Centrifuge Model Tests on Failure Behavior of Grid-Form Deep Mixing Walls During Large Earthquake


Abstract eng:
Grid-form deep cement mixing walls (DMWs) were recently employed to increase bearing capacity of foundations in soft soil as well as a countermeasure against seismic liquefaction. This paper conducted dynamic centrifuge model tests to investigate a failure behavior of DMWs in liquefiable sand during large earthquakes. Two types of models were used for DMWs. One was made of soil-cement with an unconfined compressive strength of about 4,000 kPa. The other was made of acrylic resin that had the same shear stiffness as the initial shear stiffness of soil-cement. The acrylic and soil cement models that supported the rigid weight of 206 kPa were set in a laminar shear box, and repeatedly tested by increasing the acceleration level of the input motion recorded at TAFT earthquakes, in order to investigate the influence of soil-cement’s local yielding and failure on seismic performance by comparing it with the seismic response of the acrylic model. It was observed that several cracks were locally induced in the soil-cement model after the maximum input motion of 8.0 m/s2. The cracks were observed not only in transvers walls but also longitudinal walls. The relatively large cracks at longitudinal walls induced by the inertial force of the structure. However, no significant settlement of the weight was observed even if the normal and shear stresses in the DMWs were assumed to have locally reached the tensile or shear criteria of soil-cement.

Contributors:
Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
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 Record created 2017-01-18, last modified 2017-01-18


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