关键词: 土压力, 微型土压力盒, 标定试验, 离心模型试验, 数据采集系统, 接线方法

Abstract: Earth pressure is an important test parameter in centrifugal model experiment, it can be affected by many factors such as the performance of the earth pressure cell, the stability of the centrifuge data acquisition system and the external environment, so accurate measurement of earth pressure is hard to obtain. As a component of earth pressure measurement, the performance of earth pressure cell can directly affect the accuracy of earth pressure measurement. To get more accurate test data, two common resistance strain type earth pressure cells are selected to test using the centrifuge data acquisition system. The calibration test shows that two cells’ calibration coefficients of sand are smaller than the factory calibration coefficients. The calibration coefficients of sand for the type I are 64.75% lower than the factory calibration coefficients, and that of type II are 18.77% lower. The coincidence degree between type II earth pressure cell and factory data is better than that of type I earth pressure cell. In a centrifugal model test for measuring the lateral earth pressure distribution of counterfort retaining wall with wall height of 10-30 m, type I earth pressure cell has some shortcomings, such as data distortion measured by factory calibration coefficients, poor stability and low sensitivity, compared with the type II cell. The results of calibration test and centrifugal test show that type II cell with self established data acquisition system has better performance than type I with static strain data acquisition system.

Key words: earth pressure, miniature earth pressure cell, calibration test, centrifuge model test, data acquisition system, connection method