3 . 0 0 0 . 0 0 1 7 . 2 5 4 . 8 5 9 3 7 . 0 2 0 . 6 5 1 7 . 6 0 2 4 . 0 0 3 . 7 0 0 6.066 1 3 5 . 8 9 1 j 20.66 3 3 . 0 0 0 . 0 0 1 7 . 2 5 1.85 5 6 1 . 6 6 0 . 6 5

1 .03

Note: Enter Values only in green cells T o analyse unsaturated soil s lopes , enter the title " I' X S.\ It,' K ATI •'. 1) S O 11." in the Calculat ions sheet .

At the same t ime, enter the pore air pressure and Fi-b value in Da t a -En t rv sheet Satura ted Analysis w h e n water table is at g round surface cons ider ing seepage

F O S ( 4 ) 1 .77 F O S ( 5 )

FOS(FO) FOS

1 .77

1 .77

1 .83

92

C A L C U L A T I O N O F F A C T O R O F S A F E T Y O F A S E L E C T E D F A I L U R E S U R F A C E 1 o f 3

J A N B U ' S S I M P L I F I E D M E T H O D S A T U R A T E D SOIL

APPENDIX B PUSSALLAWA SLOPE STABIL ITY ANALYSIS WHEN WATER T A B L E IS A T GROUND SURFACE AND SLOPE IS SATURATED c

M O D I F I E D JANBU'S SIMPLIFIED M E T H O D 2 of 3 SA TURA TED SOIL

Calculations

I N P U T S C A L C U L A T I O N - S T A G E 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Slice Slice Width

Pore Water Pressure

Air Pressure {(4)+(5)(/2 (2)*(12)*(13)

Matric Suction

(11)*(2) Q'

Axi 6i hi h2 Uw Ua c' *" q ' y hav wi (Ua-Uw) (kN-per tan <(>* tan 4>b

(m) (m) (m) (kN/m2) (kN/m2) (kN/m2) (deg) (deg) (kN/m2) (kN/m3) (m) (kN-per m width) (kN/m2) m w i d t h ) 1 11.20 4.0 1.85 7.7999 7.7999 20.00 33.00 33.00 17.25 0.9250 178.7100 0.6494 2 7.83 4.0 1.85 3.15 23.4459 23.4459 20.00 33.00 33.00 17.25 2.5000 337.6688 0.6494 3 14.56 4.0 3.15 5.55 40.9077 40.9077 20.00 33.00 33.00 17.25 4.3500 1092.5460 0.6494 4 11.20 4.0 5.55 7.36 59.6428 59.6428 20.00 33.00 33.00 17.25 6.4550 1247.1060 0.6494 5 11.20 4.0 7.36 8.76 74.3598 74.3598 20.00 33.00 33.00 17.25 8.0600 1557.1920 0.6494 6 14.18 4.0 8.76 11.50 93.9798 93.9798 20.00 33.00 33.00 17.25 10.1300 2477.8487 0.6494 7 9.92 11.0 11.50 10.66 89.3495 89.3495 20.00 33.00 33.00 17.25 11.0800 1896.0096 0.6494 8 10.89 13.0 10.66 10.99 98.3354 98.3354 20.00 33.00 33.00 17.25 10.8250 2033.5033 0.6494 9 11.00 16.0 10.99 11.49 99.5225 99.5225 20.00 33.00 33.00 17.25 11.2400 2132.7900 0.6494 10 11.20 20.0 11.49 10.88 98.7769 98.7769 20.00 33.00 33.00 17.25 11.1850 2160.9420 0.6494 11 11.20 24.0 10.88 8.69 95.6671 95.6671 20.00 33.00 33.00 17.25 9.7850 1890.4620 0.6494 12 8.83 24.0 8.69 7.02 84.2875 84.2875 20.00 33.00 33.00 17.25 7.8550 1196.4540 0.6494 13 11.10 24.0 7.02 6.00 69.3273 69.3273 20.00 33.00 33.00 17.25 6.5100 1246.5023 0.6494 14 11.20 24.0 6.00 3.70 52.7484 52.7484 20.00 33.00 33.00 17.25 4.8500 937.0200 0.6494 15 17.60 24.0 3 7 0 35.8948 35.8948 20.66 33.00 33.00 17.25 1.8500 561.6600 0.6494

ro I 1.030 |

93

J V

APPENDIX B PUSSALLAWA SLOPE STABIL ITY ANALYSIS WHEN WATER T A B L E IS AT GROUND SURFACE AND SLOPE IS SATURATED

(wi+Qi) * tan qi c'Dxi Uai*Dxi

(wi+Qi -UaiDxi)

22 *tanf

(Ua-Uw) *Dxi*tanfb

(20)+(23)+(24) Trial 1 Trial 1 Trial 2 Trial 2 Trial 3 Trial 3 Trial 4 Trial 4 Trial5 Trial 5

(wi+Qi) * tan qi c'Dxi Uai*Dxi

(wi+Qi -UaiDxi)

22 *tanf

(Ua-Uw) *Dxi*tanfb

(20)+(23)+(24) ni(q)

(2S)/(26) ni(q)

(25)/(28) ni(q)

(25)/(28) ni(q)

(25)/(32) ni(q)

(25)/(34) c'Dxi Uai*Dxi

(wi+Qi -UaiDxi)

(Ua-Uw) *Dxi*tanfb

(20)+(23)+(24) ni(q)

(2S)/(26) ni(q)

(25)/(28) ni(q)

(25)/(28) ni(q)

(25)/(32) ni(q)

(25)/(34)

1 2 . 5 0 2 2 4 . 0 0 1 7 8 . 7 1 1 1 6 . 0 6 3 4 0 . 0 6 1 .009 3 3 6 . 9 5 3 1 .009 3 3 7 . 1 1 1 . 0 0 9 3 3 7 . 1 1 4 1 .009 3 3 7 . 1 1 4 1 . 0 0 9 3 3 7 . 1 1

2 3 . 6 1 1 5 6 . 6 0 3 3 7 . 6 7 2 1 9 . 2 8 3 7 5 . 8 8 1 .009 3 7 2 . 4 5 5 1 .009 3 7 2 . 6 2 1 . 0 0 9 3 7 2 . 6 3 3 1 .009 3 7 2 . 6 3 3 1 . 0 0 9 3 7 2 . 6 3

7 6 . 4 0 2 9 1 . 2 0 1 0 9 2 . 5 5 7 0 9 . 5 1 1 0 0 0 . 7 1 1 .009 9 9 1 . 5 7 8 1 .009 9 9 2 . 0 3 1 . 0 0 9 9 9 2 . 0 5 0 1 .009 9 9 2 . 0 5 1 1 .009 9 9 2 . 0 5

8 7 . 2 1 2 2 4 . 0 0 1 2 4 7 . 1 1 8 0 9 . 8 8 1 0 3 3 . 8 8 1 .009 1 0 2 4 . 4 4 7 1 .009 1 0 2 4 . 9 1 1 . 0 0 9 1 0 2 4 . 9 3 5 1 .009 1 0 2 4 . 9 3 6 1 .009 1 0 2 4 . 9 4

108 . 8 9 2 2 4 . 0 0 1 5 5 7 . 1 9 1 0 1 1 . 2 5 1 2 3 5 . 2 5 1 .009 1 2 2 3 . 9 8 2 1 .009 1 2 2 4 . 5 4 1 . 0 0 9 1 2 2 4 . 5 6 5 1 .009 1 2 2 4 . 5 6 6 1 .009 1 2 2 4 . 5 7

