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

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

Tuesday, August 30, 2022
8:30 am – 5:00 pm EDT


Presented by
Daniel Messmer P.E. D. GE

Types of Retaining Walls and Appropriate Applications
Applications for retaining walls
Traditional cantilevered retaining walls
• Reinforced concrete walls
• Reinforced concrete masonry walls
Soldier pile and lagging walls
Traditional timber walls
Traditional gravity walls
Reinforced soil retaining walls
Anchored retaining walls (tie-backs, soil nailing, etc.)
Temporary retaining walls
Over-steepened reinforced slopes
Gabion walls
Crib walls
Private-sector vs. highway retaining wall systems
Cost of retaining walls

Retaining Wall Design
Soil design parameters
Lateral earth pressure
External stability
• Sliding
• Overturning
• Bearing capacity
• Settlement
• Scour
Internal stability
Global stability
Special considerations for tiered retaining walls
Service life
Design software

Slope Stabilization
Science of slope stability
Surficial vs. deep-seated slope stability
Long-term vs. short-term stability
Slope stabilization techniques
• Regrading
• Excavation and replacement
• Slope reinforcement/pinning
• Ground improvement
• Toe retaining walls

Retaining Wall and Slope Stabilization Case Histories
Commercial and residential projects
Highway and institutional projects


Webinar Instructions

Each webinar session earns continuing education credit and can be registered for individually. 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


Professional Engineers:
7.0 PDHs

7.0 HSW CE Hours

Landscape Architects:
7.0 HSW CE Hours

International Code Council:
.7 CEUs (Sitework)

Floodplain Managers:


Continuing Education Credit Information
This webinar is open to the public and is intended to offer 7.0 PDHs to professional engineers, 7.0 HSW continuing education hours to licensed architects, and 7.0 HSW continuing education hours to 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 No. 0004647), Indiana (License No. CE21700059), Maryland, New Jersey (Approval No. 24GP00000700) 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 LU|HSWs (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).

This webinar has been approved by the Association of State Floodplain Managers for 7.0 CECs for floodplain managers.

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).


Daniel Messmer P.E. D. GE

Daniel P. Messmer, P.E., D. GE  Project Manager with The Gateway Engineers, Inc., in Pittsburgh
Mr. Messmer has over 30 years of engineering experience in analysis, design, plan/specification development, and project management/personnel supervision for geotechnical, foundation and structural engineering projects in the transportation, industrial, municipal and commercial fields of civil engineering. Throughout his career he has placed an emphasis on quality control and staff training. Mr. Messmer is a member of the American Society of Civil Engineers, the American Concrete Institute, the American Society of Highway Engineers and the Society of American Military Engineers. He earned his B.S. degree in Civil Engineering from the University of Pittsburgh. Mr. Messmer was accepted into the Academy of Geo-Professionals in 2013.

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: Pennsylvania Retaining Wall Design and Slope Stabilization Techniques

Delivery Method: Live Online

Course Description: This seven-hour course covers the types of retaining walls and their applications, retaining wall design based on soil parameters, loads and other site conditions, and slope stabilization strategies specific to soils and site conditions found in Pennsylvania.

Learning Objectives:

Learning Objective 1:
Learners will be able to identify and explain the features and applications of various types of retaining walls, including cantilevered walls, soldier pile and lagging walls, timber walls, gravity walls, anchored walls, and others.

Learning Objective 2:
Learners will be able to describe the factors that must be considered when designing a retaining wall, including soil design parameters, lateral earth pressure, bearing capacity, settlement, groundwater, backfill and service life.

Learning Objective 3:
Learners will be able to describe methods to achieve slope stability, including regrading, slope reinforcement/pinning, ground improvement, retaining structures, and excavation and replacement.

Learning Objective 4:
Learners will be able to analyze and discuss real-world commercial, residential, and institutional projects involving retaining walls and slope stabilization.

LUs: 7.0                                                                                              LU Type: LU|HSWs.

Prerequisites: Experience with site evaluations and earthwork

Advance Preparation: None

Program Level: Intermediate

Course Expiration Date: 06/23/2025

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.