9 Ijaest Vol No.4 Issue No.2 Correlation Between Vertical Electric Sounding and Conventional Methods...

8/7/2019 9 Ijaest Vol No.4 Issue No.2 Correlation Between Vertical Electric Sounding and Conventional Methods of Geotechnic

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CORRELATION BETWEEN VERTICAL ELECTRIC SOUNDING AND

CONVENTIONAL METHODS OF GEOTECHNICAL SITE INVESTIGATION

RAJIV KHATRI Life Member Indian Society for Earthquake Technology, IITRoorkey,AMIE (I), Member IGS Jabalpur Chapter,Jabalpur Professor & Head Department of Civil Engineering, Hitkarini

College of Engineering & Technology,Dumna Airport Road,Jabalpur,M.P. Pin 482001; [email protected];

V.K.SHRIVASTAVAGeo-technologist, Chairman IGS Jabalpur Chapter, Professor (Retired) Government Engineering CollegeJabalpur M.P. Email - [email protected]

DR. RAJEEV CHANDAK Professor, CE Deptt., Jabalpur College of Engineering,

Jabalpur,M.P.;. Email- [email protected]

ABSTRACT :-Geotechnical site investigation is one of the important part of

design of any Civil Engineering construction project. A large

number of field investigation methods, are available, for

detailed field investigations for, civil engineering construction

purposes. These conventional methods is, in general, give

results based on empirical interpretation of test data. These

conventional methods, suffer from limitations of their

application to difficult terrains, steep hill slopes, marshy and

swampy areas, coastal regions and areas where a frequent

variation of soil and rock materials exist in the areas to be

investigated. As such a strong need is being felt to develop and

put in practice the Geo-physical methods of sub-surface

investigation for a more precise and fast assessment of largearea characteristics, economically, for all areas and

particularly where conventional methods cannot be used.

These Geo-physical methods require proper interpretation of

data which in turn needs a high degree of experience and

expertise for making the interpretation. With the availability of

computer aided interpreting software, the interpretation of the

geo-physical methods data can also be done easily. Now that,

we have entered into a phase, where large and big sized

structures are required to be built in weak and difficult and

sensitive areas, we have to take recourse to the Geo-physical

methods and develop them into a popular tool for the

enhancement and benefit of the civil engineering activities

which require better and more information of every inch of the

area. In this respect there is a great need to correlate theresults of Vertical Electric Sounding method with that of

conventional test results, particularly Standard Penetration

Test results. The paper proposes to assign special property

indii (SPI) for the soils for their proper classification based on

VES data so as to have proper understanding of the behavior

under in-situ conditions and thus to have correlation with

results of other conventional methods. The paper also proposes

to highlight the effectiveness of Vertical Electrical Sounding

technique for geo-technical site investigation.

Key Words : Vertical Electric Sounding (VES), Vertical

Electric Coring (VEC), Standard Penetration Test (SPT), Cone

Penetration Test (CPT), Special Property Index (SPI)

1.PREAMBLE:-Engineers have a significant role in planning, designing,

building and maintaining a sustainable future. We providethe bridge between science and society, in this role; we must participate in interdisciplinary teams, applying technology

to issues and challenges that require environmentallysustainable strategies and solutions. American Society of

Civil Engineers (2001).

2.INTRODUCTION:-Site investigation is the process by which geological,geotechnical, and other relevant information which mightaffect the construction or performance of a civil engineeringor building project is acquired.

The geomaterials are the natural materials and have verycomplex structure. According to Terzaghi also

Unfortunately, soils are made by nature and not by man, and

the products of nature are always complex. Karl vonTerzaghi, 1936

The fundamental behavior of the geomaterials depends ontheir permeability, compressibility and shear strengthcharacteristics. Both in-situ and laboratory test were employed

for obtaining these properties. The accuracy of the resultsobtained from the laboratory tests to represent the field

behavior is highly depends on the quality of sample and thesampling technique applied. Obtaining reasonably goodundisturbed sample from the materials like clean cohesion-less sands, residual soils, glacial tills and soft or heavily

jointed rock masses is quite challenging. In such a scenariothe engineering properties of these materials can be obtainedusing in-situ methods. Compared to traditional drilling,

sampling and laboratory testing procedures, in-situ testing hasseveral important benefits like in-situ tests are performed inthe natural condition of moisture and stress with minimumdisturbance and on large volume of soil. They are also

generally quicker and cost effective relative to the quality andquantity of data acquired.

