液化砂土流态运动模型试验系统的研制及应用

液化后的砂土具有流体的特性，在一定的初始条件下会发生侧向流动。砂土液化流动的模型试验系统包括自制的水平单向震动台、可倾斜的透明模型槽、孔压量测仪、高速摄像监控装置等主要装置。在模型试验中，首先利用水平单向振动台使砂土达到液化，然后将模型槽倾斜一定角度使液化后的砂土产生侧向流动，同时通过摄像监控装置对液化砂土的流滑构型特性进行捕捉，并对砂土地震液化的土体流动速度、流动范围和流动冲击力等流体动力学特性进行试验研究。验证试验表明：该模型试验系统可在较短时间内，有效地激发饱和砂土达到液化状态，并清晰地捕捉到液化砂土在不同坡度下流态化运动的构型特征。该试验系统可用于区域性砂土地震液化流体动力学特性的基础性研究，有助于完善地震液化试验模拟方法，为工程场地抗震设计以及灾后重建选址提供科学试验手段。

Development and Application of a Model Test System for Liquefaction-induced Sand Flow

In liquefied sands, lateral spreads and flows will occur under certain initial conditions. The model test system for liquefaction-induced flow is composed of a shaking table capable of vibrating in horizontal direction, a tilted transparent box, pore water pressure measuring system and a high-speed video monitoring system. First of all, liquefaction of sands will be triggered by using the shaking table. Then the model box is tilted to a certain angle to provide the lateral flow of the liquefied soil samples. At the same time, the high-speed video monitoring system is used to capture and record the motion characteristics of sand flow. Furthermore, experimental researches are carried out in order to investigate fluid dynamic characteristics including velocity, distance and impact force. A set of model tests were performed and the configurations of liquefied sands were captured by monitoring system clearly. In summary, the seismic liquefaction analysis theories could be improved by the results of the test. Some scientific references are provided for seismic design of engineering projects and safety assessment of site selection in reconstruction after earthquake disaster.