SHEAR STRENGTH TEST OF SOIL – ADVANTAGES, LIMITATIONS & APPLICABILITY

The choice of shear strength tests appropriate for a particular project depends on the type of soil, whether the parameters will be used in aggregate or effective stress analysis, and the relative importance of the structure. Common laboratory tests include direct shear, triaxial, unconfirmed compression and laboratory vane shear tests. The applicability, advantages and disadvantages for each test are summarized in the following table.

Table

Summary of Common Shear Strength Tests

test type applicability the gain Harm
direct shear test a. effective strength

Parameters for coarse grain and fine grain

Soil

a. simple and

cheap

b. allows thinner sampling

rapid drainage of fine-grained soil

a. For dry conditions only

b. Failed plane forced

happens at the joint in the box

C. non uniform

distribution of stress

and stress

D. no stress-strain data

triaxial shear test a. effective and total

strength parameter

for coarse cereals and

fine-grained soil

b. compared to direct

shear test, triaxial

tests are preferred

fine-grained soil

a. easy to control

drainage

b. useful stress-strain

statistics

C. can consolidate

sample hydrostatically

or to in situhey State of

Tension

D. can simulate various

loading status

a. Tools More

complicated by

other types of tests

b. Fine-grained dry test

soil should be

very slow shear

unconfirmed compression test a. untrained shears

100% strength

saturated samples of

identical,

raw clay

b. not suitable as

only basis for design

on important projects

a. very fast and

cheap

a. not applied to soil

with cracks, silt

seams, varves, other

fault, or less

100% saturation

b. sample error

not systematically

accounted for

Lab Wayne Shear Test a. untrained shears

100% strength

saturated samples of

identical,

raw clay

b. not suitable as

only basis for design

on important projects

a. very fast and

cheap

a. not applied to soil

with cracks, silt

seams, varves, other

fault, or less

100% saturation

b. sample error

not systematically

accounted for



Er. Mukesh Kumar

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Er. Mukesh Kumar is Editor in Chief and Co-Funder at ProCivilEngineer.com Civil Engineering Website. Mukesh Kumar is a Bachelor in Civil Engineering From MIT. He has work experience in Highway Construction, Bridge Construction, Railway Steel Girder work, Under box culvert construction, Retaining wall construction. He was a lecturer in a Engineering college for more than 6 years.