城市地下管线探测研究进展与发展趋势

地下管线是城市基础设施的重要组成部分,是保障城市运行和发展的"生命线".但由于建设规模不够、资料保存缺失、日常管理不足等原因,对于地下管线的精准探测变得愈加困难.为此,本文对国内外关于地下管线探测的文献进行了系统调研,详细梳理了常见地下管线的分类、材质、规格以及敷设方式,分析了不同管线的地球物理特征,并重点介绍了当前应用于管线探测的主流地球物理方法(如电磁感应法、探地雷达法等)和非地球物理方法(如惯性陀螺仪定位法、声学探测法等)的应用原理、发展概况、探测优势与应用局限.总结得知,无论是单一探测法,还是综合探测法,都取得了不错的应用效果.其中,利用电磁感应法探测金属管线优势明显、效果显著,包括追踪小口径电力、通讯电缆都能保证较高的精度.而探地雷达则是当前探测非金属管线的首选工具.两种方法互为补充,是地下管线探测应用最普遍的技术,但其抗干扰能力和仪器的探测精度仍有待进一步提高.同时惯性陀螺仪定位法、声学探测法等非地球物理方法也在近些年逐渐得到应用和推广,对主流的地球物理方法做了很好的补充.随着科技不断发展,地下管线探测技术与3S、信息网络、数字测绘等技术联合应用,建立健全集成统一的地下管线信息系统将是未来发展的必然趋势.     

国家地球物理基础设施：意义和任务

本文简要阐述了国家层面的基础设施对地球物理学科发展的重要性，讨论了国家地球物理基础设施的建设和运行在当前时间的紧迫性.指出中国地球物理发展的三个主要任务：基础地球物理探测、基础地球物理检测、基础地球物理数据共享服务.国家层面的地球物理基础设施的建设能够为相关科研机构提供高科技含量的服务.     

基于GeoMedia的考古探测综合解释系统

无损探测是考古研究的一种先进方法和手段,它是一种通过地球物理方法不用挖掘而直接探测地下遗迹、遗物的考古技术.目前地球探测技术拥有众多的方法和手段,不同方法和手段获得大量的不同尺度、不同格式的地球探测数据,为了更好管理和应用这些不同类型的庞杂的探测数据,并将探测结果与考古信息和历史记裁进行相互印证判断,我们利用Intergraph的GeoMedia GIS技术,以考古探测数据为基础建立了一套基于地球探测考古的数据存储、管理、分析以及多种方法综合解释的多功能地理信息系统.本文详述了其系统结构、实现流程,该系统被应用于国家科技攻关项目中,并且可推广应用.     

资源与环境地球物理的前沿问题综述

2016年6月在北京召开了第七届环境与工程地球物理国际会议.会议的主题是地球物理与资源环境,会议论文涉及工程、环境、生态、水资源和灾害等领域的地球物理方法、技术和仪器等方面的最新成果与新进展,以及地球物理方法技术在重大工程中的新近应用成果,反映出国内外环境与工程探测领域的发展动态.结合本次会议,提出该学科主要前沿问题是:地球物理高端装备研发、地球物理大深度探测问题、矿区环境下的强噪声去除问题以及地下目标体的精细探测问题等.     

我国海洋地球物理探测技术发展现状及展望

海洋地球物理场是一个四维的动态复杂变化系统,涉及多物理场、多界面和多尺度问题,受内外因素的共同制约.基于海洋地球物理场特征,海洋地球物理探测是揭示地球内部构造与性质的重要技术手段.通过回顾国内外海洋科学研究历史以及海洋地球物理探测技术的发展历程,对我国海洋地球物理探测技术发展进行了分析,现今的技术发展受科技进步驱动,反映国家与时代发展的需求.探讨了技术发展与需求之间的关系,依据各种地球物理探测手段及其探测平台的特点,提出了以下技术展望:优化传统的海洋地球物理勘探技术;加速并完善多样式探测平台的建设和科学载荷的研究;构建"空-天-海-潜"海洋地球物理立体探测体系;海洋地球物理探测技术与"大数据"和"人工智能"等技术深度融合.     

便携式节点地震仪数据采集和处理技术进展

地震学方法在地球物理的研究中占有重要的地位,便携式节点地震仪凭借着其灵活性、低价格、高效率等特点越来越多地出现在地球物理探测领域.本文基于已有的便携式节点地震仪应用实例,对数据采集流程和数据处理技术进行了简要介绍,还阐述了其在主动源与被动源数据采集中相比于传统采集的差异和优点.相比较宽频带流动台阵,便携式节点地震仪观测形式的主要特点是短周期密集台阵方式.近年来,便携式节点地震仪的短周期密集台阵观测在利用被动源地震开展深部结构探测的应用越来越广泛.本文就SPAC、HVSR、背景噪声成像及接收函数四种方法在节点地震仪的应用中进行了评述,分析了几种处理技术的原理和特点,最后探讨便携式节点仪器相比宽频带仪器的优缺点,为未来发展灵活地震采集技术提供一点参考.     

