Applied Mechanics and Materials Vols. 204-208

Abstract: Using Skyline and GIS technology, true three-dimensional scene of the Wenchuan earthquake is built in the area affected by the "5.12" earthquake in Sichuan is. And then the system development and model structures are done by the application development software of Visual Studio 2005. The decision analysis platform is built including the functions of the dynamic monitoring based on remote sensing for dammed lake, the lake recognition and feature extraction for dammed lake (rapid identification, the calculation of barrier dam, storage capacity calculation), submergence analysis (upstream submerged analysis, downstream image evaluation), and the function of disaster assessment and risk assessment. It can provide support for the Monitoring, and Early-Warning and aid decision-making for dammed lake.

Abstract: Using penetration resistance methods detect the wall’s mortar strength to masonry structure where in ecological farm of Sichuan Emei, and then obtain the date of field trial. We have calculated the mortar actual strength according technical specification for testing compressive strength of masonry mortar by penetration resistance method, and compare the calculated results with compression tests result, testing specimen from the engineering project field. So we obtain true mortar strength of engineering and corresponding appraisal conclusion.

Abstract: The inner product vector (IPV) was proposed in our previous research as a damage detection algorithm which uses cross correlation functions between vibration responses under band pass white noise excitation. It was verified that the IPV of a structure is a weighted summation of the mode shapes of the structure and the weighing factors for each modes are different. Structural damage detection examples in our previous research shown that the damage location can be correctly detected if the bandwidth of the band pass white noise excitation only covers the fundamental natural frequency of the structure. However, the bandwidth of the band pass white noise excitation may cover first several natural frequencies of the structure in practice. This paper just investigates the damage detection method using IPV under the situation when the bandwidth of the band pass white noise excitation may cover first several natural frequencies of the structure, i.e. the hybrid method using IPV and low pass filter technique. Firstly, the theory of IPVs and the damage detection method using IPV are reviewed shortly. Then, the hybrid method using IPV and low pass filter technique is introduced. Finally, experimental damage detection example of a shear frame structure is presented to illustrate the method proposed in this paper.

Abstract: Damage identification method of space rigid frame was based on change rate with the difference of the first axial modal, which applied to the model of space rigid frame on experiment. With extracting the experimental modal data to calculate the change rate with difference of the first axial model, the result shown that the change rate with difference of first axial model increased significantly in the injury site, and could identify well the damage location of single or multiple injuries, which was an ideal space frame damage labeled amount because of high sensitivity, less work of measure and calculation.

Abstract: With the characteristics analysis of city gas pipeline risk as a foundation, there were many uncertainty factors in gas pipeline risk assessment, the existing risk assessment methods affected assessment results due to its own limitations. The model introduce fuzzy analytic hierarchy process, utilizing its strict logic and comparative principle, the risk factor weight of pipeline were resolved in a good solution, effectively reduce the artificial subjective, greater error and lower quantitative in the existing risk assessment methods. This method is showed through the example in city natural-gas pipeline risk assessment serviceability and reliability.

Abstract: A new structural configuration that named Mega-sub controlled structure (MSCS) is presented in the process of tall buildings, super tall buildings and super tall tower construction. To further improve the structural control effectiveness of MSCS, new hybrid control method which employs active control and adjusts the stiffness of substructure is proposed. At the same time, the control law and dynamic equation are presented that assembling parameter matrixes for the MSCS subjected to horizontal seismic excitation. Then, the influence of adjusting structure parameter and active control parameter on control effectiveness, dynamic characteristic and control force of the MSCS under hybrid control is discussed. Results indicate that, the new hybrid control method proposed in the paper has the ability to develop a high level of response control effectiveness when subjected to seismic action, and a much better control effectiveness will be obtained after parameters optimization.

Abstract: Based on the analysis of the cause of destruction and damage mechanism, safety monitoring and control technology of artificial island construction on radiating sandbar is discussed. Safety monitoring system structure, monitoring plan, control standards and results are presented in this paper. By the basic principles of the finite element numerical method, the feasibility of numerical simulation is demonstrated in the safety monitoring and control.

Abstract: With the development of bridge Structural Health Monitoring (SHM) technique and digital city concept in recent years, the Cluster Health Monitoring (CHM) system for urban bridges, simultaneously real-time monitoring many important bridges in the city has been come into engineering practice. This paper introduces a CHM system of urban bridges using Digital City VPN Network at the city of Hangzhou, China, which is composed of three parts: remote monitoring center, digital city VPN network, and bridge monitoring stations, seven bridges of different types (1 viaduct, 1 overpass, 3 tied arch bridges, 1 PC cable-stayed bridge, and 1 continuous beam bridge) are being monitored. One-year monitoring data have been collected through this CHM system, it indicates that using VPN (Virtual Private Network) technology to achieve online urban bridges cluster monitoring is a safe, reliable and practical methods.

Abstract: For researching the influence of excavation constructing to the environment, we took many measures to monitor the deformation of retaining structure, underground pipelines, groundwater-bit and surface cracks, according to the actual situation of the engineering. Obtained the deformation discipline and force characteristics of the excavation, as well as the discipline of influence. From the results of monitoring, it showed that monitoring is the key to the informative construction of the excavation. Analysis the result of monitoring dynamically, can guide the construction, and adjustment the design. From the engineering, it might have large influence to the environment even the design was reasonable and the retaining system met the security conditions. So, a economic and fitting, security and reliable technology plan for protecting the buildings, roads and pipelines close to the excavation is necessary.

Abstract: Volume linearity change rule was found through contrast test of cement material net liquid of adding superfine slag power, high performance concrete and normal concrete. It is guidance significance for volume change of high strength and high performance concrete how to reduce.