This document summarizes the results of geotechnical investigations conducted for the Yamunanagar Power Plant site on the banks of the River Yamuna in India. Boreholes, cone penetration tests, plate load tests, cross-hole seismic tests and seismic refraction tests were performed to characterize the subsurface conditions and dynamic soil properties. The subsurface consists of alluvial deposits up to 21 meters depth, with zones of clayey silt, sand, boulders/pebbles and hard clayey silt. P-wave and S-wave velocities determined from the seismic tests were used along with correlations to estimate dynamic soil parameters for foundation design. Cross-hole seismic tests provided detailed localized profiles while seismic refraction tests assessed properties over

1. Sanjay GuptaSanjay Gupta Ravi SundaramRavi Sundaram
Anurag GoyalAnurag Goyal
CENGRS GEOTECHNICA PVT. LTD.CENGRS GEOTECHNICA PVT. LTD.
Sanjay GuptaSanjay Gupta Ravi SundaramRavi Sundaram
Anurag GoyalAnurag Goyal
CENGRS GEOTECHNICA PVT. LTD.CENGRS GEOTECHNICA PVT. LTD.

2. Yamunanagar Power PlantYamunanagar Power Plant
Site on banks of River YamunaSite on banks of River Yamuna
Geotechnical investigations includedGeotechnical investigations included
•• BoreholesBoreholes
•• Static Cone Penetration TestsStatic Cone Penetration Tests
•• Plate Load TestsPlate Load Tests
For dynamic behavior of soilsFor dynamic behavior of soils
•• CrossCross--hole Seismic Testshole Seismic Tests
•• Seismic Refraction TestsSeismic Refraction Tests

3. Alluvial DepositsAlluvial Deposits
00 -- 3 m3 m : Clayey Silt: Clayey Silt
33 -- 55∼∼7 m7 m : Sand: Sand
55∼∼77 -- 15 m15 m : Boulders/pebbles: Boulders/pebbles
with sandwith sand
1515 -- 2020∼∼21 m21 m : Hard Clayey Silt: Hard Clayey Silt
2020∼∼21 m +21 m + : Very Dense Sand: Very Dense Sand

4. Typical Borehole ProfilesTypical Borehole Profiles

5. Static Cone Penetration TestStatic Cone Penetration Test

6. Tests for Dynamic ParametersTests for Dynamic Parameters
Seismic Refraction Tests along 5Seismic Refraction Tests along 5
lines : For global assessmentlines : For global assessment
•• Each line 250 m long covering theEach line 250 m long covering the
Power Block and CHP areaPower Block and CHP area
CrossCross--hole Seismic Tests in 6hole Seismic Tests in 6
boreholes to 25 m depth : Forboreholes to 25 m depth : For
specific localized profile with depthspecific localized profile with depth
•• at TG, Mill Crusher Houseat TG, Mill Crusher House –– location oflocation of
dynamically loaded foundationsdynamically loaded foundations

7. Seismic Refraction TestSeismic Refraction Test

8. Seismic Energy ApplicationSeismic Energy Application
To generate PTo generate P--
Wave, steel plate isWave, steel plate is
struck vertically withstruck vertically with
a 12 lbs hammera 12 lbs hammer
Data acquisitionData acquisition
using 24 geophonesusing 24 geophones
2424--channel signalchannel signal
enhancementenhancement
seismographseismograph

9. Seismic RefractionSeismic Refraction
Test SchematicTest Schematic
TravelTravel--Time RecordsTime Records
Seismic TravelSeismic Travel--TimeTime
DiagramDiagram
–– Data AnalysisData Analysis

10. Seismic Refraction TestSeismic Refraction Test
Geophones fixed along LineGeophones fixed along Line Close up View of GeophoneClose up View of Geophone
Embedded in GroundEmbedded in Ground

