The project site’s predominant soil profile consisted of sand and sandy clay. The bearing stratum was a stiff marine deposit encountered at depths between 15 and 25 feet.
The foundations were designed for a bearing pressure of 5,000 psf with the requirement of limited differential movement once construction was completed. Liquefiable sands were also present at the site.
Menard developed a ground improvement solution using stone columns to mitigate the risk of liquefaction and to control settlement of the foundation footings installed at a maximum depth of 25 feet. Because of the site conditions, Menard used the dry-bottom fed method of construction, which introduces the stone via a side-feeder tube without removing the probe. Due to the tight project schedule, two full time crews were utilized.
In addition to the stone columns, there was also a need for wind and seismic load resistance at several key footing locations. For this aspect of the project, Menard teamed with its sister company, Nicholson Construction, to install a series of ground anchors to satisfy the engineer’s requirement for uplift and lateral loading conditions. The anchors were installed to a depth of approximately 50 feet, with the work being done in tandem with the stone column operation.
Together, Menard and Nicholson were able to use their expertise in ground improvement and knowledge of local geology to create a two-part foundation support solution that met the performance, schedule, and economic needs of the client.