Effects of Soil Modulus and Flexural Rigidity on Structural Analysis of Water Intake Basins

A water intake basin is a buried box that functions as a water reservoir near shorelines. Its bottom is located below sea water level and endures uplift pressure as well as reaction of supporting soils. In addition to common dead, live and seismic loads, special loads such as water and soil pressures act on this structure and make its behavior complicated. The unreliability in the soil parameter and in the rigidity of the basin structure is studied in this research by calculating the generated internal bending moments. Different loads and load combinations have been taken into account and finite element analysis is carried out for modeling nonlinear behavior of different types of supporting soils. It is concluded that the geometry and flexural stiffness of the basin affects the analysis more than the soil parameters because the contribution of the soil modulus in the total stiffness of the system is negligible than the structural rigidity of the basin structure. In addition, inner walls and geometry of the basin should be modeled in detail to obtain acceptable results.