摘要
高层建筑物的持力层大多为基岩,基岩面附近若存在岩溶将给建筑物基础带来重大隐患。为了更好、更精确地探测岩溶,本文从基岩面附近的多岩溶探测入手,依据射线理论进行正反演模拟研究,讨论岩溶与基岩面的距离、围岩与岩溶速度差异大小以及观测系统对反演结果的影响。研究结果表明:当所有激发点和接收点都布置在基岩中时,水平排列的两个岩溶与基岩面相隔一定距离时可以分辨其空间位置;当岩溶距离基岩面较近时,两岩溶的中心距增加到一定程度时,也可以分辨多岩溶的存在;当条带岩溶水平方向贯穿到两个钻孔时跨孔地震CT可以准确探测;岩溶充填物与围岩的速度差越大,跨孔地震CT技术越易于分辨两个水平相邻的岩溶。
Most high-rise buildings are built on the bedrock,and the existence of karsts near the bedrock will bring major potential dangers to the foundation of the buildings.In order to accurately detect karsts,based on the ray theory,this paper carries out forward and inverse simulation studies to investigate the distribution of multiple karsts near the bedrock.After discussing the distance between the karst and the bedrock and the difference in velocity between the surrounding rock and the karst,the observation system on the inversion results are obtained.The results show that,when all the seismic sources and receivers are arranged in the bedrock,two horizontally layered karsts can beidentified when the distance between the two karsts and the bedrock increases to a certain extent;when the karsts are close to the bedrock and the center distance between the two karsts increases to a certain extent,the existence of multiple karsts can also be distinguished;cross-hole seismic CT can accurately detect the karst when it penetrates through two boreholes in the horizontal direction;the greater the seismic velocity difference between the karst and the surrounding rock,the easier the cross-hole seismic CT technology can distinguish two horizontally layered karsts.
作者
李卫卫
熊鑫
蒙爱军
Li Weiwei;Xiong Xin;Meng Aijun(Zhejiang Huadong Construction Engineering Co. Ltd, Hangzhou Zhejiang 311202, China;Zhejiang Engineering Survey and Design Institute Group Co. Ltd, Hangzhou Zhejiang 315012, China)
出处
《工程地球物理学报》
2022年第1期6-15,共10页
Chinese Journal of Engineering Geophysics
基金
浙江华东建设工程科研项目(编号:KY2019-HDJS-10)。
关键词
跨孔地震CT
基岩面
岩溶
正反演
cross-hole seismic CT
the bedrock
karst
forward and inverse simulation
