Advanced Materials Research Vols. 243-249

Abstract: The curvature radius is a very important factor which influences the dynamic performance of the curved continuous long bridge badly. This paper based on the practical engineering, with large finite element program, established the curved continuous long bridge space finite element calculation model. Respectively by response spectrum method and the time-history response method, consider single-point excitation and multi-support excitation seismic action, Analyzes different radius of curvature in curved continuous long bridge self-vibration frequency, internal force and displacement on the differences, and given the internal relations between the difference and the curvature radius, offer some reasonable design reference suggestion for curved continuous long bridge of the radius of curvature.

Abstract: Rehabilitation of existing structures with fiber reinforced plastics (FRP) has been growing in popularity because they offer superior performance in terms of resistance to corrosion and high stiffness-to-weight ratio. This paper presents strain coordination results of (two groups)6 reinforced concrete beams strengthened with different methods including near-surface mounted CFRP bar and helical rib rebar in order to investigate the strain coordination of CFRP bar or HR bar and steel rebar of RC beam. Because there is relative slipping between RC beam and bar, the strain of CFRP or HR bar and steel rebar of RC beam satisfies the quasi-plane-hypothesis, that is, the strain of longitudinal fiber that parallels to the neutral axis of plated beam within the scope of effective height (h₀) of the cross section is in direct proportion to the distance from the fiber to the neutral axis, the strain of CFRP or HR and steel rebar satisfies the equation: ε_CH=βε_steel , the value of β is equal to 1.0～1.2 according to the test results.

Abstract: Taking Jiyu Bridge Station of Wuhan Metro Project as example, the deformation characteristics of supporting system of deep foundation pit was studied by means of numerical simulation (FLAC3D) in consideration of construction order. The deformation fields of different excavation depths of diaphram wall were obtained and analyzed in order to gain the maximum horizontal displacement value and settlement value. By comparison with the monitoring data, the simulation results can basically reflect the deformation characteristics. Moreover, the simulation results showed that the application of diaphram wall was feasible for foundation pit supporting in Jiyu Bridge Station, meanwhile, the results can be based on to guide the construction.

Abstract: Working aluminum towers is bound to meet the materials, dimensions, design load, safety and performance requirements of the standard EN 1004. Using the FEA(Finite element analysis) software ANSYS, the mechanical analysis of a 8m height tower made of prefabricated elements, according to standardization EN1004,is done in this paper. The geometric imperfection, Such as inclinations between vertical components the inclination position of 1% and the minor eccentricities of castor should be taken account into the finite element model.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

Abstract: The beam-type transfer structure has recently been well adopted in multi-purpose buildings. A new type of transfer structure with haunching braces is introduced in this paper through static elasto-plastic analysis of example structure with specific focus on its unique feature. Based of the deformation damaged criteria, seismic resistance performance for transfer structure with haunching braces is assessed. The results indicate that elastic and elasto-plastic displacement of structure under minor, medium and major seismic events designed against 7 degree seismic fortification intensity satisfy the requirement of the current standards, the structure’s damage status under minor and medium seismic events is Almost Intact and the structure’s damage status under major seismic events is Minor Damage. It can provide reference for engineering practice.

Abstract: The paper puts forward the one-dimensional strain rate related dynamic constitutive model of concrete-filled steel tube. The calculation results are in good agreement with the experimental results. Uniaxial compression performance finite element analysis at the strain rate among 10/s^-5—10/s^-2 is completed based on the conclusions. The results showed that considering concrete strain rate effect, the bearing performance of CFST is obviously changed. It showed that with the strength of concrete and strain rate increasing, ultimate bearing capacity of concrete-filled steel tube is improved and ductility is reduced. With the confining ratio and strain rate increasing, the ultimate bearing capacity and ductility of CFST are improved. With the slenderness ratios and strain rate increasing, the ultimate bearing capacity and ductility are reduced.

Abstract: This paper attempts to reveal the flexural behaviors of concrete slab reinforced with GFRP bars. Through flexural test, the deformation process and failure mode of concrete slabs reinforced with GFRP bars and steel bars are examined, respectively. The deflection, cracking load, ultimate load and concrete strain are compared between two kinds of concrete slabs. From the test results, it is clarified that the moment-deflection curve of GFRP reinforced concrete slab can be divided into two stages. Before concrete cracks the behaviors of two kinds of concrete slabs are almost the same. However, the deflection of concrete slabs reinforced with GFRP bars increases much faster after cracking and the stress-strain diagram is linear up to rupture with no discernible yield point. The ultimate load of concrete slabs reinforced with GFRP bars is 1.2 times of that of concrete slabs reinforced with steel bars. Based on the test results, finite element analysis is performed in order to study the influence of reinforcement ratio. Parameter analysis shows that the flexural rigidity of GFRP reinforced concrete slabs increases with the reinforcement ratio after cracking.

Abstract: On the basis of the experiment of 12 abnormal joints with different depth beams, failure process, seismic capacity and construction measure of this kind of joints are analyzed. Shear strength and failure model of joints with equivalent core height are analyzed by using mathematical model based on quadruple flexural resistance. The model satisfies equilibrium equations relating magnitude of external forces such as column shear, beam shear and axial force in column, to the magnitude of stress resultants. The results show that the model can reasonably explain the reasons for joints failure, have explicit mathematical model and good agreement between experimental results and calculated results of this model is achieved.

Abstract: On the basis of summary and analysis of the characteristics of concrete hollow blocks and composite masonry walls, this paper puts forward the concept of composite masonry wall with condensed core columns. Regarding the distance between core columns (s=600mm and s=1200mm) as the main influencing factors, two composite masonry walls were designed and built to carry out the axial compression capacity experimental study. The results of the study show that the composite masonry wall with condensed core columns can greatly improve the ultimate axial compression capacity of the wall, delay the fracture process, and influence the failure modes. In the entire experiment, the deformation of concrete hollow blocks and core columns was basically the same, and can work in coordination. The stress mechanism of the composite masonry wall which had splitting fracture changed from the composite masonry wall to the (weak) frame structure, which finally formed column hinge and got destroyed. The experimental results of this paper can provide a new way for the application of concrete hollow blocks as main wall materials in the field of high-rise buildings. The establishment of axial compression capacity formula and the eccentric compression performance of the composite masonry wall with condensed core columns deserve further study.

Abstract: The built-up cruciform section formed by two equal-leg angles has been widely applied in extra high voltage(EHV) transmission towers, however, domestic codes provide structure requirement and overlook the influence of multi filler plates to members’ bearing capacity. For the purpose of this, a pin end experiment covering 3 different cross sections(Q420, L160*12, L160*14 and L160*16) and 7 different slendernesses(25~55) has been run. This experiment contains totally 21 specimens. Furthermore, large amounts of models have been analysis by finite element method whose parameters contain variety b/t, λ, filler plate intervals and forms, amount of bolts in filler plate. A recommended formula is given for evaluating the influence of filler plates. The results show: multi filler plates enhance bearing capacity slightly for members with λ less than 35, and the better interval for filler plates is 10i-40i(i is the minimal radius of gyration); filler plates do not work well when b/t of the member is extreme large or small, a propositional b/t range for this kind of member is 11-16; the amount of bolts in filler plate has tiny influence on members’ bearing capacity; the recommended formula is applicable and feasible for design.