自适应Chirplet变换及其在探地雷达目标探测中的应用(英文)

探地雷达不仅能够探测金属目标体,而且能够探测非金属目标体,而成为UX0和地雷探测的一种重要的浅部地球物理方法。但是在地雷和UX0探测中,目标体埋藏深度浅,在探地雷达数据信噪比较低情况下,地表和土壤层的反射严重干扰对目标体的拾取。本文采用自适用Chirplet变换来消除地表层和土壤层变化的干扰,并在Radon—Wigner分布的基础上,采用自适用Chirplet变换来拾取目标体的信号。通过对实际探测实验数据应用证明,本方法处理结果比传统的偏移方法具有较高的信噪比,并能清晰地提取目标体信号。     

工程物探检测方法技术应用及展望

工程地球物理勘探是应用地球物理学的一个重要分支,20世纪90年代以来,随着地球物理勘探技术、计算机及信息技术的发展,在工程建设需求的强力推动下,得到了迅猛的发展.目前已在工程建设前期、施工期、运行期,地质、水文、环境等的地球物理问题探测或检测中发挥着重要的作用.本文简述了国内外工程物探检测方法技术的应用现状,列举了长江物探公司及相关单位在工程物探检测应用中取得的典型成果,从而说明目前我国工程物探检测技术水平,最后对工程物探检测技术的发展作了展望.     

地面核磁共振技术发展述评

核磁共振技术在医学、地质等方面都有广泛的应用.运用核磁共振技术找寻地下水资源,开创了用地球物理方法直接找水的先河.地面核磁共振技术是目前唯一能直接探测地下水的地球物理方法.本文通过对核磁共振技术在国内外的应用和发展现状的介绍,总结了地面核磁共振技术现在存在的问题及其影响,同时提出了该技术今后的发展前景.     

深地震反射剖面探测技术发展现状

由石油地震勘探发展而来的深地震反射剖面探测技术,采用炸药震源、长排列、多次覆盖等方式接收来自地壳或上地幔的反射信号,经过去噪、校正、叠加、偏移等处理过程,可获得地壳尺度范围内的精细时间剖面,是研究深部构造特征、探讨构造演化过程的重要手段,发挥着其他地球物理方法不可替代的作用.深地震反射探测技术自上世纪由美国率先提出以来,经过几十年的发展历程,依托一系列的深部探测计划,获得了多条重要的深反射剖面,解决了包括造山带演化过程、盆地构造模式、矿集区深部构造特征等众多地质问题,得到了众多地质学家和地球物理学家的认可.目前深反射探测技术已经发展成为一种系统的、方法技术成熟的、结果可靠的深部结构探测方法,在关键地区也常常作为研究深部精细结构的先行军.我们通过总结近些年深地震反射剖面探测的实例,从采集技术、数据处理、综合解释等方面概述了深地震反射剖面探测技术取得的一系列新进展及应用,包括高精度可控震源采集技术、线条图处理技术、全波形反演技术、联合解释等.这些新技术的应用不仅有效提高了深地震反射剖面成像质量,也解决了深地震反射探测中面临的地形构造复杂、施工不便等问题,使得深地震反射探测在解决特定地区地质...     

Evaluating some factors that affect feasility of using ground penetrating radar for landmine detection

Ground penetrating radar （GPR） is one of the promising technologies that can be used to detect landmines. Many factors may affect the ability of GPR to detect landmines. Among those factors are： 1） the type of landmine material （metallic or plastic）, 2） conditions of the host soil （soil texture and soil moisture）, and 3） the radar frequency utilized. The impact of these factors on the ability of GPR to detect landmines is investigated by studying their effect on the dielectric permittivity contrast between the landmine and the host soil, as well as on the attenuation of the radar waves. The impact of each factor was theoretically reviewed and modeled using the Matlab and Mathcad software packages. Results of the computer modeling were correlated with GPR data acquired for metallic and plastic landmine types. It was found that the ability of GPR to detect landmines depends to a great extent on the landmine type, water content of the host soil, utilized radar frequency, and soil texture. The landmines are much easier to detect than plastic landmines for any soil conditions and any radar frequency. Increasing the soil＇s moisture content, regardless of soil texture, eases the detection of the plastic landmine and worsens the detection of the metallic mines. Increasing the percentage of clay in the soil causes the same effect as the moisture content. However, higher radar frequency delivers better results for landmine detection as long as the percentage of clay and the moisture content in the soil remains low. The results of this study are expected to help in selecting optimum radar antennae and data acquisition parameters depending on the landmine type and environmental conditions.     

