高密度电法反演软件在邹平章丘火山岩区铜矿勘查激电测深反演中的应用

在山东省邹平-章丘火山岩区铜矿勘查工作中,为了克服地形因素引起的假异常,使勘查成果接近实际地质情况,应用高密度电法反演软件RES2DINV软件进行了带地形的激电测深资料反演,结合地质资料及激电中梯资料,推断了低阻高极化异常体,经钻探验证异常体为铜矿体引起。在地形复杂地区开展激电工作,可以应用此方法,减小预布验证钻孔难度。     

高密度电阻率法在废弃矿山滑坡灾害勘察中的应用

高密度电阻率法是一种成熟的工程物探方法,广泛应用于地质灾害调查。废弃矿山在不良天气条件下容易产生滑坡地质灾害。对由废弃渣石、杂填土人工堆积形成的滑坡体进行勘察,研究高密度电阻率法在该环境下的勘察效果。通过对视电阻率反演断面图分析,推断滑动面深度、滑床起伏形态等滑坡体地质结构信息,为废弃矿山滑坡灾害治理设计提供依据。钻探验证表明,高密度电阻率法有效的推断出滑坡体滑动面深度、滑床起伏形态信息,可用于废弃矿山滑坡灾害勘察。     

瞬变电磁法探测公路隧道工程中的不良地质构造

为了给公路设计部门提供选线依据,运用瞬变电磁法在山西境内的某两条高速公路隧道工程设计线路段上进行探测,以查明下覆不良地质构造的发育情况.通过对瞬变电磁法的探测能力进行理论上的讨论,对不同地电断面情况下的异常体电磁响应的定性分析,得出用瞬变电磁法探测不良地质体的可行性结论.经过资料处理,查出不良地质构造赋存的位置,解释结果与钻探资料完全吻合.     

Joint inversion of magnetotelluric and fullwaveform seismic data based on alternating cross-gradient structural constraints

Magnetotelluric(MT)inversion and seismic inversion are important methods for the interpretation of subsurface exploration data,but separate inversion of MT and seismic produces ambiguous and non-unique results due to various factors.In order to achieve accurate results,the authors propose a joint inversion method of two-dimensional MT and seismic data in the frequency domain.The finite element method is used for numerical simulation of electromagnetic data in the forward modelling,and the Gauss-Newton method is used for the inversion.The 9-point-finite-difference method is used to solve the seismic wave field in the acoustic wave equation,and the inverse problem of seismic data is solved by full waveform inversion with a conjugate gradient,a simple and fast method.Cross gradient functions are used to provide constraint structure between resistivity and velocity parameters to carry out the joint inversion.The joint inversion algorithm is tested by double-rectangular model synthesis data,and the accuracy of the algorithm is verified.The results show that the joint inversion results are better than those from separate inversion.The algorithm is applied to a geophysical model of a metalliferous deposit in Jinchuan and is compared with the separate inversion results.It shows that the results obtained with joint inversion are much closer to the real model.     

高密度电法在老山隧道勘察中的应用

应用高密度电阻率法勘察宁淮高速公路南京老山隧道工程,查明了隧道YK5 280~ZK5 540段的地层分布和构造特征,并推断出鹰嘴山断层的位置和产状,结合勘察资料证明该断层为高角度逆断层。预测出隧道和断层破碎带相交处为浅部裂隙岩溶含水带中的优良导水带,该处涌水的可能性很大,其推断结果在施工中得到证实。说明高密度电法是进行隧道勘察和构造裂隙岩溶富水带探测的一种可靠手段。     

大定源回线装置瞬变电磁法在浅层煤矿采空区勘查中的应用

煤矿采空区土地已成为可持续发展的重要资源,浅层煤矿采空区探测在城市规划中显得日益重要.本文采用大定源回线装置瞬变电磁法对浅层煤矿采空区进行勘查,结合具体工程案例选用合理的施工参数,对野外采集数据进行视电阻率计算并绘制成图,利用视电阻率等值线扰动异常圈定采空区位置,指导钻孔布设,解译成果与地质资料及钻孔揭露地层基本吻合....     

高密度电法在枣庄某建设场采空区注浆效果检测中的应用

在山东省枣庄市某棚户区改造项目前期的岩土工程勘察和物探勘查中,发现部分建筑物及车库基础下存在采空区及采煤巷道。根据前期工作,对其中一条巷道进行了注浆处理。处理后,利用高密度电阻率法对注浆位置进行了物探勘查,认为该处注浆后视电阻率升高,原低阻异常区明显减小或者消失,注浆采空区与未注浆采空区有明显的电性差异,未注浆区的明显低阻异常为分辨注浆区位置和效果提供了对比参考。但在使用电阻率法对注浆区进行检测时,要保证水泥浆固结,否则无法有效区分原充水采空区及未固结水泥浆引起的视电阻率异常,不利于判断注浆效果。因此,用物探方法检测注浆效果,可为工程顺利施工提供相应的参考依据。     

