用于地铁盾构区间孤石探测的三维电阻率跨孔CT方法研究及物理模型试验

发布时间：2018-02-25 22:39

本文关键词： 隧道工程地铁盾构区间孤石三维电阻率跨孔CT 装置形式影响因素　出处：《岩石力学与工程学报》2015年12期 　论文类型：期刊论文

【摘要】：城市地铁盾构区间孤石的三维定位问题一直未得到很好的解决,为了提高实际工程对孤石异常体的探测识别和定位精度,尝试将三维电阻率跨孔CT精细化探测方法引入到地铁孤石群的探测工作中。首先,从4个平行钻孔"透视对穿"的典型观测模式出发,探讨三维电阻率跨孔CT反演成像方程及适用的装置类型,通过数值模拟研究发现,利用AM-BN电极阵列装置形式采集电位梯度数据得到的孤石成像效果最佳。在此基础上,进一步针对影响探测效果的2个要素——孔距和电极间距开展系统的数值模拟试验研究,据此提出合理的三维电阻率CT探测参数,并检验对小粒径孤石、密集分布的孤石群的识别效果。最后,结合物理模型试验研究进行验证,探测结果较准确地反映了高阻异常的分布情况,表明三维电阻率跨孔CT方法用于地铁孤石探测是可行的。
[Abstract]:The problem of 3D location of solitary stone in shield section of urban subway has not been solved well. In order to improve the accuracy of detecting and locating the abnormal body of isolated stone in practical engineering, This paper attempts to introduce the three dimensional resistivity transpore CT fine detection method into the detection of the isolated rock group of the subway. Firstly, starting from the typical observation mode of "clairvoyance to penetration" of four parallel boreholes, The 3-D resistivity transpore CT inversion imaging equation and the suitable device type are discussed. Through numerical simulation, it is found that the imaging effect of solitary stone obtained by using AM-BN electrode array device to collect potential gradient data is the best. A systematic numerical simulation study is carried out on the two factors that affect the detection effect-hole spacing and electrode spacing. Based on this, reasonable 3D resistivity CT detection parameters are proposed, and small diameter solitary stones are tested. Finally, combined with the physical model test, the detection results accurately reflect the distribution of high resistivity anomalies. The results show that it is feasible to apply the three-dimensional resistivity cross-hole CT method to the detection of subway solitary stones.
【作者单位】：山东大学岩土与结构工程研究中心;
【基金】：国家重点基础研究发展计划(973)项目(2013CB036002,2015CB058101) 国家重大仪器设备研制专项(51327802)~~
【分类号】：U452.1

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