**Soil Mechanics II**

CE 480

Three Credit Hours

__Course Syllabus__

1. Introduction

Soil Classification and Physical Properties

and General Mechanical Behavior of Soil

2. Permeability and Seepage

Coefficient of Permeability

Constant Head Permeability Test

Falling Head Permeability Test

Field Permeability Test

Equation of Continuity

Flow Net and Rate of Flow

Uplift Pressure

3. Stress in a Soil Mass

Normal and Shear Stresses Along a Plane

Principal Stress and Principal Plane

Stress Due to a Point Load

Stress Due to a Live Load

Stress Due to a Strip Load

Stress Due to a Circular Load

Vertical Stress Caused by Rectangular Load

New Mark Channel

Approximate Method

4. Compressibility of Soil

Consolidation Settlement

Consolidation Test

Normally Consolidation and Over Consolidation Clays

Rate of Consolidation, Terzaghi Theory of Consolidation

Secondary Compression

Flexible and Rigid Foundation

5. Shear Strength of Soil

Mohr-Coulomb Failure Criterion

Determination of Shear Strength Parameters

Direct Shear Test, Triaxial Compression Test

Unconfined Test

Stress Path

Field Shear Test (Vane Shear Test, Penetration Test)

6. Lateral Earth Pressure

Earth Pressure At-Rest

Active Earth Pressure

Passive Earth Pressure

Rankine's Theory

Coulomb's Earth Pressure Theory

Graphic Solution of Coulomb's Method

Retaining Walls, Pressure Distribution and Stability of Retaining Wall

7. Slope Stability

Stability of Infinite Slopes

Finite Slopes

Circular Failure Surface

Stability Chart

Method of Slices

There will two midterm exams each carries 20% and homework 10%. The final carries 50%.

__Text Book__

"Principles of Geotechnical Engineering by Braja M. Das

Typical Exam

Mid-Term Exam

Question One

a)Draw Mohr circles for both the avtive and passive earth pressure for the given failure envelope.

b)A frictionless retaining wall is shown below. Draw the pressure distribution for both the active and passive cases ,and find the active and passive forces per unit length of the wall due to the surcharge q only

Question Two

For the retaining wall shown below. Determine the active force per unit length of the wall for Rankine state.Also, find the location of the resultant.

Question Three

a)For the infinite slope shown below,find the factor of safety against sliding along the planeAB

b)if there were seepage through the soil, and the ground water table coincided with the ground surface,what will be the value of the factor of safety(assume the unit weight is 18.5Kn/m3)

Final Exam

Question One

a)List two disadvantages othe direct shear test.

b)State the assumptions made in the ordinary method of slices.

c}From the figure,determine the copression index

d)Draw Mohr cicle for the unconfined copression test.Show and write relationship between the undrained shear strength and the unconfined copression strength.

Question Two

For the soil profile shown below caculate the consolidation settlement for the following cases

i) The precopression pressureis 70 knlm2

ii)the precopression pressure is 100 knlm2

Question Three

Laboratory test on a clay sample of thickness 19 mm(drained at the top and bottom)indicated that the time for 50 percent consolidation is 40 minutes

(a) Find the time for a clay layer in the field(similar to the soil sample)of a thickness of 2m to undergo 50 percent consolidation that there is a rock statum at the bottom of the clay layer

(b)Finf the time for the clay layer(described in part a) to reach 80 percent consolidation.

Question Four

(a) Write down Mohr -Coulomb failure criterion(shear strength equation),Define each term

(b) A consolidated undrained triaxial test on normally consolidated clay yielded the following results

Confined pressure is 90 knlm2

Deviator stress is 60 knlm2

Pore pressure is 40 knlm2

Find the shear strength parameters in terms of total and effective stresses What will be the normal stress and shear strength at failure?

Question Five

(a) State the main difference between Rankine and Coulomb theory for lateral earth pressure.

(b) For the retaining wall shown ,plot the active pressure distribution and determine the active pressure force and its location

Question Six

For the slope shown below ,determine the factor of safety with respect to strength.

__References__

There are several books which can be use as an alternative text book or reference book in geotechnical engineering.