基于序列二次规划方法的高密度电阻率反演

针对高密度电阻率成像法反演计算中存在的困难，探讨了基于序列二次规划（SQP）方法建立可行的电阻率反演算法的问题。在对三维点电源二维地电体电位场模型有限元法正演计算的基础上．建立了基于SQP方法的高密度电阻率成像法反演算法。根据勘测中测量电极间距的不同，提出按不同的电极间距分别建立优化模型进行参数优化。通过对模拟电阻率模型和实际观测资料的反演计算．表明该算法进行高密度电阻率反演是可行的，其具有对初始模型无特殊要求、收敛速度快的特点。这一反演算法可望在高密度电阻率成像的反演计算中得到应用。     

基于高密度电法的岩溶勘查——以枣庄某工程为例

高密度电阻率法因其测点密度高、信息量大、对探测对象不造成损伤等特点,被广泛应用于各种工程开发和建设场地的前期岩溶探测工作中.本文以山东省枣庄市某工程场地岩溶探测效果为例,系统地介绍了高密度电法在岩溶探测中的应用方法和效果.该工程场地岩溶广泛发育,给楼房基础带来严重危害,通过开展高密度电法工作并经钻孔实地验证,划分了不同...     

浅层地下水物探探测方法选择

浅层地下水探测是物探工作重点关注领域之一,本文从地球物理特征出发,结合工作实例,分析电阻率层析成像技术、电测深、大地电磁法、甚低频及浅层地震等方法在地下水探测中的效果,分析各方法探测中优缺点。本文从成本、效率、探测深度、地形条件等不同因素考虑,给出了不同条件下物探方法的选择。文中对不同勘探深度给出了不同的综合勘探手段组合,100m以浅优选层析成像技术、电测深、瞬变电磁法、浅层地震等方法组合,500m以深选择CSAMT法、EH法等组合。     

综合物探方法在马石店隧道勘察中的应用

利用高密度电阻率法和浅层地震波法对309国道马石店隧道进行勘察,以高密度电法为主,浅层地震折射波法相辅助的方法,通过综合比较,可以查明风化层和基岩分界及隐伏构造,为勘察设计提供依据,综合物探方法达到了满意的效果。     

Application of high-density resistivity method for assessing construction safety of Shimodong tunnel in Helong City of Jilin Province

Some unfavorable geological conditions can affect the construction of tunnels.In order to evaluate the damage degree of tunnel construction and determine the surrounding rock grade and stability of the tunnel,the authors used high-density resistivity method to detect the surrounding rocks of Shimodong tunnel in Xicheng Town of Helong City.The underground resistivity structures of the entrance,exit and middle parts of the tunnel are obtained.Through analysis,it is found that there are no bedrock faults near the tunnel,although some joints and fissures are developed in some locations,which are characterized by low-resistivity anomalies.The tunnel structures are stable overall,favorable for safe and efficient construction.The study also proves the good application effect of the high-density resistivity method in tunnel safety detection.     

3D joint inversion of controlled-source audio-frequency magnetotelluric and magnetotelluric data

Different geophysical exploration methods have significant differences in terms of exploration depth,especially in frequency domain electromagnetic(EM)exploration.According to the definition of skin depth,this difference will increase with the effective detection frequency of the method.As a result,when performing three-dimensional inversion on single type of EM data,it is not possible to effectively distinguish the subsurface geoelectric structure at the full scale.Therefore,it is necessary to perform joint inversion on different type of EM data.In this paper we combine the magnetotelluric method(MT)with the controlled-source audio-magnetotelluric method(CSAMT)to study the frequency-domain three-dimensional(3D)joint inversions,and we use the unstructured finite-element method to do the forward modeling for them,so that the numerical simulation accuracies of different electromagnetic methods can be satisfied.By combining the two sets of data,we can obtain the sensitivity of the electrical structure at different depths,and depict the full-scale subsurface geoelectric structures.In actual mineral exploration,the 3D joint inversion is more useful for identifying subsurface veins in the shallow part and blind mines in the deep part.It can delineate the morphological distribution of ore bodies more completely and provide reliable EM interpretations to guide the mining of minerals.     

综合物探方法在栖霞中桥地区溶洞塌陷地质灾害调查中的应用

该文论述了在溶洞引发的地面塌陷地质灾害调查中,应用高密度电法、瞬变电磁法、地震频率谐振法进行综合物探勘查的效果,根据本区第四纪地层、灰岩及溶洞充填物质的物性差异,分析研究了岩溶溶洞及塌陷区的物探异常分布特征,并结合钻探验证,有效圈定了调查区岩溶溶洞及地表塌陷区的分布范围,为地质灾害调查与防治提供了科学依据。结合本次综合物探勘查效果,分析了高密度电法、瞬变电磁法及地震频率谐振法在探测溶洞及塌陷区的有效性及局限性。     

