problem
Trinity River Authority’s landfill modification project in
grand Prairie, Texas faced many design and construction difficulties.
The 3700 m3 per day wastewater treatment plant was producing sludge
at a faster rate than originally anticipated and 50% of the landfill
areas were full. More room was required. Furthermore, the 80 hectars
landfill cell had reached its capacity and needed to be closed.
A slurry trench was proposed to intercept percolated leachate and
a cap system was designed to prevent infiltration. Low, extremely
wet and unstable areas existed over the top of the landfill.
How
could the contractor achieve proper compaction in the 0.90 m clay
cap with an inadequate subgrade? What about differential settlements
and landfill voids? What about the possibilities of the clay cap
developing cracks and allowing infiltration?
solution
Freese and Nichols, the engineers for the project specified the
use of an on-site soil sludge fill mixture to bring the cap up to
the proper elevation, sloped to allow for drainage the primary problem
was the instability of the top. The contractor had completely buried
several pieces of equipment during his first traverse of the site.
TENAX MS 500 multi-layer geogrid was incorporated into the double
layer cap system for several important reasons. The first problem
TENAX MS 500 solved was to help achieve proper compaction in the
clay cap; TENAX MS 500 geogrid utilized its excellent interlocking
capacity to help achieve the required 95% compaction in the clay.
TENAX MS 500 also served to stabilize and reinforce the soft, saturated
soilsludge mixture. And probably most importantly, TENAX MS 500
geogrid prevents the future development of desiccation cracks, which
promote infiltration
conclusions
TENAX MS 500 multi-layer bioriented geogrids have proven time and
time again their advantages for this Trinity River authority earthwork
project, TENAX MS 500 geogrids saved costly lime stabilization or
undercutting and utilized normally unsuitable on site material.
Construction time was saved due to the ability of the TENAX MS multi-layer
bioriented geogrids to be effectively installed in wet conditions
even in standing water as in this case. |
geo@tenax.net