Geotechnical studies of highways and air strips with reference to India involves various methods. Site investigation includes preliminary work like collecting existing data and site reconnaissance, followed by exploration techniques like direct methods using test pits or trenches, or semi-direct methods using borings. These methods provide disturbed and undisturbed samples. Laboratory analysis includes physical tests like grain size analysis, density, and consistency to determine soil properties. Field methods to determine bearing capacity include plate load tests, standard penetration tests, and cone penetration tests. The document provides examples of borehole logs and soil classification from a geotechnical investigation of Dholera International Airport.

1. GEOTECHNICAL STUDIES OF HIGHWAYS AND
AIR STRIPS WITH REFRENCE TO INDIA
M.G. Science Institute
(Geology Department)
Navrangpura,Ahmedabad,Gujarat 380009
mihirchaudhary1611@gmail.com
Name : Chaudhary Mihir A
Roll No : 2
GEL: 508
M.Sc Sem : 4
Supervision By Dr.H.V.Majethiya Sir

2. Content
 Introduction
 Methods of Geotechnical study of highways
 Methods of Geotechnical study of Air strips
 Reference

3. What is the need ?
• To determine the type of foundation required for the proposed project at the site i.e.
shallow foundation or deep foundation
• To make recommendation regarding the safe bearing capacity or pile load capacity
• Ultimately it is the subsoil that provides the ultimate support for the structures

4. Site investigation
• A complete site investigation will consist of :
 Preliminary work
• Collecting general information and already existing data such as study of geologic ,seismic maps, etc. at or near site.
• Study site history – if previously used as quarry, agricultural land , industrial, unit , etc.
 Site reconnaissance : Actual site inspection.
• To judge general suitability various tests and
• Decide exploration techniques

5. Method of Exploration
Direct method
Trial pits or trenches
•Semi-direct method
•Borings
•Indirect method
•Penetration tests
•Geophysical method

6. Direct and Semi-direct method
 Test pits
• Adopted for minor , small buildings
• Suitable upto small depths (˂2m)
• Geotechnical characteristics of disturbed sample
 Boring
• Used for exploration at greater depths where direct methods fail
• Provide both disturbed as well as undisturbed samples depending upon the method of boring

8. Types of samples collected in Drilling :
 Disturbed Sample (DS)
 Undisturbed Sample (UDS)
 SPT Sample

9. Disturbed Sample (DS) Undisturbed Sample (UDS)
 A disturbed sample is that in which the
natural structure of soil gets partly or fully
modified and destroyed.
 These are washed samples and are
collected for reference only. No lab
analysis is done for them
 An undisturbed sample is that in which
the natural structure and properties of
soil sample remain preserved.
 An undisturbed sample is obtained by
forcing a thin wall sampler into the soil
at the bottom of the bore hole or in a
test pit.

10. SPT Sample
 SPT or Standard Penetration Test samples are collected by a special test procedure.
 In this process, a thick wall split-tube sampler is driven into the undisturbed soil at the bottom of the hole
under the blows of a 63.5 kg drive weight with 75 cm free fall.(IS code)
 The sampler used in SPT is of dimensions mentioned in IS codes.

11. Lab analysis
• After Drilling, our Geotechnical Investigation moves to lab. analysis. Lab analysis is done as :
Physical analysis
Grain size analysis
 Consistency of soil
 Density, Moisture content
 Specific gravity

