双面叠合混凝土剪力墙大偏心受压性能试验研究

Experimental Reseasch on Structural Performance of Double-Faced Superposed Shear Walls Under Large Eccentric Compression Loading

为研究桁架筋与钢筋网片的连接形式、连接部位对双面叠合混凝土剪力墙大偏心受压性能的影响,对3片双面叠合混凝土剪力墙试件进行了试验,对比分析了各试件在大偏心荷载作用下的破坏形态、变形能力、承载能力以及刚度。试验结果表明,所有试件均表现出典型的大偏心受压延性破坏特征;下弦筋与钢筋网片全部绑扎、上弦筋与钢筋网片两端绑扎的试件(DPCW-1)和上、下弦筋与钢筋网片均全部绑扎的试件(DPCW-2),在大偏心受压下表现出的破坏形态、承载能力、刚度退化特征均相似;桁架筋与钢筋网片采用焊接连接方式的试件(DPCW-3)的峰值荷载以及整个加载过程中的刚度高于采用绑扎连接方式的试件(DPCW-2);各试件均观察到桁架筋上弦筋屈服的现象,且上、下弦筋钢筋应变大致与竖向受力钢筋应变规律相似,说明桁架筋的上、下弦筋在双面叠合剪力墙承受大偏心荷载时参与受力。在试验研究基础上,采用ABAQUS有限元软件对试件进行建模分析,模拟结果与试验结果吻合较好。参数分析结果表明,当改变试件的偏心距时,随着偏心距的增大,各试件极限承载力减小,极限挠度增大;混凝土叠合面黏结系数对叠合剪力墙在大偏心受压下的极限承载力和刚度影响不大。

In order to study the influence of the connection forms and positions of truss rebars and steel meshes on the performance of double-faced superposed shear walls under large eccentric compression loading,three double-faced superposed shear wall specimens were tested.The failure mode,deformability,deformation pattern,bearing capacity and stiffness of each specimen under large eccentric loading were compared and analyzed.The test results showed that all specimens exhibited typical ductile failure characteristics under large eccentric compression.Under large eccentric compression,the failure modes,load-bearing capacity and stiffnesses of specimens with the lower stringed tendons and the steel mesh fully tied but the upper stringed tendons and the steel mesh tied only at two ends(DPCW-1)or the upper and lower stringed tendons and steel mesh fully tied(DPCW-2)were the same.The ultimate bearing capacity and stiffness of the specimen with truss rebars and steel meshes welded(DPCW-3)were higher than those of the specimen DPCW-2.The upper and lower stringed tendons of all the truss rebars yielded,and the strain variations of the upper and lower stringed tendons was were roughly similar to that of the vertical rebars,which indicated that the upper and lower strings of the truss rebars participated in the force when the double-faced superposed shear wall bore large eccentric compression loading.On the basis of the experimental study,the finite element software ABAQUS was used to model and analyze the specimens,the numerical analysis is conducted to model the specimen,and the calculated results were in good agreement with the experimental results.The results of parameter analysis showed that the ultimate bearing capacity of all specimens decreased and the ultimate deflection increased with the increase of eccentric distance.The bond coefficient of concrete superimposed surface had little effect on the ultimate bearing capacity and stiffness of superimposed shear walls under large eccentric compression.