Earth Pressure and Retaining Wall Basics for Non-Geotechnical Engineers

Richard P. Weber

Course Outline

This course is intended for a wide range audience and in particular, the non-geotechnical engineer. Therefore it is not an exhaustive review of the subject. The objective of the course is to discuss the three types of lateral earth pressure (at rest, active and passive) that apply to a wall and describe how each is calculated. The course then uses this information and discusses the method of calculating the active earth pressure force using the Rankine and Coulomb methods described in this course. The method for calculating the factors of safety for sliding, overturning and bearing capacity are discussed. Basic examples are provided to illustrate the concepts.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

When this course has been completed, the reader will be familiar with the three types of earth pressure and how each is calculated. The reader will also be familiar with how the total force resulting from lateral earth pressure is calculated and how forces are used to determine the factors of safety with respect to sliding, overturning and bearing capacity relating to retaining wall design. These factors of safety are three of the elements required for retaining wall design.

Course Introduction

Retaining walls are used for a number of practical reasons in construction. In order to design a successful retaining wall it is necessary to know how to calculate the forces that act on the wall and how to calculate factors of safety that will assure a safe design. This course intends to provide a basic understanding of the earth pressure that acts on a wall and how this pressure is resisted. Therefore the objective of this course is to familiarize the reader with:

• Calculating earth pressure
• Applying earth pressure to calculate the earth pressure force
• Calculating factors of safety with respect to sliding, overturning and bearing capacity

Course Content

The course content is in a PDF file Earth Pressure and Retaining Wall Basics for Non-Geotechnical Engineers . You need to open or download this document to study this course.

Course Summary

Retaining wall design begins with the basics of understanding and calculating the forces that act on the wall. This course has provided an introduction to these forces and how they are applied to calculate appropriate factors of safety. In particular the reader should understand that:

• Lateral earth pressure acts to the side and is a function of the vertical effective soil overburden pressure and the applicable earth pressure coefficient.
• There are three categories of earth pressure, each dependant upon magnitude and direction of wall movement. These categories are: At Rest, Active and Passive.
• Two classical earth pressure theories in common use are Rankine and Coulomb.
• In addition to earth pressure, other lateral pressures might result from events such as surcharge, earthquake, and water. These additional pressures are superimposed onto the earth pressure to yield the total destabilizing force.
• Wall movement must occur in order to develop the full active earth pressure force.
• Retaining wall design is an iterative process that seeks to provide a wall geometry that produces suitable factors of safety for sliding, overturning and bearing capacity.
• Retaining walls must also be checked for tolerable settlement and global stability.

Disclaimer

The material presented in this course is intended only for general familiarization with the subject matter and for educational purposes. The course does not cover all aspects of the subject. Use of this material in any manner whatsoever shall only be done with competent professional assistance. The author provides no expressed or implied warranty that this material is suitable for any specific purpose or project and shall not be liable for any damages including but not limited to direct, indirect, incidental, punitive and consequential damages alleged from the use of this material. This communication is not intended to, and shall not be construed as, providing professional engineering in any jurisdiction.

References

1. Weber, Richard P., Personal Course Notes
2. Das, Braja M., "Principles of Foundation Engineering, Fourth Edition," PWS Publishing Company, Boston, MA, 1999.
3. Department of the Navy, NAVFAC, DM-7, May 1982.

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDHonline.com or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered professional engineer. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.