隧道勘察中的综合物探方法

隧道勘察中复杂的地质条件给解决工程问题造成了很大的困难,本文概括了隧道勘察中广泛应用的物探方法,阐述了单独物探方法的条件性和局限性,并引用实例论证了综合物探技术的优势及其应用的必要性.实例中,多种物探方法的有机结合,准确地查明了隧道穿越场区的不良地质情况,各岩层风化层深度、形态及分布范围,并提供了纵波速度,达到预期的勘...     

Investigation of a landslide in the new site of Badong County by integrated geophysical survey

An integrated geophysical survey which combines vertical seismic profile method, shallow reflection seismic method, electric sounding, soil temperature measurement and radioactive gas measurement was used to investigate Zhaoshuling landslide in the new site of Badong County and to assess the stability of the landslide. By rational use of these methods together with borehole geological profile and other geological information, the spatial distribution of the landslide body, the formations and structures within and without the landslide body were determined and the stability of the landslide was also assessed, thus making great contribution to the successful and rational investigation and assessment of the landslide.     

海洋地球物理测量中GPS数据问题与处理

海上走航式地球物理测量的精度在很大程度上依赖于GPS（全球导航定位授时系统）数据观测的精度.由于各种原因,船载GPS测量会遇到多种问题.对记录到的GPS数据进行处理是获得高质量GPS数据一个不可缺少的环节.本文通过对多个海洋重磁调查航次的GPS观测数据进行处理,介绍了船载GPS测量中遇到的一些典型问题,以及相应的数据处理方法.本文指出,为保证数据采集的质量,船载GPS测量一般应使用两台GPS接收机同时进行测量.在数据处理时,将其中记录较稳定、可靠的一台GPS接收机作为主机,而另一台作为辅机.数据处理时,以主机记录的数据为主,当主机数据缺失时,则使用附机的数据作为补充.我们的长期观测结果表明,主机和附机之间总是存在时间差,目前我们没有发现时间差出现的规律和这种时间差出现的确切原因.用附机的数据来补充主机数据时,应该进行时间差调整.对于同一台GPS接收机的数据,本文介绍了野值、零值、重复值、时间间断和航迹间断等现象.同时文章中介绍了对于野值、零值、重复值、时间间断和航迹间断等数据,在进行数据处理时,可用剔除、插值、补遗等办法对上述出现的问题进行处理.本文认为,天气状况、卫星分布、天线运动姿态、接收机工作的稳定性、解码模块、运算〖JP3〗速度、多路径效应等都可能对GPS观测造成影响,但目前我们还并不能确定造成海上GPS测量出现问题的确切原因.     

我国防止矿井瓦斯事故的地球物理探测技术进展

瓦斯事故是煤矿井开采作业面临的第一大灾害,它具有发生突然、动力巨大、伤亡力强、波及面宽等突出特点.瓦斯不均匀地的贮存在煤层中,突出于采动破坏的岩壁段,防止煤矿瓦斯事故是一个典型的地学问题.通过测量岩体物性差异预测瓦斯动力赋存的地质条件,通过测定物性差异体的三维空间位置可确定采矿作业的安全岩体隔离厚度,等等.近十年来地球物理探测技术为防止煤矿瓦斯事故发生发挥着关键作用.     

安徽省区调现状存在问题和发展设想

从区调任务完成情况、质量、区调技术规范、质量管理、成果出版和区调总结等方面系统地总结了安徽省基础地质调查、研究现状,简要归纳了在基础地质调查中所取得的成果.在此基础上分析了安徽省的省情,初步拟定了安徽省在基础地质调查方面存在的主要问题和进行新一轮国土资源调查的总体部署、思路和采用的主要技术路线.     

A geophysical survey on the archaeological site of Mugardos (NW Iberian peninsula)

Archaeological indications near Mugardos (Ferrol, NW Spain) suggest the existence of a Roman settlement. In fact, in the area were found pavements, walls with north-south and east-west orientations and some structures that endured heating. These remains are covered by soil, more than 1 m thick, and lie over schists. In order to determine the archaeological potential of the area and to delimit future excavations a geophysical survey, consisting of a joint resistivity and magnetic survey, was planned and carried out. The square array of electrodes was used and the data are discussed as apparent square array resistivity maps and azimuthal inhomogeneity ratio (AIR) maps. The magnetic survey included total field measurements using sensor heights of 0.30 and 2.30 m above the ground, so that a magnetic gradient could be computed.A combined interpretation of both resistivity and magnetic data is discussed. Later excavations have confirmed the geophysical interpretation.     

