Webinar instructions will be emailed before the date of the webinar.

Please log into the webinar 15 – 30 minutes before the start time.

Wednesday, August 7, 2024
9:00 am – 5:00 pm CDT


Presented by Bill Simpson, P.E.

Types of Retaining Walls and Appropriate Applications

  • Common types of walls commonly used in today’s construction
  • Best applications of a cast-in-place concrete wall
  • Alternatives to cast-in-place retaining walls
  • Advantages to using gravity retaining walls
  • Different types of gravity walls
  • Basic concepts of mechanically stabilized earth (MSE) systems
  • Best applications of an MSE wall and/or slope

Retaining Wall Design

  • Defining “the wall”
  • Identifying forces on a retaining wall
  • How to account for and resist soil pressure
  • How water pressure impacts a retaining wall
  • The properties of the soil that contribute to the wall design
  • Equations and examples

Slope Stabilization

  • Unreinforced slope stability analysis
    • Fundamentals of slope instability
    • Soil and geological mechanics related to slope instability
    • How geologic conditions affect slope stability
    • Observations of slope instability
    • Construction practices to improve or restore slope stability
    • Equations, calculations and example of an unreinforced slope
  • Reinforced slope stability analysis
    • Geosynthetic properties for use in slope stabilization
    • Deep-seated stability analysis
    • Equations, calculations, and example of using geosynthetics to reinforce a slope
    • Soil properties and conditions that contribute to slope stability
    • Material required for the exposed face of the slope to maintain long-term stability

Retaining Wall and Slope Stabilization Case Histories

  • Preventing problems or failures of walls and slopes through improved site layout
  • Commonly overlooked design code requirements related to retaining wall layout and design
  • Roles and responsibilities of the design and construction team to ensure structure success
    • Typical causes of problems or structure failure
    • Recognizing and preventing a problem during construction
    • How water (both surface and below ground) effects an earth structure
    • What measures to take during construction to ensure long term earth structure success
  • Case histories and examples of failed structures


Webinar Instructions

All attendees must log-on through their own email – attendees may not watch together if they wish to earn continuing education credit. HalfMoon Education Inc. must be able to prove attendance if either the attendee or HalfMoon Education Inc. is audited.

Certificates of completion can be downloaded in PDF form upon passing a short quiz. A link to the quiz will be sent to each qualifying attendee immediately after the webinar. The certificate can be downloaded from the Results page of the quiz upon scoring 80% or higher.

Webinars are presented via GoToWebinar, an easy-to-use application that can be run on most systems and tablets. Instructions and login information will be provided in an email sent close to the date of the webinar. It is highly recommended that you download, install and test the application before the webinar begins by clicking on the link in the email.

GoToWebinar App requirements:
Windows 7 – 10 or Mac OSX Mavericks (10.9) – macOS Catalina (10.15)

Web Browser:
The two most recent version of the following browsers:
Google Chrome, Mozilla Firefox, Apple Safari, Microsoft Edge
Internet Explorer v11 (or later) with Flash enabled.

Internet connection: Minimum of 1Mbps       Hardware: 2GB RAM or more

For more information, visit the Support section at


7.0 PDHs

7.0 HSW CE Hours

AIA - American Institute of Architects
7.0 LU|HSW

Landscape Architects
7.0 HSW CE Hours

LACES - Landscape Architecture Continuing Education System
7.0 HSW PDHs

ICC - International Code Council
.7 CEUs (Sitework)


Continuing Education Credit Information

This webinar is open to the public and is designed to qualify for 7.0 PDHs for professional engineers, 7.0 HSW continuing education hours for licensed architects, and 7.0 HSW continuing education hours for landscape architects in all states that allow this learning method. Please refer to specific state rules to determine eligibility.

HalfMoon Education is an approved continuing education sponsor for engineers in Florida (Provider License No: CEA362), Indiana (License No. CE21700059), Maryland, New Jersey (Approval No. 24GP00049300) and North Carolina (S-0130). HalfMoon Education is deemed an approved continuing education sponsor for New York engineers and architects via its registration with the American Institute of Architects Continuing Education System (Regulations of the Commissioner §68.14(i)(2) and §69.6(i)(2)). Other states do not preapprove continuing education providers or courses.

