Monitoring of Building Structure by Tiltsensors

This paper discusses about the dynamic monitoring of stability (tilt measurement) of bearing pillar of high-rise building using the electronic measuring system. The electronic measuring system consists of Libela 2800 tilt sensor, input/output device for the AE 2DN tilt sensor, measuring amplifier and also the Spider8 analog/digital converter and the registration equipment (notebook). The basic part of uniaxial tilt sensor creates a frame, on which is among damping plates hung a pendulum (ferromagnetic kernel). The tilt value is determined on a principle of electromagnetic induction by changing the position of ferromagnetic kernel in the reel. The range of pendulum movement is ± 2,5 mm/m and the accuracy of the tilt determination is 0,001 mm/m. The monitored building represents, from the point of constructional view, a ferro-concrete rectangular sceleton, which consists of vertical bearing pillars, on which are guyed longitudinal and transverse girders. The building ground-plan is rectangular with the dimensions of 75 m (distance) and 12 m (width). The building has two underground and six above the ground floors with constructional high of 3,40 m. Whole highth of the above ground part of building is 20,4 m. The pillar tilt was measured in the transverse direction of the building at the level of the second floor using the Libela 2800 electronic sensor. The sensor was situated on the metallic console (L-profile), which was assembled on a lateral side of the circuit bearing pillar at the highth of 8,3 m above the ground level. Together with the tilt monitoring, the outside air temperature in the close area of pillar was measured. The tilt measurement was carried out continuously for 168 hours with the recording frequency of 1 Hz (1 measurement/second). The file of the measured data with 603 950 records was reduced to the file with 1006 records, which corresponds to the record of the every tenth minute. The measured tilt values represent from the mathematical point of view, a time series. The time series of the measured value is a sum of the trend, seasonal, cyclic and the stochastic component. By the application of time series analysis using the regression method and the Box-Jenkinson methodology, we decompose systematic components and isolate stochastic errors, which rise by the measurement. Individual components of time series are expressed mathematically as a function of time. A precise and exact mathematic-statistical data processing guarantees the definite coefficient estimation of the time series function and enables a correct interpretation of results. The difference between the initial and the final tilt value in a range of measurement (168 hours) is 0,218 mm/m and the relative transverse movement of pillar (building) at the highth of 8,3 m would reach the value of 1,81 mm

Measurement of deformations of dynamically weighted constructions

A measure of deformation of the New bridge over Danube in Bratislava during traffic, determination of position of the target moveding on the 2D trajectory, data registration with the DocWork software, computation of coordinates in trajectory points, comparison of the determined and given trajectory, time series analysis, estimation of total station accuracy, accuracy determination by dynamic tests of automatic total station, actual error distribution, interpretation of results

Testovanie robotizovaných univerzálnych meracích staníc v laboratórnych podmienkach =Testing of Robotic Universal Measuring Stations in Laboratory Conditions

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Kinematický test univerzálnej robotizovanej stanice z pohľadu určovania výšok =Kinematic test of universal robotic station from the point of view of heights' determination

Kinematic test of robotic total station Leica TCA 1101 in vertical plane. Measuring system and testing methodology. Trajectory determination of moving observed point in the vertical plane and comparison to the reference trajectory. Test result analysis and heights differencesKinematický test robotizovanej univerzálnej meracej stanice Leica radu TCA 1101 vo zvislej rovine. Merací systém a postup testovania. Určenie trajektórie pohybujúceho sa pozorovaného bodu vo zvislej rovine a porovnanie s referenčnou dráhou. Analýza výsledkov testu a výškové odchýlky23724

Spatial Data Analysis for Deformation Monitoring of Bridge Structures

Weather conditions and different operational loads often cause changes in essential parts of engineering structures, and this affects the static and dynamic behavior and reliability of these structures. Therefore, geodetic monitoring is an integral part of the diagnosis of engineering structures and provides essential information about the current state (condition) of the structure. The development of measuring instruments enables deformation analyses of engineering structures using non-conventional surveying methods. Nowadays, one of the most effective techniques for spatial data collection is terrestrial laser scanning (TLS). TLS is frequently used for data acquisition in cases where three-dimensional (3D) data with high resolution is needed. Using suitable data processing, TLS can be used for static deformation analysis of the structure being monitored. For dynamic deformation measurements (structural health monitoring) of bridge structures, ground-based radar interferometry and accelerometers are often used for vibration mode determination using spectral analysis of frequencies. This paper describes experimental deformation monitoring of structures performed using TLS and ground-based radar interferometry. The procedure of measurement, the analysis of the acquired spatial data, and the results of deformation monitoring are explained and described

Automatizovaný merací systém na kontinuálny monitoring mostov =Automated Measurement System for Continuous Bridge Monitoring

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Monitoring of Bridge Dynamics by Radar Interferometry

The paper presents the possibilities of radar interferometry in dynamic deformationmonitoring of bridge structures. The technology is increasingly used for this purposethanks to high accuracy of realized measurements and possibility to measure deformationat multiple places of the monitored structure. High frequency of realized measurements (upto 200 Hz) enables to determine the most of significant vibration modes of bridgedeformation. This technology is presented on real case study of the cycle bridge over theriver Morava near to Bratislava (Slovak republic). A spectral analysis of vibrationfrequencies is performed by discrete Fourier transformation. The evaluation of correctnessof the obtained deformation is performed by comparison of the results with accelerometerand total station measurements and FEM (Finite Element Method) model of the structure