• 空间与固体地球物理 •

### 基于双衬套理论求解地壳岩石应变传递系数的探讨

1. 中国地震台网中心, 北京 100045
• 收稿日期:2016-10-22 修回日期:2017-06-17 出版日期:2017-08-20 发布日期:2017-08-20
• 作者简介:张凌空,男,1962年生,吉林长春市人,学士,高级工程师,长期从事钻孔应变和地形变等地震前兆方法的观测研究.(E-mail:zhll1023@163.com)
• 基金资助:

国家自然科学基金（41330314）资助.

### Discussion on solution of crustal rock strain transfer coefficient based on double bush theory

ZHANG Ling-kong, NIU An-fu

1. China Earthquake Networks Center, Beijing 100045, China
• Received:2016-10-22 Revised:2017-06-17 Online:2017-08-20 Published:2017-08-20

Abstract:

Component borehole strain observation is the main method for strain relative measurement of crustal rocks in today's world. Due to strain should be transferred in three layers of media, such as rock, cement and instrument steel tube, herefore, it is different from the non porous rock. Additional strain field exists in the observation system. The measured area strain and shear strain are not equal to the true strain of the surrounding rock. The correlation of a transfer coefficient is required. So it is very necessary to analyze the transfer process of the external strain to the probe. Firstly, according to the double bushing theory, the calculation formulas of rock area strain and shear strain transfer coefficients(βm, βj)are derived under the action of plane stress. Respectively, the influence mechanism is discussed. And give the relevant change rule curve and quantitative index. The calculation formula of area strain transfer coefficient(βm3)under three-dimensional stress is given. The relationship between βm3 and βm and its application range are discussed. The shear strain is not affected by the vertical stress. Transfer coefficient is still βj. Through the observation value and the solution transfer coefficient, finally, the real stress variables of crustal rocks can be determined. This work provides help for the physical interpretation of the observed data and the optimization of the instrument design and installation parameters.