The American Institute of Architects Continuing Education System has approved this course for 7.0 HSW LUs (Sponsor No. J885). Only full participation is reportable to the AIA/CES.

The Landscape Architecture Continuing Education System has approved this course for 7.0 HSW PDHs. Only full participation is reportable to the LA CES.

The International Code Council has approved this event for .7 CEUs in the specialty area of Sitework (Preferred Provider No. 1232).

Attendance will be monitored, and attendance certificates will be available after the webinar for those who attend the entire course and score a minimum 80% on the quiz that follows the course (multiple attempts allowed).

On-Demand Credits

The preceding credit information only applies to the live presentation. This course in an on-demand format may not be eligible for the same credits as the live presentation; please consult your licensing board(s) to ensure that a structured, asynchronous learning format is appropriate. The following pre-approvals may be available for the on-demand format upon request:

7.0 HSW LUs (AIA)


Bill Simpson, P.E.

Geotechnical Structure Design Specialist at Gradelta Engineering

Mr. Simpson founded Gradelta Engineering in 2020 with the intent to help clients better understand the combination of geotechnical and structural engineering that he has worked with for the past 20 years. He earned his B.S.C.E. and M.S.C.E. degrees from Georgia Institute of Technology. He currently provides engineering services to contractors and fellow engineers for earth structure pricing, along with the plans and calculations needed for construction. He frequently consults with clients regarding the optimal structure type and location on the construction site to minimize risk and maximize useable space. He also works in the education sector providing not just seminars such as this one, but also acting as a subject matter expert creating study guide and test prep content for the NCEES Professional Civil Engineer exam. Mr. Simpson has also worked with lawyers and insurance companies during forensic investigation and lawsuits surrounding retaining walls and slope failures. His hope is that through the instructional services that he currently provides, slopes will remain stable and retaining wall failure will be eliminated.

AIA Info

AIA Provider Statement:

HalfMoon Education Inc. is a registered provider of AIA-approved continuing education under Provider Number J885. All registered AIA/CES Providers must comply with the AIA Standards for Continuing Education Programs. Any questions or concerns about this provider of learning program may be sent to AIA/CES ( or (800) AIA 3837, Option 3).

This learning program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.

AIA continuing education credit has been reviewed and approved by AIA/CES. Learners must complete the entire learning program to receive continuing education credit. AIA continuing education Learning Units earned upon completion of this course will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.

Course Title: Retaining Wall Design and Slope Stabilization Techniques

Delivery Method: Live Online

Course Description: This seven-hour course explores the fundamental principles and advanced practices involved in retaining wall design and slope stabilization. The course will allow for a comprehensive understanding of the various types of retaining walls, the forces acting upon them, and the techniques required to ensure their stability and prevent failures.

Learning Objectives:

Learning Objective 1:
Learners will be able to identify the different types of retaining walls and their suitable applications, including cast-in-space concrete walls, gravity walls, and mechanically stabilized earth (MSE) systems.

Learning Objective 2:
Learners will be able to explain the forces and pressures affecting retaining wall design, such as soil and water pressure, and describe the methods to counteract these forces using appropriate design equations and principles.

Learning Objective 3:
Learners will be able to explore the core concepts and methodologies for unreinforced and reinforced slope stabilization, including geosynthetic properties, deep-seated stability analysis, and effective construction practices.

Learning Objective 4:
Learners will be able to analyze case histories to identify common causes of retaining wall and slope failures, recognize design code requirements, and implement preventative measures during construction to ensure long-term stability and success.

LUs: 7.0                                                                                              LU Type: LU|HSWs.

Prerequisites: Experience with civil engineering fundamentals and soil mechanics.

Advance Preparation: None

Program Level: Intermediate

Course Expiration Date: 05/24/2027

Complaint Resolution Policy:

Complaints regarding this course can be emailed to or by calling (715) 835-5900. A HalfMoon Education representative will respond within 72 hours to resolve the complaint, which will include, but not limited to, access to another CE activity at no or reduced cost or a full or partial refund. Each instance will be resolved on a case-by-case situation.

Streamable MP4/PDF Price: $349.00

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