变形监测研究现状综述外文翻译资料

 2022-12-22 17:38:12

Distortion monitor research present situation summary

[ Abstract ] this article on from distortion monitor technology, monitor data thick difference recognition, displacement analysis and distortion forecast and so on several aspects, summary distortion jail Measured the research the present situation, carries on the thorough analysis to the existing distortion monitor theory and the technical method serviceability and its the existence question, and discusses its development tendency.

[ Key word ] distorts the monitor; The displacement analyzes; Distortion forecast; Research present situation

1 introduction

The distortion (Deformation) is refers to the deformable body in under each kind of influence factor function, its shape, size and position in time air zone change. The nature has each kind of form the distortion, like the earths crust deformation, the landslide, mining cave in, the high-rise construction swings as well as the dam distortion and so on. Studies and in the project domain distortion said, when the distortion quantity does not surpass the certain scope, cannot cause the harm, but when the distortion quantity surpasses the permission scope which the deformable body can withstand, then often can bring the serious disaster. The earthquake, the volcanicer uption, the crag collapse, the landslide, the dam and the bridge breaks down collapses and so on, all is the typical distortion destruction phenomenon. These disasters occurrences, seriously harm humanitys life and property security, the various countries every year therefore suffers massive loss. Because many disaster soccur rences and the distortion have the extremely close relation, thus, the distortion monitor research in domestic and foreign has received the widespread value.

2 distortions monitors technology

Along with the science and technology progress and to the distortion monitor request unceasing enhancement, the distortion monitor technology also in unceasingly develops. Before 1980s, the distortion monitor mainly is uses the convention ground survey technology and certain special survey methods. The convention ground survey, is uses routine measurement instrument station the and so on the altazimuth, level, distance gauge, entire station meter distortion value. Its merit: (1) Can provide the deformable body whole the strained condition; (2) Is suitable to the different monitor precision request, the different form deformable body and the different monitor renvironment; (3) May provide the absolute deformation information. But field operation work load big, the stationing the topographical condition influence, is not been easy to realize the automate dmonitor. The special survey method including the strain-gauging, surveys and inclines the survey, it has the survey process simply, may monitor the deformable body interior the distortion, is easy to realize merit and so on automated monitor, but usually only provides partial and the relative distortion information.

In the recent 10 years, the short distance photo grammetry in the tunnel, the bridge, the dam, the landslide and aspect and so on high-rise construction distortion monitor obtained the wide spread application, its monitor precision may achieve the mm level. Short distance photo grammetry merit: (1) May absorb under the instantaneous precise recording the object the information and the position relations; (2) May use in the rule, is irregular or can contact the object the distortion monitor; (3) In the picture information rich, is objective and also may the long-term preservation, is advantageous tocarries on the distortion the contrast analysis; (4) The monitor work simple, fast, is safe. In recent years develops numeral photo graphic survey technology, also in distortion monitor and so on the building and landslide obtained the successful application, and demonstrates the good application prospect. At present distorts the monitor newest technology is the distortion monitors the robot the application.

The GPS global positioning system application has brought a profound revolution for the survey technology. According to the material in troduced that, overseas starts from the 1980s with GPS to carry on the distortion monitor. In recent years, our country in carried on the landslide using GPS to distort, the dam distorts, mining area aspect and so on ground settlement and earths crust deformation monitor, has done the massive research work. The GPS distortion monitor mainly has following merit: (1) The precision is higher, is bigger than 10km when the base length, its relative accuracy may achieve 10-6~10-7,obviously surpasses the tradition geodetic survey monitor technology;(2) The monitor the weather condition limit, may not carry on the all-weather monitor; (3) The monitor, the record, calculated entire automatically completes, has guaranteed monitor achievement objective and the reliability, simultaneously greatly reduced monitore dpersonnels labor intensity; (4) Between the test point does not need the inter visibility, the point sort not the topographical condition limit; (5) The test point three dimensional coordinates may also determine; (6) Its fishing net expense approximately for convention geodetic survey technology fishing net expense 1/6~1/3. Along with the computer technology, the wireless communication technology, the spatial technology and the geoscience rapid development, '3S' (GPS,GIS, RS) the technology has developed from respective in dependence enters mutually integrates the fusion the stage. '3S' the technical integration may for analyze and studies between each kind of information the reciprocity provide the technical strut, specially tense GIS (Temporal GIS, is called TGIS) the technical application, it may describe the four-dimensional space geological phenomenon, besides has general GIS the function, but also can record studies in the region each ge