1 7 3 . 2 7 2 8 3 . 6 0 2 4 7 7 . 8 5 1 6 0 9 . 1 3 1 8 9 2 . 7 3 1 .009 1 8 7 5 . 4 6 5 1 .009 1 8 7 6 . 3 2 1 .009 1 8 7 6 . 3 5 8 1 .009 1 8 7 6 . 3 6 0 1 .009 1 8 7 6 . 3 6

3 6 8 . 5 5 1 9 8 . 4 0 1 8 9 6 . 0 1 1 2 3 1 . 2 8 1 4 2 9 . 6 8 1 .001 1 4 2 7 . 5 8 0 1 .000 1 4 2 9 . 3 4 1 . 0 0 0 1 4 2 9 . 4 2 5 1 .000 1 4 2 9 . 4 2 9 1 . 0 0 0 1 4 2 9 . 4 3

4 6 9 . 4 7 2 1 7 . 8 0 2 0 3 3 . 5 0 1 3 2 0 . 5 7 1 5 3 8 . 3 7 0 . 9 9 4 1 5 4 8 . 0 8 4 0 . 9 9 2 1 5 5 0 . 3 4 0 . 9 9 2 1 5 5 0 . 4 4 5 0 . 9 9 2 1 5 5 0 . 4 5 0 0 . 9 9 2 1 5 5 0 . 4 5

6 1 1 . 5 7 2 2 0 . 0 0 2 1 3 2 . 7 9 1 3 8 5 . 0 5 1 6 0 5 . 0 5 0 . 9 7 8 1 6 4 1 . 8 0 8 0 . 9 7 6 1 6 4 4 . 7 5 0 . 9 7 6 1 6 4 4 . 8 8 5 0 . 9 7 6 1 6 4 4 . 8 9 2 0 . 9 7 6 1 6 4 4 . 8 9

7 8 6 . 5 2 2 2 4 . 0 0 2 1 6 0 . 9 4 1 4 0 3 . 3 3 1 6 2 7 . 3 3 0 . 9 4 8 1 7 1 6 . 5 5 3 0 . 9 4 6 1 7 2 0 . 4 0 0 . 9 4 6 1 7 2 0 . 5 8 0 0 . 9 4 6 1 7 2 0 . 5 8 8 0 . 9 4 6 1 7 2 0 . 5 9

8 4 1 . 6 9 2 2 4 . 0 0 1 8 9 0 . 4 6 1 2 2 7 . 6 8 1 4 5 1 . 6 8 0 . 9 1 0 1 5 9 5 . 7 5 3 0 . 9 0 7 1 6 0 0 . 0 6 0 . 9 0 7 1 6 0 0 . 2 6 5 0 . 9 0 7 1 6 0 0 . 2 7 5 0 . 9 0 7 1 6 0 0 . 2 8

5 3 2 . 7 0 1 7 6 . 6 0 1 1 9 6 . 4 5 7 7 6 . 9 9 9 5 3 . 5 9 0 . 9 1 0 1 0 4 8 . 2 2 6 0 . 9 0 7 1 0 5 1 . 0 5 0 . 9 0 7 1 0 5 1 . 1 8 9 0 . 9 0 7 1 0 5 1 . 1 9 6 0 . 9 0 7 1 0 5 1 . 2 0

5 5 4 . 9 8 2 2 2 . 0 0 1 2 4 6 . 5 0 8 0 9 . 4 9 1 0 3 1 . 4 9 0 . 9 1 0 1 1 3 3 . 8 5 9 0 . 9 0 7 1 1 3 6 . 9 2 0 . 9 0 7 1 1 3 7 . 0 6 5 0 . 9 0 7 1 1 3 7 . 0 7 2 0 . 9 0 7 1 1 3 7 . 0 7

4 1 7 . 1 9 224.66 9 3 7 . 0 2 6 0 8 . 5 1 8 3 2 . 5 1 0 . 9 1 0 9 1 5 . 1 3 1 0 . 9 0 7 9 1 7 . 6 0 0 . 9 0 7 9 1 7 . 7 1 8 0 . 9 0 7 9 1 7 . 7 2 4 0 . 9 0 7 9 1 7 . 7 2

2 5 0 . 0 7 3 5 2 . 0 0 5 6 1 . 6 6 364~.75 1 7 1 6 . 7 5 0 . 9 1 0 7 8 7 . 8 8 0 0 . 9 0 7 7 9 0 . 0 1 0 . 9 0 7 7 9 0 . 1 0 8 0 . 9 0 7 7 9 0 . 1 1 3 0 . 9 0 7 7 9 0 . 1 1

5 3 1 4 . 5 9 1 7 0 6 4 . 9 6 1 7 6 3 9 . 7 5 4 1 7 6 6 7 . 9 9 1 7 6 6 9 . 3 3 5 1 7 6 6 9 . 3 9 9 1 7 6 6 9 . 4 0

F O S ( i n i ) 3 . 2 1 1 0 F O S ( l ) 3 . 3 1 9 1 F O S ( 2 ) 3 . 3 2 4 4 F O S ( 3 ) 3 . 3 2 4 7 F O S ( 4 ) 3 . 3 2 4 7 F O S ( 5 ) 3 . 3 2 4 7

F 0 S ( F 0 ] 3 . 3 2 4 7

F O S 3 . 4 2 4 4

94

V

APPENDIX B PUSSALLAWA UNSATURATED ANALYSIS WHEN WATER T A B L E IS 5m BELOW FAILURE SURFACE

CALCULATION OF FACTOR OF SAFETY OF A SELECTED FAILURE SURFACE M O D I F I E D J A N B U ' S S I M P L I F I E D M E T H O D

U N S A T U R A T E D S O I L

1 of 3

INPUTS CALCULATION-STAGE 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

SBce SBce Width

Pore Water Pressure

Pore Air Pressure

Soil Type Matric {(4)+(5)}/2 (2)*(10)*(11)

(9)*(2) Qi

Axi 9i hi h2 Uw Ua c' f <t.b Suction qi y hav wi (kN-per tan 4>' tan «(»b

(m) (m) (m) (kN/m2) (kN/m2) (kN/m2) (deg). (kN/m2) (kN/m2) (kN/m3) (m) kN-per m width m width) 1 11.20 4.0 0.00 1.85 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 0.93 178.71 0.65 0.54 2 7.83 4.0 1.85 3.15 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 2.50 337.67 0.65 0.54 3 14.56 4.0 3.15 5.55 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 4.35 1092.55 0.65 0.54 4 11.20 4.0 5.55 7.36 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 6.46 1247.11 0.65 0.54 5 11.20 4.0 7.36 8.76 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 8.06 1557.19 0.65 0.54 6 14.18 4.0 8.76 11.50 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 10.13 2477.85 0.65 0.54 7 9.92 11.0 11.50 10.66 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 11.08 1896.01 0.65 0.54 8 10.89 13.0 10.66 10.99 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 10.83 2033.50 0.65 0.54 9 11.00 16.0 10.99 11.49 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 11.24 2132.79 0.65 0.54 10 11.20 20.0 11.49 10.88 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 11.19 2160.94 0.65 0.54 11 11.20 24.0 10.88 8.69 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 9.79 1890.46 0.65 0.54 12 8.83 24.0 8.69 7.02 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 7.86 1196.45 0.65 0.54 13 11.10 24.0 7.02 6.00 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 6.51 1246.50 0.65 0.54 14 11.20 24.0 6.00 3.70 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 4.85 937.02 0.65 0.54 15 17.60 24.0 3.70 0.00 -9.81 1 20.0 33.0 28.46 9.81 0.00 17.25 1.85 561.66 0.65 0.54

fO 1.03 Note: Enter Values only in green cells T o analyse unsaturated soil slopes, enter the title " UNSATURATED SOU." in the Calculations sheet. At the same time, enter the pore air pressure and Fi-b value in Data-Entry sheet

Unsaturated analysis when WT is at 5m below Failure surface assuming 2 0 % of full negative hvdristaric pressure

(ft1' is assumed be equal to equal to found actual value.

