Case Study
Bridgewater WWTP – Bridgewater, NJ
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Project Overview
A proposed pump station for the SRVSA Stormwater Treatment Facility located in Bridgewater, NJ would require footers and foundations to be constructed 45’ below grade. Borings revealed the soil profile consisted of 8’ of fill/alluvial material and 8.5’ residual clay overlaying shale bedrock. Engineers also had to consider live loads (1,594 psf) associated with a nearby crane. For the soil reinforced elevations, the engineer determined that a tensile capacity of at least 6,000 lbs./ft (of wall/slope) was required to satisfy a factor of safety of 1.3 for temporary support.
Solution
The engineer determined that Platipus S8 ARGS (2 Ton Capacity) anchors placed on a 5’ horizontal by 3’ vertical grid pattern would safely support the required excavation, at least to the elevation where bedrock was expected to be encountered. As with any shoring of excavation application, top-down construction was required. Beginning with the initial 4’ cut, the first row of anchors were installed 23’ deep using a mini-excavator with an attached light weight breaker/hammer. Each S8 anchor was tensioned to the design working load of 2,000 lbs using a Platipus SK1 hydraulic jack and electric pump prior to excavation of subsequent lifts. Once bedrock was encountered, the contractor transitioned to an appropriate rock bolt/anchor (provided by Williams Form Engineering) that was specified by the engineer. Platipus engineering assistance and onsite support throughout the project made the S8 ARGS system the preferred method of shoring of excavation (of soils) for the contractor.
