【摘要】 河流被填埋后形成的暗浜是城市基础工程建设的重要安全隐患.因填埋物成分复杂,结构松散,未探明的暗浜在地铁盾构施工、地下车站深基坑开挖中可能引发坍塌等安全事故.本文以宁波轨道交通暗浜勘查为例,研究二维微动剖面探测法、瞬态瑞雷波法、高密度电法三种物探方法探测暗浜的有效性.结果表明:这三种物探方法都暗浜具有较好的探测效果,显示暗浜填埋区异常形态总体一致,与钻探揭示的暗浜底界深度,误差分别小于4%、7%、7%,能满足工程精度要求.二维微动剖面探测和瞬态瑞雷波法抗干扰能力优于高密度电法,更适用于城市工程勘察,而采用天然场源(微动)的微动探测法则在闹市区强干扰环境下的轨道交通勘察中更具技术优势.以上述三种物探方法为主、配合地质调查及少量钻探,是实现暗浜"无损"、高效探测的主要途径.更多还原

【Abstract】 Underground silt,due to complex and loose compound,is a potential threat in urban infrastructure.Those underlying silts will contribute to serious accidents like collapse in building subway and underground station.This paper cite the detection of silt in Ningbo’s rail to illustrate effectiveness of these three kinds of detecting silt,that is,2D Microtremor survey,transient Rayleigh wave,high density resistivity.The results show that these three geophysical methods have better detection results,the abnormal shape are basically the same,and the depth of bottom boundary is consistent with drilling exploration.Compared with high density resistivity,Micro-tremor survey and transient Rayleigh wave can adapt to urban exploration for its powerful anti-jamming performance.As a nondestructive,high efficiency,economical and reliable means of detecting underground silt,geophysical methods is especially suitable for heavy traffic,dense buildings and other factors of the downtown area.更多还原