离心试验砂雨法试样制备研究

Study on Sample Preparation with Sand Pourer in Centrifuge Test

全国岩土工程离心模拟平行试验之一,是砂土模型地层的制备。砂土试样制备主要通过相对密度进行控制,试验中采用福建标准砂,采用砂雨法制备砂土地层和网眼式与鸭嘴式出砂头,通过对试验结果分析得到落距-相对密度标定曲线,并设定土体目标密度(55%和75%),验证曲线的可靠性;同时,考察制备模型地基的相对密度在空间上的均质性。出砂头的孔径大小、出砂量、出砂头水平移动速度对相对密度的影响,还需进一步研究。

The preparation of sand modeling stratum is included in the national geotechnical centrifuge model test in parallel.In the test,the sand sample preparation was primarily controlled through relative density,Fujian standard sand was adopted,and sand stratum was prepared by sand pourer with mesh and duckbill type sanding head.Depending on the test results analysis,the drop distance vs.relative density calibration curve was developed and,with the setting of soil mass＇ target density （55％ and 75％）,the reliability of the curve was validated; simultaneously,on a certain spatial scale,the homogeneity of relative density of the prepared modeling foundation was investigated.However,it is required to be further studied that how the Pore size,outflow,horizontal movement speed of the head affect the relative density.