高密度电法在侨城东路北延通道工程区域断裂带探测中的应用  

Application of High-Density Electrical Method in the Detection of Fracture Zone in the North Extension Channel Project Area of Qiaocheng East Road

作　　者：张玉雪 ZHANG Yuxue(Yunji Intelligent Engineering Co.Ltd.,Shenzhen 518049)

机构地区：[1]云基智慧工程股份有限公司,广东深圳518049

出　　处：《土工基础》2024年第3期520-524,共5页Soil Engineering and Foundation

摘　　要：为解决复杂地质条件下断裂带的精细化探测问题,以深圳市侨城东路北延项目为研究对象,运用高密度电法的探测方法获取场区高分辨率电阻率分布图像,推测断裂带的位置、走向。结果表明,项目沿线存在4条对线路影响较大的断层,断裂带构造岩多受挤压,岩体裂隙发育、完整性差,岩石结构性差、岩石矿物蚀变、胶结程度差,导致构造岩强度较低,为较软岩、软岩;物探推断异常区域共3处,异常区域的特征均表现为低阻异常,其电阻率与全强风化花岗岩、中微风化花岗岩层的电阻率存在明显差异,表现为相对低阻,划分地电层界面良好,异常区域的电阻率与第四系土层大致相同,电阻率范围为小于30Ω·m,而全强风化花岗岩的电阻率范围为30~50Ω·m,中微风化花岗岩层的电阻率大于50Ω·m;高密度电法解释成果与地质钻孔揭示结果一致,表明高密度电法具有高精度、高效率和图像化的特点。To solve the problem of the refined detection of the fracture zone under the complex geological conditions,a case his-tory project of north extension of Qiaocheng East Road in Shenzhen City is presented in this paper.Throughout the analyzing the engineering geological conditions of the site,the high-resolution resistivity distribution image of the site is obtained by using the high-density electrical method.The position and trend of the fracture zone are inferred.The results show that there are four faults within the project limits that have a greater impact on the alignment.The tectonite in the fracture zone is mostly squeezed,with poor rock fracture development and integrity,poor rock structure,rock mineral alteration and cementation,which results in low strength of the tectonite,which is relatively soft rock and soft rock.The geophysical exploration indicates that there are three abnormal areas,all of which are characterized by the low resistivity anomalies.Their resistivity is signifi-cantly different from that of the fully weathered granite and the moderately weathered granite layers,which indicating relatively low resistivity.The interface between the geoelectric layers is well defined,and the resistivity of the abnormal area is roughly the same as that of the Quaternary soil layer,with a resistivity range of less than 30Ω·m,while the resistivity range of the fully weathered granite is 30-50Ω·m.The resistivity of the moderately weathered granite layer is greater than 50 Ω·m.The interpretation results of the high-density electrical method are consistent with the results revealed by the geological drill-ing,indicating that the high-density electrical method has the characteristics of high accuracy,high efficiency,and visualiza-tion.

关 键 词：高密度电法 侨城东路 北延通道 区域断裂带 低电阻率 

分 类 号：TU413[建筑科学—岩土工程]