Time filter

Source Type

Cai Y.,Tongji University | Cai Y.,Shanghai Urban Construction Design Research Institute
Applied Mechanics and Materials | Year: 2011

With uniaxle penetration test method and Triaxial Shear method test, the shear strengths for asphalt mixture were analyzed. It turns out that the result of triaxial shear test is a little conservative than that of uniaxle penetration test. Then reasonable structure factor for shear strength should be considered by uniaxle penetration test. Uniaxle penetration tests at different temperatures revealed there were a linear correlation between shear strength and temperature. The asphalt was not the main fator of shear strength at high temperature. © (2011) Trans Tech Publications.

Dan D.-H.,Tongji University | Chen Z.-H.,Tongji University | Yan X.-F.,Shanghai Urban Construction Design Research Institute
Shock and Vibration | Year: 2014

The segmented vibration-governed equations and their general solutions for cables acted upon by intermediate transverse forces are derived by applying Hamilton's principle. Including the effects of sagging, flexible stiffness, clamped boundary conditions, and inclination angle of the cable, the element-wise dynamic stiffness for each cable segment, split into segments having unique transverse forces, is derived. By using methods from the global stiffness assembly process of FEM, the global level of the cables' dynamic equilibrium equation is obtained, and, as a result, the final closed-form formula of transverse dynamic stiffness is derived. Additionally, the corresponding analytic form, without considering sagging effects, is also obtained. Case studies are conducted on the aspects of accuracy, rationality of the distribution on the spatial field, and frequency domains of dynamic stiffness calculations. By comparison with the Guyan-based static FEM reduction method, it is shown that the result obtained from the proposed closed-form solution, which includes sagging effects, is exact and rational, thus creating a powerful tool in transverse vibration analysis. © 2014 Dan-hui Dan et al.

Xie S.,Shanghai Urban Management College | Ding K.,Shanghai Haoyun Water Works Planning and Design Co. | Liang Z.,Shanghai Jianfeng College | Ge M.,Shanghai Urban Management College | Zhang X.,Shanghai Urban Construction Design Research Institute
World Information on Earthquake Engineering | Year: 2014

Load experiment was adopted for completion quality test on certain bridge. During the test process, tiny cracks appeared the bottom of bridge beam. By analyzing, the tiny cracks would not affect the structure security of the bridge. Carbon fiber plastering was used to repair and reinforce the cracks. Results show that the effectiveness is good, and the expected purpose is achieved.

Fan X.-P.,Tongji University | Huang M.-S.,Tongji University | Wang H.-R.,Tongji University | Wang H.-R.,Shanghai Urban Construction Design Research Institute
Yantu Lixue/Rock and Soil Mechanics | Year: 2016

During the long-term service period of the municipal solid waste (MSW) landfill, the strength parameters of the waste body change as time elapses. In analyzing the stability of the MSW fill, we decompose the waste body into layers according to the age, and propose two failure mechanisms based on the upper bound theorem of limit analysis, including the rotational and translational mechanisms. To confirm the above two mechanisms, a comparative analysis is performed on a slope composed of horizontally soil layers, and then the case of the landfill slope layered by aging is analyzed by assuming the two mechanisms above. It is shown that the factor of safety and failure mechanism by the upper-limit solution of limit analysis are very close to those deduced from the reduction finite element analysis, and the critical failure mode obtained by the multi-block mechanism is more reasonable. In addition, the stability of the Coll Cardús MSW landfill in Spain with complex layers by aging is analyzed, and the results are consistent with those of the reduction finite element analysis. Our results indicate that, as the fill age increases, the landfill slope will become more and more stable in the absent of pore pressures. The fill age can be divided into low, middle and high levels. The safety factor of the landfill slope layered by aging is between those of the homogeneous slopes with middle to high aging levels. © 2016, Academia Sinica. All right reserved.

Xiao K.,Tongji University | Yang B.,Tongji University | Zhang Q.,Tongji University | Jia B.,Tongji University | Lu J.,Shanghai Urban Construction Design Research Institute
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2015

Quasi-static tests were performed on two one-bay, two-story specimens built at one-half scale to study the structural cyclic behavior of precast reinforced concrete frame with infill slit shear walls (PRCFW). Overall behaviors of the PRCFW structure such as deformation and ductility, energy dissipation capacity, strength and stiffness degradation were inspected. Influence of the shear connectors between the frame and infill walls on the overall structural behavior was also analyzed. Experimental results show that the designed shear connectors perform well during the loading process, and no shear fatigue failure or anchorage failure occurs. Prefabricated vertical slits in the infill walls have little effect on overall elastic stiffness of the specimen, but the vertical slits prevent the development and penetrating of diagonal cracks. The main deformation of the wall segments between vertical slits is bending deformation after the structure yields. The post-peak strength and stiffness decrease slowly, which offers the whole PRCFW structure a good ductility and energy dissipation capacity. Columns under different axial compression ratios and cast-in-place joints basically remain intact, while damage mainly occurs in the infills walls and beam ends, satisfying the principle of 'strong joint-weak component, strong column-weak beam' and the design prospective of dissipating earthquake energy by the damage of infills walls. Based on the test and analysis results, a few design recommendations including supplementary design rules and detailing requirements for this type of structure are proposed at last. ©, 2015, Science Press. All right reserved.

Discover hidden collaborations