PHISICAL PROPERTLES OF FLUIDIZED SOIL AND PREDICTION OF LIQUEFIED GROUND DEFORMATION

在第一部分的研究中，膨胀和粘度特性的各种液化砂和玻璃珠颗粒进行了研究。采用上向渗流仪模拟液化条件。本文第二部分用数值方法预测了水冲过程中的土性：1.膨胀比V/V_O与水的上升流速V成正比，可用下式表示; V/V_O=1+δ（v-v_c），其中V为液化体积，V_O为固态体积，δ为膨胀系数，v_c为临界水力梯度下的流量。该方程在形式上类似于液体的热膨胀，并且v_c被认为对应于液体的熔点。(1)用粘度计测量液化土颗粒的流变性，得到宾汉型粘度曲线。(2)粘度系数η可以用η = exp（A/v）表示，其中A是常数。由于该方程与Andrade粘度方程相似，因此渗流速度v与液体温度对应。3.在CIP（cubic interpolated pseudoparticle）格式基础上引入Bingham粘度，对CIP格式进行了改进。利用该方法对液化地基模型进行了振动台试验模拟。结果表明，该方法能较好地模拟液化层的变形特性。4.采用宾汉模型模拟液化土的变形特性。用数值方法验证了液化地基流动变形的相似律。数值方法很好地再现了实验结果的变化趋势以及所提出的相似律。

In a first part of the study, the expansion and viscosity characteristics were investigated on various kinds of liquefied sands and glasss beads particles. Upward seepage flow apparatus was used in order to make liquefied conditions. In a second part, an attempt was made to predict the soil behavior during liquefaction-indeuced flow by using a numerical method.1.Expansion ratio, V/V_O, was proportional to the upward flow rate of water v and may be expressed by the equation ; V/V_O=1+δ(v-v_c), where V is liquefied volume, V_O is solid state volume, δ is the coefficient of expansion, and v_c is the flow rate at the critical hydraulic gradient. This equation is similar in the form to thermal expansion of a liquid, and v_c is considered to correspond to the melting point of a liquid.2.(1) Rheological measurements of liquefied soil particles with the viscometer produced Bingham-type viscosity curves. (2) The viscosity coefficient η may be expressed by η∝exp(A/v), where A is constant. Because this equation and Andrade-viscosity equation are similar, the seepage water flow rate v is considerd to correspond to the temperature of a liquid.3.The CIP (cubic interpolated pseudoparticle) based numerical scheme was modified by incorporating the Bingham viscosity. The method was used to simulate shaking table tests on a liquefied subsoil model. From the results, the numerical method was found to satisfactorily reproduce the deformation behavior of liquefied layer.4.Bingham model was used to represent the behavior of liquefied soil. A numerical method was used to verify the similitude law for flow deformation of liquefied ground. The numerical method repreduced the tendency of the experimental results as well as the proposed si militude law very well.