Iit Rigid -Stresses
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Transcript of Iit Rigid -Stresses
Input from axle load survey conducted at km 415
Single Axle (in Tons)Number of Axle Loads Tandem Axle
(Both Front and Rear)0-1 0 30 4211'-2 0 31 22'-3 3 32 33'-4 24 33 14'-5 75 34 05'-6 163 35 06'-7 213 36 07'-8 273 37 08'-9 61 38 0
9'-10 31 39 010'-11 27 40 011'-12 28 41 012'-13 32 42 013-14 30 43 014-15 60 44 015-16 35 45 016-17 28 46 017-18 2 47 018-19 0 48 019-20 0 49 020-21 0 50 021-22 0 51 022-23 0 52 023-24 0 53 024-25 0 54 0
Number of Axles Weighted 1085 427Total Axles weighted 1512
Percentage of single axle repetitions 71.76%Percentage of tandem axle repetitions 28.24%
Percentage of Single Axle RepetitionsLoad interval Mid-Value No of Axles
0 1 0.5 01 2 1.5 02 3 2.5 33 4 3.5 244 5 4.5 755 6 5.5 1636 7 6.5 213
Number of Axle Loads
7 8 7.5 2738 9 8.5 619 10 9.5 31
10 11 10.5 2711 12 11.5 2812 13 12.5 3213 14 13.5 3014 15 14.5 6015 16 15.5 3516 17 16.5 2817 18 17.5 218 19 18.5 019 20 19.5 020 21 20.5 021 22 21.5 022 23 22.5 0
Percentage of Tandem Axle Repetitions29 30 29.5 42130 31 30.5 231 32 31.5 332 33 32.5 133 34 33.5 034 35 34.5 035 36 35.5 036 37 36.5 037 38 37.5 038 39 38.5 039 40 39.5 040 41 40.5 041 42 41.5 042 43 42.5 043 44 43.5 044 45 44.5 045 46 45.5 046 47 46.5 047 48 47.5 048 49 48.5 049 50 49.5 050 51 50.5 051 52 51.5 0
Percentage of Single Axle RepetitionsPercentage of axles (%)
0.000.000.201.594.96
10.7814.09
18.064.032.051.791.852.121.983.972.311.850.130.000.000.000.000.00
Percentage of Tandem Axle Repetitions27.840.130.200.070.000.000.000.000.000.000.000.000.000.000.000.000.000.000.000.000.000.000.00
Design Traffic Calculations for Rigid Pavement at Km.415- Ahmadabad to UdaipurTraffic in terms of AADT
Year LCV Bus 2 Axle 3 Axle MAV Total AADT
2012 167 363 132 352 546 15602013 176 378 138 379 590 16612014 185 392 145 409 636 17672015 195 408 152 441 686 18822016 205 422 160 473 735 19952017 215 437 168 506 787 21132018 226 453 176 542 843 22402019 237 468 185 580 902 23722020 249 485 195 622 966 25172021 261 499 204 657 1021 26422022 274 513 214 694 1079 27742023 288 527 225 734 1140 29142024 302 542 236 775 1205 30602025 317 557 248 819 1273 32142026 333 568 261 860 1337 33592027 350 580 274 903 1404 35112028 367 591 287 948 1474 36672029 386 603 302 996 1548 38352030 405 615 317 1045 1625 40072031 425 627 333 1098 1706 41892032 447 639 349 1153 1792 43802033 469 652 367 1210 1881 45792034 492 665 385 1271 1975 47882035 517 678 404 1334 2074 50072036 543 691 425 1401 2178 52382037 570 705 446 1471 2287 54792038 598 719 468 1545 2401 5731
Traffic distribution Factor = 0.25Design Traffic = 7962475Single Axle repetitions of Commercial Vehicles = 5713814
Tandem Axle repetitions of Commercial Vehicles = 2248662
Single axles Tandem Axles
Load in Tonnes Percentages of Axle loads Load in Tonnes
0.5 0.00 0 Less than 301.5 0.00 0 30.52.5 0.20 15799 31.53.5 1.59 126389 32.54.5 4.96 394965 33.55.5 10.78 858389 34.56.5 14.09 1121698 35.57.5 18.06 1437670 36.58.5 4.03 321238 37.59.5 2.05 163252 38.5
10.5 1.79 142188 39.511.5 1.85 147454 40.512.5 2.12 168518 41.513.5 1.98 157986 42.514.5 3.97 315972 43.515.5 2.31 184317 44.516.5 1.85 147454 45.517.5 0.13 10533 46.518.5 0.00 0 47.519.5 0.00 0 48.520.5 0.00 0 49.521.5 0.00 0 50.522.5 0.00 0 51.5
Total Single Axle Repetion 5713822
Expected repetitions
Total Tandem Axle Repetion
