A study on mitigation of tilting problems in liquefiable soil

Abstract

Tilting of foundations during liquefaction of soil is one of the primary concerns for stability of structures constructed in saturated sand in seismically active areas. Niigata earthquake resulted in tilting of a number of buildings. Once tilted, the structure is to be dismantled. Tilting also results in loss of life and property. The main aim of this study is to restrict tilting and allow the structure to float on liquefied soil. During a high-magnitude earthquake, the structure may not float for a long time, but may sink instead of tilting. Archimedes principle has been applied in the present study. The shape of conventional rectangular footing is changed to spherical and trapezoidal section. Shake table tests were performed at different frequencies like 0.5, 1 and 1.5 Hz. Comparisons of tilting and sinking of all the three types of footings were performed. Accelerations imposed on the footings were also measured. Results showed a positive response for a footing with spherical cross sections.