A homeowner reported extensive settlement damage approximately two weeks after the groundwater in the vicinity of the home was lowered at a nearby construction project. The infrastructure improvement project consisted...A homeowner reported extensive settlement damage approximately two weeks after the groundwater in the vicinity of the home was lowered at a nearby construction project. The infrastructure improvement project consisted of installing a 27-inch-diameter sanitary sewer main with an invert elevation about 19 ft below existing grade. Groundwater was lowered 12 ft during construction, down to a depth of 23 ft below existing grade. This paper addresses the following key questions regarding settlement and potential structural damage as a result of a temporary drop in groundwater caused by construction dewatering: (1) How could a decrease in groundwater elevation cause settlement? (2) Is this a highly unusual or atypical phenomenon that cannot be explained or estimated using science and engineering techniques available to the engineering profession? (3) Based on the standard of care at the time, should these problems have been anticipated, or at least examined, by the engineering firms engaged on this project? Answers to these questions are addressed herein using results from geotechnical analyses and data obtained from laboratory and in-situ tests.展开更多
文摘A homeowner reported extensive settlement damage approximately two weeks after the groundwater in the vicinity of the home was lowered at a nearby construction project. The infrastructure improvement project consisted of installing a 27-inch-diameter sanitary sewer main with an invert elevation about 19 ft below existing grade. Groundwater was lowered 12 ft during construction, down to a depth of 23 ft below existing grade. This paper addresses the following key questions regarding settlement and potential structural damage as a result of a temporary drop in groundwater caused by construction dewatering: (1) How could a decrease in groundwater elevation cause settlement? (2) Is this a highly unusual or atypical phenomenon that cannot be explained or estimated using science and engineering techniques available to the engineering profession? (3) Based on the standard of care at the time, should these problems have been anticipated, or at least examined, by the engineering firms engaged on this project? Answers to these questions are addressed herein using results from geotechnical analyses and data obtained from laboratory and in-situ tests.