断裂带隧道岩体应力场变化与地表非连续沉陷过程研究

Ground surface discontinuous subsidence deformation caused by tunnel engineering construction in fault zone is the key scientific problem of environmental geotechnical engineering. Based on the essential internal cause -- the change of in-situ stress field, it is a difficult point to recognize the discontinuous surface subsidence caused by the opening, closing and slip of the fault. Due to the lack of observation and experimental data, quantitative research is rarely seen.. This project based on a large number of engineering monitoring, indoor and outdoor experimental data accumulation, to analyse stress change and structural surface development process, create a fracture slide and propagation simulation algorithm with structural plane model by displacement discontinuity method(DDM); understand the variation law of ground stress field and displacement field around the fault in the process of tunnel construction; reveal the mechanism of surface discontinuous subsidence caused by in-situ stress variation; and explore the inversion method of the stress field and displacement field in the area without measured data.. The project intends to enrich the stress field deformation theory in tunnel construction, which provides a scientific basis for the evaluation method of ground deformation and technological innovation.

断裂构造带隧道等地下工程建设造成的地表非连续沉陷变形是环境岩土工程学亟待解决的关键科学问题，从地应力场变化这一本质内因出发认识断层的张开、闭合与滑移等引起的地表非连续沉陷成为突破的难点，因观测、实验数据缺乏，定量研究更是鲜见。. 本项目基于大量工程监测和室内外实验数据积累，分析应力变化和结构面发展过程，创建含结构面模型的断裂滑移与分步扩展的位移不连续模拟算法（DDM）；认识隧道建设过程中断层周边地应力场、地层沉陷位移场变化规律；揭示地应力变化引起的地表非连续沉陷机理；探索无实测数据地段应力场与位移场的反演方法。. 项目拟充实断裂带隧道建设应力场变形理论，为地表变形测评方法和技术创新提供科学依据。

断裂构造带隧道等地下工程建设造成的地表非连续沉陷变形是环境岩土工程学亟待解决的关键科学问题，项目从地应力场变化这一本质内因出发认识断层的张开、闭合与滑移等引起的地表非连续沉陷，取得了以下成果：. （1）建立了三维复杂构造应力场DDM数值方法。针对断层构造发育特点，建立DDM数值方法在有限边界、粘弹性介质条件下的控制方程组和非线性控制变量的循环迭代计算方法，有效解决了断层带岩体非线性变形特性的模拟计算问题。. （2）随机节理发育岩体剪胀机理及评价方法研究。研究解明了裂隙岩体在压载条件下体积扩容的力学成因，有效解决了考虑裂隙面非线性变形特性、岩块弹塑性变形、节理断裂扩展等复杂条件下裂隙岩体体积应变（剪胀）的三维DDM数值模拟方法. （3）提出了断裂构造区初始地应力场反演方法。基于DDM对断层产装和断距的模拟，建立了无实测地应力条件下的地应力场方法方法。. （4）揭示了地应力变化引起的地表非连续沉陷机理。研究了断层破碎带围岩地压特性，以及断裂扩展导致的地层变形，继而提出了断层带隧道支护控制方法。. 项目充实了断裂带隧道建设应力场变形理论，可为地表变形测评方法和技术创新提供科学依据。