TEC was retained to provide engineering and oversight for the innovative development of a new parking lot for a private marina with a clubhouse, restaurant and banquet facility on Lake St. Clair. Land was limited, and for this reason, the owner opted for a portion of one of the boat docking facilities to be filled in and the new parking lot to be laid over the top.
Due to low water levels, dredging activities (on the lake) were scheduled to occur at the same time. TEC consulted with a geotextile supplier and contractor and developed a design to fill the channel with dredge spoil. The hydraulically dredged spoil would be pumped into Geotubes that were placed in the channel. The existing channel was constructed with anchored sheet piling. TEC designed a cantilevered sheet pile wall to close off the end of the channel. A cantilevered system was chosen to avoid constructing tiebacks within the Geotubes. In addition, the retention of the soil in the Geotubes practically eliminated lateral earth pressures on the sheet wall. TEC performed laboratory testing to determine the engineering characteristics of the dewatered spoil for load support.
This method offered the advantage of retaining the potentially contaminated dredge spoil on site and eliminating the need for costly off-site disposal and import of new fill, as well as providing a more environmentally friendly use.