地质定年方法综述与地球物理定年

年代确定在地学中得到广泛应用.而作为地史学中重要的组成部分，年代确定为地质时期中地球岩石圈在时间上发展和演变提供了重要的时间约束.本文综述了四种定年方法：即古生物法；古地磁法；同位素法和地球物理法.随着地球物理的探测技术的发展，地球内部精细结构得到揭示.我们认为，应用地球物理资料确定年龄将可以弥补其它方法的缺陷，可能为地球内部三维岩石定年提供支撑.     

Technique development of PC104 embedded module and its application in the geophysical instrument design

Introduction Electronic technique has been developing to so large scale integrated and high intelligent that the microprocessor has been the core in the electronic equipment or in the process control system design relying on its strong controlling and computing power, convenience to be application designed and to be programmed. Now the mainstream solutions widely used in the geophysical appliance are the single chip microprocessor (MCS), the digital signal processor (DSP), the common compute…     

On the problem of the existence and uniqueness of a discrete,surface, optimum wiener filter,applied to the filtering of geophysical fields

Summary Proof is given of the existence and uniqueness of a discrete, surface, optimum (in the Wiener sense) filter for filtering geophysical fields considering a spectral approach to the construction of the said filter. It is also shown that the filtration coefficients and the filtration errors of the filter, constructed with the help of statistical estimates of the required spectral densities, converge towards their theoretical values. From the mathematical point of view, this paper concludes the building-up of the mathematical model of the discrete Wiener optimum surface filtration, suitable for geophysical fields.     

发展技术,增强基础-地球物理仪器国际化与地球物理技术在工程上的应用研讨会综述

2004年,中国地球物理学会仪器专业委员会在北京召开了“地球物理仪器国际化问题”(4月)和“地球物理技术在工程上的应用”(8月)两个研讨会。会议发表了大量论文,展示了目前我国先进的地球物理仪器和地球物理技术在工程方面的应用成就．承《地球物理学进展》编辑部支持,决定在2004年第四期和2005年第一期,连续刊载经专家审查和推荐的地球物理仪器和技术方面的部分优秀论文,     

The geophysical significance of oceanic plagiogranite

Rocks ranging in composition from trondhjemite to diorite (plagiogranites) have been recovered from ocean ridges and are common constituents of ophiolites. Velocities and densities of diorite and trondhjemite from the Mid-Atlantic Ridge are shown to differ significantly from similar properties of metadolerite and gabbro. Compressional (V_p) and shear (V_s) velocities of plagiogranites are relatively low (V_p = 4.78–5.91km/s at1kbar,V_s = 2.81–3.37km/s at1kbar), as are densities (2.57–2.64 g/cm³) and Poisson's ratios (0.24–0.27). These data lend strong support to the probable existence of a low-velocity/density zone within layer 3 of the oceanic crust. Based on observations in ophiolites, it is postulated that this zone can be up to 1 km in thickness and is laterally discontinuous.     

EH4高频电磁测深在断层构造探测中的应用研究——以川藏路高尔寺山隧道为例

将EH4高频大地电磁测深法应用于高原特长隧道—高尔寺山隧道构造、岩性的勘察,通过与钻探及地质调绘的资料对比,EH4音频大地电磁法可以在宏观上查明深埋隧道地层岩性分界、地质构造及其赋水性,为钻孔布置及隧道设计、施工提供地球物理依据,在高原地区深埋隧道勘查中能达到较为理想的效果。     

The spatial and temporal distribution of marine geophysical surveys

We examine how bathymetric mapping coverage varies with distance from the coastline, here a proxy for the effort involved in collecting the data. Distances to the nearest coastline were evaluated on a 1′ × 1′ global grid. We evaluate the density of marine survey track lines, which falls off with increasing distance from the coastline and drops off precipitously for the most remote regions. Bathymetric coverage shows a marked asymmetry between the southern and northern hemispheres, the latter having a factor of 2–4 denser coverage. We find a rapid decrease in data acquisition for previously unexplored regions beginning in 1973–1975. This rate change may reflect a transition from serendipitous exploration to more targeted investigations as the plate tectonics hypothesis became accepted, but it could also reflect the 1970s oil shocks. Coverage of the seafloor varies logarithmically with mapping resolution. At 0.5° resolution, only ∼60% of the seafloor has been mapped; the 50% mark was reached in 1979 and coverage of unexplored seafloor has since been less rapid. For comparison, at 1′ resolution less than 10% of the seafloor has been mapped. Given rising fuel costs we predict the most remote areas will see a decline in future surveys. Better coordination of exploration among agencies and nations could mitigate this concern and improve global coverage, as could future altimetric mapping dedicated to bathymetric prediction.     

