基于铝模的全混凝土外墙对剪力墙结构抗震性能的影响

Influence of All-Concrete Exterior Wall Based on Aluminum Formwork on Seismic Performance of Shear Wall Structure

基于铝模的全混凝土外墙(带拉缝外墙)因其在施工中的显著优势被广泛应用于高层建筑中,现阶段结构设计未考虑拉缝对结构刚度的影响。通过计算,提出拉缝材料水平和竖向的等效弹性模量。针对带拉缝外墙对梁刚度的贡献和对结构刚度的影响,基于典型双肢剪力墙模型数据库、神经网络和结构抗震性能评估方法,研究带拉缝外墙剪力墙结构的抗震性能。以双肢剪力墙中的梁跨度和高度、层高和层数、单肢墙宽和墙宽比共6个特征参数为变量,设计20 160榀剪力墙,批量生成等效梁尺寸放大系数和结构刚度放大系数,并通过神经网络回归带拉缝外墙对梁刚度贡献的映射关系,在设计阶段结合周边构件的几何参数预测出梁等效尺寸放大系数,以此将实际工程中外围梁的尺寸放大来考虑带拉缝外墙对梁刚度的贡献。通过小震弹性设计、大震弹塑性复核,说明不考虑带拉缝外墙的刚度贡献,实际降低了剪力墙的抗剪富裕度。

The all-concrete exterior wall based on aluminum formwork(the exterior wall with tensile joints)is widely used in high-rise buildings because of its remarkable advantages in construction.At the present stage,the influence of tension joints on structural stiffness is not considered in structural design.Through calculation,the equivalent elastic modulus of horizontal and vertical tensile joints is proposed.In view of the contribution of jointed external walls to the beam stiffness and the influence on the structural stiffness,the seismic performance of shear wall structure with jointed external walls is studied based on the database of typical double-leg shear wall model,neural network and structural seismic performance evaluation method with six characteristic parameters,including the beam span and height,storey height and number of stories,single wall width and wall width ratio in double-leg shear wall,20160 groups of single shear walls are designed and the equivalent size amplification factor and structural stiffness amplification factor are generated in batches.Through the neural network regression of the contribution of the external wall with tension joint to the beam stiffness,the equivalent size magnification factor of the beam is predicted in the design stage combined with the geometric parameters of the surrounding members.In order to consider the contribu‐tion of jointed external walls to the beam stiffness,the size of the outer beam in the actual project is enlarged in the actual project.Through the elastic design of frequent earthquakes and the elastic-plastic review of rare earthquake,which shows that without considering the stiffness contribution of the external wall with tension joints,the shear margin of the shear wall is actually reduced.