音频大地电磁法在某隧道勘察中的应用

新建池州到黄山铁路是一条致力服务于旅游业的高速铁路,全线隧道比超过60%,该铁路设计多条长大隧道,其中某隧道全长8986m,洞身距离地表的最大高差达775m,一般的勘探方法很难达到这个深度,而且隧道沿线沟壑纵横、地貌多变,断裂构造非常发育,地下暗河众多,地质情况极其复杂。音频大地电磁法勘探深度较大、施工成本低、对低阻分辨率较高,它装备轻便,通过性好,目前已成为国内外用于山区长大深埋隧道勘察的主要方法。该文介绍了音频大地电磁测深法的工作原理、野外技术方法和资料处理流程,阐述了该方法在某隧道勘察中的实际应用效果。该隧道的音频大地电磁测深工作野外数据采集精度较高,数据处理方法得当,基本查明了隧道沿线地层分布情况及断层等不良地质体特征,推断成果与钻探结果吻合较好,圆满完成了预期任务,依据物探结果对地层完整性进行了评价,对隧道围岩进行了分级划定,为下一步隧道施工提供了可靠的地球物理依据,也为今后类似工作起到了一定的借鉴作用和参考价值。     

综合物探在寿阳煤矿水害探测中的应用

利用瞬变电磁法和环形测深相结合的综合勘探方法,对煤矿富水区域进行探测。瞬变电磁法施工方便,该方法对低阻含水体特别灵敏,受体积效应影响小,分辨率高,从平面上控制富水区域大小。环形测深可以探测不同方向的岩层视电阻率变化情况,对于地下径流方向进行控制。2种方法相结合,即平面控制区域,含水区域延伸变化情况也得到控制。对于富水区域的探测,使用综合勘探,可以减少单一方法多解性问题,使探测结果更符合实际,这2种方法相结合的理论,有助于今后这方面的探测研究。     

冻土路基微动探测方法应用探讨

以哈尔滨某高铁路基勘探为例,采用空间自相关方法提取微动信号频散特征,获取地下150 m介质的横波速度结构及分层特征.结果表明,微动方法可穿透冻土区较厚的覆盖层探测基岩面,且分层界面与钻孔资料一致.该方法施工便利、适用性强,结合钻探资料可精确刻画地下地质层位分布,减少钻探工作量,节约经济成本,具有较高的应用价值和科学意义...     

Investigation of fractured rock aquifer in South China using electrical resistivity tomography and self-potential methods

Assessment of fractured rock aquifers in many parts of the world is complicated given their strong heterogeneity. Delineation of the subsurface geological formation in the weathered terrain is essential for groundwater exploration. To achieve this goal, 2D electrical resistivity tomography(ERT) and self-potential(SP) in combination with joint profile method(JPM) and boreholes have been carried out to delineate the subsurface geological units, detect the fracture/fault zones in hard rock, monitor the groundwater flow, and estimate the groundwater reserves contained within the weathered terrain at a complex heterogeneous site of Huangbu, South Guangdong of China. The integration of resistivity images with the borehole lithology along three profiles delineates three subsurface distinct layers namely topsoil cover, weathered and unweathered layers. The incorporation of ERT and SP with JPM reveal five fractures/faults, i.e., F_1, F_2, F_3, F_4 and F_5. 2D ERT models interpret the less resistive anomalies as the fractures/faults zones, and high resistive anomalies as the fresh bedrock. The inversion program based on the smoothness-constraint is used on the resistivity field data to get more realistic three layered model. SP measurements are obtained along the same electrical profiles which provide the negative anomalies clearly indicating the groundwater preferential flow pathways along the fracture/fault zones. Hydraulic parameters namely hydraulic conductivity and transmissivity were determined to estimate the groundwater resources contained within the fractures/faults. The integrated results suggest that the fractures/faults zones are most appropriate places of drilling for groundwater exploration in the investigated area. Geophysical methods coupled with the upfront borehole data provides better understanding about the conceptual model of the subsurface geological formations. The current investigation demonstrates the importance of the integrated geophysical methods as a complementary approach for groundwater assessment in the hard rock weathered areas.     

水域地震映像在火成岩发育区的应用与探讨——以厦门某海底隧道勘察为靶区

以厦门某海底隧道勘察为靶区,采用电磁气泡震源系统激发地震波,在火成岩发育区进行水域地震映像实验,较好地查明了海底水深界面、淤泥（砂层）和基岩面的分界线。实验结果表明,水域地震映像法对海域火成岩发育区是一种有效的物探方法,可以为海域地质勘察提供可靠的地质参考依据;利用水域地震映像勘探既可以较好地弥补钻探缺陷,又能极大地节约经济成本。     

利用SH横波反射资料中的勒夫面波反演浅部横波速度结构

由于勒夫波速度与纵波速度无关,勒夫波多道分析方法具有频散曲线简单、能量清晰、反演过程中未知参数少、对初始模型依赖小、反演结果稳定、分辨率高等特点。实验结果表明,利用浅层SH横波反射地震数据中的勒夫面波信息,反演得到近地表横波速度结构,在浅层地质构造、断层位置、上断点埋深等方面与浅层SH横波反射地震剖面以及地质钻孔数据吻合较好。该方法可为地下构造解释提供更多依据,提高探测成果的可靠性。