Numerical computation of anti-liquefaction effect of lattice-type cement-mixed soil countermeasure

Abstract

Continuous soil-cement wall confinement method to resist liquefaction is a new kind of process. However, whether it also has a good effect on anti-liquefaction or not needs to be urgently answered for earthquake engineering. Quiet boundary is adopted on the lateral face while free field boundary is employed at the bottom. Byrne model on dynamic pore water pressure generation is accepted and natural seismic wave EI Centro whose peak acceleration is adjusted to 0.2 g in proportion is used for input. A double-layer foundation with sandy soil in the upper portion while clay soil in the lower part is chosen as the calculation model, which is 30 m in length and 20 m in width. The groundwater level is on the ground surface. Excess pore water pressure rate is considered as a liquefaction index in the three-dimensional non-linear earthquake response computation. The anti-liquefaction effectiveness and its influencing factors, such as confinement element area are studied. For the natural double-layer foundation, it is liquefied when the excess pore water pressure rate reaches 1.0 under the seismic load. Under the same earthquake load, the peak excess pore water pressure reduces to 0.56 after adopting reinforcement of the continuous soil-cement wall, which is 46% lower than before. It indicates that continuous soil-cement wall confinement method can attain the purpose of anti-liquefaction. Accordingly, it can be a sort of engineering measure to carry on the anti-liquefaction foundation treatment.

Keywords

lattice-type cement-mixed soil countermeasure / anti-liquefaction / excess pore pressure ratio / the smallest lattice area

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