Applied Mechanics and Materials Vols. 71-78

Abstract: Strong typhoon and earthquake seriously threaten the safety of the life and property of the people. A cost-effective and reliable method is proposed to monitor the natural frequency response of building under excitation of external forces based on the applying digital image correlation method, DIC. The analysis accuracy of this dynamic DIC method is tested and verified by comparing with numerical analysis program, accelerometers, ACC and fast Fourier Transform, FFT. The test results reveal that the analysis accuracy of this DIC method near to the ACC and FFT traditional experimental methods. They demonstrate that using this DIC method to detect dynamic response of building under the excitation of external force has high practicability.

Abstract: By studying the definition of DHT (distinguished hyperbolic trajectory) and existing measure function in phase space, a measure function in the extended phase space is presented in this paper. Effect of system frequency on computation of DHT is explored. Two-dimensional and three-dimensional Duffing systems are taken as examples. The comparison between measure function in extended phase space and that in phase space and the comparison between natural frequency and twice frequency are both given by figures.

Abstract: It is important to search the position of the dangerous sliding surface and to design the reinforcement measures in the study of the slope stability. At present, anti-sliding pile is one of the popular reinforcement measures. In this paper, to optimal design the anti-sliding pile, the residual thrust method (RTM) and genetic algorithm are carried out, while the idea that based on the position of the largest anti-sliding force rather than the most dangerous sliding surface to design the anti-sliding piles is presented. The new idea eliminates the possible unsafe situation. In the process of the optimization design of anti-sliding pile, firstly, chromosomes in the genetic algorithm are coded by using decimal method. Secondly, taking the residual thrust as the fitness function in the genetic algorithm, cross probability and mutation probability are all adjusted according to the fitness of individual population, while the best individual population is saved as population of the next step so that to improve the efficiency. Finally, the sliding surface which needs the largest anti-sliding force is searched out. The reasonability and the reliability of the idea are verified by an example.

Abstract: The external foam glass thermal insulating system on walls has become a new thermal insulation wall system in china's building wall, It is green energy - saving building wall product with good prospect and used for wall thermal insulation of building. In this paper, real-time monitoring with thermal sensor and analysis on temperature for external foam glass thermal insulating system on walls by weathering test in Jiaxing area, and study on temperature distribution for each layer of walls. The experiment showed that, the external foam glass thermal insulating system on walls caused by foam glass insulation layer of adiabatic effect, Interface layer and thermal insulation layer of temperature difference between change significantly, existing 50 °C, which can cause greater temperature stress, and have certain effect of durability for external foam glass thermal insulating system on walls.

Abstract: As a resource-intensive industry, the policy, processes and practices in relation to sustainable development of the construction industry is critical. An important theoretical and practical concern is the creation of indicator systems that assist with the measurement of sustainable urban development. Past research and practice has tended to focus on the measurement of sustainability of the construction projects in relation to the individual projects or at the organizational level. This paper introduces a new measurement of sustainable development for construction industry as a whole so that countries can make comparisons. The model is based on the previous research, the fundamental meaning of sustainable development and the characteristics of the construction industry.

Abstract: The stability of ballast is the key to guarantee the traffic safety. This paper is on the back -ground of ballast settlement monitoring of a bridge constructed by jacking method. And the bridge is located at the 1094 kilometers in Jingha railway line. Monitoring data is analyzed by the time series method. Then we build an ARIMA model for these data. Through the AIC principle, the orders of the model are obtained. Then we predict the settlement of the ballast. By the comparison of predictive value and the true monitoring data, it shows that using time series to analyze the settlement of ballast is reasonable and reliable. Therefore it is a new method to analyze the settlement of ballast. At the same time, this method only relay on the monitoring dates but not on other conditions.

Abstract: In order to inquiry the effect of manganese slag powder on the asphalt mixture pavement performance, With the asphalt mixture specimens produced by adding manganese slag powder of 1.5, 3.0, 4.5and 6.0 % into AC-16I asphalt mixture, the Marshall test, freeze thaw split test and rutting test were conducted. From the diagrams the corrosion resistance and high temperature stability performance and low temperature anti-cracking performance of these manganese slag powder asphalt mixture were determined. It was observed that high temperature stability performance and corrosion resistance began to significantly increase by adding rubber. By the analysis for the pavement performance mechanisms of manganese slag powder asphalt mixture, the change relation between manganese slag powder mixing amount and asphalt mixture pavement performance is presented.

Abstract: According to the reliability theories and the characteristics of transportation networks, the layout adaptability is defined as the coupling and coordination degree of transportation network capacity and demand firstly. Then a layout adaptability model is built adopting the optimization methods, degree of layout adaptability index and coefficient of variation are used to evaluate the adaptability of scale and distribution respectively. Meanwhile, the heuristic algorithm suitable for large scale is designed to solve the proposed model. At last, a numerical example and its results are provided to demonstrate the validity of the proposed model and algorithm.

Abstract: In this paper, the flexibility method of damage identification for transmission tower based on Wigner-Ville Distribution (WVD) signal amplitude vector is forwarded. The damage coefficient equation involving modal parameters and damage parameters is firstly established, on the basis of the linear relation of flexibility matrix and structure parameters. Then, the mathematical deduction of WVD signal term reveals the function relation between WVD signal terms and modal parameters. Lastly, the damage coefficient equation is solved by substituting mode shape vector with the signal amplitude vector of response under suddenly unloading to identified the position and extent of structural damage. A numerical example demonstrates its accuracy for damage identification and excellent noisy immunity.

Abstract: A competitive contractor is the guarantee of project’s success, so how to choose a suitable contractor is critical for the owners. However, among the influencing factors considered in the selection, some can be quantitatively evaluated with clear evaluation criteria while others can only be qualitative evaluated so that no specific scores can be obtained. For the above reasons an improved fuzzy comprehensive evaluation method is proposed in which all assessment factors are divided into two categories and are evaluated with different criteria. The method integrates the advantage of quantitative evaluation and qualitative evaluation. Finally it is verified by a case and the result shows that the application of the improved fuzzy approach to choose contractor is effective and reasonable.