Patient Details
Alpha Structural performed an extensive retaining wall and structural deck project at this Los Angeles property. As detailed on page 1 of the contract, the work centered on constructing a new pile-supported sister retaining wall to reinforce an existing failing wall, building a new rear-yard deck, and repairing the upper-level deck.
The project began with demolition of existing stucco and wood framing at the upper deck while leaving the existing steel in place. Existing stairs, concrete slabs, portions of the retaining wall, and a rear-yard storage shed were also removed. The rear-yard grade was lowered to create space for the new deck, with temporary shoring installed as necessary during structural work.
A new deep foundation system was then constructed using nine piles extending approximately 16 to 18 feet deep. Grade beams were excavated according to the engineered plans, and reinforcing steel was installed throughout the piles, grade beams, and new retaining wall. The foundation and wall system was poured using a minimum 4,000 PSI high-strength concrete mix.
Drainage improvements were incorporated directly into the retaining wall construction. New 12-by-12-inch drainage pockets were cut into the bottom of the existing wall and fitted with gravel pockets and drainage pipes wrapped in filter fabric. A new concrete swale was also constructed along the top of the retaining wall, incorporating a box drain at each end and two new dispersal boxes at the bottom of the wall.
The deck structures were rebuilt using new pressure-treated structural framing and engineered hardware connections. The upper deck received new wood framing, while the new lower deck incorporated pressure-treated beams, posts, and joists. The lower deck was designed to align with the existing sliding glass doors, with its supporting posts bearing on the newly constructed retaining wall.
Additional structural support was provided beneath the house with three new pipe columns supported by three new pile foundations, further integrating the deep foundation work with the property's structural framing system.
Together, the nine deep piles, reinforced concrete grade beams, sister retaining wall, drainage system, structural columns, and pressure-treated deck framing provided a comprehensive solution for stabilizing the existing retaining wall while rebuilding and strengthening the property's upper- and lower-level deck structures.
