   Chapter 12, Problem 12.17P Principles of Geotechnical Enginee...

9th Edition
Braja M. Das + 1 other
ISBN: 9781305970939

Solutions

Chapter
Section Principles of Geotechnical Enginee...

9th Edition
Braja M. Das + 1 other
ISBN: 9781305970939
Textbook Problem

Consider the triaxial tests in Problem 12.16. a. What are the normal and shear stresses on a plane inclined at 33° to the major principal plane for specimen I? b. What are the normal and shear stresses on the failure plane at failure for specimen II? 12.16 The results of two consolidated-drained triaxial tests on a clayey sand are given here. Calculate the shear strength parameters of the soil.

(a)

To determine

Find the normal and shear stress on a plane inclined at 33° to the major principal plane for specimen I.

Explanation

Given information:

Specimen I:

The chamber pressure σ3 is 70kN/m2.

The deviator stress is (σ1σ3)f is 155kN/m2.

The inclined angle with major principal plane θ is 33°.

Specimen II.

The chamber pressure σ3 is 140kN/m2.

The deviator stress (σ1σ3)f is 265kN/m2.

Calculation:

For specimen I:

Find the major principal effective stress at failure (σ1) as shown below:

(σ1)=σ3+(Δσd)f (1)

Substitute 70kN/m2 for σ3 and 155kN/m2 for (Δσd)f in Equation (1).

(σ1)=70+155=225kN/m2

Find the normal stress (σf) on a plane inclined at 33° to the major principal plane for

specimen I using the equation.

σf=σ1+σ32+σ1σ32cos2θ (2)

Here, σ3 and σ1 minor and major effective principal stress, ϕ is angle of friction, and c is cohesion

(b)

To determine

Find the normal and shear stress on the failure plane at failure for specimen II.

Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started

Find more solutions based on key concepts 