| |
| DALLAS
EASTSIDE WATER TREATMENT PLANT RETENTION LAGOONS |
| Location: |
Sunnyvale,
Texas, USA |
| Owner: |
City
of Dallas Water Utilities |
| Engineer: |
CDM |
|
| General: |
Archer
Western Contractors |
| Installation: |
Colorado
Lining International |
| Aggregate
Sub: |
AAA
Nursery Sand & Stone, Inc. |
| Technical
Consultants: |
Soil
Stabilization Products Company |
| |
|
MATERIAL:
|
|
QUANTITY: |
| Geotextile |
28
oz. nonwoven/ |
657,000
sq. ft. |
| Geomembrane |
40
mil HDT/ |
587,500
sq. ft. |
| Geocellular
System |
12
oz. Geoweb®/ |
572,000
sq. ft. |
|
|
Problem:
Prior
to the installation of geosynthetics, the levee was plagued by
erosion.
Chronic
problems caused by more than a dozen sliding failures per year
on the outer slopes of the facility's water retention lagoons.
The
lagoons, enclosed within a perimeter
levee, were constructed with
flexible membrane containment liners. The tops of the levees
were capped with
a paved access road. Challenge:
To develop alternate means of resolving the sliding issues.
The
exterior slopes, which had been constructed at a gradient
of 3H: IV, were
composed of highly expansive clay soils with PI (plasticity index)
ranging from 21 to 75.
Because of the expansive nature of the levee embankment soils,
the slope surfaces suffered from severe shrinkage cracking during
the dry summer months. Water entered these cracks during the
rainy season and found pathways into the deeper soil layers,
creating
instability in the slope structure. |
|
offices