分量式钻孔应变仪监测的附加应变场面应变分析

Analysis on the plane strain of the additional strain field monitored by component-type borehole strain meter

根据钻孔加衬模型和应变理论,得出分量式钻孔应变仪观测值不等于实际的线应变,但相互垂直的应变元件观测值之和与面应变成正比例。利用四分量钻孔应变仪的"自检"功能,对观测数据进行校正。以漳州地震台分量式钻孔应变仪资料为例,计算校正系数。校正前后的残差分析结果表明,校正效果明显。

According to the lined borehole model and strain theory, we derived that observation value of component-type borehole strain meter is not equal to actual line strain, but sum of observation values of strain sensors laid vertically each other is proportional to the plane strain. The observation data is decomposed into long trend part and part of high frequency tide. Accordingly, the dynamic strain field can be decomposed into a relatively stable background strain field and a real-time changing additional strain field. We make correction for observation data using the ＂self test＂ function of 4-component borehole strain meter. The correction coefficients are calculated with data of component-type borehole strain meter at Zhangzhou Seismic Station. Residual analysis before and after correction shows the effect is obvious.