Specifications for an MSE Large Panel Retaining Wall

MSE Retaining Walls

• Mechanically stabilized earth retaining walls are constructed with soil, or with aggregates and horizontal layers of reinforcement. These are faced with precast concrete panels, segmental concrete blocks, vegetation or rocks.

  MSE walls retain filled earth to substantial heights and bear heavy loads at less cost than concrete. They use gravity wall design, relying on weight and an angle, or batter, back into the soil being retained, for stability. MSE retaining walls are often chosen as a substitute for concrete retaining walls.

MSE Large Panel Retaining Wall

• Large panel retaining wall systems use mesh or strips in the backfill material to reinforce the soil structure, and the backfill is faced with pre-cast concrete wall panels. These panels are set on a concrete leveling pad, using equipment to lift them, and they held in place with wedges, as backfilling is executed in lifts, or layers, and is then compacted.

  The joints between panels meet a prescribed distance. When the compaction for each layer is completed, reinforcing material is placed on the prepared lift, extending horizontally from the panel.

Materials

• The backfill soil is specified as well-drained aggregate, with little to no organic content. Reinforcing material for large panel construction is either metal or geosynthetic. It holds the wall panel and the soil backfill together as a single mass.

  Concrete wall panels have to meet specifications for compression strength, but the face may be finished with an architectural treatment. The height of the wall depends on the load-bearing capacity of the soil on which the panels are placed.

Drainage

• Drainage is an important factor in MSE retaining wall design. The main cause of MSE wall failure is poor drainage, causing hydrostatic pressure from the buildup of water in the soil to bear against the structure.

  A drainage aggregate layer and drain tile -- usually perforated pipe -- is installed behind the wall to relieve hydrostatic pressure. The drainage system and backfill material are specified by the soils engineer, according to site conditions and the wall design.