FOS(5) 3.51 F0S(F0) 3.51

FOS 3.62

95


MODIFIED JANBU'S SIMPLIFIED METHOD 2 of 3 UNSA TURA TED SOIL

Calculations

1 INPUTS CALCULATION-STAGE 1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Slice Slice

Width Axi

(m) 0i h i

(m) h2 (m)

Pore Water Pressure

Uw ( k N / m 2 )

Air Pressure

Ua ( k N / m 2 )

c' ( k N / m 2 ) <dee) (deP)

qi ( k N / m 2 )

y ( k N / m 3 )

{(4)+(5)}/2 hav (m)

(2)*(12)*(13)

wi kN-per m width

Matric Suction

(Ua-Uw) ( k N / m 2 )

(11)*(2)

Qi (kN-per

m width) tan <|>' tan((ib

1 11.20 4.0 1.85 -9.81 20.0 33.0 28.46 17.25 0.925 178.710 9.81 0.6494 0.5421 2 7.83 4.0 1.85 3.15 -9.81 20.0 33.0 28.46 17.25 2.500 337.669 9.81 0.6494 0.5421 3 14.56 4.0 3.15 5.55 -9.81 20.0 33.0 28.46 17.25 4.350 1092.546 9.81 0.6494 0.5421 4 11.20 4.0 5.55 7.36 -9.81 20.0 33.0 28.46 17.25 6.455 1247.106 9.81 0.6494 0.5421 5 11.20 4.0 7.36 8.76 -9.81 20.0 33.0 28.46 17.25 8.060 1557.192 9.81 0.6494 0.5421 6 14.18 4.0 8.76 11.50 -9.81 20.0 33.0 28.46 17.25 10.130 2477.849 9.81 0.6494 0.5421 7 9.92 11.0 11.50 10.66 -9.81 20.0 33.0 28.46 17.25 11.080 1896.010 9.81 0.6494 0.5421 8 10.89 13.0 10.66 10.99 -9.81 20.0 33.0 28.46 17.25 10.825 2033.503 9.81 0.6494 0.5421 9 11.00 16.0 10.99 11.49 -9.81 20.0 33.0 28.46 17.25 11.240 2132.790 9.81 0.6494 0.5421

10 11.20 20.0 11.49 10.88 -9.81 20.0 33.0 28.46 17.25 11.185 2160.942 9.81 0.6494 0.5421 11 11.20 24.0 10.88 8.69 -9.81 20.0 33.0 28.46 17.25 9.785 1890.462 9.81 0.6494 0.5421 12 8.83 24.0 8.69 7.02 -9.81 20.0 33.0 28.46 17.25 7.855 1196.454 9.81 0.6494 0.5421 13 11.10 24.0 7.02 6.0*6 1 -9.81 20.0 33.0 28.46 17.25 6.510 1246.502 9.81 0.6494 0.5421 14 11.20 24.0 6.00 3.70 -9.81 20.0 33.0 28.46 17.25 4.850 937.020 9.81 0.6494 0.5421 15 17.60 24.6 3.70 -9.81 20.0 33.0 28.46 17.25 1.850 561.660 9.81 0.6494 0.5421 16

fO 1.0300

96

V


MODIFIED JANBU'S SIMPLIFIED METHOD 3 of 3

Calculations

C A L C U L A T I O N - S T A G E 2

1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 3 2 3 3 3 4 3 5

Trial 1 Trial 1 Trial 2 Trial 2 Trial 3 Trial 3 Trial 4 Trial 4 T r i a l 5 T r i a l S

(wi+Qi)

tan qi c'Dxi Uai*Dxi

(wi+Qi

-UaiDxi) (22)*tanf

(Ua-Uw)

*Dxi*tanfb

(20)+(23)+(24)

ni(q)

(2S) / (26)

ni(q)

(25 ) / (28 )

ni(q)

(25) / (28)

ni(q)

( 2 5 ) / ( 3 2 )

ni(q)

( 2 5 ) / ( 3 4 )

1 2 . 5 0 2 2 4 . 0 1 7 8 . 7 1 1 1 6 . 0 6 5 9 . 5 6 3 9 9 . 6 1 2 1 . 0 0 8 3 9 6 . 2 4 9 1 .008 3 9 6 . 4 3 3 1 . 0 0 8 3 9 6 . 4 4 2 1 . 0 0 8 3 9 6 . 4 4 2 1 . 0 0 8 3 9 6 . 4 4 2

2 3 . 6 1 1 5 6 . 6 3 3 7 . 6 7 2 1 9 . 2 8 4 1 . 6 4 4 1 7 . 5 2 1 1 . 0 0 8 4 1 4 . 0 0 7 1 . 0 0 8 4 1 4 . 2 0 0 1 . 0 0 8 4 1 4 . 2 0 8 1 . 0 0 8 4 1 4 . 2 0 9 1 . 0 0 8 4 1 4 . 2 0 9

7 6 . 4 0 2 9 1 . 2 1 0 9 2 . 5 5 7 0 9 . 5 1 7 7 . 4 2 1 0 7 8 . 1 3 1 1 . 0 0 8 1 0 6 9 . 0 5 7 1 . 0 0 8 1 0 6 9 . 5 5 5 1 . 0 0 8 1 0 6 9 . 5 7 7 1 . 0 0 8 1 0 6 9 . 5 7 8 1 . 0 0 8 1 0 6 9 . 5 7 8

8 7 . 2 1 2 2 4 . 0 1 2 4 7 . 1 1 8 0 9 . 8 8 5 9 . 5 6 1 0 9 3 . 4 3 6 1 . 0 0 8 1 0 8 4 . 2 3 4 1 . 0 0 8 1 0 8 4 . 7 3 9 1 . 0 0 8 1 0 8 4 . 7 6 1 1 . 0 0 8 1 0 8 4 . 7 6 2 1 . 0 0 8 1 0 8 4 . 7 6 2

1 0 8 . 8 9 2 2 4 . 0 1 5 5 7 . 1 9 1 0 1 1 . 2 5 5 9 . 5 6 1 2 9 4 . 8 0 9 1 . 0 0 8 1 2 8 3 . 9 1 2 1 . 0 0 8 1 2 8 4 . 5 0 9 1 . 0 0 8 1 2 8 4 . 5 3 6 1 . 0 0 8 1 2 8 4 . 5 3 7 1 . 0 0 8 1 2 8 4 . 5 3 7

1 7 3 . 2 7 2 8 3 . 6 2 4 7 7 . 8 5 1 6 0 9 . 1 3 7 5 . 4 0 1 9 6 8 . 1 3 6 1 . 0 0 8 1 9 5 1 . 5 7 3 1 . 0 0 8 1 9 5 2 . 4 8 1 1 . 0 0 8 1 9 5 2 . 5 2 2 1 . 0 0 8 1 9 5 2 . 5 2 3 1 . 0 0 8 1 9 5 2 . 5 2 3

