Experimental Study on Seismic Behavior of Penetrated Interior Diaphragm on One Side Beam-to-Column Connection for Concrete-Filled Square Steel Tube

A total of three experimental specimens of penetrated interior diaphragm on one side had been tested under low-cyclic reversed loading to study the hysteric behavior,strength and stiffness degradation,ductility,energy dissipation capacity and the failure modes.The only difference of all specimens was the axial compression ratio.Experimental results show that the story drift ductility ratios are 2.11~2.32,and the energy dissipation ratios are 1.141~1.502 at the peak load.Additional anti-seismic design and research recommendations are presented.     

Research on Seismic Behavior of Frame with T shaped SRC Columns

Referring to the criterion of seismic fortification intensity 8 specified by national seismic design code, a /2 scaled model of single span and two story frame composed of RC beams and T shaped steel reinforced concrete (SRC) columns has been made. A seismic evaluation was performed by the quasi static testing, including failure pattern, stiffness degradation, ductility and energy dissipation. The experimental results show that the frame has good seismic behavior, and section steel in the columns plays an important role in earthquake resistance. On the basis of experimental study and analysis, it concludes that the seismic behavior of frame with SRC special shaped columns can satisfy the requirements of seismic fortification.      

Study on Effect of Longitudinal Reinforcement Ratio on Shear Behavior of Restrained Beams with Web Reinforcement

In this paper, five restrained beams with web and different longitudinal reinforcement ratio as well as above longitudinal reinforcement truncated were tested under static point loads. On this basis, the overall process of cracking development under shear and the effect of longitudinal reinforcement ratio on shear strength was investigated     

偏载下板柱结构中柱节点破坏试验研究

采用重剪比以及配筋率两个试验变量对4个板柱中节点的破坏过程进行了对比试验,并在试验过程中采用特制应变测杆对试件内部斜裂缝的形成和发展予以监测。试验结果表明：试件最终破坏形态受重剪比和配筋率两因素共同影响;重剪比相同的试件,配筋率的提高也可有效提高中柱节点对不平衡弯矩的承载力;板内斜裂缝在节点发生冲切破坏之前已产生,并从靠近柱头的受压区向板底受拉区开展。基于试验结果和历史试验数据,将中国规范GB 50010—2010所采用的基于偏心剪应力模型的计算方法和欧洲规范Eurocode2-04进行对比,分析了偏心剪应力模型不足的原因。     

Experimental Investigation on the Aseismic Behavior of Seismic Damage Masonry Wall Retrofitted with Grouting and Steel Hoops

In order to accurately evaluate the aseismic behavior of the seismic damaged masonry pagodas destroyed by Wenchuan earthquake and strengthened after the earthquake, a test was conducted to acquire related parameters on seismic performance from the specimens made by masonry and retrofitted with grouting and steel hoops. Taking a seismic damaged ancient masonry pagoda in Sichuan as a case study, four kinds of primitive specimens are fabricated by simulating the conformation of the masonry pagoda. Then the primitive specimens are destroyed under cycle loads and the damaged specimens are repaired by grouting and steel hoops. Cycle controlling tests are conducted with the specimens and relevant data are acquired. Experimental results showed that grouting combined with steel hoops could improve the ductility and energy dissipation capacity of a seismic damage of brick masonry structure, but it do a little to improve the stiffness of a seismic damage structure. And the cracking load of the repaired masonry is much lower than the original undamaged structure.     

Experimental Research on Seismic Shear Capacity of I-Shape Ductile Reinforced Concrete Structural Walls

The shear design formula for seismic shearwalls in the Chinese standard (Code for Design of Concrete Structures) have not been verified by tests yet, In order to compensate for it, the authors undertake the task of testing on the shear behavior of seismic shearwalls organized by the Code association. After discussing on the particular conditions controlling tests and philosophy in specimen designing, the results of the first group of tests on the seismic shear behavior of shearwalls, which are I-shaped and with relatively large scale and axial force ratio of 0.2 and tested under reversed cyclic horizontal forces, are introduced. The results are analyzed and discussed.     

