This document discusses soil testing for civil engineering projects. It explains that soil testing is essential to understand soil properties and ensure proper design. The key aspects of a soil testing program are identifying appropriate tests, accurately measuring properties, and analyzing test data. Tests are selected based on the project type and soil type. Laboratory tests measure classification, physical properties, shear strength, compressibility, and other parameters. Field tests include standard penetration tests, dynamic cone penetration tests, and plate load tests for foundations, and CBR and plate load tests for pavement design. Accurate soil testing is important for successful project design and construction.

1. SOIL TTESTING
Karthik V
Assistant Professor
KPRIET

2. INTRODUCTION:
• Soil is an essential construction material for Civil Engineers.
• Hence, the accurate measurement of soil properties is very important in the design
and execution of a civil engineering project.
• Soil is used as
• (i) construction material (Example: roadways, railways, earthen embankments, earthen dams),
• (ii) Supporting material (Example: Foundations) and
• (iii) Surrounding material (Example: Underground pipelines, tunnels).
• Based on the type of soil and nature of the project a detailed test programme is
planned.

3. NEED FOR SOIL TESTING :
• Soil testing is an essential part of a Civil engineering project, the failure of a project
due to improper/ inadequate soil testing is very expensive and sometimes
irreparable.
• Hence, understanding the properties of soil and its consideration in the design are
important.

4. The three important aspects in soil testing
program are:
• Identification of appropriate soil test.
• Accurate measurement of soil properties.
• Analysis of test data and interpretation of properties for the design of
structure

5. IDENTIFICATION OF TESTS
• Identification of appropriate tests is the most important aspect in the soil
testing programme.
• The required tests for a given project depend on
• 1. The nature of the project.
• 2. The nature of the soil.

6. Nature of project:
The important civil engineering projects where soil properties considered are:
• 1. Earthen embankment to store water
• 2. Road construction
• 3. Foundation
• 4. Filling behind a retaining wall

7. Nature of soil :
• Soil testing not only depends on the type of the project as explained above but
also on the type of the soil.
• Shear parameters of clay soils are measured by performing either unconfined
compression tests or Vane shear test or Direct shear test or Triaxial shear test.
• . The compactness of cohesive soils is measured in terms of OMC conditions (by
performing compaction test) and the same is represented in terms of relative
density (by conducting minimum and maximum density tests) in case of sandy
soils.

8. CLASSIFICATION OF TESTS
INTRODUCTION
• There are a number of tests available to measure the engineering
properties of soils in laboratory and field.
• The tests to be performed depend on the type of soil and the
nature of project.

9. LABORATORY TESTS
• The samples are either collected in an undisturbed state, in the form of core
samples, or in a disturbed state, in the form of loose soils collected in bags.
• The laboratory tests, classified for the purpose for which the soil is being used are
as follows:
• 1. Classification tests
• 2. Test to obtain physical properties of soil
• 3. Shear tests
• 4. Compressibility tests
• 5. Other specific tests

10. Classification
Test
Soil Type
Sieve Analysis
Hydrometer Analysis
Atterberg Limits
Classification Of Soil
Non –Cohesive soil Cohesive soil

11. PHYSICAL PROPERTIES OF SOIL
Unit Weight
Specific GravityMoisture content
Specific
Gravity
Pycnometer
Method
Sand
Replacement
Core cutter
Method
Degree of
SaturationPorosity
Void
Ratio

12. Strength properties
Direct
Shear
Test
Vane
Shear
Test
Trial
Test
Triaxial
Test
Unconfined
Compression
Test
Direct
Shear
Test
Soil Type
Non –Cohesive soil Cohesive soil

13. Consolidation Properties
Coefficient of
Consolidation
Compression Index

14. Other Special Tests
Compaction
Test
CBR Test
Permeability
Tests
Swelling
Properties
Soil
Type
Relative Density Test
Standard Proctor
Compaction Test
Heavy
Compaction
Test
Constant
Volume
Method
Consolidation
Method
Free Swell
Index Test
Swelling
Pressure Test
Variable Head TestConstant
Head Test
Cohesive soil
Non -Cohesive
soil

15. FIELD TESTS
• A reasonably good undisturbed soil sample can be collected from clay layer.
• If the soil at the site is non-cohesive, it is difficult to obtain a good undisturbed
soil sample.
Hence the field tests are broadly classified as:
• 1. Field tests for foundations
• 2. Field tests for pavement design

16. Field tests for foundation design
The following tests are useful in measuring the strength of soil in the field to
estimate the bearing capacity of soils for foundation design.
• 1. Standard penetration test. (SPT)
• 2. Dynamic cone penetration tests (DCPT)
• 3. Static cone penetration test
• 4. Field vane shear test
• 5. Plate load test (PLT)

17. Field tests for pavement design
The Commonly used field tests to obtain soil parameters required for designs of
pavements are
• 1. Field CBR
• 2. Plate load test Field
• CBR test gives the CBR valves of soil in the field conditions. The CBR valves are
useful in the design of flexible pavement.