Advanced Materials Research Vols. 446-449

Abstract: In this paper, a few issues are discussed to solve traffic congestion problem in China, which include: city zoning, layout of traffic network, scheduling of working time and increasing road-using efficiency, which are successfully used in Canada and western countries. If the above measures are used in Chinese cities, the current traffic congestion situation can be relieved by improving management without increasing investment cost to much.

Abstract: The bond characteristics between reinforcement and self-compacting concrete under dynamic loads was analyzed experimentally. The tests were conducted by pulling-out with setting strain gauge in reinforcment. The bond stress distribution laws were analyzed with concrete strength change.

Abstract: Aiming at the problem of dynamic analysis of SSI system, the dynamic influence of different parts of foundation soil is studied on the linear elastic assumption according to the actual mechanism of Soil-Structure Interaction (SSI); in addition, a simplified model on the condition of the lumped mass method is put forward and the corresponding motion equations of SSI system are built, which can be a reference for the structural seismic design method considering SSI effect.

Abstract: Buildability seeks to improve efficiency of the overall building process by developing construction sensitive designs. The objective of this study is to investigate the relative importance of the key performance indicators of construction projects with respect to buildability at the design stage in the Malaysian construction industry. To achieve this objective, a questionnaire survey was distributed among key construction personnel to identify the most common buildability attributes in Malaysia. Then, an interview with eight construction professionals was conducted to compare the common buildability attributes with project performance criteria such as time, cost, quality, safety, and environment. The results reveal the equal importance of time and cost for buildability of the building, followed by quality, safety, and the environment.

Abstract: Based on the two different lateral load distributions of the uniform distribution and the inverse triangle distribution, the mechanical characteristic and failure mode of mega steel frame-prestressed composite bracing structure under the different lateral load distributions are studied by using the pushover analytical method in this paper. The results indicate that the failure modes of all members of the mega steel frame-prestressed composite bracing structure under lateral loads are as follows: supports between the giant column limbs appear to yield at first, and then the giant beams, floor beams, giant column limbs, giant Λ-shape steel brace truss in order.

Abstract: Engineering application of the flat tensegrity structures was studied based on the genetic algorithm. Optimal design of the tensegrity structure considering both the size of cross-section and prestress variables is presented and the related optimization problems are studied. Mutual influence and constraints of prestressed state and components were considered.

Abstract: This paper takes the rammed earth buildings as the research object and summarizes their common defects. Finite element analysis method is used to analyze the cause of the common defects. These will provide a reference for improving the seismic behavior of these buildings.

Abstract: It is very difficult to analysis three-dimensional model of composite foundation because there are many unit numbers if piles, soil and plate unit are divided separately. three-dimensional problem is made into the axisymmetric finite element model and numerical analysis is more convenient as the periphery piles of the group piles into the pile system " equivalent ring " . Eamples shows the conclusion is reasonable and the simplified model is feasible.

Abstract: Abstract. The relationship of pre-stressed concrete (PSC) beam natural frequency and pre-stressed force is difficult to described accurately with mechanical model. The past experimental data are collected. Then five unbonded post-tensioned PSC beams are designed. Frequencies and damps are collected in the dynamic experiment of five PSC beams. Radial basis function neural network is constructed to identify the natural frequencies of prestressed beam with different levels prestressing force based on previous test data and new dynamic test beam data. Then the input and output node numbers of neural network are selected and the appropriate training algorithm and expansion coefficient is determined. In order to verify that the network performance, one prestressed concrete beam test data are left to simulation test. Simulation results show that the radial basis function neural network is feasibility to recognize the frequency of PSC beams.

Abstract: Based on theory of Lematire’s equivalent strain of the damage and with the damage of bars of the shallow reticulated spherical shell, on the basis of the nonlinear dynamical foundational equations and introducing dimensionless quantity of shells with uniform thickness, the nonlinear dynamic equation of the shallow spherical shells with initial damage were established by the method of quasi-shells. Then, the critical conditions of that chaos motion of the structure with initial damage are given by the Melnikov function. Finally, further using the digital simulation plotted the plane phase and it approved existence of the chaotic motion. It is found that the natural frequency of shallow reticulated spherical shells considering initial damage becomes bigger and the critical value of chaotic motion is smaller.