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J.F. White was awarded the sitework package at Novartis Cambridge Campus Expansion Project that included designing and installing an earth support system to allow a 3.2 acre site excavation to a depth ranging from 38’‐0” to 50’‐0” down from surface level.
The earth support wall system consisted of soil mix wall (700LF) by using W24 x 162 soldier piles at 75’‐0’ lengths and AZ19‐700 sheet piles wall (950LF) with a typical tip elevation depth of 47’‐0”. The second level of bracing consistent of tiebacks and cross lot struts that were laid‐out identical to the first level bracing with exception of certain structural members that were increased in section to resist the higher loads. The second level of bracing located on average of 25.5’ from existing grades. The next excavation cut allowed installation of the third level of bracing within the Soil Mix Wall limits that consisted of seventy‐one (71) tiebacks and five (5) diagonal corner and straight cross lot struts with walers.
The fourth and deepest cut adjacent to Mass. Ave. was excavated down 44’ from existing grade to allow for the installation of ninety‐nine (99) drilled tiebacks. The tiebacks were tested and lockedoff to 125% of design load prior to proceeding with the excavation to 50’ from existing grade.
Contract value: $30,400,000. |