分层介质中微型土压力盒匹配误差分析

在岩土工程领域,为了研究分层介质与微型土压力盒的相互作用对量测误差的影响,结合匹配误差理论,通过微型土压力盒的室内砂土标定试验,探讨了分层介质中微型土压力盒的埋设方法及微型土压力盒下部填砂厚度对标定曲线的影响.试验结果表明:对于单膜电阻式微型土压力盒应用于分层介质中土体应力监测时,使其受压面朝向平均粒径较小的均匀介质放置时,能够有效减小量测误差.对其进行室内标定时,随着下部填砂厚度的增加,匹配误差逐渐减小,当填砂厚度不小于压力盒直径的4倍时能够有效提高室内标定精度.

Matching Error Analysis of Micro Earth Pressure Cell in Layered Media

In order to study the influence of the interaction between layered media and micro earth pressure cell on the measurement error,combining with the matching error theory,the influence of the embedding method of micro earth pressure cell in layered media and sand filling thickness at the bottom of micro earth pressure cell on the calibration curve were discussed through laboratory sand calibration test of micro earth pressure cell in the field of geotechnical engineering.The test results show that when the single-membrane resistance micro earth pressure cell is applied to soil stress monitoring in layered media,the measurement error can be effectively reduced by placing the pressure surface of the micro earth pressure cell towards uniform media with smaller average particle size.During the indoor calibration,with the increase of the thickness of the lower sand,the matching error is gradually reduced.When the thickness of the sand filling is not less than 4 times the diameter of the micro earth pressure cell,the accuracy of the laboratory sand calibration can be effectively improved.