A REVIEW AND ANALYSIS OF FAILURE CRITERIA FOR ASEISMIC STRUCTURES

This paper Extensively discusses the current failure criteria for aseismic structures and points out the drawback. A method how to thoroughly study the failure criteria is presented.     

轴向加压剪切过程中静水应力场及其作用分析

The distribution of hydrostatic pressure and the influence of axial pressure and clearance,the main technical factors,on it during cropping under axial load are revealed by using elasto-plastic Finite Element Method. The relationship between the quality o     

Experimental and Parametric Analysis of the Flexural Behavior of HRBF RC Beams

In order to investigate the flexural behavior of concrete beams reinforced with high strength hot rolled bars of fine grains, static bending test on four rectangle cross section HRBF400, HRBF500 RC beams was conducted. The results show that the experimental maximum crack width under short term load meets the requirement of current code while calculated value does not meet; mid span deflection of RC beams with HRBF400 under short term load still meets the requirement of current code while RC beams with HRBF500 does not meet. Bearing capacity calculating formula under conditions of crack/deflection control was proposed and conception of component's bearing capacity utilization coefficient (BCUC) was put forward. The influences of reinforcement strength, reinforcement diameter, concrete grade, reinforcement ratio, concrete cover thickness and high span ratio on BCUC were analyzed. Within the range of economic reinforcement ratio, ductility of HRBF RC beams meets the requirement. Energy dissipation capacity of HRBF RC beams is similar to that of normal RC beams at low reinforcement ratio but it decreases faster than normal RC beams with the increasing of reinforcement ratio. Energy dissipation capacity of HRBF RC beams is higher than that of normal RC concrete beams in elastic stage and it enhances with the increasing of reinforcement ratio.     

Experimental Study on Size Effect of Flexural Behavior of Reinforced Concrete Beams

Reinforced concrete specimens with concrete compressive strength varied from 46.5 to 50.6 MPa and with depth of cross section from 250 mm to 1 000 mm subjected to bending were tested. Size effects of flexural behavior with respect to bending capacity and deformation capacity were investigated based on the analysis of the test results and those of high-strength specimens (fcu=72.1~72.4 MPa) of which the geometry and reinforcement layouts were identical to those of specimens tested in this study. It is shown that beam depth does not has any apparent influence on nominal cracking moment, nominal yield moment and nominal ultimate moment, and that it has significant influence on displacement ductility and plastic rotation capacity of plastic hinges of members. For normal-strength concrete specimens and high-strength concrete specimens, both the displacement ductility and the plastic rotation capacity decrease with the increasing of depth in the similar ways, and are independent of concrete strength. It is also demonstrated that the lengths of plastic hinges of members with different depth and concrete strength are approximately equal to the depth.     

Pseudo-Static Test on Seismic Deformation Capacity of Masonry Wall Constrained by Core-Tie-Columns

A new tie column such as core column, named as core tie column, for the substitution of cast in place tie column was used to improve seismic performance of mansonry structures. Pseudo static testes of 11 wall specimens including 6 walls constrained by core tie columns, 2 walls constrained by cast in place tie columns, and 3 walls without constraints were carried out to study the seismic deformation capacity of mansonry walls with core tie columns. The skeleton load displacement curves and the normalized skeleton curves, displacement ductility factors,drift angels of the specimens were analyzed and compared. The effects of the level of vertical compress load, aspect ratio and the wall style on the deformation capacity of the wall with core tie columns were distinguished. It is shown that the constraints effects of core tie columns on masonry wall are effective and the walls with core tie columns have good deformation capacity as those with cast in place tie columns.     

Test and Finite Analysis to Non-strong Column and Weak Beam Concrete Frames

Through the test of two concrete frames under vertical load and nonlinear finite programme analysis,the performances of strong beam with weak column and equal strength column and beam are studied,such as ultimate load,deflection,displacement ductility,redistribution of internal force.When the reinforcement is proper,the research proved that strong beam with weak column" and "equal strength column and beam" have better displacement ductility and can realize full redistribution of internal force,the width of cracks and deflections can satisfy the rules of code for design of concrete structures.     

钢筋混凝土箱形截面延性分析的计算机方法

以切比雪夫(Chebyshev)近似积分法为基础,提出了计算任意钢筋混凝土箱形截面M-φ关系的计算机方法.该法不仅可以减少循环次数,而且可有效地避免迭代过程中可能出现的死循环.此外还讨论了混凝土抗拉强度对截面延性和刚度的影响以及轴压比对截面延性的影响.文中给出了两个数值例题,并将其结果与文献的结果作了对比.     

Structural Design of the Multi_Purpose Building for the Public Security Bureau,Xin Xiang City Henan Province

This paper introduces the methods of reducing and controlling differential settlement by changing the length and load_bearing capacity of the piles,and other means,rather than setting settlement gaps between the main building and the podium structure.By using these methods,the size of differential settlement observed is only 1mm.Because of the building with a tower 45m high,the earthquake magnification factor is taken as 3 with considering whiplash effect.