NASCLA Accredited Commercial General ContractorSite WorkHard
A commercial construction project requires the installation of a new storm sewer line that runs adjacent to an existing building. The excavation for the sewer line will be 12 feet deep in cohesive soil. To ensure the safety of workers and the stability of the adjacent structure, which shoring system is generally most appropriate for this scenario?
- ATimber Shoring
- BSheet Piling
- CSloping or Benching
- DHydraulic Shoring
Show answer & explanationAnswer & explanation
Correct answer: B. Sheet Piling
Sheet piling is ideal for deep excavations, especially when working adjacent to existing structures where space is limited and groundwater might be present. It provides a continuous, robust support system that prevents soil movement and protects adjacent properties.
Why the other options are wrong
- A. Timber shoring can be effective but is often less practical or robust for 12-foot deep excavations near existing buildings compared to sheet piling.
- C. Sloping or benching requires significant space, which is often not available next to existing buildings.
- D. Hydraulic shoring is good for trench protection but may not offer the continuous, rigid support needed for deep excavations next to structures.
Sheet Piling
A shoring method using interlocking steel or concrete sheets driven into the ground to create a continuous wall, providing robust support for deep excavations, especially near existing structures or in unstable soils.
- Forms a continuous, rigid wall.
- Suitable for deep excavations and unstable soil.
- Protects adjacent structures and prevents groundwater intrusion.
Memory trick: Shoring choices depend on Depth, Soil, Space, and adjacent Structures.