The strata along the upper-middle lake water system connectivity project of Huama-Lake are mainly composed of Yanshanian monzonite and Triassic sedimentary rock.The rock mass is strongly weathered and the fractures are devel-oped.The height of the excavation slope of the connecting channel is from 7 m to 75 m,and the slope stability problem is prominent.In this paper,based on the slope instability occurred in the excavation construction process,the slope in-stability mechanism,deformation and failure characteristics and geological conditions are systematically analyzed,the slope instability mode is divided into four types by using the principle of engineering geological analysis:homogeneous or quasi-homogeneous creep slip-tensile cracking type(Ⅰ),sliding-tensile cracking type of gentle-middle dip slope(Ⅱ),shear-sliding type of the block structure wedge block(Ⅲ)and composite type(Ⅳ).and the countermeasures are put for-ward according to the main control factors of each type of instability.The slope ratio of the all-strength weathered bedrock is 1∶1～1∶0.75,and theⅠslope should not be too steep,so spray protection should be carried out in time.For typeⅡslope,the anchor(cable)system is used to strengthen and the locking treatment.For typeⅢslope,the unstable block is mainly supported in time.For typeⅣslope,the key instability modes should be found out and corresponding measures should be taken according to geological conditions.According to different geological conditions,different excavation slope ratio and bolt support measures are adopted to ensure the safety of excavation slope and achieve good results.It can provide reference for similar slope engineering investigation,design and construction.
关键词
边坡失稳模式/蠕滑-拉裂型/顺向坡滑移-拉裂型/楔形体剪切-滑移型/复合型
Key words
the slope instability mode/creep slip-tensile cracking type/sliding-tensile cracking type of the dip slope/shear-sliding type of the wedge block/composite type/countermeasures
维普
万方数据