综合物探在高家湾滑坡群前缘裂缝探查中的应用

Application of Integrated Geophysical Exploration in the Cracks Detection of the Front Edge in Gaojiawan

2011~2012年在青海省西宁市乐都区高家湾滑坡群中的H 1滑坡后壁及后缘发育了长约500 m的拉张裂缝,至2016年1月,该裂缝增加到950 m,同时,H 2-1滑坡前缘北侧约100 m处地表新增鼓胀裂缝,使高家湾村局部民房出现裂缝和变形,严重威胁高家湾村村民及滑坡体中后缘的兰新高速铁路张家庄隧道等基础设施。针对高家湾滑坡群前缘裂缝的展布特征及形成原因,开展了高密度电法、地质雷达及土壤测氡的调查。土壤测氡结果显示,滑坡群前缘断层活动性较弱,排除了裂缝的“断裂构造”成因,根据高密度电法和地质雷达探测结果,查明了滑坡前缘的17条裂缝发育展布特征,结合已查明的滑坡体滑动面及剪切口位置,推断前缘裂缝是由于滑坡体深部未贯通的潜在滑动面间应力传递作用形成,为高家湾滑坡前缘裂缝综合防治提供了基础资料和依据。

From 2011 to 2012,a 500 m long crack was developed in the rear and rear edges of the H 1 landslide in the Gaojiawan landslide group in Ledu district,Xining city,Qinghai province.By january 2016,the crack increased to 950 m,and at the same time,H 2-1 newly bulging cracks on the surface of the front side of the landslide at about 100 m caused cracks and deformations in some houses in Gaojiawan village,seriously threatening the infrastructureof the villages of Gaojiawan,the Lan-Xin high-speed railway and Zhangjiazhuang Tunnelin the back edge of the landslide.Aiming at the distribution characteristics and formation causes of the front edge cracks of Gaojiawan landslide group,the investigation of high-density resistivity method,geological radar and radon survey was carried out.The results of radon surveydisplaythatthe fault activity of the frontal fault of the landslide group is weak,and the cause of the“fracture structure”of the crack is excluded.According to the results of high-density resistivity method and geological radar,the development of 17 cracks andcharacteristics in the leading edge of the landslide is ascertained,combined with the identified sliding surface of the landslide body and the position of the shear outlet of landslide,it is concluded that the leading edge crack is formed by the potential transfer between the sliding surfaces of the landslide body,which provides for the comprehensive prevention and control of the crack in the front edge of the Gaojiawan landslide and basic information.