Design Traffic Calculations for Rigid Pavement at Km.415- Ahmadabad to UdaipurTraffic in terms of AADT
365 * AADT
569400606265644955 644955686930 1331885728175 2060060771245 2831305817600 3648905865780 4514685918705 5433390964330 6397720
1012510 74102301063610 84738401116900 95907401173110 107638501226035 119898851281515 132714001338455 146098551399775 160096301462555 174721851528985 190011701598700 205998701671335 222712051747620 240188251827555 258463801911870 277582501999835 297580852091815 31849900
Tandem Axles
Cumulative Number of
Vehicles
Percentages of Axle loads
27.84 22170650.13 105330.20 157990.07 52670.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 00.00 0
2248664
Expected repetitions
Total Tandem Axle Repetion
Rigid Pavement Design for Toll Plaza at Km 415
Cumulative number of vehicles C = 31849900
( obtained from traffic projection )
D = 7962475
Load Safety factor I = 1.2
Modulus of subgrade reaction k = 5.5
Thickness of DLC 150 mm
K value over DLC k design = 41.7
Concrete grade proposed M= 40
Concrete flexural strength 44.27
Modulus of Elasticity of concrete E = 300000
Poisson’s ratio µ = 0.15
Co efficient of thermal expansion 0.00001
Design Wheel Load P = 8000 kg
Design tyre pressure p = 8
Percentage of Single Axle from the Axle Load Survey = 71.76 %
Percentage of Tandem Axle from the Axle Load Survey = 28.24 %
Single Axle repetitions of Commercial Vehicles = 5713814
Tandem Axle repetitions of Commercial Vehicles = 2248662
Stress Ratio
Single Axle 8.5 10.2 12.88 0.299.5 11.4 14.10 0.32
10.5 12.6 15.28 0.3511.5 13.8 16.44 0.3712.5 15 17.57 0.4013.5 16.2 18.69 0.4214.5 17.4 19.79 0.4515.5 18.6 20.87 0.4716.5 19.8 21.94 0.5017.5 21 23.00 0.5218.5 22.2 0.0019.5 23.4 0.0020.5 24.6 0.0021.5 25.8 0.0022.5 27 0.00
Tandem Axle
Less than 30 36 15.742 0.3630.5 36.6 15.937 0.3631.5 37.8 16.323 0.3732.5 39 16.705 0.3833.5 40.2 0.00
Design Traffic ( total repetitions of commercial vehicles)
kg/cm3
kg/cm3
fcr = kg/cm2
kg/cm2
a = per o C
kg/cm2
Axle load (Tonnes)
With Safety Load (Tonnes)
Stress by Axle (from Chart/Formula)
34.5 41.4 0.0035.5 42.6 0.0036.5 43.8 0.0037.5 45 0.0038.5 46.2 0.0039.5 47.4 0.0040.5 48.6 0.0041.5 49.8 0.0042.5 51 0.0043.5 52.2 0.0044.5 53.4 0.0045.5 54.6 0.0046.5 55.8 0.0047.5 57 0.0048.5 58.2 0.0049.5 59.4 0.0050.5 60.6 0.0051.5 61.8 0.00
Hence the Design is Safe From fatigue consideration.
Rigid Pavement Design for Toll Plaza at Km 415
Fatigue life N
Single Axle 321238 Unlimited 0.0000163252 Unlimited 0.0000142188 Unlimited 0.0000147454 Unlimited 0.0000168518 Unlimited 0.0000157986 Unlimited 0.0000315972 Unlimited 0.0000184317 4579264.15152382 0.0403147454 947850.831204851 0.155610533 333142.521624437 0.0316
0 Unlimited 0.00000 Unlimited 0.00000 Unlimited 0.00000 Unlimited 0.00000 Unlimited 0.0000
Tandem Axle
2217065 Unlimited 0.0000
10533 Unlimited 0.0000
15799 Unlimited 0.0000
5267 Unlimited 0.0000
0 Unlimited 0.0000
Expected Repetitions
Fatigue Life Consumed - (Total
fatigue life)
0 Unlimited 0.0000
0 Unlimited 0.0000
0 Unlimited 0.0000
0 Unlimited 0.0000
0 Unlimited 0.0000
0 Unlimited 0.0000
0 Unlimited 0.0000
0 Unlimited 0.0000
0 Unlimited 0.0000
0 Unlimited 0.0000
0 Unlimited 0.0000
0 Unlimited 0.0000
0 Unlimited 0.00000 Unlimited 0.00000 Unlimited 0.00000 Unlimited 0.00000 Unlimited 0.00000 Unlimited 0.0000
Total Fatigue Life 0.2274 < 1
Hence the Design is Safe From fatigue consideration.