11. Seismic Refraction Test inSeismic Refraction Test in
progressprogress

12. Typical ResultsTypical Results

13. Lithology interpreted from SRTLithology interpreted from SRT

14. CrossCross--Hole Seismic TestsHole Seismic Tests
Horizontally traveling P & S WavesHorizontally traveling P & S Waves
are generated in a borehole atare generated in a borehole at
desired depthdesired depth
Arrival times are recorded at twoArrival times are recorded at two
adjacent receiver boreholes spaced 4adjacent receiver boreholes spaced 4
m apartm apart
Test conducted at every 1.5Test conducted at every 1.5--m depthm depth
intervalinterval

15. DownDown--hole Sensorshole Sensors
Geophone Assembly withGeophone Assembly with
inflatable bladderinflatable bladder
CloseClose--up view of orthogonalup view of orthogonal
Sensors encased in waterSensors encased in water--tighttight
assemblyassembly

16. CrossCross--hole Seismic Testhole Seismic Test
Geophone being
lowered in
borehole

17. SchematicSchematic –– CrossCross--holehole
Seismic TestSeismic Test
Source
Borehole
Receiver
Boreholes
Impact Hammer
Geophones
4 m 4 m
SeismographSeismograph

18. SPT Hammer as Energy SourceSPT Hammer as Energy Source

19. Data AcquisitionData Acquisition –– SeismicSeismic
TestsTests

20. Typical CHST ResultsTypical CHST Results
Plot of PPlot of P--WaveWave
velocity and Shearvelocity and Shear
Wave Velocity withWave Velocity with
depthdepth
VVpp and Vand Vss
correlated to E, Gcorrelated to E, G
andand μμ

21. P & S Wave VelocitiesP & S Wave Velocities
Depth
(m)
Soil
Classi-
fication
SPT
(N)
Value
qc
Value
kg/cm2
P-Wave
Velocity,
m/s
S-Wave
Velocity,
m/s
SRT CHST SRT CHST
0 – 3 Clayey Silt 8-10 10 -20
300-
600
300-
600
120-
250
105-
230
3 – 8 Fine Sand 15-30 40 -60
800-
900
600-
1000
400-
450
275-
450
8 – 13
Pebbles /
Cobbles with
Sand
50-
100+
Refusal
1600-
1800
1400-
2000
850-
1000
700-
975
>13
Hard Clayey
Silt / Dense
Sand
50+ >100
2100-
2600
2000-
2500
1050-
1300
900-
1100

22. Design ParametersDesign Parameters
Depth,
m
Lithology
Design
Vp
m/s
Design
Vs
m/s
Poisson’s
Ratio
E
MPa
G
MPa
0 – 3 Clayey Silt 450 180 0.40 165 59
3 – 8 Fine Sand 710 350 0.33 595 224
8 – 13
Pebbles /
Cobbles with
Sand
1650 850 0.30 3741 1439
>13
Hard Clayey
Silt / Dense
Sand
2000 1000 0.34 5198 1939

23. Published CorrelationsPublished Correlations
VVss (m/s) = 91 N(m/s) = 91 N0.3370.337 Imai (1977)Imai (1977)
G (MPa) = 12 NG (MPa) = 12 N0.80.8 Ohasaki &Ohasaki &
IwasakiIwasaki
LayerLayer NN
VVss
m/sm/s
GG
MPaMPa
1 9 191 70
2 25 270 158
3 200 543 831
4 75 390 380
Vs & G from NVs & G from N––valuevalue
correlations showcorrelations show
reasonable agreementreasonable agreement
for N<30for N<30
In hard/dense soils,In hard/dense soils,
NN--value correlationsvalue correlations
underestimate Vs & Gunderestimate Vs & G

24. Concluding RemarksConcluding Remarks
CrossCross--hole seismic tests and seismichole seismic tests and seismic
refraction tests provide useful datarefraction tests provide useful data
for design of dynamically loadedfor design of dynamically loaded
foundationsfoundations
Data superior to block vibration testData superior to block vibration test
Successfully used at YamunanagarSuccessfully used at Yamunanagar
Power PlantPower Plant

25. Thank You!Thank You!