岩质高边坡卸荷带形成及其工程性状研究

首先针对边坡开挖或河谷下切的卸荷过程, 讨论了边坡应力场的分布, 提出了边坡二次应力的驼峰应力分布规律。在此基础上, 分析了伴随边坡二次应力场的形成, 岩质高边坡卸荷带的形成机理。进-步, 结合三峡船闸高边坡的开挖和监测实践, 讨论了卸荷带的工程地质意义及其力学性状表现。最后, 利用本文的基本观点, 对三峡船闸高边坡卸荷带进行了合理的数值模拟研究。

FORMATION MECHANISM OF UNLOADING FRACTURE ZONE OF HIGH SLOPES AND ITS ENGINEERING BEHAVIORS

The unloading fracture zone of high rock slope is very significant in rock slope engineering. In this paper, firstly, the basic regularities of secondary stress distribution resulted from slope excavation and river during cutting are studied, and then a general model for formation mechanism of unloading fracture zone is suggested. It reveals that the unloading fracture can be discriminated into two basic types, i. e. tensile fracturing and shear relaxing. Moreover, the engineering behaviors of the unloading fracture zone and its mechanical significance are discussed. On this basis, we propose a numerical simulation approach to the unloading fracture zone in slope excavation. Finally, as a typical example, the distribution of unloading fracture zone of high slope at Three-Gorges shiplock is figured out and its progressive development process is simulated numerically.