基于微动勘探技术的断裂带堆积层滑坡滑动面提取分析

Extraction and analysis of landslide sliding surface of the fault zone accumulation layer based on fretting exploration technology

选择舟曲县东山镇牙豁口滑坡作为研究对象,采集滑坡体的微动信号进行后期处理,通过与钻孔数据对比发现,单点反演获得的S波速度结构与视S波速度剖面均能清晰显示滑动面位置.微动探测结果显示新滑坡的滑动面埋深在10~35 m,平均埋深为9.1 m,钻孔揭露新滑动面平均埋深为10 m;微动探测结果显示老滑坡滑动面埋深在15~52 m,平均埋深为19.6 m,钻孔揭露新滑动面平均埋深为20 m.测试不同的采集时间、不同频率的检波器对探测深度和精度的影响,发现对该类滑坡应选取三重圆台阵, 4.5 Hz检波器, 90 min的采集时长.表明微动勘探方法是探测断层破碎带堆积层滑坡滑动面的一种有效方法,对于白龙江流域广泛分布的断层破碎带堆积层滑坡滑动面的探测,具有很好的技术优势以及应用前景.

The Yahuokou landslide in Dongshan Town,Zhouqu County was selected as the research object,and the micro-motion signal of the landslide was collected and post-processed.A comparison with borehole data found that the S-wave velocity structure and apparent S-wave velocity profile obtained by single point inversion could clearly show the position of the sliding surface.The micro-motion detection results showed that the buried depth of the sliding surface of the new landslide was 10-35 m,with the average buried depth being 9.1 m,while that revealed by drilling was 10 m.The fretting detection results show that the buried depth of the old landslide sliding surface to be 15-52 m,with an average buried depth of 19.6 m,while that revealed by drilling was 20 m.The influence of geophone was also tested with different acquisition times and frequencies on the detection depth and accuracy,and it was found that in this kind of landslide a triple circular array,a 4.5 Hz geophone and a collection time of 90 min should be selected.This study showed that the microdynamic exploration method,being of a good technical advantage and application prospect,could be an effective method for detecting the landslide slip surface of the fault fracture zone accumulation layer that is widely distributed in the Bailongjiang River basin.