We went through several revisions (more than 8 in total over the 4 pits) for highway, railway, and creek trenchless crossing designs on one project site.
The client’s choice of another engineering contractor for adjacent pits needlessly complicated the site, leading to the incorrect application of design criteria to our pit, resulting in instability. We issued a stop work order, collaborating with the client to ensure safety. Arch Engineers’ solution involved using a trench box to maintain the working area at depth and backfilling the area up to 3.5m below grade to meet design requirements, allowing safe completion of remaining pipe hammering.