Maple Valley Retaining Wall, Maple Valley, WA (2022)

Shoring System: Permanent Soil Nail and Anchored Soldier Pile Retaining Walls

Client: Terra Associates, Inc.

General Contractor: Sierra Construction Company, Inc.

Shoring Contractor: DBM Contractors Inc.

Shoring Face Area: 60,000 Square Feet

Wall Depth Range: Up to 50 feet

Status: Completed 2022

The project consisted of the reclamation of sand and gravel open pit excavation to develop the site for surface parking and a commercial building. To do this, permanent retaining walls were required in the pit sidewalls that consisted of both native soils and reclamation fills. Two different retaining wall systems were used, depending on the nature of the soil conditions encountered. Where compacted fill soils were to be retained, permanent anchored soldier pile walls were used together with a permanent shotcrete facing attached to the soldier piles. Wall heights were up to 41 feet and a total wall surface area of 22,000 square feet was used. Where native soils were to be retained, permanent soil nails walls were used. Wall heights were up to 50 feet and a total wall surface area of 38,000 square feet was used. The wall was finished with a painted and carved shotcrete fascia.