3 6 8 . 5 5 1 9 8 . 4 1 8 9 6 . 0 1 1 2 3 1 . 2 8 5 2 . 7 5 1 4 8 2 . 4 3 3 1 . 0 0 0 1 4 8 3 . 1 2 3 0 . 9 9 8 1 4 8 4 . 9 9 9 0 . 9 9 8 1 4 8 5 . 0 8 3 0 . 9 9 8 1 4 8 5 . 0 8 7 0 . 9 9 8 1 4 8 5 . 0 8 7

4 6 9 . 4 7 2 1 7 . 8 2 0 3 3 . 5 0 1 3 2 0 . 5 7 5 7 . 9 1 1 5 9 6 . 2 8 0 0 . 9 9 1 1 6 1 0 . 0 3 4 0 . 9 9 0 1 6 1 2 . 4 3 6 0 . 9 9 0 1 6 1 2 . 5 4 5 0 . 9 9 0 1 6 1 2 . 5 5 0 0 . 9 9 0 1 6 1 2 . 5 5 0

6 1 1 . 5 7 2 2 0 . 0 2 1 3 2 . 7 9 1 3 8 5 . 0 5 5 8 . 4 9 1 6 6 3 . 5 4 3 0 . 9 7 5 1 7 0 6 . 4 2 8 0 . 9 7 3 1 7 0 9 . 5 5 9 0 . 9 7 3 1 7 0 9 . 7 0 1 0 . 9 7 3 1 7 0 9 . 7 0 7 0 . 9 7 3 1 7 0 9 . 7 0 7

7 8 6 . 5 2 2 2 4 . 0 2 1 6 0 . 9 4 1 4 0 3 . 3 3 5 9 . 5 6 1 6 8 6 . 8 8 8 0 . 9 4 5 1 7 8 5 . 6 4 1 0 . 9 4 3 1 7 8 9 . 7 4 5 0 . 9 4 2 1 7 8 9 . 9 3 0 0 . 9 4 2 1 7 8 9 . 9 3 9 0 . 9 4 2 1 7 8 9 . 9 3 9

8 4 1 . 6 9 2 2 4 . 0 1 8 9 0 . 4 6 1 2 2 7 . 6 8 5 9 . 5 6 1 5 1 1 . 2 3 7 0 . 9 0 6 1 6 6 8 . 2 7 4 0 . 9 0 3 1 6 7 2 . 8 9 9 0 . 9 0 3 1 6 7 3 . 1 0 8 0 . 9 0 3 1 6 7 3 . 1 1 7 0 . 9 0 3 1 6 7 3 . 1 1 8

5 3 2 . 7 0 1 7 6 . 6 1 1 9 6 . 4 5 7 7 6 . 9 9 4 6 . 9 5 1 0 0 0 . 5 4 0 0 . 9 0 6 1 1 0 4 . 5 0 9 0 . 9 0 3 1 1 0 7 . 5 7 1 0 . 9 0 3 1 1 0 7 . 7 1 0 0 . 9 0 3 1 1 0 7 . 7 1 6 0 . 9 0 3 1 1 0 7 . 7 1 6

5 5 4 . 9 8 2 2 2 . 0 1 2 4 6 . 5 0 8 0 9 . 4 9 5 9 . 0 2 1 0 9 0 . 5 1 3 0 . 9 0 6 1 2 0 3 . 8 3 1 0 . 9 0 3 1 2 0 7 . 1 6 8 0 . 9 0 3 1 2 0 7 . 3 1 9 0 . 9 0 3 1 2 0 7 . 3 2 6 0 . 9 0 3 1 2 0 7 . 3 2 6

4 1 7 . 1 9 2 2 4 . 0 937'.*02 1 6 0 8 . 5 1 5 9 . 5 6 8 9 2 . 0 6 4 0 . 9 0 6 9 8 4 . 7 6 1 0 . 9 0 3 9 8 7 . 4 9 1 0 . 9 0 3 9 8 7 . 6 1 5 0 . 9 0 3 9 8 7 . 6 2 0 0 . 9 0 3 9 8 7 . 6 2 1

2 5 0 . 0 7 3 5 2 . 0 5 6 1 . 6 6 3 6 4 . 7 5 9 3 . 5 9 8 1 0 . 3 3 5 0 . 9 0 6 8 9 4 . 5 3 9 0 . 9 0 3 8 9 7 . 0 1 9 0 . 9 0 3 8 9 7 . 1 3 1 0 . 9 0 3 8 9 7 . 1 3 6 0 . 9 0 3 8 9 7 . 1 3 6

1 . 0 0 0 1 . 0 0 0 1 . 0 0 0 1 . 0 0 0 1 . 0 0 0

5 3 1 4 . 5 9 1 7 9 8 5 . 4 7 8 1 8 6 4 0 . 1 7 2 1 8 6 7 0 . 8 0 4 1 8 6 7 2 . 1 8 7 1 8 6 7 2 . 2 5 0 1 8 6 7 2 . 2 5 3

F O S ( i n i ) 3 . 3 8 4 2 F O S ( l ) 3 . 5 0 7 4 F O S ( 2 ) 3 . 5 1 3 1 F O S ( 3 ) 3 . 5 1 3 4 F O S ( 4 ) 3 . 5 1 3 4 F O S ( 5 ) 3 . 5 1 3 4

F 0 S ( F 0 ) 3 . 5 1 3 4

F O S 3 . 6 1 8 8

97

J


CALCULATION OF FACTOR OF SAFETY OF A SELECTED FAILURE SURFACE MODIFIED JANBU'S SIMPLIFIED METHOD

UNSATURATED SOIL

1 of 3

INPUTS CALCULATION-STAGE 1 10 11 12 13 14 15 16 17 18

Slice Slice Width

Axi (m)

ei hi (m)

h2 (m)

Pore Water Pressure

Uw

(kN/m2)

Pore Air Pressure

Ua (kN/m2)

SoU Type

c' (kN/m2) ..«f8).

33.0

4>b

28.46

Matric Suction (kN/m2)

19.62

q« (kN/m2)

Y (kN/m3)

{(4)+(5)}/2 hav (m)

[2)*(10)*(11 wi

V-per m wkii

(9)*(2) Qi

(kN-per m width)

tan <)>' tan <)>b

1 11.20 4.0 0.00 1.85 -19.62 1 20.0 ..«f8).

