IDP in Educational Technology, IIT Bombay 1

PATHAN IRFAN KHAN

SHEAR STRENGTH OF SOIL

GEOTECHNICAL ENGG.

CIVIL ENGG.

TCOE, MUMBAI UNIVERSITY

3rd YEAR UG STUDENTS IN CIVIL ENGINEERING

IDP in Educational Technology, IIT Bombay 2

Out-of-class Activity Outcomes

Learning Objective(s) of Out-of-Class Activity

At the end of watching the videos student should be able to

Knowledge of Shear Strength of soil.

Explain the Mohr – coulomb theory in 2D.

Explain the Mohr – coulomb theory in 3D.

How to draw Mohr circle & find stress & shear by example solving.

Key Concept(s) to be covered

Mohr - coulomb theory .

Mohr circle.

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Video

National Repositories

• NPTEL Videos - https://www.youtube.com/watch?v=LViTxWFa7tQ

• YouTube Channel - https://www.youtube.com/watch?v=uP6iv_PQQAY

- https://www.youtube.com/watch?v=YumSQUcmGow

- https://www.youtube.com/watch?v=p59Gi9AfHdE

International Repositories

• OCW Consortium - http://www.oeconsortium.org/courses/search/?search=soil+mechanics

Internet Video Repositories

• Youtube - https://www.youtube.com

• Vimeo - https://vimeo.com/

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Out-of-class Activity https://www.youtube.com/watch?v=ypEydcakJAk

CC BY-SA on June 29, 2012

CONCEPT VIDEO SEGMENTDURATION

(in min)

STRESS STRAIN ON A BODY V1 - 0:00 – 13:00 13.00

STRESS STRAIN AT A POINT V2 - 13:01 – 21:15 8.14

MOHRS CIRCLE 2D V3 - 21:16 – 32:26 11.10

MOHR CIRCLE 2D EXAMPLE V4 - 32:27 – 37:32 5.05

MOHRS CIRCLE 3D V5 - 37:33 – 45:30 7.97

MOHR CIRCLE 3D EXAMPLE V6 - 45:31 – 52:28 6.97

TOTAL DURATION 52 minutes 28 seconds

Main Video Source URL

License of Video

Mapping Concept to Video Source

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Out-of-class Activity

Learning Objective Assessment Questions

ExpectedDuration(in min)

Additional Instructions (if

any)

Knowledge of Shear

Strength of soil.

Q1. Explain normal stress & shear stress.

Q2. What are sign convention for stresses on plane.

08 minutes

Watch V1 & Pause the video at 3:35 and then answer

Q1.

Watch V2 and then attempt assessment

question Q2.

2marks

2marks

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Out-of-class Activity

Learning Objective Assessment Strategy

ExpectedDuration(in min)

Additional Instructions (if

any)

Explain the Mohr –

coulomb theory in 2D.

Q3. What are effects if Biaxial tensile forces act along shear forces on a body.

Q4. Draw Mohr circle for • Normal Stress – 200Kn/m2• Shear Stress - 30Kn/m2

15 minutes

Watch V3 & Pause the video at 27:23 and then answer

Q3.

Watch V4 and then attempt assessment

question Q4.

3marks

5marks

IDP in Educational Technology, IIT Bombay 7

Out-of-class Activity

Learning Objective Assessment Strategy

ExpectedDuration(in min)

Additional Instructions (if

any)

Explain the Mohr –

coulomb theory in 3D.

Q5. What are the new stresses that are included in Mohr circle 3D as compared to 2D.

07 minutes

Watch V5 & Pause the video at 40:20 and then answer

Q5.

submit answers to all questions 3 hours before

coming to class.

Total activity duration - 30 minutes

3marks

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In-class Activity Outcomes

Learning Objective(s) of In-Class Activity

At the end of the class, students will be able to,

Solve problems based on Mohr circle 2D & 3D.

Differentiate between Mohr concept & Mohr coulomb theory.

Can calculate Shear strength on different values of shear stress & normal stress .

Key Concept(s) to be covered

Use of Expression of Mohr circle in Real World Problem Solving.

Implementation using Mohr coulomb theory .

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In-class Activity

Active Learning activity(ies) Plan to do –

Real world problem solving using.

Think-Pair-Share

Concept clarification using.

Peer Instruction.

Using sample student papers.

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In-class Activity (Peer Instruction)

Peer Instruction Strategy – What Teacher Does –Pose the two PI questions at the start of the class and provide summary of basic identities and expression simplification.

Q 1: Pick up the correct statement from the following-

a) Failure plane carries maximum shear stress.

b) Failure plane does not carry maximum shear stress.

c) Failure plane carries shear stress equal to maximum shear stress.

d) None of these.

Q 2: The angle between the directions of the failure and the major principal plane, is equal to-

a) 90° + half of the angle of shearing resistance.

b) 90° + effective angle of shearing resistance.

c) 45° - half of the angle of shearing resistance

d) 45° + half of the angle of shearing resistance.

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In-class Activity (Peer Instruction)

Peer Instruction Strategy – What Student Does –

For each question they will first vote individually.

Then they will discuss with peers and come to consensus.

Listen to instructors explanation.

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In-class Activity (Think-Pair-Share)

TPS Strategy – What Instructor does

Statement - Explain Following theory based on Shear Strength Of soil.

1. Mohr Theory.

2. Mohr Coulomb Theory.

3. Mohr Coulomb Revised Theory.

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In-class Activity (Think-Pair-Share)

TPS Strategy – What Instructor does

Think (2 minutes)

Instruction: Assuming that Soil is Cohesionless draw the Graphs Between Normal Stress & Shear Stress based On Different Theories.

Think individually and identify the scenario in which Failure Envelope is High.

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In-class Activity (Think-Pair-Share)

TPS Strategy – What Instructor does

Pair (5 minutes)

Instruction: Now pair up and compare your answers. Agree on one final answer.

While students are pairing and discussing, instructor goes to 2-3 sections to see what they are doing.

Now assuming that in Failure is High in Mohr Coulomb theory , Now plot the Graph between Normal Stress & Shear Stress For Cohesive Soil.

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In-class Activity (Think-Pair-Share)

TPS Strategy – What Instructor does

Share (8 minutes)

Instructor asks a group to share their answer with class and see whether there are different answers.After sharing is done, instructor gives feedback on the correct solution and how Shear Strength of soilEffect the Bearing Capacity Of soil.

In the next iteration of TPS, in the Think Phase we ask students to convert the Graphs Between “Normal Stress & Shear Stress” expression in the form of Graphs Between “Effective Stress & Shear Stress” .

In the pair phase we ask students to compare the answers.

In the share phase again the different answers are sought.

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In-class Activity

Justify why the above is an active learning strategy

It gives students time to think about an answer and activates prior knowledge. It enhancesstudents oral communication skills as they discuss their ideas with one another. Thisstrategy helps students become active participants in learning and can include writing as away of organizing thoughts generated from discussions.