The conventional laboratory and in-situ tests are often timeconsuming, cost intensive, require sophisticated equipmentsand skilled personal in the field and lab as well as for theinterpretation. Majority of times, planners and engineers are

interested only in sufficiently accurate estimate of differentengineering properties of geomaterials with or withoutconducting the expensive experiments. In view of the above

facts number of correlations has been developed to estimatethe engineering properties of different geomaterials from theirindex properties.

3.CONVENTIONAL METHODS FOR GEO-TECHNICALSITEINVESTIGATION:-

Various field methods are prescribed in the Codes of Practicewhich are conventionally adopted in different types ofterrains. These common methods are

1. Plate Load Test,2. Standard Penetration Test,3. Cone Penetration Test,4. Auguring, drilling and collection of cores of soils &

rocks, & testing in Lab5. Pressure Meter Test,6. Permeability Test,7. Dilatometer Test etc.

RAJIV KHATRI, et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIESVol No. 4, Issue No. 2, 042 - 053

ISSN: 2230-7818 @ 2011 http://www.ijaest.iserp.org. All rights Reserved. Page 42


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All these methods belong to the category of destructive orsemi-destructive testing tools.

Table (1) gives the relative merits of these methods.

4.GEOPHYSICAL METHODS FOR GEO-TECHNICALSITEINVESTIGATIONS:-

There has been a steady growth in the application ofgeophysical techniques to geo-civil, geo-earthquakeengineering and geo-environmental engineering studies.Geophysical methods have proven useful as rapid means ofobtaining subsurface information on a continuous profilingbasis, over large areas. They are generally non-destructive innature and can be carried out from the ground or water

surface, and / or from within boreholes. Geophysicalmethods rely on a significant contrast in physical propertiessuch as density, resistivity or electrical conductivity,magnetic susceptibility and velocity of shock waves being

present in the subsurface materials under investigation..

Geophysical techniques offer the chance to overcome someof the problems inherent in more conventional groundinvestigation techniques. Many methods exist with the potential of providing profiles and sections, so that (for

example) the ground between boreholes can be checked tosee whether ground conditions at the boreholes arerepresentative of those elsewhere. Geophysical techniques

also exist which can be of help in locating cavities,backfilled mineshafts, and dissolution features in carbonaterocks, and there are other techniques which can beextremely useful in determining the stiffness properties of

the ground.

Geophysics plays a vital role between geologicinterpretation of ground and its structure and geotechnical &other relevant field information vitally required for theconstruction or performance of Civil Engineering projects.As geophysical methods are non-destructive in-situ field

exploration methods & from the array of methods availableany one method or a combination of methods can be chosento get a proper and fuller information from the subsurface up

to any desired depths. Various problematic conditions mightexist below the ground such as discontinuities of strata,cavities, mine shafts, solution channels, buried channels and back filled parts of earlier use of land like mining etc.Geophysical methods are also very useful under such

conditions. Geophysical techniques are relatively cheap, andare also highly regarded in such a speculative environment.

Common geophysical methods employed for geotechnicalsite investigation can be classified as

1. Electrical Methods2. Seismic Methods3. Gravity Methods

Electrical methods consists of measurements of resistivity /conductivity measurements, locating water table positions,

measurement of self potential along ground profile forgenerating pseudo sections and for electrical logging of

bores and wells and for measuring telluric currents.

Seismic methods consists of generating artificial shock

waves in the ground at any depth and measuring the time of

arrival of the shock waves at recording stations arranged inmany patterns equidistant from the centre. This is done toinvestigate continuity of geomaterials and (or) presence ofcavities, channels and holes along the path of the seismic

waves arriving at some of the receiving stations. Reflectiveand refractive shooting, reciprocal shooting are some of thevariations that can be used during investigations. Generation

of shear waves in soil strata for ascertaining their liquefactionvulnerability is also done through the seismic methods. The

system works mostly on exactly identifying and locating theanomalies.

In gravity measurements, a simple gravimeter is used to findout the value of g at any place corresponding to any

theoretically obtained value of g for that area. During actualground measurements +ve & -ve departure values can beobtained and on a regular grid pattern these +ve and veanomalies are plotted similar to the plotting of contours andthe interpretation regarding presence of excessive or deficientmass distribution below the ground surface can be foundleading to identifying the buried structures like domes, folds,

faults and paleo channels etc. accurately.

