摘要
以宜巴高速公路上的彭家湾上覆堆积体及其下伏软硬岩互层构成的缓倾顺层复合介质边坡为例,在分析边坡滑移破坏形成与演变的基础上,探讨地下水力作用对边坡稳定性的影响机制。通过对边坡中水力作用特性进行分析,认为地下水力作用主要包括堆积体层处的动水压力和软硬岩层处的后缘张裂缝静水压力、潜在滑动面的扬压力及动水压力,堆积体层处的水力大小与岩层面的倾角有关,软硬岩层处的水力大小均取决于后缘张裂隙的充水高度;推导出不同滑动面下决定边坡稳定性的张裂隙临界充水高度和临界降雨强度的表达式,建立边坡滑移破坏判据,认为当张裂隙充水高度或临界降雨强度达到临界值后,边坡在水力作用下发生滑移破坏。通过计算和分析,验证公式的合理性,结果表明边坡滑移破坏的实现取决于外界水力作用的触发,地下水力作用下边坡稳定性系数的降低主要与张裂缝中的静水压力和滑动面上的扬压力有关,而动水压力的影响很小。
An example taken from Yiba highways Pengjiawan slope（landslide） with overlying accumulation and inter-beddings of soft and hard rock,based on analysis of formation and evolvement of slope（landslide） bedding-slip failure due to hydraulic drive,the effect mechanism of groundwater on rock slope stability is discussed. By analysizing the effect of groundwater hydraulic pressure characteristics on slope,it is pointed out that groundwater hydraulic pressure including the dynamic water pressure of accumulation layer,and the fissured hydrostatic tension,the uplift force on potential sliding surface and the dynamic water pressure of inter-beddings of soft and hard rock. The dynamic water pressure of accumulation layer associated with obliquity of rock layer,and hydraulic pressure of inter-beddings of soft and hard rock are all decided by water filling at the back edge of the fissure;equations for calculating the critical water highness in the splay fracture and the critical rainfall intensity are developed. The bedding-slip failure criterions of rock slope are put forward,that is,the slope will lose its stability once the water highness of the splay fracture or the critical rainfall intensity reaches to a critical value. Through calculation and analysis,the proposed formula is proved to be reasonable,and it is also concluded that the decrease in slope stability under the influence of groundwater is mainly related to hydrostatic pressure and uplift force instead of its penetration.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2014年第A02期3766-3775,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
西部交通科技项目(2009353342540)
关键词
边坡工程
水力作用
缓慢顺层
复合介质边坡
稳定性
滑移破坏
slope engineering
hydraulic pressure
gently inclined bedding
compound rock mass slope
stability
sliding failure
