Geosynthetic Institute
Introduction to Geosynthetic
Certification Institute-Inspectors Certification Program for
“Mechanically
Stabilized Earth (MSE) Walls, Berms and Slopes Using Geosynthetic
Reinforcement”
(GCI-ICP)
The
Geosynthetic Certification Institute-Inspectors Certification Program (GCI-ICP)
for “MSE Walls, Berms and Slopes Using Geosynthetic Reinforcement” is
administered by the Geosynthetic Certification Institute which is a branch of
the Geosynthetic Institute. It is located in Folsom, Pennsylvania about
four-miles from the Philadelphia International Airport. Dr. George R.
Koerner (Program Director) and Dr. Robert M. Koerner (Oversight) and Ms. Jamie
Koerner (Administrator) are the principals involved.
Definition of CQA
(as opposed to CQC)
Construction
quality assurance (CQA) and construction quality control (CQC) are widely
recognized as critically important factors in overall quality management of
constructed facilities of all types.
This includes MSE walls, berms, and slopes using geosynthetic
reinforcement. The best of designs and
regulatory requirements will not necessarily translate to facilities that are
protective of human health and environment unless they are properly
constructed. Additionally, for geosynthetics,
both manufacturing quality assurance (MQA) and manufacturing quality control
(MQC) are equally important.
Geosynthetics refer to factory fabricated polymeric materials like geogrids,
geotextiles, etc. The natural soils
involved are backfill and drainage soils of various types. In this context, the definitions of CQA as
contrasted to CQC are as follows:
- Construction
Quality Assurance (CQA): A planned
system of activities that provides the owner and permitting agency
assurance that the facility was constructed as specified in the
design. Construction quality
assurance includes inspectors, verifications, audits, and evaluations of
materials and workmanship necessary to determine and document the quality
of the constructed facility.
Construction quality assurance (CQA) refers to measures taken by
the CQA organization to assess if the installer or contractor is in
compliance with the plans and specifications for the project.
- Construction
Quality Control (CQC): A planned
system of inspections that is used to directly monitor and control the
quality of a construction project.
Construction quality control is normally performed by the
geosynthetics installer, or for natural soil
materials by the earthwork contractor, and is necessary to achieve quality
in the constructed or installed system.
Construction quality control (CQC) refers to measures taken by the
installer or contractor to determine compliance with the requirements for
materials and workmanship as stated in the plans and specifications for
the project.
The
certification program to be described herein focuses on CQA but can (and should)
pertain to CQC as well.
The
following flow chart describes the interactions of MQA/CQA and MQC/CQC as they
apply to a particular project so as to produce an appropriate level of quality.
Figure 1 - Organizational Structure
of Quality Control and Quality Assurance Activities
*Note that
this certification program focuses on construction quality assurance (CQA) of
MSE walls, berms and slopes, and only indirectly on manufacturing quality
assurance (MQA) of their components.
The Value of CQA
While the overall performance of MSE
walls, berms, and slopes using geosynthetic reinforcement might be considered
as being reasonable, it has certainly been less than perfect. Figure 1a shows several cases of excessive
wall deformations, and Figure 1b shows cases of actual wall collapse. Clearly, it is problems such as these which
have prompted this program. At a GSI
Workshop held on April 1, 2010 representatives from about twenty member
organizations suggested the need for a program reducing the causes for such failures. It was also discussed that inadequate design
and improper construction were the root causes of the failures in part because
there was rarely any construction oversight which could have identified both
the design inadequacies and the construction deficiencies. This inspectors
certification program is aimed at correcting these issues. This two-way orientation by field inspectors
(notification of design anomalies and correction of contractors
errors) should help stem the number of failures of MSE walls, berms, and
slopes.
Figure 1a – Cases of excessive wall
deformations (GSI photos ands others).
Figure 1b – Cases of wall collapse
(GSI photos and othes).