5.GEOPHYSICALINSTRUMENTATIONMETHODFORSUB-SURFACEEVALUATION:-

Since the construction activity has now been taken to all typesof ground locations and conditions, these destructive

conventional tools no longer serve the purpose. Geophysicalinstrumentation is gradually being preferred as a viable andmore versatile tool which can provide all importantinformation of these subsurface areas up to any depth, as analternative to the destructive methods and tools.

An electrical measurement through GeophysicalInstrumentation is a non-destructive or non-invasivemethodology which is capable of being used in any type ofterrain / topographic conditions and it has, practically, no

limitations. The instrument used are handy and can be carriedany where. The instrumentation can be done in much smallertime frame as compared to any of the destructive equipments;it is economical, dependable and is repeatable.

In the Middle Amur sedimentary basin (MASB) VerticalElectrical Sounding method has been used for discovery of

lacustrine sediments in the southwestern and eastern parts ofthe MASB. The Correlation of seismic and drilling data

confirmed the correctness of the interpretations and showedthat boreholes penetrated a thin sequence of deep-water

lacustrine sediments.

Vertical Electrical Sounding Method has also been used in thecity of Burdur in southwestern part of Turkey for determiningthe settlement properties of the soil and for defining the zones

vulnerable for liquefaction in the city. The VES data has also provided very useful information on vertical and horizontal

extends of geologic units and water content in the subsurface.

6.CORRELATION BETWEEN VERTICAL ELECTRICSOUNDING DATA AND CONVENTIONALMETHODS OF GEOTECHNICAL SITE

INVESTIGATION:-




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Among the emerging trends of field investigation methodsused for geotechnical site investigation in Civil Engineeringpractices Vertical Electric Sounding (VES) is finding a videacceptance due to its versatility of the method as also the

comparable results obtained through this method and theother conventional field methods like SPT etc. As VerticalElectric Sounding method for geotechnical site

investigations is becoming popular, an attempt is made tocorrelate these data with that of conventional geotechnical

site investigations data. One case study is presented here oillustrate this.

7.CASEHISTORY:-In order to illustrate the effectiveness of the method casehistory of one of the investigation sites are is beingpresented here.

Case History

Geotechnical Site investigation for the LPG Filling Plant,

Maneri, Niwas Road, Mandla (M.P.) of HindustanPetroleum Corporation Limited, Mumbai, had been carriedout at the premises of A.K.V.N. at Maneri Village Niwas

Road, Distt. Mandla (M.P.). The work included geo-technical explorations covering the following aspects :-

(i) Geotechnical Investigations :- Which included thetests for bearing capacity of soil, drilling for core

logging up to 10 m depth, tests for index propertiesof soil etc.

(ii) Geological Investigations : which include theelectrical resistivity logging location of groundwater tube well, soil profiling etc.

(iii)Chemical tests for soil and water .(iv)Interpretations of collected data.

For the purpose of correlation between the values obtainedthrough VES method and those obtained with conventional

methods supported by laboratory test results, it was decidedto run parallel test at Maneri (the industrial township ofAKVN, M.P. Jabalpur where a LPG bottling plant had to bebuilt on a land area of approximately 37.5 acres. The authorwas the part of this investigation team of GEC, Jabalpur andhad done the VEC work for the investigation.

For conducting the conventional tests it was planned to have10 number of bore holes drilled in the area, to collect soil

samples, to conduct SPT during drilling of bore holes at aninterval of 1.5 m and to arrange the core so that actual borelog could be obtained at all the 10 drilling locations. Calyxmethod of core drilling was preferred up to the depth of hardrock (approximately 4 to 5 m below ground level). Certaintest were also proposed to be conducted on the rock cores inthe laboratory such as crushing strength test, RQD and otherroutine tests like density, water absorption etc.

Since the area under the investigation was very large andtesting was to be conducted in the entire area, there were

constraints of time and funds. At this juncture it was decidedto conduct geophysical tests for supplementing and for

corroborating the results and specifically for the opportunityfor establishing a correlation between the findings of the

conventional methods and VES method.

