试谈工程建筑的变形监测

Unit 19 Deformation Monitoring of Engineering Structure（工程建筑【Engineering Structure或者工程结构】的变形观测）Overview（概述【Overview纵览、总的看法】）Deformation refers to the changes of a deformable body (natural or man-made objects) undergoes in its shapes, dimension and position in space and time domain.（变形指一个形变体【deformable body】（自然或人工物体）在空间和时间范围【domain领域、范围】在形状、尺度和位置上经受【undergo经受、收到】的变化）【变形指一个形变体在空间和时间上经受的形状、尺度和位置的变化】Due to factors such as changes of ground water level, tidal phenomena, tectonic phenomena, etc, engineering structures (such as dams, bridges, high rise buildings, etc.) are subject to deformation.（由于【Due to】诸如地下水位变化、潮汐现象、地壳构造【tectonic构造的、地壳构造的】现象等等的因素【factor】，工程建筑物（如大坝、桥梁、高层建筑等等）受到变形【deformation】影响【subject受影响】）Deformation of engineering structures is often measured in order to ensure that the structure is exhibiting a safe deformation behavior.（工程建筑物的变形经常观测以保证建筑呈现【exhibit展现】安全变形行为）【工程建筑物的变形经常观测以保证建筑物的变形在安全范围内】Cost is more than offset by savings and by improvements in safety both during and after constructions.（As a result, the design, execution and analysis of such surveys are a matter of considerable practical importance.（作为结果，这种测量的设计、实施和分析是一件有着相当大【considerable相当大的】的实际【practical实际的】重要性【importance重要性】的事情）Expanded resource development, the trend towards potentially-deformation-sensitivity engineering and construction projects, and growing geosciencetific interest in the study of crustal movement have all combined to increase awareness of the need for a comprehensive integrated approach to the design and analysis of such deformation surveys.（随着资源扩张的发展，趋势朝向潜在变形敏感度工程和建筑项目，成长的地球科学感兴趣的地壳运动研究已经全部结合来增加全面整合方法的需求的知识变形测量的设计和分析）Therefore it is important to measure this movements for the purpose of safety assessment and as well as preventing any disaster in the future.（因此，为了安全评估【safety assessment安全评估，assessment评估】和未来灾害【disaster】预防【prevent】，变形的测量非常重要）Deformation Monitoring of natural and man-made structures is an engineering survey activity during which repeated observations are made within a specified time frame for the purpose of detecting and quantifying movements of structures.（自然和人工结构的变形观测属于工程测量行为，为了探查和测定【quantify确定数量】结构的变动，在一个指定【specified指定的】时间框架下重复观测）Such monitoring could be of a routine nature (e.g. a dam at high and low water marks) or made necessary by an abnormal condition (e.g. major works near a tall building).（这样的监测可以是Under ordinary circumstances, the interval of time between monitoring and analysis may extend over several days or more.（在普通【ordinary平常的、普通的】情况【circumstances情况、环境】下，监测和分析之间的时间间隔可能延续几天甚至更长时间）Under critical condition, this may have to be nearly instantaneous in order to provide a warning, if necessary.（在危急【critical危急的】情况下，如果需要【if necessary】，为了提供预警【warning警报】这【this 指上句的时间间隔】可能必需是几乎【nearly几乎、密切地】即时的【instantaneous】）The volume of data may consist of only several items, in the simplest routine investigation, or of hundreds or thousands of different data, in very complex or critical conditions.（数据量【volume】可以是，简单的例行调查中，仅由几项组成【consist of由组成】；或者在复杂或危急状况下，由成百上千的不同数据组成）The rate of monitoring may be annually, monthly, weekly, daily, hourly, or even more frequently.（监测频率【rate速率、比例】可以是一年一次【annually一年一次、每年，下同】、一月一次，一周一次、一天一次、每小时一次，甚至更频繁）Detecting and quantifying movements require the use of very precise equipment. （检测和测定变形需要非常精确的仪器。）Such movements are very small and to accurately measure them requires meticulous fieldwork as well as rigorous analysis of observed data.（这种变形非常小，准确测量他们需要细心的【meticulous小心的】外业，还有观测数据的严格【rigorous严格的】分析）Deformation monitoring techniques can be generally divided into geotechnical, structural and geodetic (survey) methods.（变形监测技术可以一般【generally】分为：土木技术的、结构的和测绘的方法）The geodetic methods (highly understood by engineering surveyors) that can be used are Global Positioning System (GPS), close-range photogrammetry with the use of terrestrial camera, precise theodolite and levels, total station, laser scanners, and vibration monitoring systems, a very long baseline interferometry and satellite laser ranging.（测绘法（非常为工程测量人员所理解）可以使用的是GPS，使用地面摄影机【terrestrial camera地面摄影机】的近景摄影测量，精密经纬仪和水准仪，全站仪，激光扫描仪，和振动【vibration振动】监测系统，甚长基线干涉测量【very long baseline interferometry】和卫星激光测距）A number of traditional surveying techniques have also been modified and applied to yield the highest possible accuracies.