33.0

4>b

28.46

Matric Suction (kN/m2)

19.62 0.00 17.25 0.93 178.71 0.65 0.54 2 7.83 4.0 1.85 3.15 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 2.50 337.67 0.65 0.54 3 14.56 4.0 3.15 5.55 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 4.35 1092.55 0.65 0.54 4 11.20 4.0 5.55 7.36 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 6.46 1247.11 0.65 0.54 5 11.20 4.0 7.36 8.76 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 8.06 1557.19 0.65 0.54 6 14.18 4.0 8.76 11.50 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 10.13 2477.85 0.65 0.54 7 9.92 11.0 11.50 10.66 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 11.08 1896.01 0.65 0.54 8 10.89 13.0 10.66 10.99 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 10.83 2033.50 0.65 0.54 9 11.00 16.0 10.99 11.49 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 11.24 2132.79 0.65 0.54 10 11.20 20.0 11.49 10.88 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 11.19 2160.94 0.65 0.54 11 11.20 24.0 10.88 8.69 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 9.79 1890.46 0.65 0.54 12 8.83 24.0 8.69 7.02 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 7.86 1196.45 0.65 0.54 13 11.10 24.0 7.02 6.00 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 6.51 1246.50 0.65 0.54 14 11.20 24.0 6.00 3.70 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 4.85 937.02 0.65 0.54 15 17.60 24.0 3.70 0.00 -19.62 1 20.0 33.0 28.46 19.62 0.00 17.25 1.85 561.66 0.65 0.54

f O 1.03 Note: Enter Values only in green cells T o analyse unsa tu ra ted soil s lopes , enter the title " U N S A T U R A T E D S O I L " in the Calcula t ions sheet

At the same t ime, enter the po re air p ressure and I'i-b value in D a t a - E n t r y sheet

W a t e r table at 10m be low failure surface and20% of full negat ive hydris tat ic p ressu re a s s u m e d .

(j)b is assumed to be equal to equal to found actual value.

FOS(4) 3.70 FOS(5) FOS(FO)

FOS

3.70 3.70

3.81

98


MODIFIED JANBU'S SIMPLIFIED METHOD UNSA TURA TED SOIL 2 o f 3

Calculations

1 INPUTS CALCULATION-STAGE 1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Slice Slice

Width Axi (m)

9i

(d eP> h i (m)

h2 (m)

Pore Water Pressure

Uw ( k N / m 2 )

Air Pressure

Ua ( k N / r r ^

c ' ( k N / m 2 )

V

( d e P) V

( k N / m 2 ) T

( k N / m 3 )

{(4)+(5)}/2 hav (m)

(2)*(12)*(13)

wi N-per m wid

Matric Suction

(Ua-Uw) ( k N / m 2 )

Qi (kN-per tan <)>' tan <|>b

Slice Slice Width

Axi (m)

9i

(d eP> h i (m)

h2 (m)

Pore Water Pressure

Uw ( k N / m 2 )

Air Pressure

Ua ( k N / r r ^

c ' ( k N / m 2 )

V

( d e P) V

( k N / m 2 ) T

( k N / m 3 )

{(4)+(5)}/2 hav (m)

(2)*(12)*(13)

wi N-per m wid

Matric Suction

(Ua-Uw) ( k N / m 2 ) m width)

tan <)>' tan <|>b

1 11.20 4.00 1.85 -19.62 20.00 33.00 28.46 17.25 0.93 178.7100 19.62 0.6494 0.5421 2 7.83 4.00 1.85 3.15 -19.62 20.00 33.00 28.46 17.25 2.50 337.6688 19.62 0.6494 0.5421 3 14.56 4.00 3.15 5.55 -19.62 20.00 33.00 28.46 17.25 4.35 1092.5460 19.62 0.6494 0.5421 4 11.20 4.00 5.55 7.36 -19.62 20.00 33.00 28.46 17.25 6.46 1247.1060 19.62 0.6494 0.5421 5 11.20 4.00 7.36 8.76 -19.62 20.00 33.00 28.46 17.25 8.06 1557.1920 19.62 0.6494 0.5421 6 14.18 4.00 8.76 11.50 -19.62 20.00 33.00 28.46 17.25 10.13 2477.8487 19.62 0.6494 0.5421 7 9.92 11.00 11.50 10.66 -19.62 20.00 33.00 28.46 17.25 11.08 1896.0096 19.62 0.6494 0.5421 8 10.89 13.00 10.66 10.99 -19.62 20.00 33.00 28.46 17.25 10.83 2033.5033 19.62 0.6494 0.5421 9 11.00 16.00 10.99 11.49 -19.62 20.00 33.00 28.46 17.25 11.24 2132.7900 19.62 0.6494 0.5421

10 11.20 20.00 11.49 10.88 -19.62 20.00 33.00 28.46 17.25 11.19 2160.9420 19.62 0.6494 0.5421 11 11.20 24.00 10.88 8.69 -19.62 20.00 33.00 28.46 17.25 9.79 1890.4620 19.62 0.6494 0.5421 12 8.83 24.00 8.69 7.02 -19.62 20.00 33.00 28.46 17.25 7.86 1196.4540 19.62 0.6494 0.5421 13 11.10 24.00 7.02 6.00 -19.62 20.00 33.00 28.46 17.25 6.51 1246.5023 19.62 0.6494 0.5421 14 11.20 24.00 6.00 3.70 -19.62 20.00 33.00 28.46 17.25 4.85 937.0200 19.62 0.6494 0.5421 15 17.60 24.00 3.70 -19.62 20.00 33.00 28.46 17.25 1.85 561.6600 19.62 0.6494 0.5421 16

fO | 1.030

99

V


MODIFIED JANBU'S SIMPLIFIED METHOD 3 O f 3

Calculations


1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 3 2 3 3 3 4 3 5

Trial 1 Trial 1 Trial 2 Trial 2 Trial 3 Trial 3 Trial 4 Trial 4 Trials Tria lS (wi+Qi)

tan qi c'Dxi Uai*Dxi (wi+Qi

-UaiDxi) (22)*tanf (

[Ua-Uw)*Dxi *tanfb

20)+(23)+(24 ) ni(q)

(25)/(26) ni(q)

(25)/(28) ni(q)

(25)/(28) ni(q)

(25)/(32) ni(q)

(25)/(34)

1 2 . 5 0 2 2 4 . 0 1 7 8 . 7 1 1 1 6 . 0 6 1 1 9 . 1 1 4 5 9 . 1 6 8 1 .008 4 5 5 . 5 9 8 1 .007 4 5 5 . 8 1 3 1 .007 4 5 5 . 8 2 2 1 .007 4 5 5 . 8 2 1 .007 4 5 5 . 8 2 2 2 3 . 6 1 1 5 6 . 6 3 3 7 . 6 7 2 1 9 . 2 8 8 3 . 2 7 4 5 9 . 1 5 7 1 .008 4 5 5 . 5 8 7 1 .007 4 5 5 . 8 0 2 1 .007 4 5 5 . 8 1 1 1 .007 4 5 5 . 8 1 1 . 0 0 7 4 5 5 . 8 1 1 7 6 . 4 0 2 9 1 . 2 1 0 9 2 . 5 5 7 0 9 . 5 1 1 5 4 . 8 5 1 1 5 5 . 5 5 4 1 .008 1 1 4 6 . 5 6 8 1 .007 1 1 4 7 . 1 0 9 1 .007 1 1 4 7 . 1 3 2 1 .007 1 1 4 7 . 1 3 1 . 0 0 7 1 1 4 7 . 1 3 3 8 7 . 2 1 2 2 4 . 0 1 2 4 7 . 1 1 8 0 9 . 8 8 1 1 9 . 1 1 1 1 5 2 . 9 9 3 1 .008 1 1 4 4 . 0 2 7 1 .007 1 1 4 4 . 5 6 7 1 .007 1 1 4 4 . 5 9 0 1 .007 1 1 4 4 . 5 9 1 . 0 0 7 1 1 4 4 . 5 9 1