Geology of the Area :-

The land belonging to the AKVN, Jabalpur where HPCL plantwas to be constructed forms a raised plateau in the basaltic

terrain which has been formed due to multiple lava flowscutting across the Lameta sedimentary formation, overridingthem up to a thickness of approximately 400 ft. or more. The

top layer has been weathered over a period of time and formedbrownish and black top soil varying in thickness from 1 m to 2

m. Below the soil cover exist a layer of weathered rockconsisting of rounded detached boulders in a matrix of soil.This is followed downwards by massive continuous bed rockof basalt at a depth of about 5 to 6 m below the groundsurface.

The area is occupied by Basaltic rocks which are capped bysoil cover and at nowhere the rock out crop is visible. Thethickness of the soil cover is variable from place to place andlot numbers of sink holes are present which indicate heavywater infiltration from the top soil to the weathered rock below. The sink holes have interconnection at a depth of

about 1 m.

The drilling plan consisted of drilling four boreholes at the

central part of the area and the remaining six bore holes to bedrilled elsewhere within the area. The location of these boreholes has been clearly marked in Map (1). In order to bring inthe VES methodology for the purpose of direct correlation,

five VES cross sections were preferred. These have also beenmarked in the reference Map (1).

The first cross section was chosen to be in the close proximityof bore holes No. 7, 8, 9 and 10 for the initial calibration ofthe electrical resistance values of various geomaterials present

in this part. The Calibration VES log, which has been

generated from the electrical apparent resistivity data, is givenin Fig (3) and the corresponding actual bore log for the bores7, 8, 9 and 10 near its vicinity is given in Fig (2). A close

observation of these two would reveal the fact. Further fourother VES cross sections were subsequently selected and VESlogs were prepared from the electrical resistivity data obtainedat those locations. Their logs are also given in fig (3).

From the calibration the Special property indii range has been

prepared to indicate the identity of different geomaterialsarranged in the depth. The values are given in the Table.

SPT were conducted and the values of N obtained, (corrected

N) have been used to indicate the Safe Bearing Capacity andcompressive strength values respectively for soils,decomposed rock or fresh rocks materials. Values close to the

N values have also been obtained from the computations ofthe true resistivity value for different strata as obtained in theVES test and it has been found that they are more or less in

the same range.

Soil Tests

As the basaltic rock up to the drilled depth is traversed bymultiple joints, the core recovery was poor. Besides the Calyx

drilling was not helpful in obtaining proper core under thesame conditions through double or triple split core barreldiamond drilling methods. As such RQD was neither possible

nor desired as per the specifications.




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Factor of safety taken in the case of conventional methodsand that taken for the VES values was 2 for the soils and 6for the rock materials.

The soil profile has been presented on the basis of VECmethod, covering the entire area and representing the top

soil layer according to its thickness in terms of thicknesscontours, as shown in the drawing No. (2) having contour

interval of 0.5 m. The thickness of the layer of weatheringhas also been represented as profile of weathering on thisdrawing. The allowable bearing capacity values has beenobtained for soils, weathered rock and fresh rock at variouslevels. As there is uniformity in the material present at

different depths, this soil profile and the bearing capacitydata, as given in Table (4) can be used as ready reckoner tofind the safe bearing capacity at any point.

Interpretation of Resistivity Data

In resistivity instrumentation normally the field data is

obtained in the form of apparent resistivity values. Theinterpretation of vertical electrical soundings data basicallyinvolves converting / transforming apparent electricalresistivity values recorded at different current penetrationdepths (electrode separations, a) into true resistivity andthicknesses of various subsurface strata through which the

electric current passes. The true electrical resistivity () isfundamental property of the material, which is independent

of volume and remains constant for the isotropic andhomogeneous material. For an-isotropic, non-homogeneousand stratified/layered subsurface materials the resistivitydoes not remain constant throughout the depth of such

deposit. The effective resistivity value measured for layered

deposit is referred as mean or apparent resistivity (a). Theapparent resistivity is a function of true resistivities andthicknesses of various subsurface strata through which

current flows Interpretation for various information can beobtained from this data provided a thorough knowledge ofthe local geologic conditions and stratigraphic setup isknown to the investigator. For more precise field datarequired for engineering characteristics of the geomaterialstrue resistivity values have to be obtained from the apparent

resistivity values using various empirical relationshipsavailable.

