地下洞室松动区模型及其在反馈分析中的应用

在地下洞室的开挖过程中，由于钻孔、爆破以及其它施工操作的影响，将会在洞室周围的岩体中产生出一个松动区．在这一区域中的岩体将会呈现出强烈的非线性特征．这种性征对围岩的位移有重要的影响，在基于位移监测所进行的反馈分析中必须加以考虑，否则会引起很大的误差．笔者在介绍了前人的几种松动区模型之后，提出了一种更适合于地下厂房复杂洞室群位移反馈分析的松动区模型，位移相关松动区模型（DDM）的概念，并介绍了它在我国最大的地下水电站地下厂房施工中的应用．

Modelling and Application in Back Analysis for the Loosening Zones in the Surrounding Rock Mass of the Underground Powerhouse

In the underground engineering, during the excavation of an opening, drilling, blasting and oth-er construction operations will result in a zone so called loosened zone, in which the Young's modulus will re-duce nonlinearly. This will have important influence on the displacements in the surrounding rock mass around the opening and must be taken into consideration in the numerical mode1ing and back analysis to the openings based on the monitoring displacements. This paper presents a practical model, the so-called Displacement-De-pendent Model (DDM), to allow a simple mathematical representation of the zones in the back analysis for the excavation of a large underground power house complex.