Design Error Leads to Building Settlement
Design build contractor responsible for 11-story dormitory for University housing. Deep foundation package was a design-build subcontract. Geotechnical study was commissioned and subcontracted by the design build contractor. Differential settlement was specified to be no more than ½”. Construction of the rammed-aggregate pier system completed with no apparent issues. Installation of the building cast-in-place concrete framing proceeded once foundation complete. While constructing the eighth floor, the contractors noticed settlement and surveys revealed excessive differential settlement throughout the tower. Some areas of the tower had settled as much as 5 inches and construction of the tower was stopped. The rammed-aggregate-pier subcontractor discovered and acknowledged that they had made a design calculation error that accounted for half of the settlement experienced, however they firmly stated that not all of the settlement was caused by their design error. It appears it also involved the compaction of soils, or the lack thereof when the lifts were completed. Rectification was to install micro pile and because of a $9 million limit of liability, protective indemnity was also triggered. $30 million in damages, including $12 million hard costs, $10 million acceleration, $2 million in extended general conditions, $2 million in lost productivity and $4 million in overhead and profit. Resolved through arbitration with $9 million from designer, which liability was limited to fees of $9 million.