宁波轨道交通暗浜勘察物探方法研究

发布时间：2019-04-13 16:45

【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.
[Abstract]:The dark creek formed by river landfills is an important hidden danger in the construction of urban infrastructure projects. Because of the complex composition and loose structure of landfill, the underground station deep foundation pit excavation may lead to collapse and other safety accidents due to the unproven dark creek construction in subway shield construction. This paper studies the effectiveness of the two-dimensional fretting section method, the transient Rayleigh wave method and the high-density electrical method in detecting the dark Bang by taking the exploration of the dark Bang of Ningbo Rail Transit as an example. The results show that the three geophysical prospecting methods all have better detection results, showing that the abnormal shape of the landfill area is generally consistent with the depth of the bottom boundary revealed by drilling, the errors are less than 4%, 7%, 7%, respectively, and the results show that the depth of the underground boundary is less than 4%, 7% and 7%, respectively. Can meet the requirements of engineering accuracy. The anti-jamming ability of two-dimensional fretting section detection and transient Rayleigh wave method is better than that of high density electric method, and it is more suitable for urban engineering investigation. The fretting detection rule based on natural field source (fretting) has more technical advantages in the investigation of rail transit under the environment of strong disturbance in downtown area. The above three geophysical prospecting methods, combined with geological investigation and a small amount of drilling, are the main ways to realize the "non-destructive" and efficient detection of the dark creek.
【作者单位】：浙江省地球物理地球化学勘查院;中国科学院地质与地球物理研究所;宁波市轨道交通指挥部;日本地学数据分析研究所;
【分类号】：P631;U212.2

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