Advanced Materials Research Vols. 243-249

Abstract: There are much mountainous areas in China. Mountainous traffic is greatly different from the plain.Interrelation of mountain landform and the traffic there is analyzed first. Because mountainous traffics and towns are greatly influenced by the disasters there, chain reaction of disasters and its dispersing impact are in particular demonstrated. The course of a disaster could be divided into several stages. Through analyzing their characteristics, solutions in turn to treat disaster are listed. A case is given to elaborate the disaster and its impact on the traffic and town.

Abstract: In order to investigate the debonding failure mechanism,the distributions of interfacial shear stress between cracks and the influence of preload of on the ultimate load and interfacial shear stress,one reference beam and five beams strengthened with CFRP and steel plate at different level of perload were tested and analyzed.The experimental result indicated that the perload level has less influence on the ultimate capacity.Moreover,when debonding failure of sheet-end interface of concrete beams strengthened with CFRP and steel plate is avoided,the debonding failure of reinforced beams at perload level will occur in the position of midspan.At last,on the basis of cross-sectional equilibrium and compatiable conditions,an analytical model of interfacial bond shear stress is obtained, meanwhile the analytic model favorably matched with the experimental results.

Abstract: To fully integrate the unique architectural style of the coliseum in Huai’an Sports Center, spatial truss-arch is used as the major structure and the truss-arches are connected by horizontal truss to form a composite structure with truss-arch and folded plate. In this paper the design concept and structure system is described firstly. And then, the main calculating results of its linear static, spectral response and overall stability are shown in detail.

Abstract: Static load tests are conducted for two outer-plated steel-concrete continuous composite beams. Performance of the tested beams, including the load-deflection curve，load-strain curve，load-moment curve, plastic-hinge region and the crack of concrete flange of specimens, is analyzed. The test results indicate that effective cooperation can be achieved by the shear connector between the concrete part and the outer-plated steel beam; the composite beams have good overall performance. The concrete filling inside the U-shaped steel beam enhances the global and local stability of the outer-plated steel beam. At the bearing capacity limit state, the plastic strain on sections of both the negative and positive maximum moment develops fully so that ideal plastic hinges are formed relatively. At the serviceability limit state, the deformation and the crack width of continuous composite beams can be controlled effectively.

Abstract: Bonding fiber reinforced polymer (FRP) laminates to the tension face of RC members has been proven to be an effective method to improve the flexural strength. However, structural members are not only needed to have adequate strength, but also to have adequate performance of deformation at service load levels. To evaluate the deflection of externally FRP-strengthened RC beams, a total of 18 RC beams, including 16 beams strengthened with CFRP laminate under different preload levels and 2 control beams, were tested. Based on the assumption that the section of the beam behaves a tri-linear moment-curvature response characterized by pre-crack stage, post-crack stage and failure stage and the test results, this paper presents a modified model to evaluate the deflection of CFRP-strengthened RC beams. The present modified model was verified by the similar test results, and shows a good agreement with the test results.

Abstract: Folded plate structure with flat truss is applied in the roof steel structure of the natatorium in Huai’an sports center. In this paper, mechanical analysis on loading case and dynamic characteristics of the roof steel structure is accomplished. Overall stability analysis is also completed by FEM software STRAND7. Analysis results indicate the scheme is in accordance with safety and aesthetic is appropriately designed, which could figure out that bearing capacity and seismic performance of the folded plate structure are satisfactory.

Abstract: Seismic performance under low cyclic experimental study on the six of constructional column- core column composite reinforcement concrete block masnory wall is preasented in this paper, considering the height-width ratio, window hole and without window hole, the setting of the horizontal reinforcing steel bar in the walls. Failure process and failure pattern, hysteresis characteristics, bearing capacity, ductility, skeleton curves, the viscous damping coefficient, stiffness and steel strain change the properties are analyzed, respectivily. Test results shown that this kind of composite reinforced concrete block masnory system has better seismic performance.

Abstract: It is important to determine the shear resistance of the cold-formed steel stud composite wall which is a main component of the light-weight steel housing. A finite element model (FEM) was introduced in this paper to simulate the shear resistance of this type of composite walls. The material and geometric nonlinear were considered, and the single side gypsum walls and columns are simulated by shell elements, respectively while the screws and frame are modeled by coupling method. The results obtained from FEM were verified against the others’ experimental results. Parametric study is carried out with materials of wall panel, strength of steel members, stud spacing, wall height, and screw spacing to analyze the shear-carrying capacity of the walls. A simplified formula for shear resistance of the composite wall was proposed based on parametric analysis.

Abstract: Debonding failure is commonly observed in FRP-strengthened RC beams. It can be classified into two types: plate end debonding and intermediate crack induced debonding. Intermediate crack induced debonding is the main failure mode in FRP-strengthened RC beams.There is no specialized experiment study on this failure mode. To investigate intermediate crack induced debonding failure of FRP-strengthened reinforced concrete beams, 9 CFRP-strengthened reinforced concrete beams were tested. Based on the investigation of the strain in the FRP laminates, the width of the main crack and tributary crack, as well as the phenomena of the test beams, the whole debonding process can be separated into three stages: initial debonding stage, stable debonding stage, and the final debonding failure. The fundamental reason of intermediate crack indued debonding are the opening-up of intermediate crack and the flexural deformation induced high interfacial shear stress and peeling stress. When the principal tension stress acting on the concrete substrate exceeded the tension stress of concrete, the CFRP laminate would debond from the concrete substrate.

Abstract: The nearby reservoir water impounding causes the water level rise of Minjiang River where Leshan Giant Buddha locate at. It may affects the microclimate of the Buddha area, and the possible microclimate changes mainly include the temperature and rainfall, for the reason of protecting the long-term stability of the cultural relics, it is necessary to assess the rock weathering sensitivity of the Leshan Giant Buddha sandstone because of these changes. Via the indoor temperature cycling test, humidity cycling test and humiture cycling test, the stone samples’ elastic wave velocity and mass are determined in different condition of temperature and humidity. And the influence to the Buddha stone weathering caused by the changes of temperature and humidity is analyzed.