Michalek points out that geotechnical engineers take soil samples with a drill-like apparatus down to a depth where it is anticipated that the structure to be built will interact with the soils beneath the potential grain storage structure. From the soil samples, the geotechnical engineer identifies the soil type encountered and performs laboratory analysis to determine the suitability of the soils at the proposed site. From this analysis, recommendations are made regarding design parameters, which will facilitate foundation earthwork operations.
The geotechnical engineer’s recommendations are synthesized into a formal report and are used extensively during the structural design, earthwork, and foundation construction phases of a project.
Nationwide points out that from time to time, the insurer encounters clients who utilize a geotechnical engineer only for the preliminary site investigation, but they fail to continue to retain the engineer’s services for the actual construction operations that will take place later.
Ideally, the geotechnical engineer should be retained to provide quality control measures as construction progresses. Typical tasks may include inspection of foundation bearing surfaces, groundwater mitigation, fill placement verification, and other responsibilities.
Other quality control issues during the concrete pour include verification of the rebar size used and its proper placement, along with the proper aggregate size used in the mix.
According to Michalek, soil conditions are the single greatest unknown at a construction site, because we physically can see only the soil surface. This very cursory analysis really tells neither little about the structural properties of the soil on-site nor anything about the soil stratification at various depths below the surface.
A geotechnical engineer will examine the potential loads and calculate the best ways to support the weight of the structure filled with grain and how to transmit those loads efficiently into the foundation and grounds. Thompson points out that “the owner and engineer together should provide general oversight to ensure quality control and the structural integrity of the storage complex.&rdquo