Li Liren , Li Ming , Zhi Yunfang , Niu Shaoren
1996, 18(2):1-9. DOI: 10.11835/j.issn.1674-4764.1996.02.001
Abstract:On basis of the experiment on sixteen high strength concrete columns, their shear behaviors are analysed. The effects of shear-span ratio and axial compression ratio on failure behavior, cracking shear and shear strength are analysed. The authors have discussed the suitability of the design equations for shear strength in the code. This experimental study on shear strength of high strength concrete frame columns is the first one in this field at home and the results can be served as reference for the code of high strength concrete design.
Zou Zhaowen , Fu Jianping , Bai Shaoliang
1996, 18(2):10-19. DOI: 10.11835/j.issn.1674-4764.1996.02.002
Abstract:In this paper through the static loading tests of 6 inflexion zones and 2 cantilever zones in full-size constrained R/C beams, the stress performance in rebars cut-in-phases and subjected to negative moment is studied. The stress properties of extended length of rebars with different shear-span ratiosare analysed on basis of the full measurement of strain distributions combined with the investigation on state and regularity of the diagonal cracks development and series of new knowledge are obtained. It is found that current Concrete Design Code provisions on the extended length are inadequate for the high shear-span ratio and superfluous for the low shear-span ratio. The theoretical and experimental foundations are provided for determining proper value of extended length for rebars cut-in-phases.
Xiao Mingkui , Liu Bo , Bai Shaoliang
1996, 18(2):20-33. DOI: 10.11835/j.issn.1674-4764.1996.02.003
Abstract:In this paper, the total input earthquake energy and influencing effects for shear type,shear-bending type, bending type aseismic structures of the single freedom system and multiple freedom elastic-plastic system are analyzed by synthesizing various effects and employing the timehistory analysis method. Based on the analysis results, the total input earthquake energy spectrum is presented.The simplified methods for analyzing the total input energy of multiple freedom elastic-plastic systems are proposed to provide some basis for developing aseismic structure design method and Double-Failure Criteria.
1996, 18(2):34-42. DOI: 10.11835/j.issn.1674-4764.1996.02.004
Abstract:Under seismic action, the damage of critical regions in ductile reinforced concrete structures can be regarded as combined results of cumulative damage caused by positive/ negative displacements with different displacement levels after yielding. On the basis of symmetric low-cyclic fatigue experiments on eight half-scale RC columns under different displacement levels, the development of cumulative damage and relationships between low-cyclic fatigue life and symmetric displacement amplitude are investigated. It is hoped that on this ground, more rational damage criteria for RC structures can be put forward.
Fu Jianpin , You Yuan , Bai Shaoliang
1996, 18(2):43-52. DOI: 10.11835/j.issn.1674-4764.1996.02.005
Abstract:On the basis of a summary of achievements from a large quantity of experimental studies both at home and abroad, in combination with the authors'experience in the experimental works on the reinforced concrete frame joints, their force-transferring characteristics are fully studied. The important fact that there is also a confined mechanism besides the inclined compressive strut and the truss mechanisms,is clearly pointed out. The influences of the three mechanisms upon the mechanical behaviors of the joint core concrete, the transverse and the vertical reinforcements,as well as upon the failure characteristics of the joint are also explored. Mechanical behaviors of the inclined concrete compressive strut and the factors causing its failure are specially discussed. These analyses provide theoretical bases for establishing more rational earthquake-resistant design criterion for reinforced concrete frame joints.
Zhi Yunfang , Niu Shaoren , Zhang Yizuo
1996, 18(2):53-60. DOI: 10.11835/j.issn.1674-4764.1996.02.006
Abstract:Based on the test of high strength concrete (HSC)short columns confined with stirrups 8 under axial loads and 6 under small eccentric loads, the influence of stirrups confinement on stressstrain relationship and related parameter under monoaxial compression are studied, and the effect of the type of stirrups, stirrup ratio, etc. on the HSC columns ductility is analysed. Besides, the strength and deformation behavior of HCS columns under small eccentric compression are explored.Based on the experimental study, the complete stress-strain curves of confined HSC and the formula for calculating the related parameter are presented in this paper.