（许多传统测量技术也经过改良【modify改良】并用于产生【yield产生】尽可能最高的精度）Geodetic measurements involve the observables of horizontal angles, or direction; spatial distance; and height difference.（测绘方法测量【即，geodetic型的变形监测测量工作】包括水平角或方向的观测【observable观测n.，词性变换】；空间距离；高差【height difference】的观测【observable观测n.，词性变换】）Geotechnical measurements consist of similar geometric quantities, but over a much smaller extent than for geodetic measurements (distances to a few meters rather than hundreds of meters), as well as measurements of the physical or mechanical state of the object being monitored.（土木技术方法的测量工作由类似的几何量组成，但是比测绘法测量（距离上从几米），The survey methods can be further subdivided into the survey network method and direct measurement method. （测量方法可以进一步细分为【subdivide细分】测量网和直接测量法。）In geodetic method there are two types of geodetic networks, namely the reference (absolute) and relative network.（测地学方法中有两种类型的测量网，被称为参考（绝对）网和相对网）Monitoring Schemes（监测方案）A deformation survey requires the assessment of project expectations.（变形观测需要项目预期的估计）This would include accuracy statements in order to detect the movement and external effects of the object suspected of movement.（包括The observation period and frequency must also be established. The selection of most appropriate technique or combination of techniques for any particular application will depend upon cost, the accuracy required, and the scale of the survey involved. Therefore several aspects related to the optimal design of the networks, measurement and analysis techniques suited to the monitoring surveys have to be considered. The design of monitoring scheme should satisfy not only the best geometrical strength of the network but should primarily fulfill the needs of subsequent physical interpretation of the monitoring results. Selection of monitoring techniques depends heavily on the type, the magnitude and the rate of the deformation. Therefore, the proposed measuring scheme should be based on the best possible combination of all available measuring instrumentation. A common feature for both geodetic and satellite methods in monitoring scheme involves the following three stages:The design of the scheme required to undertake the deformation survey must consider the instrumentation to be used, the geometry of the network, the location of observables points, the types of observables, preanalysis of possibly environmental influences, and frequency of observation of the observables to the expected form of deformation. The reference datum must be appropriate, secure, and stable and not influenced by the suspected or anticipated movement within the local site area.The execution process that runs a designed network into reality should be carefully done, which deals with both the documentation of the proposed network stations and the actual field measurement techniques in which the equipment used must be adjusted and in good working order with appropriate calibrations completed.Data processing deals with the processing and analysis of the collected geodetic data, quality assurance and control that must be followed to confirm the expected results. Processing occurs simultaneously with capture and subsequent to capture with different tasks at each time. During capture, the points involved must be identified an ancillary observations, such as temperature, must be requested along with dealing with the observation. The observation would likely be repeated in order to obtain a mean and an estimated of its standard deviation and the mean would be compared with the predicted or most recent value as a check on consistency. Subsequent processing would further reduce the observation and the data into series file or campaign file following the structure of the data management system. Consistency would be checked either again for the observation or further for the reduced data.Trend AnalysisOnce more than one campaign has been observed or once enough data are contained in a series, it is necessary to determine the tendency that is being exhibited in space or over time or both. The observed tendencies are then brought together to suggest possible forms of models, i.e., the choice of parameters to be estimated. The trend analysis acts as a filter by extracting the behavior of interest, e.g., the annual trend or rate, from the time series, e.g., the noise being the seasonal cycle that is a reaction to the change in temperature. The extr