Soil structure interaction

About: Soil structure interaction is a research topic. Over the lifetime, 3653 publications have been published within this topic receiving 48890 citations.

Centrifuge Study of Faulting Effects on Tunnel

Abstract: If a tunnel crosses a geological fault which is considered to be active, the possibility of a displacement in the fault must be accounted for in the tunnel design. When the tunnel is embedded in soil, the assessment of the effect of the fault movement is not easy to assess. As a guide to analysis, a series of correctly scaled model experiments in a centrifuge is undertaken. The deflections and stresses induced in a tunnel crossing a fault caused by: (a) Fault displacement; and (b) differential earthquake motions across the fault are quantified by a series of centrifuge tests on a finite length model tunnel. The centrifuge results are used to calibrate a one‐dimensional finite element model of the tunnel for soil‐tunnel interaction effects. The numerical model is then used to predict the response of an essentially infinite length tunnel for design purposes. Bending movements, displacements and shears are displayed. Surprisingly small changes in the bending movements from the finite‐length to the infinite tunnel case are obtained.

A new type of damper with friction-variable characteristics

Abstract: Professor T. T. Soong is one of the early pioneers in field of earthquake response control of structures. A new type of smart damper, which is based on an Energy Dissipating Restraint (EDR), is presented in this paper. The EDR by Nims and Kelly, which has a triangle hysteretic loop, behaves like an active variable stiffness system (AVS) and possesses the basic characteristics of a linear viscous damper but has difficulty in capturing the output and large stroke simultaneously needed for practical applicataions in engineering structures. In order to overcome this limitation, the friction surface in the original Sumitomo EDR is divided into two parts with low and high friction coefficients in this paper. The results of finite element analysis studies show that the new type of smart friction damper enables large friction force in proportion to relative displacement between two ends of the damper and has a large allowable displacement to fit the demands of engineering applications. However, unlike the EDR by Nims and Kelly, this type of friction variable damper cannot self re-center. However, the lateral stiffness can be used to restore the structure. The nonlinear time history analysis of earthquake response for a structure equipped with the proposed friction variable dampers was carried out using the IDARC computer program. The results indicate that the proposed damper can successfully reduce the earthquake response of a structure.