Market Street Place, San Francisco – California
The Market Street Place development – a multi-use retail and office project – is located in downtown San Francisco. The site is 275 x 170 feet in plan dimension and required a shored excavation depth of 40 feet. The subsurface materials at the site consisted of fill, fine dune sand, marsh deposit, and dense sands to a depth of 80 feet. Ground water was approximately 30 feet below street level.
The project delivery was a design-build for the entire shoring system using deep soil mixing shoring walls, slant drilled underpinning piles with jet grout infills and tiebacks for 3 sides of the project. The Market Street side required a large, 2 level internal bracing scheme since tiebacks would have conflicted with the public transport tunnels running under Market Street. We prefabricated the up to 70 feet long raker pipes off-site, so that installation was as fast and efficient as possible. In addition to the shoring work, we also installed a crane trestle that was heavy utilized for deliveries, equipment staging, and material laydown. Last but not least, the site was dewatered by unitizing 10 dewatering wells inside the excavation and 5 recharge wells along Market Street as part of our design-build shoring & dewatering scope.
For more information on this project please contact Rob Small at rsmall@malcolmdrilling.com