The geophysical significance of geomagnetic variation anomalies

Analytic procedures in classical geomagnetic deep sounding and in two-dimensional magnetometer array studies are outlined. Three types of magnetic variation anomaly are considered, and anomalies of one geographical area. Continental-edge anomalies remain somewhat ambiguous as to the contribution of structure in the upper mantle; the geophysical significance in geothermal terms is understood, if the effect exists. Subduction-zone anomalies in the Peruvian Andes and in central Japan are considered in relation to the ascent of an andesitic melt fraction from the lithosphere slab, a process which accounts also for uplift and support of the mountains. In western North America anomalies are closely related to heat flow and indicate complex tectonic activity with considerable fine structure in general agreement with seismological parameters. The Basin and Range Province has a highly conductive upper mantle and still higher conductivities are found under the Wasatch fault belt and under the southern Rockies. Under the northern Rockies the evidence is for only a thin conductive layer in the upper mantle and in general for much lower heating than in mid-latitudes of the United States. Crustal anomalies are discussed in relation to the current concentration effect. It is suggested that some of them may mark metamorphic belts in crystalline basement rocks. This association has been demonstrated for the North American Central Plains anomaly.     

我国地球物理仪器的发展

本文回顾了我国地球物理仪器的发展历程,指出了大量进口对我国地球物理仪器发展的影响,强调了我国地球物理仪器工作者所进行的不懈努力,提出了我国地球物理仪器今后发展的四点意见：(1) 反复宣传地球物理仪器、观测、实验的重要性;(2) 逐步形成对地球物理仪器评价标准的共识;(3) 关注发展高新领域;(4) 营造国内仪器快速发展的环境.     

基于褶积模型的地球物理反演模型增强

地球物理数据在采集和处理过程中,由于存在噪声、模型误差、以及数据离散化误差等系统误差,导致了异常体边界模糊和模型分辨率降低等一些不可避免的不良系统退化效应的产生.本文提出了一种新的地球物理反演模型增强方法,通过消除反演估计模型中的系统误差,压制模型中的不良系统退化效应,增强反演模型的分辨率.文章从理论上分析了数据中存在的系统误差对模型求解的影响,提出了一个新的系统误差褶积退化模型,并根据该模型提出了一种基于混合范数总变分正则化的盲反褶积模型增强算法.最后,文章通过1D线性反演增强试验和2D大地电磁反演增强试验,验证了所提出的地球物理系统退化模型的正确性,以及盲反褶积增强算法的有效性.试验结果表明,方法可以有效地提高反演参数模型的分辨率.     

The specific features of geophysical fields in the fault zones

Instrumental measurements of geophysical fields in several regions of the Earth’s crust with a complex structure and tectonics are analyzed. The observed geophysical fields include the electric field in the boundary layer of the atmosphere and in the subsurface crust, the ground magnetic field, and the fields formed by microseismic vibrations and natural radon emanation. It is shown that the fault zones are characterized by noticeably higher (compared to the middle segments of crustal blocks) variations in the geophysical fields, a stronger response to the faint external impacts in the form of lunisolar tides, and baric variations in the atmosphere, as well as by higher intensity relaxation processes. Energy transformations between the geophysical fields of different origins are observed predominantly in the fault regions.     

采场坍塌空区地球物理探测及矿山恢复生产设计与安全评价

采用空场法开采的某金矿Au3号矿体于2006年12月4日发生了冒落垮塌事故,迫使矿山停产.为了尽快恢复矿山生产,确保今后矿山生产安全,有必要进行采场坍塌原因分析,了解采场塌埋填实情况,并根据实际塌落情况,进行安全评价和恢复生产的初步设计.针对这一要求,本文首先简要介绍了Au3号矿体的地质、采矿条件,并采用了地球物理勘探方法,进行了塌落采场的空区探测,揭示了采场的空区填埋情况,并进行采场稳定性评价;在此基础上,提出了恢复矿山生产的采矿设计.目前,该矿山正在基于本文的研究成果和提出的初步设计方案进行恢复性生产.     

抗震设计中多遇地震的问题和讨论

指出作为截面抗震验算标准的“小震”混淆了两种明显不同的概念:其一是对应于50年超越概率63％的地震动参数(以下简称“多遇小震”);其二是50年超越概率10％的地震动参数经过折算得到的参数(以下简称“折算小震”).上述混淆导致抗震设计中实际上执行着不同的标准.文中讨论了中、小地震动参数之间关系的复杂性,包括从地震危险性分...