1 0 8 . 8 9 2 2 4 . 0 1 5 5 7 . 1 9 1 0 1 1 . 2 5 1 1 9 . 1 1 1 3 5 4 . 3 6 5 1 . 0 0 8 1 3 4 3 . 8 3 3 1 .007 1 3 4 4 . 4 6 7 1 .007 1 3 4 4 . 4 9 4 1 .007 1 3 4 4 . 5 0 1 .007 1 3 4 4 . 4 9 6 1 7 3 . 2 7 2 8 3 . 6 2 4 7 7 . 8 5 1 6 0 9 . 1 3 1 5 0 . 8 1 2 0 4 3 . 5 3 9 1 . 0 0 8 2 0 2 7 . 6 4 8 1 . 0 0 7 2 0 2 8 . 6 0 4 1 .007 2 0 2 8 . 6 4 5 1 .007 2 0 2 8 . 6 5 1 .007 2 0 2 8 . 6 4 7 3 6 8 . 5 5 1 9 8 . 4 1 8 9 6 . 0 1 1 2 3 1 . 2 8 1 0 5 . 5 0 1 5 3 5 . 1 8 3 0 . 9 9 8 1 5 3 8 . 5 9 1 0 . 9 9 7 1 5 4 0 . 5 6 7 0 . 9 9 6 1 5 4 0 . 6 5 2 0 . 9 9 6 1 5 4 0 . 6 6 0 . 9 9 6 1 5 4 0 . 6 5 5 4 6 9 . 4 7 2 1 7 . 8 2 0 3 3 . 5 0 1 3 2 0 . 5 7 1 1 5 . 8 2 1 6 5 4 . 1 8 8 0 . 9 8 9 1 6 7 1 . 8 9 4 0 . 9 8 8 1 6 7 4 . 4 2 7 0 . 9 8 8 1 6 7 4 . 5 3 6 0 . 9 8 8 1 6 7 4 . 5 4 0 . 9 8 8 1 6 7 4 . 5 4 1 6 1 1 . 5 7 2 2 0 . 0 2 1 3 2 . 7 9 1 3 8 5 . 0 5 1 1 6 . 9 9 1 7 2 2 . 0 3 6 0 . 9 7 2 1 7 7 0 . 9 2 5 0 . 9 7 1 1 7 7 4 . 2 2 7 0 . 9 7 1 1 7 7 4 . 3 6 9 0 . 9 7 1 1 7 7 4 . 3 8 0 . 9 7 1 1 7 7 4 . 3 7 6 7 8 6 . 5 2 2 2 4 . 0 2 1 6 0 . 9 4 1 4 0 3 . 3 3 1 1 9 . 1 1 1 7 4 6 . 4 4 5 0 . 9 4 2 1 8 5 4 . 5 7 9 0 . 9 3 9 1 8 5 8 . 9 1 2 0 . 9 3 9 1 8 5 9 . 0 9 9 0 . 9 3 9 1 8 5 9 . 1 1 0 . 9 3 9 1 8 5 9 . 1 0 7 8 4 1 . 6 9 2 2 4 . 0 1 8 9 0 . 4 6 1 2 2 7 . 6 8 1 1 9 . 1 1 1 5 7 0 . 7 9 3 0 . 9 0 2 1 7 4 0 . 6 9 0 0 . 9 0 0 1 7 4 5 . 5 9 9 0 . 9 0 0 1 7 4 5 . 8 1 1 0 . 9 0 0 1 7 4 5 . 8 2 0 . 9 0 0 1 7 4 5 . 8 2 0 5 3 2 . 7 0 1 7 6 . 6 1 1 9 6 . 4 5 7 7 6 . 9 9 9 3 . 9 1 1 0 4 7 . 4 9 4 0 . 9 0 2 1 1 6 0 . 7 9 1 0 . 9 0 0 1 1 6 4 . 0 6 5 0 . 9 0 0 1 1 6 4 . 2 0 5 0 . 9 0 0 1 1 6 4 . 2 1 0 . 9 0 0 1 1 6 4 . 2 1 2 5 5 4 . 9 8 2 2 2 . 0 1 2 4 6 . 5 0 8 0 9 . 4 9 1 1 8 . 0 5 1 1 4 9 . 5 3 7 0 . 9 0 2 1 2 7 3 . 8 7 1 0 . 9 0 0 1 2 7 7 . 4 6 4 0 . 9 0 0 1 2 7 7 . 6 1 8 0 . 9 0 0 1 2 7 7 . 6 3 0 . 9 0 0 1 2 7 7 . 6 2 5 4 1 7 . 1 9 2 2 4 . 0 9 3 7 . 0 2 6 0 8 . 5 1 1 1 9 . 1 1 9 5 1 . 6 2 1 0 . 9 0 2 1 0 5 4 . 5 4 8 0 . 9 0 0 1 0 5 7 . 5 2 2 0 . 9 0 0 1 0 5 7 . 6 5 0 0 . 9 0 0 1 0 5 7 . 6 6 0 . 9 0 0 1 0 5 7 . 6 5 6 2 5 0 . 0 7 3 5 2 . 0 5 6 1 . 6 6 3 6 4 . 7 5 1 8 7 . 1 8 9 0 3 . 9 2 3 0 . 9 0 2 1 0 0 1 . 6 9 2 0 . 9 0 0 1 0 0 4 . 5 1 7 0 . 9 0 0 1 0 0 4 . 6 3 8 0 . 9 0 0 1 0 0 4 . 6 4 0 . 9 0 0 1 0 0 4 . 6 4 4

1 . 0 0 0 1 . 0 0 0 1 .000 1 . 0 0 0 1 . 0 0 0 5 3 1 4 . 5 9 2 5 1 8 9 0 5 . 9 9 6 1 9 6 4 0 . 8 4 2 1 9 6 7 3 . 6 6 2 1 9 6 7 5 . 0 7 3 1 9 6 7 5 . 1 3 1 9 6 7 5 . 1 3 7

100

V

APPENDIX B PUSSALLAWA UNSATURATED SLOPE STABILITY ANALYSIS WHEN WATER TABLE IS 5m BELOW FAILURE SURFACE

CALCULATION OF FACTOR OF SAFETY OF A SELECTED FAILURE SURFACE MODIFIED JANBU'S SIMPLIFIED METHOD

UNSATURATED SOIL

of 3

INPUTS CALCULATION-STAGE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Slice Sbce Pore W a t Pore A i r SoU (9)*(2) W i d t h Pressun Pressure Type M a t r i c {(4)+(5)} /2 [2 ) * (10) * (11 Q i

A x i 6 i h i h.2 U w Ua c' «t»' * b Suct ion q> y hav w i ( k N - p e r tan <(>' tan 4>b

(m) (m) (m) (kN/m2) ( k N / m 2 ) (kN /m2) (<J«g). ( k N / m 2 ) ( k N / m 2 ) ( k N / m 3 ) (m) V-per m w id m w i d t h ) 1 11.20 4.0 0.00 1.85 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 0.93 178.71 0.65 0.54 2 7.83 4.0 1.85 3.15 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 2.50 337.67 0.65 0.54 3 14.56 4.0 3.15 5.55 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 4.35 1092.55 0.65 0.54 4 11.20 4.0 5.55 7.36 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 6.46 1247.11 0.65 0.54 5 11.20 4.0 7.36 8.76 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 8.06 1557.19 0.65 0.54 6 14.18 4.0 8.76 11.50 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 10.13 2477.85 0.65 0.54 7 9.92 11.0 11.50 10.66 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 11.08 1896.01 0.65 0.54 8 10.89 13.0 10.66 10.99 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 10.83 2033.50 0.65 0.54 9 11.00 16.0 10.99 11.49 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 11.24 2132.79 0.65 0.54 10 11.20 20.0 11.49 10.88 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 11.19 2160.94 0.65 0.54 11 11.20 24.0 10.88 8.69 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 9.79 1890.46 0.65 0.54 12 8.83 24.0 8.69 7.02 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 7.86 1196.45 0.65 0.54 13 11.10 24.0 7.02 6.00 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 6.51 1246.50 0.65 0.54 14 11.201 24.0 6.00 3.70 1 -29.43 1 20.00* 33.00 28.46 29.4*3 1 o'.'oo 17.25 4.85 937.02 0.65 1 6.54 15 17.60 24.0 3.70 0.00 -29.43 1 20.00 33.00 28.46 29.43 0.00 17.25 1.85 561.66 0.65 0.54

Note: Enter Values only in green cells fO 1.03 T o analyse, unsaturated soil slopes, enter the title " U N S A T U R A T E D SOIL." in the Calculations sheet.

