2011-10-06_REVISION - M1980244 ‎(3)‎

• Permit No: M1980244
• IBM Index Class Name: REVISION
• Doc Date: 10/6/2011
• Doc Name: Submittal- LOB Liner System Enhancements and VLF Ph 4c Berm Raise.
• From: CC&V
• To: DRMS
• Type & Sequence: TR62
• Media Type: D
• Archive: No

•
amec
3.05 ANCHORAGE
3.06 SEAMING
the ENGINEER OF RECORD to facilitate hydration of the GCL upon placement. At completion of
this activity, no wheel ruts, footprints, or other irregularities shall exist in the subgrade. Protrusions
extending more than one -half inch (0.5 in) from the surface shall be either removed, crushed, or
pushed into the surface with a smooth -drum compactor.
C. On a continuing basis, the CQA Monitor and INSTALLER shall observe acceptance of the subgrade
prior to GCL placement. Thereafter, it shall be the INSTALLER's responsibility to indicate to the
CQA Monitor any change in the condition of the subgrade that could cause the subgrade to be out of
compliance with any of the requirements listed in this Section.
A. The end of the GCL roll shall be placed in an anchor trench at the top of the slope or an equivalent
runout design shall be utilized. When utilizing an anchor trench design, the front edge of the trench
should be rounded so as to eliminate any sharp corners. Loose soil should be removed from the floor
of the trench. The GCL should cover the entire trench floor but does not extend up the rear trench
wall.
A. The GCL seams are constructed by overlapping adjacent panel edges and ends. Care should be taken
to ensure that the overlap zone is not contaminated with loose soil or other debris.
B. Longitudinal seams should be overlapped a minimum of six (6) inches for Bentomat ST, or per the
MANUFACTURER's recommendations for an approved equivalent GCL. If the GCL is
manufactured with a grooved cut in the nonwoven geotextile that allows bentonite to freely extrude
into the longitudinal overlap, then no bentonite - enhanced seam is required for this overlap. If the
GCL does not have a grooved cut in one of the nonwoven geotextiles in the longitudinal overlap, then
longitudinal bentonite- enhanced seams are required as described below.
C. End -of -roll overlapped seams should be constructed with a minimum overlap of twenty-four (24)
inches for Bentomat ST, or per the MANUFACTURER's recommendations for an approved
equivalent GCL. Seams at the ends of the panels should be constructed such that they are shingled in
the direction of the grade to prevent the potential for runoff flow to enter the overlap zone.
D. Bentonite- enhanced seams are constructed between the overlapping adjacent panels described above.
The underlying edge of the longitudinal overlap is exposed and then a continuous bead of granular
sodium bentonite is applied along a zone defined by the edge of the underlying panel. A similar bead
of granular sodium bentonite is applied at the end -of -roll overlap. The granular bentonite shall be
applied at a minimum application rate of one quarter pound per lineal foot (0.25 lb /ft).
3.07 DETAIL WORK
A. The GCL shall be sealed around penetrations and embedded structures embedded in accordance with
the GCL MANUFACTURER recommendations.
B. Cutting the GCL should be performed using a sharp utility knife. Frequent blade changes are
recommended to avoid damage to the geotextile components of the GCL during the cutting process.
Section 02776.2 Page 6 of 7 September 15, 2011
Geosynthetic Clay Liner (GCL) Revision 0
S: \Projects \1125E CCV CQA \H2 - Design \ LOB_ Liner _September2011 \02776.2.r0.doc