Centrifuge shaking table tests on effect of vertical drain systems for liquefied soil

Abstract

It was observed that liquefaction induced by earthquake causes series damages to buildings and threatens the people and their properties. From the past studies, a number of countermeasures were proposed to reduce the build-up of excess pore water pressure and to enhance the stiffness of the soil during earthquake. The vertical drain systems are well known methods and used as remediation against earthquake-induced soil liquefaction for many years. The purpose of the study is to investigate the effect of different vertical drain systems for the liquefiable soil by centrifuge modeling technique. The seismic behavior of liquefiable soil was performed firstly. The free field soil models were then prepared with alternatively arranged drain-belts and gravel-pile drains to investigate the effect of different vertical drain systems on the liquefiable soil. Several arrays of accelerometers, the pore water pressure transducers and displacement transducers were placed to monitor the shear wave propagation, the excitation and dissipation of pore water pressure. Displacement transducers were placed to measure the ground surface settlement. From the test results, it was observed that the vertical drain systems reduce the settlement and excess pore water pressure significantly. In the future, the vertical systems will be applied around the structure and the test results would give engineers suggestions to deal with the arrangements of drain-belts and gravel drains to reduce the damage during and after the earthquake.

Analysis of Deformations of Gravel Columns in Tailings Dams Using the Finite Element Method and Constitutive Equations

“…Most tailings dam failures are induced by seismic events that trigger displacements and/or deformations due to increased interstitial pressures generating the potential development of liquefaction. Moreover, it is the main factor influencing instability, it is concluded that failure mechanisms directly affect the instability of the containment structure causing an increased risk of collapse [18]. The main cause of dam failures is the liquefaction phenomenon, so international standards have classified the type of tailings dams and the consequences of environmental impact.…”

Data-Driven Vibration Control Strategy for Hypergravity Centrifugal Shaking Table

“…The hypergravity centrifugal shaking table [1,2] is mainly composed of two parts: a centrifuge that generates an additional heavy force field and an airborne shaking table that is used to reproduce highfrequency seismic waveforms. By using a large centrifuge to attach the heavy force field of the airborne shaking table, the stress equivalence between the scale experiment under hypergravity and the original physical model experiment under normal gravity is realized.…”