Advanced Materials Research Vols. 594-597

Abstract: According to design requirements, to reduce the construction difficulty for crane beam on rock wall in underground main power house of JinpingII hydropower, and to condense construction time limit for a main building, theconcreting time for crane beam on rock wall is needed to be specially analyzed. As the property of JinpingII hydropower station is under high field stress, numeric analysis uses rock mass deterioration constitutive model RDM. Considering the special mechanics behavior between concrete and rock wall, softening element and interface element are used respectively to make the simulation. By analyzing the stress for different placement times of crane beam of main house, it is shown that placement timing has certain extent effect on upper stress of crane beam. As a result, in order to assure stability of constructing and operating periods of crane beam, the calculation and analysis suggest that the concreting should be after the third excavation, but certain structural joint need to be installed.

Abstract: Part of the east wing belt roadway in -450 level east, NO.1 mining area, Dashu village coal mine, Jizhong Energy Fengfeng Group was under the 172102 working face’s stop mining coal pillar. The phenomenon of the stress concentration was obvious, the pressure of the roadway was large and the surrounding rock damaged severely. Concrete filled steel tube supports were used in stress concentration region. The supports type was φ194×8mm, and distance between supports was 800mm. They were of rapid construction speed, better supporting effect. The numerical simulation results also showed that the concrete filled steel tube supports can reduce deformation of the roadway surrounding rock in stress concentration region effectively.

Abstract: In this paper, numerical study results using ABAQUS are presents to demonstrate the failure modes and the behaviour of endplate connection with different parameters at elevated temperature. Numerical models and simulation methodology are first validated by the comparison to experimental data. Then the behaviour of beam and the failure modes endplate connection with different parameters- including beam span, beam load ratio, column cross section, endplate type- are studied. It can be concluded that all these parameters has a effects on the behaviour of the connection, while some parameters has a great influence on the survivability of the joint.

Abstract: Due to the axial curvature and the eccentric vehicle loads, bending-torsion couple effects will be generated in the curved steel-concrete composite box beam bridges. To study the bending-torsion couple characteristics, six steel-concrete composite box model beams are tested under the bending-torsion couple loads, with the initial torsion-bending ratios and shear connection degrees as the design parameters. The ultimate bearing capacity, section strain, and interfacial slip of the steel-concrete composite box beams are measured. The test results show that, the fully connected composite beams mainly express bending or bending-torsion failure modes, but the partially connected composite beams are mainly sliding failure modes. The existence of the torque doesn’t have great influence on the ultimate bearing capacity and bending moment of the composite box beams. Under the bending-torsion couple loads, there are not only the longitudinal slip between the steel girder and concrete slab of the composite box beam, but also the transverse slip perpendicular to the beam axis.

Abstract: The large span roof structures need to be designed to withstand wind and snow loads. This paper presents practical design method of snow load for low rise roof structures in GB 50009-2001(China), ASCE 7-10, AIJ 2006, NBCC 2005 and Euro code 2003, and discusses approaches to improving consistency and uniformity of methods by comparison of the differences and similarities of wind and snow provisions in the codes of various countries.

Abstract: A displacement-based optimization design method of RC structure was proposed by combining direct displacement-based design method with nonlinear programming technique. To avert the influence of target displacement, the stationary constraint displacement was presented, and the target displacement can be updated during the optimal design process. Principle of virtual work and Gaussian integral method was employed to simplify the explicit relationship between horizontal displacement and the section dimension. Comparison analysis of the local optimal results corresponding to different displacement shapes was conducted to achieve global optimal design. The numerical tests presented demonstrate the computational advantages of the discussed methods and suggesting that the proposed method is a reliably and efficiently tool for displacement-based optimal design.

Abstract: The resonance phenomenon may occurs when the frequency of the external load which is carried on the structure similar to the structure nature frequency. The structure is unsafe.The displacement and internal forces of structure can reach the maximum. This paper take modal analysis for point-fixed glass facades,get the natural frequencies and modes,calculate various parameters effecting structural frequencies and the variational rules of those frequencies by changing those various parameters.

Abstract: For concrete double mixing with slag powder and fly ash, in order to more accurately measure the temperature and crack, the calculation model of transient temperature field is established by finite element method, as taking the temperature controlling of massive concrete mixing with slag powder and fly ash of pile cap in Dongsha Bridge for example. The effect of cooling water temperatures and pouring temperature on temperature field of pile cap are analyzed. The results show that the cooling water temperature has less effect on central maximum temperature in early days, but more effect on cooling rate in late stage. The pouring temperature has more effect on maximum temperature. The temperature peak will rise with pouring temperature increasing, but the time of temperature peak arising is invariant.

Abstract: At present, the finite element method is used to calculate the strength and deformation of the steel transmission pole less. Using ANSYS to model steel transmission pole, loading, analysis, the results show that, the traditional method of strength calculation and finite element analysis results are very close, the traditional method of deformation calculation and finite element analysis results has a certain bias. As long as the establishment of three-dimensional model of the steel transmission pole, the applied load and boundary conditions to meet the actual, finite element analysis can provide a more reliable basis for the design and verification of the steel transmission pole.

Abstract: The pushover analysis had been done for a R.C frame model, vertex displacement、base shear 、 appear order and development situation of plastic hinges of the model had been get in different steps of pushover analysis, The pictures of basal shear-vertex displacement and response spectrum displacement-accelerated speed had been studied. The analysis results show that ,the R.C frame model correspond with the seismic design principle of stronger column weaker beam ’,and meet the seismic requirements of the first stage and the calculating resistance to collapse of the second stage.