Experimental Research on the Seismic Behavior of the Interior Joint with High Shear - Compression Ratios in the Frame

The reversed cyclic loading tests of 5 nearly full-scale beam-column assembly specimens with high shear-compression ratio under different axial loads in reinforced concrete plane frames have been completed,which cover the shortage in the field of high shear-compression parameter among seismic joint experiments in the world.Based on relatively complete measuring and analyses of the law for the bond and slip of the beam bar through the joint,the stress of the level stirrup legs and hysteretic dissipated energy and the change of rigidity,the characteristic of shear transfer mechanisms and damage development and comprehensive seismic behavior of the assembly are proposed in this paper.It makes it possible to improve design codes and to establish relatively reasonable analytic modes and hysteretic modes in inelastic dynamic response analyses of the frame.     

新型土坯墙体房屋抗震性能试验研究

提出了一种新型土坯墙房屋,对新型土坯墙房屋承重墙体的受力及抗震性能进行试验研究。设计三片新型土坯墙试件,研究土坯墙体在竖向荷载和反复水平荷载作用下的破坏过程、破坏形态、滞回曲线和骨架曲线特征以及墙体水平承载力和变形能力等,同时,研究新型构造措施对土坯墙抗震性能的作用。试验表明：新型土坯墙体的破坏模式与配筋混凝土小型空心砌块相似,土坯墙体具有良好的承载力和变形能力。新型构造措施对墙体整体抗震性能作用明显,其连接构造至关重要。与计算结果比较得出,在建筑抗震概念设计原则指导下,抗震设防7度区采用新型土坯墙建造二层房屋具有可行性。     

HDPF加固钢筋混凝土柱抗震性能试验研究

为了研究高延性聚酯纤维加固钢筋混凝土柱的抗震性能,共进行了7根柱的低周反复试验,其中,3根在未加固状态下进行试验,4根柱粘贴高延性聚酯纤维加固后进行试验,针对位移延性系数、等效粘滞阻尼系数、总耗能、承载力和纤维带的应变进行了研究与分析。研究结果表明：未加固柱的承载力、耗能能力和延性都比较低,采用高延性聚酯纤维加固后的试件裂缝发展缓慢,加固后柱的承载能力、耗能能力、延性均有不同程度地提高;在塑性铰区域内增加局部配筋,能够提高纤维布的约束效果。     

Numerical Analysis on Seismic Behavior of Batter Pile Group with High-rise Pile Cap

In order to reveal seismic behavior of batter pile group with high-rise pile cap, taking three kinds of earthquake waves as example, the effect laws of inclination angle and free pile length on seismic response were analyzed based on three-dimensional elastic-plastic dynamic finite element model. The results show that the maximum axial force of pile appears in 25 m approximately beneath the maximum erosion line and the maximum bending moment is located in the interface between pile cap and pile shaft. The vertical displacement and Y-orientation bending moment are symmetrically distributed along the pile shaft, and acceleration, lateral displacement, axial force, bending moment distributions along pile shaft are in the same trend. The greater free pile length, axial force of pile is larger and bending moment of pile is smaller. The greater inclination, axial force and bending moment of pile are larger. The influence on internal force is greater by the pile free length than the pile inclination. Subjected to the seismic load, acceleration and displacement of batter pile decrease, but its axial force and bending moment increase. The total bending moment of batter pile is controlled by Y-orientation bending moment.     

配置500 MPa纵筋钢筋混凝土框架顶层端节点抗震性能试验研究

按照《混凝土结构设计规范》(GB 50010—2010)设计了6个配置500 MPa纵筋的钢筋混凝土框架顶层端节点,并进行了低周反复加载抗震性能试验,验证了规范规定的抗震措施对配置500 MPa钢筋的顶层端节点的有效性,分析了配置500 MPa级钢筋的顶层端节点的受力特点、节点区的破坏形态以及节点的综合抗震性能,并与受力条件基本相同的配置HRB335级纵筋节点的受力性能进行了对比,对采用不同延性指标评价配置不同强度钢筋节点的延性性能差异进行了讨论。     

X形配筋增强高强钢筋异形柱边节点抗震性能试验研究

通过对核心区应用X形配筋增强的高强钢筋异形柱边节点和同等条件下未被增强的高强钢筋异形柱边节点进行拟静力试验研究,对比分析异形柱边节点的破坏特征、滞回曲线、承载能力、位移及延性、刚度退化、耗能能力等抗震性能指标。研究结果表明,配置HRB500高强钢筋异形柱边节点比配置600 MPa级的边节点承载能低,但滞回性能好,变形能力强,刚度退化推迟,耗能能力强;在核心区加入X形配筋,均可以改善高强钢筋异形柱边节点的破坏特征,使边节点抗剪能力、变形能力、耗能能力增强,刚度退化推迟,提高异形柱边节点抗震性能,配置HRB500高强钢筋的试件核心区应用X形配筋加强后抗震性能提高效果更好。     