At the same time, enter the pore air pressure and Fi-b value in Da ta -En t ry sheet Unsaturated analsis wahen W T is at 15m below failure surface assuming 10% of full negative hydristatic pressure

<j)b is assumed to be equal to equal to found actual value.

FOS(5) FOS(FO)

FOS

3.89 3.89

4.01

101

4 v

APPENDIX B PUSSALLAWA UNSATURATED SLOPE STABILITY ANALYSIS WHEN WATER TABLE IS Sm BELOW FAILURE SURFACE

M O D I F I E D J A N B U ' S S I M P L I F I E D M E T H O D 2 o f 3

UNSA TURA TED SOIL

Calculations

1

I N P U T S C A L C U L A T I O N - S T A G E 1

1 2 3 4 5 6 7 8 9 10 11 1 2 13 1 4 15 16 17 18

Slice Slice

Width

Axi

(m)

9i

( d e &)

hi

M h2

H

Pore Water

Pressure

Uw

(kN/m2)

Air

Pressure

Ua

(kN/m2)

c*

(kN/m2 < d e&)

4>b

<defi> (kN/m2) y

(kN/m3)

{(4)+(5)}/2

hav

(m)

(2)*(12)*(13)

wi

N-per m wid

Matric

Suction

(Ua-Uw)

(kN/m2)

(11)*(2)

Qi

(kN-per tan <(>' t a n f

Slice Slice

Width

Axi

(m)

9i

( d e &)

hi

M h2

H

Pore Water

Pressure

Uw

(kN/m2)

Air

Pressure

Ua

(kN/m2)

c*

(kN/m2 < d e&)

4>b

<defi> (kN/m2) y

(kN/m3)

{(4)+(5)}/2

hav

(m)

(2)*(12)*(13)

wi

N-per m wid

Matric

Suction

(Ua-Uw)

(kN/m2) m width) tan <(>' t a n f

1 1 1 . 2 0 4 .0 1.85 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 0 . 9 2 5 1 7 8 . 7 1 0 0 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

2 7 . 8 3 4 .0 1.85 3 .15 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 2 . 5 0 0 3 3 7 . 6 6 8 8 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

3 1 4 . 5 6 4 .0 3 .15 5 .55 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 4 . 3 5 0 1 0 9 2 . 5 4 6 0 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

4 1 1 . 2 0 4 . 0 5 .55 7 . 3 6 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 6 . 4 5 5 1 2 4 7 . 1 0 6 0 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

5 1 1 . 2 0 4 . 0 7 .36 8 .76 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 8 . 0 6 0 1 5 5 7 . 1 9 2 0 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

6 1 4 . 1 8 4 .0 8 .76 1 1 . 5 0 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 1 0 . 1 3 0 2 4 7 7 . 8 4 8 7 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

7 9 . 9 2 1 1 . 0 1 1 . 5 0 1 0 . 6 6 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 1 1 . 0 8 0 1 8 9 6 . 0 0 9 6 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

8 1 0 . 8 9 1 3 . 0 1 0 . 6 6 1 0 . 9 9 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 1 0 . 8 2 5 2 0 3 3 . 5 0 3 3 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

9 1 1 . 0 0 1 6 . 0 1 0 . 9 9 1 1 . 4 9 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 1 1 . 2 4 0 2 1 3 2 . 7 9 0 0 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

10 1 1 . 2 0 2 0 . 0 1 1 . 4 9 1 0 . 8 8 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 1 1 . 1 8 5 2 1 6 0 . 9 4 2 0 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

11 1 1 . 2 0 2 4 . 0 1 0 . 8 8 8 .69 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 9 . 7 8 5 1 8 9 0 . 4 6 2 0 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

1 2 8 .83 2 4 . 0 8 .69 7 .02 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 7 . 8 5 5 1 1 9 6 . 4 5 4 0 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

13 1 1 . 1 0 2 4 . 0 | 7 .02 6 . 0 0 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 6 . 5 1 0 1 2 4 6 . 5 0 2 3 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

1 4 1 1 . 2 0 2 4 . 0 6".00 3 . 7 0 -29.4 _ 3 1 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 4 . 8 5 0 9 3 7 . 0 2 0 0 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

15 1 7 . 6 0 2 4 . 0 3 .70 - 2 9 . 4 3 2 0 . 0 3 3 . 0 2 8 . 4 6 1 7 . 2 5 1 .850 5 6 1 . 6 6 0 0 2 9 . 4 3 0 0 0 . 6 4 9 4 0 . 5 4 2 1

16

fO 1 . 0 3 0 0

102

APPENDIX B PUSSALLAWA UNSATURATED SLOPE STABILITY ANALYSIS WHEN WATER TABLE IS 5m BELOW FAILURE SURFACE

MODIFIED JANBU'S SIMPLIFIED METHOD

Calculations

3 o f 3


19 2 0 2 1 2 2 2 3 2 4 25 2 6 2 7 2 8 2 9 3 0 3 1 3 2 3 3 3 4 3 5

Trial 1 Trial 1 Trial 2 Trial 2 Trial 3 Trial 3 Trial 4 Trial 4 Trial 5 Trial 5 (wi+Qi)*

tan qi c'Dxi Uai*Dxi (wi+Qi -UaiDxi) (22)*tanf

(Ua-Uw) *Dxi*tanfb

(20)+(23)+(24) ni(q)

(25)/(26) ni(q)

(25)/(28) ni(q)

(25)/(28) ni(q)

(25)/(32) ni(q)

(25)/(34)

1 2 . 5 0 2 2 4 . 0 1 7 8 . 7 1 0 1 1 6 . 0 5 6 1 7 8 . 6 6 9 5 1 8 . 7 2 5 1 . 0 0 7 2 5 1 4 . 9 9 1 .007 5 1 5 . 2 3 7 1 .007 5 1 5 . 2 4 7 1 .007 5 1 5 . 2 5 1 .007 5 1 5 . 2

2 3 . 6 1 1 5 6 . 6 3 3 7 . 6 6 9 2 1 9 . 2 8 5 1 2 4 . 9 0 9 5 0 0 . 7 9 3 1 . 0 0 7 2 4 9 7 . 1 9 1 .007 4 9 7 . 4 2 6 1.007 4 9 7 . 4 3 6 1 .007 4 9 7 . 4 4 1 .007 4 9 7 . 4