12. Field method to determine bearing capacity of soil
Plate load test Standard penetration test (spt)

13. Static cone penetration test (scpt) Dynamic cone penetration test (dcpt) Field vene shere test

14. 1.5 UDS 2.63 1.89 11.7 0 48 47 6 52 27 22 5 0.30 24.0 8.0 0.014
3.0 SPT 2.65 - - 1 28 63 7 70 33 18 15 - - NIL 0.011
4.5 UDS 2.63 2.12 15.5 1 54 43 2 45 20 0.00 28.4 NIL 0.017
6.0 SPT 2.60 - - 11 74 12 3 15 25 19 6 - - NIL 0.049
7.5 UDS 2.60 1.96 12.4 26 63 11 1 11 0.00 30.6 NIL 0.066
9.0 SPT 2.60 - - 33 65 3 0 3 22 - - NIL 0.259
10.5 DS 2.58 - - 0 82 17 1 18 - - NIL 0.042
12.0 SPT 2.62 - - 0 80 16 4 20 32 18 14 - - NIL 0.038
13.5 DS 2.62 - - 0 83 14 3 17 25 22 3 - - NIL 0.044
15.0 SPT 2.63 - - 1 83 13 3 17 28 19 9 - - NIL 0.046
16.5 DS 2.60 - - 0 86 13 1 14 - - NIL 0.054
18.0 SPT 2.66 - - 3 39 46 12 58 40 22 18 - - 17.0 0.013
19.5 UDS 2.62 1.98 14.3 9 47 36 8 44 25 19 6 0.15 24.0 NIL 0.017
21.0 SPT 2.60 - - 6 77 16 1 17 - - NIL 0.045
22.5 UDS 2.64 1.94 19.3 0 27 64 8 73 32 18 20 0.42 13.0 19.0 0.010
24.0 SPT 2.60 - - 12 65 21 2 23 - - NIL 0.033
25.5 UDS 2.62 1.99 18.8 4 73 21 2 23 0.00 32.0 NIL 0.033
27.0 SPT 2.66 - - 25 23 39 13 52 47 22 25 - - 27.0 0.014
28.5 UDS 2.64 2.09 14.7 1 17 67 16 82 36 19 17 0.58 7.4 25.0 0.009
30.0 SPT 2.65 - - 5 19 61 15 75 40 19 21 - - 26.0 0.010
31.5 UDS 2.66 2.15 21.7 19 11 54 16 70 45 20 25 0.20 34.7 21.0 0.011
33.0 SPT 2.68 - - 8 13 60 19 80 58 27 31 - - 33.0 0.009
34.5 UDS 2.63 2 7.9 6 66 24 4 28 30 20 10 0.07 20.8 6.0 0.027
36.0 SPT 2.64 - - 11 23 54 12 66 37 18 19 - - 26.0 0.011
37.5 DS 2.63 - - 0 53 37 9 47 34 19 15 - - 22.0 0.016
Silt
(%)
Depth
(m)
Sample
Type
Specific
Gravity
Dry
Density
(gm/cc)
Angle
of
Friction
Water
Content
(%)
Free
Swell
Index
(Cc)
Diameter
at
10%
finer
(micro)
D
10
Gravel
(%)
Sand
(%)
Clay
(%)
Fine
Content
(%)
Cohesion
(kg/cm
2
)
NP
NP
NP
NP
Liquid
Limit
%
(W
L
)
Hydrometer
Plastic
Limit
%
(W
p
)
Plasticity
Index
%
Atterberg's Limit
NP
NP
NP
Borehole No.: Depth:
Particulars Grain Size Analysis
NP
.63 1.89 11.7 0 48 47 6 52 27 22 5 0.30 24.0 8.0 0.014 0.072 ML
.65 - - 1 28 63 7 70 33 18 15 - - NIL 0.011 0.053 ML
.63 2.12 15.5 1 54 43 2 45 20 0.00 28.4 NIL 0.017 0.110 SM
.60 - - 11 74 12 3 15 25 19 6 - - NIL 0.049 0.245 SC
.60 1.96 12.4 26 63 11 1 11 0.00 30.6 NIL 0.066 2.152 SP
.60 - - 33 65 3 0 3 22 - - NIL 0.259 3.504 SP
.58 - - 0 82 17 1 18 - - NIL 0.042 0.331 SP
.62 - - 0 80 16 4 20 32 18 14 - - NIL 0.038 0.190 SC
.62 - - 0 83 14 3 17 25 22 3 - - NIL 0.044 0.230 SC
.63 - - 1 83 13 3 17 28 19 9 - - NIL 0.046 0.227 SC
.60 - - 0 86 13 1 14 - - NIL 0.054 0.422 SP
.66 - - 3 39 46 12 58 40 22 18 - - 17.0 0.013 0.064 MI
.62 1.98 14.3 9 47 36 8 44 25 19 6 0.15 24.0 NIL 0.017 0.148 SC
.60 - - 6 77 16 1 17 - - NIL 0.045 0.225 SP
.64 1.94 19.3 0 27 64 8 73 32 18 20 0.42 13.0 19.0 0.010 0.052 ML
.60 - - 12 65 21 2 23 - - NIL 0.033 0.164 SP
.62 1.99 18.8 4 73 21 2 23 0.00 32.0 NIL 0.033 2.602 SP
.66 - - 25 23 39 13 52 47 22 25 - - 27.0 0.014 0.376 MI
.64 2.09 14.7 1 17 67 16 82 36 19 17 0.58 7.4 25.0 0.009 0.046 MI
.65 - - 5 19 61 15 75 40 19 21 - - 26.0 0.010 0.050 MI
.66 2.15 21.7 19 11 54 16 70 45 20 25 0.20 34.7 21.0 0.011 0.053 MI
.68 - - 8 13 60 19 80 58 27 31 - - 33.0 0.009 0.047 MH
.63 2 7.9 6 66 24 4 28 30 20 10 0.07 20.8 6.0 0.027 0.285 SC
.64 - - 11 23 54 12 66 37 18 19 - - 26.0 0.011 0.057 MI
.63 - - 0 53 37 9 47 34 19 15 - - 22.0 0.016 0.125 SC
Silt
(%)
Specific
Gravity
Dry
Density
(gm/cc)
Angle
of
Friction
Water
Content
(%)
Free
Swell
Index
(Cc)
Diameter
at
10%
finer
(micro)
D
10
Diameter
at
50%
finer
(micro)
D
50
IS
Classification
Gravel
(%)
Sand
(%)
Clay
(%)
Fine
Content
(%)
Cohesion
(kg/cm
2
)
NP
NP
NP
NP
Liquid
Limit
%
(W
L
)
Hydrometer
Plastic
Limit
%
(W
p
)
Plasticity
Index
%
Atterberg's Limit
NP
NP
NP
Borehole No.: Depth:
articulars Grain Size Analysis
NP

17. DHOLERA INTERNATIONAL AIRPORT

18. Grain size analysis
Liquid limit test
Plastic limit test Compaction test

19. Reference
 https://en.m.Wikipedia.org/wiki/geotechnical_investigation
 https://bvmengineering.ac.in/NAAC/Criteria1/1.3/1.3.4/Group_10_16
CE121_LBZ_Report.pdf

20. THANK YOU