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变形监测研究现状综述

【摘 要】本文就从变形监测技术、监测数据粗差的识别、位移显著性分析和变形预报等几个方面,简述变形监测研究的现状,对现有变形监测理论和技术方法的适用性及其存在的问题进行深入分析,并探讨其发展趋势。

【关键词】变形监测;位移分析;变形预报;研究现状

1 引 言

变形(Deformation)是指变形体在各种影响因素的作用下,其形状、大小及位置在时空域中的变化。自然界存在各种形式的变形,如地壳形变、滑坡、采矿塌陷、高层建筑的摆动以及大坝变形等。就地学和工程领域中的变形来说,当变形量不超过一定范围时,不会造成危害,而当变形量超过变形体所能承受的允许范围时,则往往会带来严重的灾难。地震、火山爆发、岩崩、滑坡、溃坝和桥梁的垮塌等等,都是典型的变形破坏现象。这些灾害的发生,严重地危害人类的生命财产的安全,世界各国每年都因此而遭受巨大的损失。由于许多灾害的发生与变形有着极为密切的联系,因而,变形监测研究在国内外受到了广泛的重视。

2 变形监测技术

随着科学技术的进步和对变形监测的要求的不断提高,变形监测技术也在不断地发展。在20世纪80年代以前,变形监测主要是采用常规地面测量技术和某些特殊测量手段。常规地面测量,是采用经纬仪、水准仪、测距仪、全站仪等常规测量仪器测定点的变形值。其优点:①能够提供变形体整体的变形状态;②适用于不同的监测精度要求、不同形式的变形体和不同的监测环境;③可以提供绝对变形信息。但外业工作量大,布点受地形条件影响,不易实现自动化监测。特殊测量手段包括应变测量、准直测量和倾斜测量,它具有测量过程简单、可监测变形体内部的变形、容易实现自动化监测等优点,但通常只提供局部的和相对的变形信息。

近10年来,近景摄影测量在隧道、桥梁、大坝、滑坡及高层建筑变形监测等方面得到了广泛应用,其监测精度可达到mm级。近景摄影测量的优点:①可在瞬间精确记录下被摄物体的信息及点位关系;②可用于规则、不规则或不可接触物体的变形监测;③像片上的信息丰富、客观而又可长期保存,有利于进行变形的对比分析;④监测工作简便、快速、安全。近几年发展起来的数字摄影测量技术,也在建筑物及滑坡等变形监测中得到了成功的应用,并显示出良好的应用前景。目前变形监测的最新技术是变形监测机器人的应用。

GPS全球定位系统的应用给测量技术带来了一场深刻的革命。据资料介绍,国外从20世纪80年代开始用GPS进行变形监测。近年来,我国在利用GPS进行滑坡变形、大坝变形、矿区地面沉陷和地壳形变监测等方面,做了大量的研究工作。GPS变形监测主要有如下优点:①精度较高,在基线长度大于10km时,其相对精度可达到10-6~10-7,明显优于传统大地测量监测技术;②监测不受天气条件限制,可以进行全天候监测;③监测、记录、计算全自动完成,确保了监测成果的客观性及可靠性,同时大大减小了监测人员的劳动强度;④监测点之间不需通视,选点不受地形条件限制;⑤监测点的三维坐标可以同时测定;⑥其建网费用约为常规大地测量技术建网费用的1/6~1/3。随着计算机技术、无线电通讯技术、空间技术及地球科学的迅速发展,“3S”(GPS、GIS、RS)技术已从各自独立发展进入相互集成融合的阶段。“3S”技术集成可为分析和研究各种灾变信息之间的相互关系提供技术支撑,特别是时态GIS(Temporal GIS,简称TGIS)技术的应用,它可以描述四维空间的地质现象,除具有一般GIS的功能外,还能够记载研究区域内各种地质现象随时间的演绎过程,这对滑坡等地质灾害的监测预报具有非常重要的作用。因此,研究基于“3S”集成的变形监测系统,是变形监测技术的一个重要发展趋势。另外,利用测量机器人进行工程建筑物的自动化变形监测,一般可根据实际情况采用两种方式:一种是固定全自动持续监测方式;一种是移动周期性网观测方式。在工程建筑物的变形自动化监测方面,测量机器人正渐渐成为首选的自动化测量技术设备。

3 位移显著性分析方法

变形监测网两期平差后求得的坐标差,可能是位移量,也可能是观测误差的反映(即监测点并未移动)。因此,在变形监测数据处理中必须进行位移显著性分析。现有的变形监测网位移分析方法,可归纳为单点位移显著性分析、整体位移显著性分析和稳健迭代权估计3种方法。

