Remediation of Grain Off-Loading Facility in Corpus Christi, TX

Above and underwater inspections of the Interstate Grain ship dock indicated that the foundations supporting the tower structures for the grain off-loading conveyor system were tilting northward towards deeper water. The existing foundations consisted of a pile-supported system constructed in a clay soil slope, and there was concern that the damage was due to movement of the slope. A barge-based exploration program was conducted adjacent to the existing foundations to evaluate the soil conditions, which included borings, cone penetration test (CPT) soundings and pressuremeter testing. In addition, laboratory testing was conducted to estimate the peak and residual strength values for the clay soils for both undrained and drained soil conditions. The results from the marine exploration and the laboratory tests indicated that a surficial upper soft clay (mud) layer had moved in the past and is likely to move in the future. However, the explorations confirmed that a deep-seated global failure was likely not a concern. The marine exploration and the laboratory testing helped better understand the slope performance and provided a new design solution that reduced the deep foundation costs by approximately $3,000,000, for an exploration cost of around $180,000. This paper presents a summary of the work conducted for the new foundation design, and discusses the lessons learned in developing an economical foundation design.