1996, 18(2):61-76. DOI: 10.11835/j.issn.1674-4764.1996.02.007
Abstract:In this paper, ultimate loading capacity of eccentric compressed timber column and elastic-plastic behaviour of the material of the cross section are considered.An approximate theoretic method dealing with the maximum mid-span deflection of the column when breaking is advanced.As a result, a formula calculating failure deflection of the rectangular cross section is derived. The results of theoretic calculation are well coincident with those of tests.
Huang Zongming , Xiao Mingkui , Bai Shaoliang
1996, 18(2):77-84. DOI: 10.11835/j.issn.1674-4764.1996.02.008
Abstract:Based on the data of inelastic dynamic-static comparison tests of three pairs of SDOF small steel frames, the problem of hysteretic restoring force in damping identification of structures in elasto-plastic range is investigated.
Fu Jianping , You Yuan , Bai Shaoliang
1996, 18(2):85-91. DOI: 10.11835/j.issn.1674-4764.1996.02.009
Abstract:On the basis of analysis and induction of experimental results on earthquake-resistant frame joint both at home and abroad, it is clearly pointed out that the mechanical characteristics of the joint in which shear failure may occur after yielding of longitudinal rebars at the beam end or at the column end are classified into three types, i. e ., diagonal tension, diagonal compression and a combination of diagonal tension and diagonal compression. A region of these three types of mechanical characteristics in the coordinates composed of relative shear force and relative ratio of transverse reinforcement is given, and the variation law and the corresponding reasons for the mechanical behaviors with the relative transverse reinforcement are analysed.
1996, 18(2):92-99. DOI: 10.11835/j.issn.1674-4764.1996.02.010
Abstract:For the sake of setting up more rational damage criteria for RC structures based on the relationship between displacement amplitude after yielding and low-cyclic fatigue life, this paper Presents six RC columns test results focusing on development of cumulative damage and low-cyclic fatigue life varying with displacement amplitude and positive/ negative displacement ratio. On this basis, expression is provided to describe the relation between low-cyclic fatigue life and positive/negative displacements amplitude ratio under different displacement levels.
Liu Bo , Xiao Mingkui , Lai Ming
1996, 18(2):100-109. DOI: 10.11835/j.issn.1674-4764.1996.02.011
Abstract:This paper discusses the distribution regularity of earthquake total input energy of structures between hysteretic energy and damping energy and their influencing factors taking account of various factors.The results can serve as the basis for the energy method of aseismic structural design and energy analysis in the study of damage criteria.
1996, 18(2):110-114. DOI: 10.11835/j.issn.1674-4764.1996.02.012
Abstract:Based on the data of dynamic tests of small single-storey steel frames,the suitability of simplified hi-linear restoring force model in earthquake response analysis is discussed, and the Maximum displacement response MD, the sum of squares of the displacements in the whole vibrating history SSD, and the total dissipated energy EI are considered respectively as equivalent object.
1996, 18(2):115-121. DOI: 10.11835/j.issn.1674-4764.1996.02.013
Abstract:This paper promotes a method of using laminated beam as heavy beam to improve middle Plate stability and overcome the shortcomings of heavy beam in manufacture and installation. With a practical example, the design method and analysis for the beam body and its connectors are put up.
Dai Guoxin , Liu Chunzhong , Guo Hong
1996, 18(2):122-127. DOI: 10.11835/j.issn.1674-4764.1996.02.014
Abstract:By now, for the domestic design theory of engineering structures the "Probability-Based Limit States Design Method"is adopted. One of its main points is how to make structures possess expected design reliability in the design reference period. The purpose of this paper is striving objectively to estimate the reliability for discussion.
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