采空区地震与电法探测数据的联合反演研究及应用

综合地球物理技术在采空区的探测中发挥了重要作用.目前通常采用单方法反演、仅对不同方法反演结果进行对比解释的综合勘探方式,单方法反演的多解性严重降低了其探测精度.如何提高采空区的探测精度,对采空区进行有效探测一直被认为是地球物理技术面临的首要难题.为了提高地震与电法技术的探测精度,基于交叉梯度联合反演理论,设计了地震初至折射走时数据和高密度电法数据的联合反演算法流程,对采空区理论模型和野外实际数据进行了联合反演处理.结果发现通过两者的联合反演,不仅可以提高采空区电阻率反演模型的成像效果,而且能够获得地震单方法反演难以成像的采空区低速异常体,从而提高了地震与电法技术对采空区的探测精度.表明地震与电法探测数据联合反演是一种提高采空区探测精度的有效方法.     

Theoretical Developments in Electromagnetic Induction Geophysics with Selected Applications in the Near Surface

Near-surface applied electromagnetic geophysics is experiencing an explosive period of growth with many innovative techniques and applications presently emergent and others certain to be forthcoming. An attempt is made here to bring together and describe some of the most notable advances. This is a difficult task since papers describing electromagnetic induction methods are widely dispersed throughout the scientific literature. The traditional topics discussed herein include modeling, inversion, heterogeneity, anisotropy, target recognition, logging, and airborne electromagnetics (EM). Several new or emerging techniques are introduced including landmine detection, biogeophysics, interferometry, shallow-water electromagnetics, radiomagnetotellurics, and airborne unexploded ordnance (UXO) discrimination. Representative case histories that illustrate the range of exciting new geoscience that has been enabled by the developing techniques are presented from important application areas such as hydrogeology, contamination, UXO and landmines, soils and agriculture, archeology, and hazards and climate.     

Low-frequency characteristics extension for vibration sensors

Traditional magneto-electric vibration sensors and servo accelerometers have severe shortcomings when used to measure vibration where low frequency components predominate. A low frequency characteristic extension for velocity vibration sensors is presented in this paper. The passive circuit technology, active compensation technology and the closedcycle pole compensation technology are used to extend the measurable range and to improve low frequency characteristics of sensors. Thses three types of low frequency velocity vibration sensors have been developed and widely adopted in China.     

基于结构振动信息的损伤识别研究综述

随着传感技术、信号采集与处理和系统建模等技术的发展,基于结构振动信息的损伤识别已经成为土木工程结构健康监测与损伤检测领域的研究热点。本文系统地综述了近20年来国内外基于振动信息的结构损伤识别的研究和应用现状,评述了各类方法的优缺点,并针对土木工程结构损伤识别的特点,对有待于进一步研究的问题进行了展望。     

Underground Storage Tank Monitoring: Observation Well Based Systems

A growing number of state and local governments and petroleum-related companies require the use of release detection systems for underground petroleum storage tanks. This has resulted in a confusing array of commercially available petroleum product detection devices, many of which have not been extensively field-tested. These systems, which are installed in ground water observation wells, vapor wells or U-tubes, include hydrocarbon-detecting paste, bailers, interface probes, electrical resistivity sensors, thermal-conductivity sensors, hydrocarbon-soluble devices, hydrocarbon-permeable materials and vapor detectors. This paper describes the available state-of-the-art technology for leak detection and the application for which each system is best suited.     

Review of the development of laser fluorosensors for oil spill application

As laser fluorosensors provide their own source of excitation, they are known as active sensors. Being active sensors, laser fluorosensors can be employed around the clock, in daylight or in total darkness. Certain compounds, such as aromatic hydrocarbons, present in petroleum oils absorb ultraviolet laser light and become electronically excited. This excitation is quickly removed by the process of fluorescence emission, primarily in the visible region of the spectrum. By careful choice of the excitation laser wavelength and range-gated detection at selected emission wavelengths, petroleum oils can be detected and classified into three broad categories: light refined, crude or heavy refined.

This paper will review the development of laser fluorosensors for oil spill application, with emphasis on system components such as excitation laser source, and detection schemes that allow these unique sensors to be employed for the detection and classification of petroleum oils. There have been a number of laser fluorosensors developed in recent years, many of which are strictly research and development tools. Certain of these fluorosensors have been ship-borne instruments that have been mounted in aircraft for the occasional airborne mission. Other systems are mounted permanently on aircraft for use in either surveillance or spill response roles.     

