某少墙-框剪结构设计方法探讨

某地震重点监视防御区新建学校综合楼,结构高度临近框架结构最大适用高度限值,采取提高抗震性能目标措施进行抗震设计加强;同时,采用少墙-框剪结构方案,进行二道防线设计增强。考虑塑性内力重分布的影响,采用少墙-框剪结构与纯框架结构进行地震剪力包络设计,并针对中大震作用下的剪力墙进行刚度折减计算复核。分析结果表明,采取提高抗震性能目标,增强框架结构二道防线作用,各项计算指标均满足规范要求,结构具有足够的安全冗余度。

针对超限高层剪力墙中震拉应力问题的工程实践

水平地震作用会对高层结构的底部竖向构件产生轴向拉压作用。在高烈度地区,对超限高层建筑进行中震不屈服计算时,这种作用可引起结构底部某些剪力墙墙肢的拉应力,该拉应力可能大于混凝土抗拉强度标准值。在进行超限高层抗震专项审查时,按照《超限高层建筑工程抗震设防专项审查技术要点》的要求,剪力墙构件需满足中震不屈服墙肢平均拉应力不超过2倍混凝土抗拉强度标准值的要求。基于高烈度地区的超限高层设计实践,讨论了中震计算方法;论述了剪力墙拉应力与受剪承载力的关系;阐述了墙体中震拉应力的工程计算方法;最后,给出了中震拉应力不满足要求时的一种工程处理方法。

用平面元和杆系元耦合方法计算框支剪力墙

采用二维平面元计算框支剪力墙导致节点自由度个数过多，作者根据框支剪力墙板、柱混合体系的特点分别采用二维矩形元和一维杆系元，并引进拉格朗日乘子来反映框支剪力墙板、柱节点的约束条件，用势能最小化方法建立起框支的力墙结构的刚度方程。计算实例表明，该方法不仅有足够的精度，而且也可减少计算机的运行时间。

钢筋混凝土剪力墙施工裂缝的分析与控制

钢筋混凝土剪墙在施工过程中，易产生裂缝。其影响因素有：温度应力，原材料质量，地基不均〉--j沉降，模板支撑不稳，结构配筋，混凝土振捣及养护达不到要求等。针对交通枢纽站侧墙裂缝产生的原因，改进施工方案，加强了各个环节的监控管理，消除了裂缝产生的原因。

模块化冷弯薄壁型钢结构体系低层村镇住宅设计研究

在传统冷弯薄壁型钢结构体系的基础上,从模块化、装配化角度出发,提出了一种适用于低层村镇住宅的新型结构体系——模块化冷弯薄壁型钢结构体系。首先,简述了墙体模块单元的构成,给出了7种通用标准化墙体模块单元,并介绍了基于通用标准化模块单元的村镇模块化户型构建原则及过程;其次,详述了便于快速装配安装的标准墙体单元间模块化连接方式,对模块连接节点进行了受力分析及数值模拟,并给出了模块化冷弯薄壁型钢结构体系构建的原则;最后,重点介绍了适用于所有冷弯薄壁型钢结构体系的抗剪墙长简化设计方法以及基于模块化冷弯薄壁结构体系的抗剪墙长设计方法,并通过实际案例详述了墙长确定过程,同时对比了不同计算方法的抗剪墙长,进一步验证了所提出的抗剪墙长简化设计方法的可行性。结果表明:所提出的模块化冷弯薄壁型钢结构体系可大幅提高冷弯薄壁型钢结构低层村镇住宅的工业化和产品化水平,大幅缩减了工期;所提出的抗剪墙长简化设计方法可显著降低设计门槛,便于该类体系的推广应用。

框剪结构填充墙渗漏通病分析与防治措施

本文主要分析了框剪结构填充墙在材料质量方面、砌筑质量方面、外粉刷处理不当等方面造成渗水的原因并提出了相应的防治措施。

少墙框架-剪力墙结构抗震设计探讨

文章针对工程设计中遇到的特殊框-剪结构类型:少墙框-剪结构体系,结合理论及规范规定,提出切实可行的设计建议,以供工程设计人员参考。

钢筋砼剪力墙及楼板后开洞粘钢加固法的实施

1 引言 粘钢加固法具有简单、快速、受力明确的优点,这种加固法已在国内许多工程中应用。但是精心设计及施工操作的好坏对粘钢加固质量及耐久性影响非常大。下面结合工程实例,介绍在钢筋混凝土剪力墙及楼板上后开洞的粘钢加固法的设计与施工。