7 6 . 4 0 2 9 1 . 2 1 0 9 2 . 5 4 6 7 0 9 . 5 0 8 2 3 2 . 2 7 0 1 2 3 2 . 9 7 7 1 . 0 0 7 2 1 2 2 4 . 1 1 1 .007 1 2 2 4 . 6 8 7 1.007 1 2 2 4 . 7 1 1 1 .007 1 2 2 4 . 7 1 1 .007 1 2 2 4 . 7

8 7 . 2 1 2 2 4 . 0 1 2 4 7 . 1 0 6 8 0 9 . 8 8 0 1 7 8 . 6 6 9 1 2 1 2 . 5 4 9 1 . 0 0 7 2 1 2 0 3 . 8 2 1 .007 1 2 0 4 . 3 9 7 1.007 1 2 0 4 . 4 2 0 1 .007 1 2 0 4 . 4 2 1 .007 1 2 0 4 . 4

1 0 8 . 8 9 2 2 4 . 0 1 5 5 7 . 1 9 2 1 0 1 1 . 2 5 2 1 7 8 . 6 6 9 1 4 1 3 . 9 2 1 1 . 0 0 7 2 1 4 0 3 . 7 5 1 .007 1 4 0 4 . 4 1 5 1.007 1 4 0 4 . 4 4 2 1 .007 1 4 0 4 . 4 4 1 .007 1 4 0 4 . 4

1 7 3 . 2 7 2 8 3 . 6 2 4 7 7 . 8 4 9 1 6 0 9 . 1 3 4 2 2 6 . 2 0 8 2 1 1 8 . 9 4 2 1 .0072 2 1 0 3 . 7 0 1 .007 2 1 0 4 . 6 9 5 1 .007 2 1 0 4 . 7 3 6 1 .007 2 1 0 4 . 7 4 1 .007 2 1 0 4 . 7

3 6 8 . 5 5 1 9 8 . 4 1 8 9 6 . 0 1 0 1 2 3 1 . 2 8 3 1 5 8 . 2 5 0 1 5 8 7 . 9 3 3 0 . 9 9 6 2 1 5 9 3 . 9 9 0 . 9 9 5 1 5 9 6 . 0 5 8 0 . 9 9 5 1 5 9 6 . 1 4 2 0 . 9 9 5 1 5 9 6 . 1 5 0 . 9 9 5 1 5 9 6 . 1

4 6 9 . 4 7 2 1 7 . 8 2 0 3 3 . 5 0 3 1 3 2 0 . 5 7 2 1 7 3 . 7 2 4 1 7 1 2 . 0 9 6 0 . 9 8 7 6 1 7 3 3 . 6 8 0 . 9 8 6 1 7 3 6 . 3 2 6 0 . 9 8 6 1 7 3 6 . 4 3 5 0 . 9 8 6 1 7 3 6 . 4 4 0 . 9 8 6 1 7 3 6 . 4

6 1 1 . 5 7 2 2 0 . 0 2 1 3 2 . 7 9 0 1 3 8 5 . 0 5 0 1 7 5 . 4 7 9 1 7 8 0 . 5 2 9 0 . 9 7 0 1 1 8 3 5 . 3 2 0 . 9 6 8 1 8 3 8 . 7 7 0 0 . 9 6 8 1 8 3 8 . 9 1 2 0 . 9 6 8 1 8 3 8 . 9 2 0 . 9 6 8 1 8 3 8 . 9

7 8 6 . 5 2 2 2 4 . 0 2 1 6 0 . 9 4 2 1 4 0 3 . 3 3 2 1 7 8 . 6 6 9 1 8 0 6 . 0 0 1 0 . 9 3 9 0 1 9 2 3 . 3 9 0 . 9 3 7 1 9 2 7 . 9 2 3 0 . 9 3 7 1 9 2 8 . 1 1 0 0 . 9 3 7 1 9 2 8 . 1 2 0 . 9 3 7 1 9 2 8 . 1

8 4 1 . 6 9 2 2 4 . 0 1 8 9 0 . 4 6 2 1 2 2 7 . 6 8 0 1 7 8 . 6 6 9 1 6 3 0 . 3 4 9 0 . 8 9 9 2 1 8 1 3 . 0 2 0 . 8 9 7 1 8 1 8 . 1 8 0 0 . 8 9 7 1 8 1 8 . 3 9 3 0 . 8 9 7 1 8 1 8 . 4 0 0 . 8 9 7 1 8 1 8 . 4

5 3 2 . 7 0 1 7 6 . 6 1 1 9 6 . 4 5 4 7 7 6 . 9 8 6 1 4 0 . 8 6 1 1 0 9 4 . 4 4 8 0 . 8 9 9 2 1 2 1 7 . 0 7 0 . 8 9 7 1 2 2 0 . 5 3 8 0 . 8 9 7 1 2 2 0 . 6 8 0 0 . 8 9 7 1 2 2 0 . 6 9 0 . 8 9 7 1 2 2 0 . 7

5 5 4 . 9 8 2 2 2 . 0 1 2 4 6 . 5 0 2 8 0 9 . 4 8 8 1 7 7 . 0 7 4 1 2 0 8 . 5 6 2 0 . 8 9 9 2 1 3 4 3 . 9 7 0 . 8 9 7 1 3 4 7 . 7 9 9 0 . 8 9 7 1 3 4 7 . 9 5 6 0 . 8 9 7 1 3 4 7 . 9 6 0 . 8 9 7 1 3 4 8 . 0

4 1 7 . 1 9 2 2 4 . 0 9 3 7 . 0 2 0 6 0 8 . 5 0 8 1 7 8 . 6 6 9 1 0 1 1 . 1 7 7 0 . 8 9 9 2 1 1 2 4 . 4 7 0 . 8 9 7 1 1 2 7 . 6 7 4 0 .897 1 1 2 7 . 8 0 5 0 . 8 9 7 1 1 2 7 . 8 1 0 . 8 9 7 1 1 2 7 . 8

2 5 0 . 0 7 3 5 2 . 0 5 6 1 . 6 6 0 3 6 4 . 7 4 6 2 8 0 . 7 6 6 9 9 7 . 5 1 2 0 . 8 9 9 2 1 1 0 9 . 2 7 0 . 8 9 7 1 1 1 2 . 4 3 4 0 . 8 9 7 1 1 1 2 . 5 6 4 0 . 8 9 7 1 1 1 2 . 5 7 0 . 8 9 7 1 1 1 2 . 6

1 . 0 0 0 0 1 .000 1 .000 1 .000 1 .000 ; „ 5 3 1 4 . 5 9 1 9 8 2 6 . 5 1 4 2 0 6 4 1 . 7 3 2 0 6 7 6 . 5 5 9 2 0 6 7 7 . 9 8 9 2 0 6 7 8 . 0 5 2 0 6 7 8 . 1

5" 5" F O S ( i n i ) 3 . 7 3 0 6 F O S ( l ) 3 . 8 8 4 0 F O S ( 2 ) 3 . 8 9 0 5 F O S ( 3 ) 3 . 8 9 0 8 F O S ( 4 ) 3 . 8 9 0 8 F O S ( 5 ] 3 . 8 9 0 8

5" F 0 S ( F 0 3 . 8 9 0 8 •J I F O S 4 . 0 0 7 5

C,

103

\ rr- r>

f 01 .."*"• '• ['^i^l^i '£&wtir.i."3* ••'••'.V. ~%'

CHAPTER S CONCLUSIONS CHAPTER 05 CONCLUSIONS

Documents

Transcript of CHAPTER S CONCLUSIONS CHAPTER 05 CONCLUSIONS