Experimental Analysis on Seismic Behaviors of Inclined Column-shaped and Beam-shaped Transfer Floor

In order to analyse seismic behaviors of inclined column-shaped and beam-shaped transfer floor,the pseudo static testing is carried out,which are subjected to vertical loads and horizontal cyclic loads,respectively on two specimens,including the framed short-leg shear wall inclined column-shaped transfer plane framework and the same dimension beam-shaped transfer frame.The load transfer is direct,inclined column transfer structure can reduce the beam dimension effectively,and it is easier to implement the aseismatic design principles,including "strong column and weak beam,strong shearing and weak bend,stronger nodes".Lateral rigidity of inclined column-shaped transfer stories is large,making it difficult to engender structure weakness stories.If the design is reasonable,inclined column-shaped transfer structure can get better seismic behavior.     

Interlayer Seismic Dynamic Analysis of Seismic Responses of Frame Structure

Earthquakes for the loss of life and property to people is immeasurable. Want to reduce such losses, on the one hand we hope that Government departments can forecast and notify you in a timely manner, on the other hand we need to develop anti-seismic structure of the building, reducing losses when the earthquake happened. Interlayer seismic isolation frame structure is the latest development of a seismic isolation structure.It compared with the ordinary seismic structural damping performance is better, had a large advantage.     

Static Behavior of Rigid Connections of H-beams with Corrugated Webs

Steel H-beams with corrugated webs can provide high shear-buckling resistance with very thin webs, which results in saving of steel. Common beam-to-column rigid connections are not suitable for H-beams with corrugated webs, so 2 types of rigid connections are proposed .In this paper,2 static tests of beam-to-column rigid connections of H-beams with corrugated webs were conducted. And the test results were compared with the results from finite element analysis and the results calculated from the practical design formulas to verify the validity of the results from ABAQUS FEA and reliability from the practical design formulas. Parametric studies were carried out to investigate the bearing capacity of the pinned connection with variations in the thickness of the endplate, the connecting plate and the corrugation at the breaking point.     

Experimental Analysis of Rotational Behavior of Timber Beam-column Connection of Ancient Tibetan Architecture

Static experiment was carried out to study rotation behavior of timber beam-column connection. The influence of length of Gongmu and position of dowel on the initial rotational stiffness of the joint was analyzed. Rules of stiffness degradation under cyclic loading were studied as well. The results show that: the moment-rotation curve of typical timber beam-column connection can be simplified as bilinear model; the initial rotational stiffness of the joint is enhanced with the increase of the length of Gongmu, and it is decreased with the inward movement of dowel; under the same conditions, the influence of the inward movement of Gongmu-beam dowel on the initial rotational stiffness of the joint is smaller than that of Dianmu-Gongmu dowel; and stiffness degrades under cyclic loading and there exists obvious transition phenomenon.     

Seismic Behavior of a Slope Protected by a Soil Nailing Retaining Wall during an Earthquake

The dynamic elastic plastic finite element method was used to study the seismic performance of a slope protected by a soil nailing retaining wall. On the basis of working in parallel and interaction between loess and a flexible retaining wall, a 3 D nonlinear finite element method (ADINA) also was established. Rational earthquake excitation and damping were discussed for geological engineering. Horizontal and vertical excitations were considered simultaneously in the analyses. A model capable of simulating the nonlinear static and dynamic elastic plastic behavior of soil was used to model the soil, and a bilinear elastic plastic model having hardening behavior was used to model the soil nailing. A friction element was employed to describe the soil structure interaction behavior. Our research focused on the seismic performance of the horizontal and vertical slope deformation, soil nailing axial force, and earth pressure subjected to horizontal and vertical excitations. The results show that the seismic performance of slope protected by soil nailing is good; soil nailing axial force increases after an earthquake; permanent slope displacement occurs during an earthquake; and the peak earth pressure distribution during an earthquake is similar to the earth pressure before the earthquake. These conclusions can provide references for seismic analyses and design in soil nailing engineering.