浅谈框剪结构填充墙渗漏通病及防治措施

框剪结构填充墙渗漏水通病,应着重从砌块材料,砌筑,粉刷,镶贴及构造处理等每一个环节来消除外来水源浸湿外墙面而渗水的隐患。施工方只要严格要求施工操作人员按工序道道把关,控制细节,就能够基本杜绝框架、框剪结构填充外墙渗漏通病的发生。

某地震重点监视防御区学校结构设计探究

根据地震重点监视防御区学校结构抗震设计要求,采取提高抗震性能目标水准进行抗震设计加强。分析探索孝德学校新建综合楼结构抗震性能设计、竖向体型收进、斜柱、局部转换等不规则项结构设计方法。结果表明,采取提高抗震性能目标水准后,各项计算指标均满足规范要求,结构具有足够的安全冗余度。

底层框剪结构多层砖房抗震设计建议

本文通过试验研究和理论分析,表明在底层框剪结构多层砖房的底层采用边框柱和墙板内埋交叉型钢骨架的劲性钢筋砼低剪力墙,可以有效减轻房屋底层的变形集中程度,提高房屋的整体抗震能力,提出了这类房屋抗震设计的一般原则和设计建议。

Shear resistance performance of steel-concrete-steel composite shear wall

For a deeper understanding of the shear resistance performance of the steel-concrete-steel composite shear wall, the main influence factors such as the thicknesses of the steel plates and the concrete, the strength grades of the concrete and the span-depth ratios of the composite wall, which have impacts on the shear resistance performance of the composite shear wail, are analyzed by the numerical simulation method. Meanwhile, the simplified calculation formulae of the initial elastic lateral-resisting stiffness and the shear bearing capacity of the composite shear wall are also proposed. The research shows that with the increase in the thicknesses of the steel plates and the concrete and the increase in the strength grades of the concrete, the shear performance of the shear wall improves obviously; the span-depth ratios of the composite wall have a significant effect on the initial elastic lateral- resisting stiffness, but a small effect on the shear bearing capacity. Comparing the results of the simplified calculation formulae with those of the nonlinear finite element method, it is obvious that the presented formulae are reasonable and meet the real force state of the structure. These conclusions can serve as a preliminary design reference for the steel-concrete- steel composite shear wall.

Experimental validation of horizontal joints in an innovative totally precast shear wall system

To investigate the feasibility and seismic performance of the horizontal joints in an innovative precast shear wall system, two test walls were fabricated, and the monotonic and cyclic loading tests were performed on the two test walls, respectively. Then, the lateral load-top displacement curves, load beating capacity, ductility, lateral stiffness, strains of steel bars, strain distribution on the connecting steel frame （CSF）, and relative slippages between the CSF and embedded limbic steel frame （ELSF） were discussed in detail. The test results show that the load bearing capacity and ductility of the test wall are both favorable with a displacement ductility factor of more than 3.7. The normal and shear stresses in the CSF except for the compression end are far smaller than the yield stresses throughout the test procedure. Certain slippages of about 1.13 mm occurs between the CSF and ELSF on the compression side of the test wall, while almost no slippages occurs on the tension side. The seismic performance of the test wall is favorable and the new-type scheme of the horizontal joints is both feasible and reliable.

FREE VIBRATION ANALYSIS OF SHEAR WALLS WITH SHORT PIERS

The equations of the lateral deflection curve of the short pier shear wall under a lateral concentrated load at any level are derived by employing a continuous approach. Lateral flexibility matrixes for the dynamic analysis are also obtained by repeatedly calculating the lateral unit load on the wall at each level where a lumped mass located. Dynamic analyses are implemented for short pier shear walls with different parameters, called the integrative coefficient and the pier strength coefficient related to the dimensions of walls. The influences of two coefficients on the dynamic performances of the structure are studied. Results indicate that with the increase of the integrative coefficient, the periods of top two modes apparently decrease but the other periods of higher frequency modes show little variation when the pier strength coefficient remains constant. Similarly, if the integrative coefficient is constant, the top two periods of the free vibration decrease with the increase of the integrative coefficient but the other periods of higher frequency modes show less variation.

