Applied Mechanics and Materials Vols. 578-579

Abstract: Gui Dan intercity cable-stayed bridge adopted the cantilever construction technique, and controlled construction work to ensure that the internal force and linear be similar to the design value. Linear control was mainly carried out by construction position elevation monitoring. Therefore, the construction control point elevation and the axis measure should be strengthened, and the results of each measure stage should be analyzed and compared with the results of monitoring model calculation to modify calculation model, and get a precise simulation model for the construction state. Calculating on account of the bridge state and adjusting the formwork elevation made the bridge linear approach to the design value, to ensure the project quality, safety and duration meet the contract requirement.

Abstract: This paper is aiming to present the whole situation of a three spans prestressed continuous concrete rigid frame bridge’s SHM (structural health monitoring) system. Hardware structure and software exploitation of the system were respectively elaborated combining with the practical application situation, including details of sensors layout, data acquisition, storage and transform, the developing of monitoring and management system, etc. Emphasis is placed on data processing and analyzing which is collected from the bridge in the online continuously, such as modal identification of the measured acceleration responses, calculation of deflection curves in real time, observation of changing strains and stresses on the measuring points.

Abstract: Complex structural pattern and behavior of Large-span steel structure result in famous research of health monitoring technology of this kind structure all over the world. Health monitoring to key parts of large-span steel structures during the construction and service process grasp the stress situation, which can ensure the safety of structures. In this paper, health monitoring project of Jinan Olympic Sports Center is introduced and the basis of test points’ layout is elaborated in detail. The result shows that the system designed is running stable, which means it has certain application value to other health monitoring to major engineering.

Abstract: To solve the problem of the overall reliability evaluation for the specific batch high-reliability monitoring instrument, for the practical problems for zero-failure data of the high-reliability instrument, we propose the batch production instrument overall reliability evaluation method based on E-Bayes theory, and give the point estimation and interval estimation of instrument overall reliability. Case study demonstrates the rationality and feasibility of the proposed method, which provides a reference for the dam safety monitoring management.

Abstract: Complex structural patterns and behaviors promote hot researches of health monitoring technology to large-span steel structures all over the world. Health monitoring to key parts of large-span steel structures during construction and service processes grasp the stress situation, which can ensure the safety of the structure. In this paper, self-developed health monitoring system which use vibrating wire sensor, had been developed to monitor Jinan Grand Theatre Concert Hall. The monitoring results show that there is no significant damage occurred in monitoring positions, which proves a reasonable design and a safe and stable state of the structure. Meanwhile, the self-developed health monitoring system has a high accuracy and good stability and can be widely applied.

Abstract: Cracking of basement structure are common problems in civil building, so it’s most import and difficult to inhibiting cracking of building structures. In this paper, real-time continuous monitoring data of strain and temperature were obtained by embedding sensors in practical engineering, including slab and sidewall of reinforcement concrete, while ambient conditions were monitored to assess their effects. The cracking mechanism of such kind of structure was analyzed based on the investigation and monitoring data. The results show that sidewall is easier to crack than slab for basement structures of civil building, therefore, sidewall cracking of basement structure is the most difficult and key point to inhibit cracking. The measures adopted in this project can effectively reduce crack risk of structure. At the same time, the measured data can provide useful reference to control crack for similar projects and research, and they can also be used to verify the numerical results.

Abstract: Identification of structural parameters by using observation data with noise in time domain was studied. Autoregressive-moving-average (ARMA) time-series model of a vibrating structure was established, and the identification problem of structural parameters was transformed into the identification problem of parameters of ARMA mode1. Based on the assumption of the unknown but bounded noise, an interval algorithm for set-membership identification of parameters of linear time-invariant system was used to seek the minimal hyper-rectangle of parameters, which is compatible with the measurements and the bounded noise, so that the structural parameters can be obtained. Then the Taian pumped-storage power station engineering project illustrates its feasibility and effectiveness.

Abstract: The high formwork system monitoring program of the project example of high formwork support system of fastener-style steel pipe is carried out in detail, including monitoring content , measuring points arrangement, monitoring frequency etc. Based on the analysis of the monitoring data, influential factors of upright tube subsidence and the development trend of high formwork are presented. The site safety control suggestions are given for the high formwork system.

Abstract: In present study, ANSYS finite element method was utilized to analyze the modal of simply supported beam and then the study on damage identification was performed based on modal strain energy method. The comparative analysis of results obtained by modal strain energy changes rate method and modal strain energy index demonstrates that modal strain energy index is an effective damage identification parameter.

Abstract: In this paper, 2 high-rise building models with ladder and cascade irregularities of elevation were tested in a wind tunnel respectively to measure the mean and fluctuating wind pressure distributions. The mean and RMS (root-mean-square) coefficients of the drag, lift and torsion moment on the measuring layer were obtained from the wind pressures. In the direction which the buildings were positive in the wind, the variation of these above mentioned coefficients with height and the power spectrum densities of the fluctuating wind loads on sudden changed positions were analyzed in detail. Compared with the elevation regular tall building, the wind load characteristics of irregular ones were more complicated.