Whether true or apparent resistivity values for qualitative

interpretation of the data, the apparent resistivity valueshave been found to be adequate e.g. distinction between soil(different stratifications) and bed rock position or even for

distinguishing different major soil strata within the soilformation can also be distinguished. Thickness of backfillover the natural ground surface can be determined along

with the profile of such backfill over the natural groundsurface. Similarly, weathered rock zones sandwichedbetween the soil overburden and the bed rock, in the case of

soil formed in-situ as undisturbed residual soils is alsoaccurately possible to be determined.

Through the intensive resistivity survey in different areas

and in different geologic & meteorological conditions it has been found that different geomaterials invariably alwaysidentify themselves by certain numerical values obtained as

apparent resistivity values. Special Property Indices (SPI)

have been assigned to such geomaterials as shown in the tablebelow

SN SPI Description

1 0-4 Clear sand / Gravel / Sand soil withmore than 60% of sand, showingsaturated condition

2 4 to 5 Sandy-silty clayey soil 40-50%,

Saturated

3 5 to 6.28 Clayey Soil, Saturated4 6.25 to 7.53 Black Cotton Soil, Saturated

5 7.53 to 8.24 Compact Clayey Soil / Stiff Clay,Saturated

6 8.24 to 9.42 Detached Boulders / Highlysaturated permeable zone

7 9.42 to 11.30 Detached Boulders / Highlysaturated permeable zone

8 11.30 to 12.56 Partly saturated compact imperviousclayey soil

9 12.56 to 15.00 Transition zone between soil and

weathered rock, partly saturated

10 15.00 to 25.00 Weathered Rock

11 > 25 Rocks

8.INTERPRETATION:-During the Vertical Electrical Sounding the data obtained foreach 1.0m thick layer represented the apparent resistivityvalues for all subsequent layers except the top 1.0 m layer.

The values had to be converted into true resistivity values foreach layer and also from the values the identity of thegeotechnical character of the material was also interpreted and

is given in the log.

For generating safe compressive strength values for the layer,the true resistivity values were processed considering theconfinement conditions of the layer and with the help of thesuitable multiplication factor, the values for ultimatecompressive strength for the layer were computed and safe

compressive strength values were obtained using a factor ofsafety of 5 or 6.

On the basis of the generalized VES log it is inferred that thetop soil cover is very thin and is underlain by layers of pebblesand boulders of variable thickness which merges

imperceptibly into thick layer of boulders and ledges restingon thick slabs of basalt. With this type of arrangement and thedata analysis from the laboratory test sufficient informationregarding the type of foundation which can be provided to any

structure being planned on such terrains and of course thefoundation depth of the structure can also be decideddepending upon the details of the structure.

9.CONCLUSION:-From the above study of the terrain and instrumentation it is

clear that Vertical Electrical Sounding data if carefullyobtained, processed and interpreted in the light of the terraincharacteristics, it is possible to generate numerical values for

safe bearing capacity or safe compressive strength, as the case




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may be, without using the conventional field equipmentsand the laboratory support needed by such equipments. Thisalso is evidently clear that such terrains are not friendly tothe use of conventional tools and methods, yet the terrain

has to be characterized for the engineering behaviour of thematerials present.

From the above comparative parallel studies it becomesevidently clear that the logs prepared using VEC data are

identical with the actual Bore Logs. Similarly thecompressive strength values for rocks and safe bearingcapacity values for soil materials are found to lie within theclose range of values as obtained through the ConventionalMethods and Laboratory tests, thereby indicating that theVertical Electric Coring data is a suitable and dependablereplacement for the field data obtained through a

cumbersome, costly and time consuming process involvinglarge number of equipments and manpower. It may even beclaimed that the applicability of Geophysical ElectricalInstrumentation is unrestricted for any type of geological

terrain having any geomaterial and for any topographicconditions where most of the conventional methods,

probably, can not be moved in field for the investigations.

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t) Kulhawy F.H. and Mayne, P.W. (1990). Manual onEstimating Soil Properties for Foundation design , ReportNo. EL-6800, Electric Power Research, Palo Alto,CA.

u) Liao , S.S.C. and Whitman, R.V. (1985). Overburdencorrection factors for SPT in sand, Jl. Of GeotechnicalEngineering, ASCE, Vol. 112, No. 3, pp. 373-377.


