SOE / Retention Systems

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Support of Excavation (SOE) / Retention Systems

Soil Mix Walls

Soil Mixing is a process of mixing a cementitious grout with in-situ soils.  The compressive strength of the soil mix mass can increase with increasing injection rate and cement content in the grout.

Cutter Soil Mix Walls (CSM)

Cutter Soil Mixing is a process of mixing a cementitious grout with in-situ soils utilizing sets of counter rotating wheels on a Kelly bar system.  This process allows for construction of rectangular panels eliminating the necessity of grinding or shotcreting the resulting scalloped shape of a secant wall. 

Secant Pile Walls

Secant Walls are overlapping (secant) concrete piles typically around the perimeter of a site to provide a groundwater cutoff and support of excavation.

Tangent Pile Walls

Tangent Walls are installed by drilling a casing into the ground and filling with grout.

Sheet Piling

Interlocking steel sheets are installed by vibratory or impact hammers.  They are used to create a relatively water tight temporary lateral support for excavations or permanent lateral support to retain soil on waterfronts. 

Soldier Pile and Lagging

Soldier pile and lagging is a very common method of support of excavation above the groundwater level. 


Underpinning is a means of extending an existing buildings foundation to a lower elevation. 

Tiebacks and Anchors (Soil and Rock)

Tiebacks are small diameter grouted anchors installed at a slight angle from horizontal typically installed to provide lateral restraint.   Rock Anchors can be used to locally to support an unstable rock block or in groups to stabilize an entire rock face.