Applied Mechanics and Materials Vols. 204-208

Abstract: The article analyzes the prestressed concrete cable-beam structure system when it is on the condition of sigle span and sigle direction.The paper summaries the application of cale and presents the design ideas of cable,arranges reasonably the shape of cable,deduces the equation of cable when it is under the condition of curve,and gets the conclusion. The height of the middle bar decides the height of the cable-beam,so it limits the ratio of sag and span to make the reasonable design in the paper and to embody the superiority of prestressed concrete cable-beam structure system.

Abstract: The steel deep beam infilled steel frame is a new type of lateral resisting system. It can realize the modulation of structural stiffness in a certain range. By utilizing ANSYS software, hysteretic property of the different ribbed steel deep beams was carried out. The result shows that primary stiffness, yield load and ultimate capacity of the ribbed steel deep beams can be effectively improved. The hysteretic loops are replete, which means better energy dissipation capacity.

Abstract: Energy dissipation structure is favored by designers because the earthquake energy can be dissipated by the dampers, which can avoid or reduce the damage caused by earthquake. However, the energy dissipation structure design is complex and the most domestic designers can not master it easily. In this paper, a simple and practicable design method for viscous damper dissipation structure by using the PKPM design software is proposed based on a 7-storey frame structure in highly seismic region. Firstly, lower half or one degree for the design intensity to design out an uncontrolled structure. Secondly, determine the supplemental damping ratio required for the fortification intensity via modal analysis method of PKPM software, and identify the numbers of the required dampers as well as their corresponding installation positions in line with the methods in the seismic code of China. Finally, the ETABS program is adopted to conduct the time-history analysis of the designed dissipation structure, showing that the proposed method in this paper can produce a satisfied result.

Abstract: Comparative analyses of dynamic characteristics between two aluminum alloy single-layer spherical shells, which have the same span, same rise-span ratios and same bars but different material characters of elasticity and visco-elasticity, are presented. Influences about material viscosity on vibration behaviors of single-layer spherical aluminum alloy reticulated shells are illustrated. The results show that: there are great differences between the resonance frequencies of two shells but the linear harmonic response properties are basically the same; the dynamic characteristics of these two shells are greatly different under harmonic loads or seismic loads, and the dynamics characteristics are greatly influenced by the viscous properties of the material itself.

Abstract: The objective of this work is to find the law of combined effect of steel reinforcement and expansion agent (EA) on the crack resistance of ready-mixed concrete by doing flat-plate method experimental study on the crack resistance of ready-mixed concrete with EA, also with EA and steel reinforcement, with a deep analysis of the mechanism of reinforcement and EA on ready-mixed concrete. The paper comes to the role of ready-mixed concrete cracking performance which is influenced by reinforcement steel and EA.

Abstract: According to pull-off test on reinforced concrete specimens with different corrosion rate, their failure patterns, relationship between bonding strength and slippage, variation laws of bonding strength and slippage are studied. The calculating formula of reduction coefficient of bonding strength and slip ratio is proposed. Based on these studies, constitutive model of bond-slip performance for corroded reinforced concrete is set up. It can be seen after verification and analysis that calculated results of this model agree well with trial values, which suggests that the bond-slip constitutive model of this paper is reliable and universal.

Abstract: The dynamic response of a pile group embedded in a layered poroelastic half space subjected to axial harmonic loads is investigated in this study. Based on Biot's theory and utilizing Muki's method, the second kind of Fredholm integral equations describing the dynamic interaction between the layered half space and the pile group is constructed. Numerical results show that in a two-layered half space, for the closely populated pile group with a rigid cap, the upper softer layer thickness has considerably different influence on the center pile and the corner piles, while for sparsely populated pile group, it has almost the same influence on all the piles.

Abstract: The elastic modulus of steel will decrease in case of high temperature which makes the reticulated shells easier to have the global instability phenomenon. In order to obtain the elasto-plastic stability bearing capacities for K6 single-layer reticulated shells [1], nonlinear finite analysis compete process was conducted by ANAYS software under on the two typical cases which include global non-uniform temperature distribution and localized high temperature. Based on the calculation formula for single-layer reticulated shells at ambient temperature, the calculation formula for elasto-plastic stability bearing capacity for K6 single-layer reticulated shells was obtained.

Abstract: With the development of economy and society, urban construction rose to a new level in China. High-rise and super high-rise building increase rapidly. In the high-rise and super high-rise buildings (H≥150 m), the structural system usually adopts the conventional reinforced concrete, including frame tube structure, tube in tube structure, steel frame with reinforced concrete core tube hybrid structure and tube in tube steel - concrete mixed structure. These traditional structural systems often lead to the problems of fat beam fat column and high expenditure, which is not economic and unfriendly to the environment. This paper not only presents a new type of concrete core wall and prefabricated space steel grid cassette tube in tube structure system, but also discusses the superiority of the new type structure through the innovation and practice of a super high (266 m) five-star hotel and office building integrated engineering construction.

Abstract: A new reinforcement technique with prestressed helical rib steel wires is presented, and one control beam, three strengthened beams under monotonous loads are tested. The flexural capacity, load-deflection relation, cracks and deformation of reinforced concrete beams are systematically studied under the same initial prestress level and amount of reinforcement, different groove size. The test results indicate that the strengthening technique could significantly improve the first-crack load, steel-yielding load, ultimate load of the beams, and improves the service performance of the strengthened beams. The high performance of the helical rib steel wires is allowed for a better utilization. The results provide a reference for engineering applications.