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6

DRAWING (1) REFERENCE MAP FOR RESISTIVITY SURVEY OF MANERI

DRAWING (2) CONTOUR MAP SHOWING SOIL PROFILE AT MANERI SITE




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7

TABLE (1) COMPARITIVE MERITS OF VARIOUS METHODS OF GEOTECHNICAL

SITE INVESTIGATIONDescription SPT CPT Pressure meter Dilatometer VEC

Simplicity &

Durability ofApparatus

Simple;Rugged

Complex;Rugged

Complex;Delicate

Complex;

ModeratelyRugged

Simple;Rugged

Ease of Testing Easy Easy Complex Easy EasyContinuous

Profile or PointValue

Point Continuous Point Point Continuous

Basis forInterpretation

EmpiricalEmpirical;

TheoryEmpirical;

TheoryEmpirical;

TheoryEmpirical;

Theory

Suitable SoilsAll except

gravelsAll except

gravelsAll

All exceptgravels

All

EquipmentAvailability &Use in Practice

UniversallyAvailable;

used routinely

GenerallyAvailable;

used routinely

Difficult tolocate; used onspecial projects

Difficult tolocate; used onspecial projects

UniversallyAvailable;

used routinely

Potential forFuture

DevelopmentLimited Great Great Great Unlimited

TABLE (2) LABORATORY TEST RESULTS AS PER CONVENTIONAL METHODS

SNBore

Hole

No.

Specific

Gravity

Liquid

Limit

Plastic

Limit

Plasticity

Index

Shrinkage

Limit

Shrinkage

Ratio

Soil Classification

%

Gravel

%

Sand

% Fine


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8

TABLE (3) ALLOWABLE BEARING CAPACITY AT VARIOUS DEPTHS AS PER SPT

VALUES (AS PER CONVENTIONAL METHODS)

SN Bore Hole No.

SPT RESULTAllowable Bearing

CapacityDepth

Corrected

N-Value

1 BH - 1 1.50 m 16 110 kN/sqm

2 BH - 2 2.00 m R 500 kN/sqm

3 BH - 3

1.50 m 26 250 kN/sqm

3.20 m R 500 kN/sqm

4.50 m R 750 kN/sqm

4 BH - 4 2.00 m 15 110 kN/sqm

5 BH - 51.50 m 31 290 kN/sqm

2.70 m R 1600 kN/sqm

6 BH - 61.50 m 23 200 kN/sqm

3.30 m R 800 kN/sqm

7 BH - 71.80 m 15 130 kN/sqm

3.00 m R 800 kN/sqm

8 BH - 81.60 m 20 170 kN/sqm

2.10 m R 600 kN/sqm

9 BH - 91.60 m 22 200 kN/sqm

2.60 m R 900 kN/sqm

10 BH - 101.60 m 26 240 kN/sqm

3.30 m R 900 kN/sqm

R = Refusal

TABLE (4) ALLOWABLE BEARING CAPACITY AT VARIOUS DEPTHS AS PER

VERTICAL ELECTRIC SOUNDING VALUES (AS PER VEC METHOD)

SN DepthAllowable Bearing

Capacity Material

1 1.00 m 120 kN/sqm Soil

2 2.00 m 250 kN/sqm Soil

3 3.00 m 550 kN/sqm Soil - WR Interface

4 4.00 m 660 kN/sqm WR

5 5.00 m 1200 kN/sqm WR

66.00 m &

more

1500 kN/sqm Rock




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9

FIG (1) LABORATORY TEST RESULTS PARTICLE SIZE DISTRIBUTION - AS PER

CONVENTIONAL METHODS

Particle Size Distribution CurveBORE HOLE - 1, HPCL Maneri

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.001 0.010 0.100 1.000 10.000

Particle Size (mm) ---->

%F

iner---->


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.001 0.010 0.100 1.000 10.000


%F

iner---->




10/12

10


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.001 0.010 0.100 1.000 10.000


%F

iner---->


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.001 0.010 0.100 1.000 10.000


%F

iner---->




11/12

11


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.001 0.010 0.100 1.000 10.000


%F

iner---->


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.001 0.010 0.100 1.000 10.000


%F

iner---->




12/12

12

FIG (2) BORE LOG DETAILS AS PER CONVENTIONAL METHODS

FIG (3) BORE LOG DETAILS AS PER VES (VEC) METHOD



9 Ijaest Vol No.4 Issue No.2 Correlation Between Vertical Electric Sounding and Conventional Methods...

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