Nonlinear Behavior of Reinforced Concrete Slit Shear Walls under Seismic Actions *

A reinforced concrete slit shear wall is a new breed of earthquake resistant structure recently proposed by the authors. In this paper, the seismic responses of the slit shear walls under the shake of earthquake excitation have been dealt with. Based on a simplified structural model, which is shown to have a sufficient accuracy for the real slit shear wall structure, the analysis focuses on the influence of nonlinear behavior of the connecting beams between the slits on the dynamic performance of the whole slit shear wall structure. It has been found that the yielding of connecting beams in a slit shear wall can provide significant improvement in reducing the structural responses, and by choosing an appropriate strength value for the connecting beams, it is possible to optimize the seismic response of the slit shear wall.

Effect of fiber angle on LYP steel shear walls behavior

Steel shear wall(SSW) was properly determined using numerical and experimental approaches.The properties of SSW and LYP(low yield point) steel shear wall(LSSW) were measured.It is revealed that LSSW exhibits higher properties compared to SSW in both elastic and inelastic zones.It is also concluded that the addition of CFRP(carbon fiber reinforced polymers) enhances the seismic parameters of LSSW(stiffness,energy absorption,shear capacity,over strength values).Also,stress values applied to boundary frames are lower due to post buckling forces.The effect of fiber angle was also studied and presented as a mathematical equation.

Post-fire cyclic behavior of reinforced concrete shear walls

The effects of fire exposure,reinforcement ratio and the presence of axial load under fire on the seismic behavior of reinforced concrete(RC) shear walls were investigated.Five RC shear walls were tested under low cyclic loading.Prior to the cyclic test,three specimens were exposed to fire and two of them were also subjected to a constant axial load.Test results indicate that the ultimate load of the specimen with lower reinforcement ratio is reduced by 15.8%after exposure to elevated temperatures.While the reductions in the energy dissipation and initial stiffness are 59.2%and 51.8%,respectively,which are much higher than those in the ultimate load.However,this deterioration can be slowed down by properly increasing reinforcement due to the strength and stiffness recovery of steel bars after cooling.In addition,the combined action of elevated temperatures and axial load results in more energy dissipation than the action of fire exposure alone.

Lateral load-carrying capacity analyses of composite shear walls with double steel plates and filled concrete with binding bars

A method is developed to predict the lateral load-carrying capacity of composite shear walls with double steel plates and filled concrete with binding bars(SCBs). Nonlinear finite element models of SCBs were established by using the finite element tool, Abaqus. Tie constraints were used to connect the binding bars and the steel plates. Surface-to-surface contact provided by the Abaqus was used to simulate the interaction between the steel plate and the core concrete. The established models could predict the lateral load-carrying capacity of SCBs with a reasonable degree of accuracy. A calculation method was developed by superposition principle to predict the lateral load-carrying capacity of SCBs for the engineering application. The concrete confined by steel plates and binding bars is under multi-axial compression; therefore, its shear strength was calculated by using the Guo-Wang concrete failure criterion. The shear strength of the steel plates of SCBs was calculated by using the von Mises yielding criterion without considering buckling. Results of the developed method are in good agreement with the testing and finite element results.

Performance index limits of high reinforced concrete shear wall components

The deformation performance index limits of high reinforced concrete （RC） shear wall components based on Chinese codes were discussed by the nonlinear finite element method. Two typical RC shear wall specimens in the previous work were first used to verify the correctness of the nonlinear finite element method. Then, the nonlinear finite element method was applied to study the deformability of a set of high RC shear wall components designed according to current Chinese codes and with shear span ratio λ≥2.0. Parametric studies were made on the influence of shear span ratio, axial compression ratio, ratio of flexural capacity to shear capacity and main flexural reinforcement ratio of confined botmdary members. Finally, the deformation performance index and its limits of high RC shear wall components under severe earthquakes were proposed by the finite element model results, which offers a reference in determining the performance status of RC shear wall components designed based on Chinese codes.