巴东组易滑地层异性层面细观损伤演化机理及本构模型研究

Research on bedding planes between two different rock types of sliding-prone stratum in Badong formation is essential to stability evaluation of rock slope and mechanism investigation of geological hazards in Badong formation. Three typical bedding planes between two different rock types were chosen as subjects to be investigated. Based on studies of lithofacies palaeogeography and sedimentary environment evolution of Badong formation, combined sedimentary feature of wall rocks of the typical bedding planes between two different rock was determined by techniques of X ray diffraction, chemical analysis and scanning electron microscopy. Microscopic techniques including three dimensional laser scanning and scanning electron microscopy (SEM) were used to explore the meso-damage mode of wall rock surface morphology of bedding planes between two different rocks by conducting indoor shear test. The whole process of meso-damage evolution and influences of wall rock combination & stress level on meso-damage evolution of wall rock surface morphology of bedding planes between two different rocks were analyzed in PFC3D numerical simulation to reveal the interaction mechanism of two wall rocks of the typical bedding planes between two different rock types. Based on the meso-damage evolution mechanism,damage variable was defined and its evolution process was analyzed to build the damage constitutive equation of bedding planes between two different rocks in Badong formation. The built constitutive model was then applied in the stability investigation of typical soft and hard interbedded rock slope in Badong formation by secondary-developing of 3DEC software.

巴东组易滑地层异性层面（不同岩性岩层之间的接触面）研究是该组地层岩体稳定性及地质灾害致灾机理研究的基础。选取巴东组易于发生滑动破坏的三类典型异性层面为研究对象，在巴东组地层岩相古地理及沉积环境演变规律研究的基础上，采用X光衍射、化学分析及电镜扫描方法，确定典型异性层面壁岩沉积组合特征；开展巴东组典型异性层面剪切损伤演化试验，结合三维激光扫描和SEM电镜扫描等细观技术，分析异性层面壁岩表面形态细观损伤演化模式；同时开展三维颗粒流PFC3D数值试验，研究异性层面壁岩表面形态细观损伤演化全过程，分析巴东组异性层面壁岩表面形态损伤演化与壁岩组合及应力水平的相关性，进而揭示巴东组异性层面两侧壁岩交互作用机理。基于巴东组典型异性层面损伤演化机理，定义损伤变量并分析其演化规律，提出巴东组异性层面损伤本构方程。通过3DEC二次开发，将所建立的异性层面损伤本构模型用于巴东组典型软硬互层岩质高边坡稳定性研究。

三峡库区巴东组异性层面（不同岩性岩层之间的接触面）研究是该组地层岩体稳定性及地质灾害致灾机理研究的基础。选取三峡库区巴东组易于发生滑动破坏的三类典型异性层面为研究对象，在巴东组地层沉积环境演变规律研究的基础上，研究了壁岩微观特征及其对异性层面剪切特性的影响研究。考虑壁岩组合、法向应力及表面形态的影响，开展了异性层面相似材料模型试验，基于试验数据建立了异性层面抗剪强度准则，并研究了锯齿形异性层面剪切破坏规律。进行了巴东组典型天然异性层面剪切演化试验，研究了异性层面壁岩表面形态剪切演化模式；同时开展了三维颗粒流PFC3D数值试验，研究了异性层面壁岩表面形态细观损伤演化全过程，分析了巴东组异性层面壁岩表面形态损伤演化与壁岩组合及应力水平的相关性，进而揭示了巴东组异性层面两侧壁岩交互作用机理。