相似模型试验中土压力盒的标定试验  

Calibration of Earth Pressure Cell in the Calibration Chamber

作　　者：殷杰 YIN Jie(Shanghai Tunnel Engineering Quality Inspection and Testing Co.Ltd.,Shanghai 201109)

机构地区：[1]上海隧道工程质量检测有限公司,上海201109

出　　处：《土工基础》2023年第3期535-538,共4页Soil Engineering and Foundation

摘　　要：厂家油标所得土压力盒灵敏度K0与缩尺模型试验所需土压力盒灵敏度K之间存在差异。为提高微型土压力盒在地下结构模型试验中的测量精度,开展以V级土质地层相似材料为介质的土压力盒标定试验。试验结果表明:V级土质地层相似材料的最优标定上覆土层厚度为1~3cm,标定试验数据相关系数R2均大于0.99,土压力盒荷载~应变曲线的线性相关性较强且斜率相近。土压力盒标定试验中,其加载曲线线性较好,但卸载曲线存在一定滞回效应;标定所得灵敏度K略小于厂家给定的K0,因此在土压力盒使用前应视具体工作环境重新标定。The earth pressure cell sensitivity K in the actual working medium within reduced-scale model experiment is quite different from the sensitivity K0obtained from the manufacturer’s oil calibration environment.To improve the measurement accuracy of the miniature earth pressure cell in model tests of underground structures,a serial of calibration tests for earth pressure cell were carried out by using the similar materials from grade V soil stratum as the working medium.The test results show that the optimal overburden thickness is 1-3cm for the similar material of grade V soil stratum.The correlation coefficients R2for calibration test data are all greater than 0.99,and the load-strain curves of earth pressure cell with different overburden thicknesses are almost identical and linear.The unloading stress-strain curves,on the contrary,show hysteresis effect to a certain extent in the earth pressure cell calibration test.The sensitivity K obtained from the calibration test is slightly less than the K0provided by the manufacturer,which implies that the earth pressure cell should be re-calibrated before usage corresponding to the specific working environment.

关 键 词：土压力盒灵敏度 土质地层相似材料 标定试验 最优标定土层厚度 

分 类 号：TU413[建筑科学—岩土工程]