房山贾峪口土洞崩塌危岩带特征及稳定性分析

Analysis of Characteristics and Stability for Jiayukou Soil Cave Unstable Rock Belts in Fangshan

贾峪口土洞崩塌灾害隐患点位于房山区佛子庄乡贾峪口村北侧,坡顶处存在两条近东西走向的危岩带,坡顶及坡面处植被发育较好,坡顶处未发现明显后缘裂缝,整体稳定性较好,但危岩带内大面积基岩裸露,受雨水冲刷及差异风化等作用影响,表面较为破碎,呈块状、碎裂状,岩腔、裂隙发育。通过勘查掌握了该危岩带及危岩体的基本特征,分析了其主要破坏方式及危岩的运动特征,并对其稳定性进行了定性分析与定量计算。结果表明,危岩带及危岩体在暴雨、地震等工况条件下处于不稳定状态,具有发生崩塌灾害的隐患。针对危岩带的特点,提出危岩清削+主动防护网+被动防护网的治理措施,较为有效地解除了该区域的安全隐患。

Due to concentrated rainfall and heavy rain,the possibility of geological disasters in the western mountainous areas of Beijing has increased dramatically.Jiayukou collapse hazard points are located in the north of Jiayukou village in Fozizhuang of Fangshan district.Two unstable rock belts are located on the top of the slope,which have huge potential safety problems.As their high location,potential collapse hazard and high risks,unstable rock belts will directly affect the safety of people in Jiayukou village.Through on-site survey,it finds that the vegetation is developed well on the surface and top of the slope,so obvious trailing edge fracture were not found at the top of the slope,and the overall stability of the slope was satisfactory.But large areas of bedrock were exposed,broken and fractured by rain wash and differential weathering.This paper analyzed the basic characteristics of unstable rock belts and typical dangerous rocks in this area by using various means such as surveying,mapping,trenching and sampling test.The main damage modes and the movement characteristics of dangerous rocks were analyzed and their stability was qualitative analyzed and quantitative calculated.The unstable rock belts and the typical dangerous rocks were in unstable state under the condition of rainstorm and earthquake,which are the hidden danger of collapse disaster.According to the characteristics of unstable rock belts,the treatment measures of cleaning dangerous rock+active protective net+passive protective net were put forward,which can effectively eliminate the safety risks in this area.