土工离心模型试验大流量供水系统设计研究

Study on design of large flow water supply system for geotechnical centrifugal model experiment

当前的土工离心模型试验的几种供水方式存在流量小、不稳定、测不准、造价高等问题,针对这些问题,研发了一套离心机大流量供水及控制系统。系统主要包括:上层供水系统、下层储水和供水系统、排水系统以及流量量测控制系统。系统采用环形水箱作为二级储水、供水箱,利用离心机旋转产生的巨大离心力驱动水流向模型试验箱内供水,同时采用离心实验专用孔隙水压力传感器来辅助监测流量,通过计算机控制布置在重力场与低离心力侧的电控阀门来实现流量的分级控制。该系统当前管路在50 g离心力场下持续供水最大流量可达8 L/s,100 g离心力场下理论最大供水流量可达100 L/s,结合不同的模型试验箱布置,系统可开展降雨、库水位变动导致的滑坡、溃坝、枢纽泄洪消能等需水离心模型试验研究。

At present,some problems,such as small flow rate,unstable flow rate,low measurement accuracy,high cost,etc.,are there in several water supply modes of geotechnical centrifuge model experiment,for which a set of large flow water supply and control system for the centrifuge is developed.The system mainly consists of upper-level water supply system,lower-level water storage and supply system,drainage system and flow measurement system,while annular water tank is adopted as the secondary water storage and supply tank,and the huge centrifugal force generated by the rotation of the centrifuge drives the water flow into the model experiment chamber.Meanwhile,special pore water pressure sensors for the centrifugal experiment are used to assist in monitoring the rate of flow,while the stepping-control of the flow rate is realized by means of controlling the electronic control valves arranged in gravity field and at the low centrifugal force side by computer.At present,the maximum flow rate of continuous water supply of the system pipeline under the centrifugal field of 50 g can reach 8 L/s,while the theoretical maximum water supply flow rate for the centrifugal field of 100 g can reach to 100 L/s.In combination with different layouts of the model experiment chamber,the experimental study of the centrifugal model experiment requiring water for the landslide and dam failure caused by rainfall and fluctuation of reservoir water level as well as the flood discharge and energy dissipation of water control project,etc.,can be carried out by this system.