Check for Stresses
Design Wheel Load P = 8000 kg
Tyre Pressure p = 8 kg/cm2
c/c Distance Between Two Tyres S = 31 cm
28 Days Compressive Strength of Concrete 400
Flexural Strength of Concrete 44.27
Modulus of Elasticity of Concrete E = 300000
Poisson's Ratio of Concrete µ = 0.15
K Value of Subgrade 5.500 kg/cm3
Thickness of DLC subbase = 15 cm
K Value of Subbase = 41.700 kg/cm3
Coefficient of Thermal Expansion of Concrete 10.0E-6
Temp. Difference b/w Top and Bottom Layers Dt = 14.45
Assumed ConcreteSlab Thickness h = 25.5 cm
Contraction Joint spacing L = 350 cm
Lane width B = 350 cm
L/B = 1 OK
Radius of load contact area
a = 26.511 cm
Radius of relative stiffness
l = 56.4712 cm
Radius of equal distribution of pressure b = a
b =
b = 24.916 cm
L/l = 6.20 and
B/l = 6.20
From interpolation,
Warping stress coefficient 0.942
fCK = kg/cm2
FCR = kg/cm2
kg/cm2
Ksg =
α = Per oCo C
(Sqrt (1.6 x a2 ) + h2) - 0.675 x h
CL =
𝑎= [(0.8521𝑃 /𝑑 )+ ( / ) (𝑞𝜋 𝑆 𝜋 𝑃 /(𝑑 0.5227 ))^0.5 ]𝑞 ^0.5
25.0
2
3
*)1(*12
*
=k
hEl
Warping stress coefficient CB = 0.942
Design Warping stress coefficient C = 0.942
Check For Temperature Stress
Temperature stress at edge region
20.42
= 43.41 < 44.27
safe
Check For Corner StressCorner load stress
14.33
safe
ste = kg/cm2
Total of temperature warping stress and Highest axle load stress kg/cm2
sc = kg/cm2
𝜎_𝑡𝑒=[(𝐸 ∗ 𝛼 ∗ Δ𝑡)/2] * C
=
2.1
2 1
21
3 a
h
Pcs
a/h > 1.724
a/h < 1.724
Slab thickness 30cm 27.5cm 27cmSingle AxleAxle load AL with SF
8.5 10.2 9.875 11.217 11.5219.5 11.4 10.828 12.287 12.617
10.5 12.6 11.761 13.332 13.68811.5 13.8 12.696 14.357 14.73712.5 15 13.575 15.362 15.76613.5 16.2 14.458 16.351 16.77814.5 17.4 15.329 17.324 17.77515.5 18.6 16.188 18.284 18.75816.5 19.8 17.035 19.232 19.72817.5 21 17.873 20.169 20.68718.5 22.2 18.702 21.094 21.63419.5 23.4 19.522 22.009 22.5720.5 24.6 20.335 22.914 23.496
Tandem AxleLess than 30 36 12.206 13.756 14.113
30.5 36.6 12.362 13.928 14.2931.5 37.8 12.671 14.272 14.64132.5 39 12.978 14.612 14.98933.5 40.2 13.283 14.949 15.33434.5 41.4 13.585 15.284 15.67635.5 42.6 13.844 15.616 16.01536.5 43.8 14.182 15.946 16.35237.5 45 16.27238.5 46.239.5 47.440.5 48.641.5 49.842.5 51 18.31843.5 52.2 18.63844.5 53.445.5 54.6 19.26946.5 55.8 19.58247.5 5748.5 58.249.5 59.4 20.507
50.5 60.651.5 61.852.5 6353.5 64.2 21.711
k = 41.7 kg/cm3
26.5cm 26 cm 25.5cm 250 mm 24.5cm 240 mm 235 mm 230 mm 225 mm 200 mm
11.839 12.171 12.519 12.883 13.265 13.666 14.087 14.993 17.72712.962 13.323 13.7 14.095 14.509 14.943 15.399 16.381 19.33914.059 14.447 14.853 15.278 15.723 16.190 16.680 17.735 20.91115.134 15.548 15.982 16.436 16.912 17.410 17.934 19.060 22.44716.188 16.629 17.09 17.573 18.078 18.607 19.163 20.359 23.95017.225 17.692 18.179 18.690 19.224 19.787 20.371 21.636 25.42318.246 18.738 19.252 19.789 20.352 20.942 21.560 22.890 26.86719.253 19.769 20.309 20.873 21.464 22.082 22.731 24.124 28.28420.246 20.787 21.351 21.942 22.560 23.206 23.884 25.339 29.67621.227 21.791 22.38 22.996 23.640 24.134 25.020 26.536 31.04522.196 22.784 23.397 24.037 24.707 25.408 26.141 27.716 32.29323.154 23.764 24.4 25.066 25.760 26.487 27.247 28.879 33.72024.101 25.393 26.081 26.800 27.553 28.340 30.026 35.029
14.489 14.885 15.302 15.742 16.207 16.699 17.219 18.354 21.87814.67 15.07 15.492 15.937 16.407 16.904 17.429 18.577 22.137
15.029 15.438 15.869 16.323 16.803 17.310 17.847 19.018 22.65015.385 15.802 16.242 16.705 17.195 17.713 18.261 19.455 23.15815.738 16.164 16.612 17.085 17.584 18.112 18.670 19.888 23.65916.088 16.522 16.979 17.461 17.969 18.508 19.076 20.316 24.15516.435 16.877 17.343 17.833 18.351 18.899 19.478 20.740 24.645
17.703 18.72918.06118.41518.76719.11619.46119.805 20.353
20.701
21.39021.731
22.737
24.045
0.678