LARGE-SCALE FIELD MODEL TEST ON DYNAMIC SOIL-BOX FOUNDATION-STRUCTURE INTERACTION

A large-scale (1:2) field model experiment of dynamic soil-box foundation-structure interaction was carried out. Based on the pulsation and release tests, the nature frequency and damping ratio of the model were tested. By comparing the differences of nature frequency between experimental and three-dimensional finite element method analysis results, it is found that the fundamental nature frequency of the system considering soil-structure interaction (SSI) is about 8.5% less than that of the fixed-base structure. Comparison of the velocity spectra at the measuring points on the foundation and on the ground surface shows that the main portion of the velocity response on the ground surface is longitudinal and the high frequency component close to the soil natural frequency is amplified. The results of near-field blasting vibration test show that the main portion of the velocity response at the top of flexible super structure is rocking, followed by elastic deformation. The swing response is very small. The experiment provides test data for further numerical modeling of soil-structure interactions.