Uptake and tissue distribution of C4-C7 alkylphenols in Atlantic cod (Gadus morhua): relevance for biomonitoring of produced water discharges from oil production

The sensitivity of different tissues for assessment of chronic low-dose environmental exposure of fish to alkylphenols (APs) was investigated. We exposed Atlantic cod (Gadus morhua) in the laboratory to tritium labelled 4-tert-butylphenol, 4n-pentylphenol, 4n-hexylphenol, and 4n-heptylphenol via seawater (8 ng/l) and via contaminated feed (5 μg/kg fish per day). Measurements of different fish tissues during eight days of exposure and eight subsequent days of recovery revealed that APs administered via spiked seawater were readily taken up whereas the uptake was far less efficient when APs were administered in spiked feed. AP residues were mainly located in the bile fluid whereas the concentrations in liver were very low, indicating a rapid excretion and the liver-bile axis to be the major route of elimination. The biological half-life of APs in the exposed cod was short, between 10 and 20 h. Our study shows that in connection with biomonitoring of AP exposure in fish, assessment of AP metabolites in bile fluid is a more sensitive tool than detection of parent AP levels in liver or other internal tissues.     

Monitoring ephemeral headwater streams: a paired‐sensor approach

This paper introduces a paired‐sensor approach to monitoring ephemeral streamflow. Part of this approach includes the design of a new flow detection sensor. This flow detection sensor addresses the limitation of previous electronic resistance sensors that use water presence as a proxy for flow for assessing hydrological connectivity, by explicitly measuring flow presence. Using paired electronic resistance and flow detection sensors, this paper evaluates the performance of each sensor individually, and as a pair. Individually, the sensors were tested for the amount of noise they contain and the types of errors they were prone to committing. As a paired set, the sensors were analysed by the percent of time they were in valid states versus invalid states. Valid states included when water was present but flow was absent, when water and flow were both present and when water and flow were both absent during a storm. One invalid case existed, where the sensors recorded flow presence but not water presence. These valid and invalid cases were assessed using data collected from sensor networks established at two study sites in southern Ontario. This analysis was completed for the overall corroboration at each site, for each storm at each site and based on the relative position of the sensors in the channel at each site. The sensors were in valid states 83% and 94% of the time at each respective study site. Differences in local site conditions were found to affect the performance of the sensor network; however, no significant correlation was found between storm characteristics and sensor performance. Particularly, bed roughness was found to be a factor as it restricted the placement of the sensors. Despite this, the paired‐sensor network helps to increase the understanding of the flow dynamics within headwater streams by explicitly separating the two hydrological characteristics. A discussion of the challenges, limitations and opportunities of monitoring ephemeral flow is presented, and insights into how to address those limitations are provided. Copyright © 2015 John Wiley & Sons, Ltd.     

Internet of Things‐based wireless networking for seismic applications

There is growing pressure from regulators on operators to adhere to increasingly stricter regulations related to the environment and safety. Hence, operators are required to predict and contain risks related to hydrocarbon production and their infrastructure in order to maintain their licence to operate. A deeper understanding of production optimisation and production‐related risk requires strengthened knowledge of reservoir behaviour and overburden dynamics. To accomplish this, sufficient temporal and spatial resolution is required as well as an integration of various sources of measurements. At the same time, tremendous developments are taking place in sensors, networks, and data analysis technologies. Sensors and accompanying channels are getting smaller and cheaper, and yet they offer high fidelity. New ecosystems of ubiquitous wireless communications including Internet of Things nowadays allow anyone to affordably connect to the Internet at any time and anywhere. Recent advances in cloud storage and computing combined with data analytics allow fast and efficient solutions to handle considerable amounts of data. This paper is an effort to pave the way for exploiting these three fundamental advances to create Internet of Things‐based wireless networks of seismic sensors. To this aim, we propose to employ a recently developed Internet of Things‐based wireless technology, so‐called low‐power wide‐area networks, to exploit their long range, low power, and inherent compatibility to cloud storage and computing. We create a remotely operated minimum‐maintenance wireless solution for four major seismic applications of interest. By proposing appropriate network architecture and data coordination (aggregation and transmission) designs, we show that neither the low data rate nor the low duty cycle of low‐power wide‐area networks imposes fundamental issues in handling a considerable amount of data created by complex seismic scenarios as long as the application is delay tolerant. In order to confirm this claim, we cast our ideas into a practical large‐scale networking design for simultaneous seismic monitoring and interferometry and carry out an analysis on the data generation and transmission rates. Finally, we present some results from a small‐scale field test in which we have employed our Internet of Things‐based wireless nodes for real‐time seismic quality control over clouds.