Zhen Bao Li

Experimental Study on Axial Compression Performance of Full-Scale Square Columns of Reinforced Concrete Confined by High-Strength Reinforcement Hoops

Axial compression experiments of four full-scale reinforced concrete columns of two groups were carried out. One group of three columns used high-strength steel with the yield strength of 1000MPa as reinforcement hoops, and the second group used the ordinary-strength steel with yield strength of 400MPa. The axial compressive performances between these two groups were assessed. Compared to the specimen using the ordinary-strength steel, the axial compressive bearing capacity of using the high strength steel dose not increase significantly, while the deformation ability increases greatly. The results also indicate that the stress redistributions of the hoops and the concrete sections are obvious, and long-lasting when specimens achieve the ultimate bearing capacity after the yield of the rebar and local damage of concrete materials, at this time the strain of the specimens developes a lot, especially stress - strain curves of speciments with high-strength hoop all show a wide and flat top.

Seismic Performance of Steel Beam-Column Joint under Low Cyclic Loading with Multiple Cycles

An experiment of three T-shape beam-column steel joints with intensive cover plate was conducted under low cyclic loading with different cycle numbers, to study seismic performance of the joints subjected to long-period ground motions. Effects of cycle number on mechanical performance and length of plastic hinge were analyzed. The results show that as the cycle number increases, capacity of the joint decreases, and plastic hinge of the joint develops longer which appears closer to the cover plate, and the platform of skeleton curve grows longer, and the stiffness attenuates slightly.

The Experimental Research on the Vertical and Horizontal Bearing Capacity of Hollow Latticed Steel Columns

The paper researched on the strain, the deformation and the failure mode of hollow latticed steel columns through two experimental conditions. They were respectively about the vertical load and the horizontal load. The results showed that for the hollow latticed steel columns with upper columns, because of the stiffness of upper columns was obviously higher than the lower ones’, the upper columns were destroyed earliest under the vertical load. In addition, the columns had good horizontal bearing and deformation capacity, and the gravity second-order effects were not obvious for the columns.

The Development on the Synthetic Seismic Waves and its Relative Issues

The influential factors on synthetic seismic waves and seismic codes in China are described in detail in this paper. And the evolution of synthetic seismic waves is overviewed. The methods of synthetic ground motion in the earthquake engineering field are summarized in order to provide references for the synthetic ground motion. Based on the study situation over the world, the issues and trend are presented. Some suggestions are provided for improving the codes and standards.

Seismic Performance Study on Side-Strengthened Concrete Beam Using Finite Element Analysis Method

Side-strengthened reinforced concrete or precast prestressed concrete beam for inadequate seismic performance is proposed in this paper. The factors are simulated by ABAQUS software for the impact of seismic performance, which are difference of material strength grade, initial load and the order of prestressing and pretightening. The strengthening technology can improve the seismic performance of side-strengthened beam. The meterials with different strength grades which used for beams give full play to their role. The initial load has little effect on the seismic performance. The way of prestressing after pretightening plays a favorable effect for the seismic performance. The simulation results can accurately reflect the impact of these factors on the side-strengthened beam.

Comparative Study of Standards EC2 ECP203 and CBA93 for the Design of a Rectangular Section

Because of the predominance of construction techniques, a solid knowledge of reinforced concrete principles and rules is necessary and crucial. This study focuses on a comparative studies of different sizing standards, the Euro Code 2,the Egyptian Code 203 and the Algerian Code 93 for a rectangular reinforced concrete section subjected to simple bending in limit states and is well supported on one hand by one of the determining factors in design and on the other hand by the economy and security. The comparison of sizing standards in the limit states will assist the designer in their choice of a suitable design code.

Simulation Study on a New Type Buckling Restrained Brace

A new type buckling restrained brace ensuring to work under different levels of earthquakes is analyzed in this paper. The brace is simplified by LINK elements of SAP2000. The skeleton curve of the mode is clarified. Three specimens with different slot widths are designed to evaluate the simplified model used in the software SAP2000. The evaluation work is accomplished through the software ABAQUS. The force mechanism, the hysteretic model and proposed reasonable scopes of slot widths are grasped. The numerical simulation work proves that the new type buckling restrained brace performs excellently.

Dynamic Response of Frame Structure with Different Stiffness in Two Horizontal Directions under Oblique Seismic Action

The ground motion is multidimensional, random and uncertain in directions when earthquakes occur, so dynamic response under oblique seismic action needs to be considered in the structure design. A frame structure with different stiffness in two horizontal directions was analyzed under seismic action with different input angles. The maximum response of beams and columns was obtained. The seismic mechanism of structures under oblique seismic action was discussed.

The FEM Analysis of Mechanical Properties of RC Short Columns under Oblique Horizontal Seismic Action

Simulation analyses of RC short columns are conducted under oblique horizontal seismic action monotonically using ABAQUS software. Concrete damaged plasticity model is used for concrete. Ideal elastic-plastic model is taken for steels. The results show that when the axial compression ratio was relatively low, the capacity of the columns increased with the increasing of load angle, because of the effect of tensile bars. For the relatively high axial compression ratio, the bearing capacity decreased with the increasing of angle, because of the effect of concrete in compression area.

Finite Element Analysis of Reinforced Concrete Beam-Column Joint under Low Cyclic Loading with Different Load Systems

Seismic performance of RC beam-column joints under low cyclic loading with different cycle numbers was analyzed by FEA software, to study duration effect of long period ground motion. The loading with different cycle numbers was used to simulate the duration of the ground motion. Hysteretic curves and skeleton curves of the joints were obtained. The results indicate that as the cycle number increases, the capacity and ductility of the joint declines, and the stiffness of the joint attenuates faster.