滑坡灾害应急处置中物探技术的作用——以湖北恩施州屯堡乡沙子坝滑坡为例

恩施州屯堡乡马者村沙子坝滑坡是该州地质灾害重点监测对象之一,属特大型土质滑坡。2020年6月8日入梅以来,连续的强降雨诱发马者村沙子坝滑坡体滑移,产生滑坡泥石流并堵塞清江形成堰塞湖。在接到上级执行防汛抢险任务的指令后,携带物探设备连夜立即赶赴现场,探测滑坡体厚度。这是一次临时性、突发性的应急勘探,没有时间搜集研究测区地质资料,也没有时间仔细研究设计方案,上级要求就一个快字。在滑坡体后缘及西侧共布设了6条高密度电法剖面,使用温纳装置,针对区内覆盖层厚度开展探测工作,为划定滑坡影响范围及估算滑坡体积提供数据支撑,根据探测结果同时结合现场地形地貌及区域地质资料,对区内覆盖层厚度进行了推断,同时在滑坡体后缘发现了一条疑似破碎带,为应急抢险指挥部的相关决策提供了科学依据。结果表明,地球物理勘探在地质灾害应急处置中可发挥积极的作用。

Application of Geophysical Prospecting in Emergency Responseto Landslide Disaster--A Case Study of Shaziba Landslide in Enshi,Huabei

The Shaziba landslide in Mazhe village is one of the key monitoring objects of geological disasters in Enshi prefecture.It is an extra large soil landslide.Since the plum rain on June 8,2020,due to continuous heavy rainfall,the Shaziba landslide in Mazhe village has been induced to slide,trigering landslides and mudslides and blocking the Qingjiang river to form a barrier lake.After receiving instructions from the superiors to perform flood prevention and rescue missions,We immediately rushed to the scene with geophysical equipments.There was no time to collect and study the geological data of the survey area,and no time to study the design plan carefully,the leadership requires only one word,speed.A total of 6 high-density electrical methods were installed on the trailing edge and west side of the landslide body.The Wenner method was used to cover the area.Exploring the thickness of the layer to provide data support for delineating the impact area of the landslide and estimating the volume of the landslide.Based on the detection results,combined with the site topography and regional geological data,the overburden thickness in the area was inferred,at the same time,a suspected fracture zone was found at the rear edge of the landslide,providing information for the relevant decision-making the scientific basis.It shows that geophysical prospecting can play an active role in the emergency response to geological disasters.