单点位移显著性分析有比较法和t检验法。比较法使用简单,但比较粗糙,t检验法效果较好,目前应用广泛。Pelzer在1971年提出了目前广泛采用的整体位移显著性分析的平均间隙法。

稳健迭代权估计法是首先由任意的自由网平差方法对两期网进行平差,求得坐标的两组最小二乘解及坐标差。然后,通过单点稳定性检验和选取权函数,不断地改变平差参考基准中的基准权,逐次迭代计算,最终使稳定点的位移权为1,活动点的位移权依其位移量大小取小于1的正数。由于稳健迭代权估计具有较强的定位模型误差的能力,用于位移分析效果较好,尤其当存在较大位移时效果更好。但上述各种位移显著性分析方法均存在如下缺点:①对于具体的形变网,其点位移动情况不同、观测值预处理时选择的平差基准不同,对位移的判定将得出不同的结论,有时甚至得出错误的结论;②如果两期监测的精度不同,即两期的母体单位权方差不一致,则不能应用;③进行假设检验时,显著水平的选取带有极大的主观随意性。因此,位移显著性的分析方法尚需进一步研究和完善。

4 变形分析与预报方法

由于变形体的结构、组成物质的物理力学性质、外力作用的复杂性和不确定性,建立合适的确定性模型困难,因此,通过揭示变形监测数据序列的结构与规律,建立动态预测模型,反映变形特征,推断变化趋势,就成为一种有效的方法。近年来,用数学模型来逼近、模拟和揭示变形体的变形和动态特性成为新的研究方向,其中比较有代表性的模型是:确定函数模型、回归分析模型、时间序列分析模型、灰色系统模型、神经网络模型、马尔柯夫模型

确定函数模型的主要特点是:利用变形体的力学性质和物理参数,建立荷载与变形之间的确定性函数关系,是一种具有“先验”性质的预报方法。建模不需要大量的变形监测资料,在变形监测的初期就能进行变形预报。但复杂变形体的变形难以用确定的理论关系式来表达,采用有限单元法计算时,由于变形体不可能是完全的弹性体,会由于弹性假设而引入误差,故这种方法未能推广应用。回归分析模型是依据实测数据用最小二乘法确定回归方程的参数,所建模型属于经验模型或“后验模型”的范畴。这类模型的建模过程简单,使用方便,目前在国内外应用广泛。如果采用扩展回归法,则预测精度会更高。但在监测数据较少或变形体发生以往未曾经历的变形情况时,回归模型的预报偏差较大。该模型又分为以下几种:①曲线拟合,此法适合于各种光滑曲线来近似描述事物发展的基本趋势。②多元线性回归分析,该方法通过分析所观测的变形(效应量)和外因(原因)之间的相关关系,来建立荷载-变形之间关系的数学模型。

逐步线性回归模型是建立在F检验的基础上逐个接纳显著因子进入回归方程。该方法应用于变形观测数据处理是一种静态的数据处理方法,所建立的模型是一种静态的模型。时间序列分析模型用于变形分析有较好效果,并可对“动态”变形用Fourier变换法进行分析。但该法在模型适用性和时序间距等方面有待进一步研究。该方法是建立在输出等价原则上的等价系统的数学模型。灰色系统模型,部分系统已知部分系统未知的系统称为灰色系统。灰色系统理论是研究解决灰色系统分析、建模、预测、决策和控制的理论。灰色系统模型的优点是在数据样本较少(4个以上)时就可建模预测,能够克服回归分析方法的不足,当监测数据序列中蕴含有确定性的指数函数规律时,其预测精度高。但若监测数据为不等时距,必须进行变换。

5 展 望

随着变形分析研究的全面开展,尤其是控制论、信息论、运筹学、系统动力学、模糊数学和灰色理论构成的系统科学体系的兴起以及在变形分析研究领域中的重大应用,在测绘界,权威测量学家已普遍感到,变形分析已经到了致力于变形动态模型的研究与应用。非线性理论的迅速发展,特别是突变论、分形论、混沌动力学理论以及神经网络理论的出现与应用,为自然界复杂现象的研究带来新的方法。在自然灾害的预测预报研究方面,人们开始运用突变理论进行滑坡危险性判断与预测,用分型理论研究地震发生前后的维数变化等。随着现代科学技术的发展和计算机应用技术水平的提高,各种理论和方法为变形分析与变形预报提供了广泛的研究途径。

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