论文部分内容阅读
还原深部破裂岩体赋存地应力场演化过程,研究深部破裂岩体成因、形成年代及发展演化趋势。以岩体深部破裂特征为基础,结合构造演化、河谷演化及浅生改造理论,采用数值模拟方法,从地应力场变化及应变能释放角度解释深部破裂形成演化过程。研究表明,宽谷期大规模夷平作用使深部破裂赋存应力场发生根本性改变,与现今应力场趋于一致,但并未导致深部破裂形成;侧向卸荷是深部破裂形成的主要原因,侧向卸荷导致主应力减小,但方向维持不变,当侧向临空面出现,伴随应变能释放,NW向结构面拉张形成具有继承性的NW向深部破裂;错动带的差异回弹形成残余拉应力,导致NE向新生性深部破裂形成;深部破裂形成地质年代应大致对应于Ⅲ级阶地形成初期,即Q2晚期～Q3早期阶段。
Restore the evolution of stress field in deep-ruptured rock mass, study the genesis, formation age and development trend of deep-ruptured rock mass. Based on the deep rupture of the rock mass, and combining the theory of tectonic evolution, valley evolution and shallow regeneration, numerical simulation is used to explain the evolution of deep rupture from the perspective of the variation of geostress and the release of strain energy. The results show that the extensive rifting at broad valleys causes a fundamental change in the stress field of deep rupture and is consistent with the present stress field, but does not lead to the formation of deep rupture. Lateral unloading is the main reason for deep rupture , The lateral unloading leads to the decrease of principal stress, but the direction remains the same. With the appearance of lateral spontaneous surface, the NW-oriented structural plane expands to form inherited NW deep fracture along with the release of strain energy. The differential rebound causes the residual tensile stress, resulting in the NE neoclassical deep-rupture. The geological formation of deep-rupture should roughly correspond to the initial stage of Ⅲ terrace formation, that is, the late Q2 ~ early Q3 stage.