初始张拉力对预应力-CLT组合结构受力影响研究

Study on the influence of initial tension on the stress of prestressed-CLT composite structure

正交胶合木(CLT)是一种适合于建筑工业化的人工绿色材料,具有可预制、可再生、自重轻但强度和刚度较高等特点,有较好的环境效应。如果能够在正交胶合木基础上加上预应力,则该组合结构受力性能将会得到进一步提升。主要对不同初始张拉力下预应力-正交胶合木组合结构进行试验研究:考虑预应力钢绞线的2种不同初始张拉力,设计了2个CLT剪力墙构件进行拟静力往复加载试验,得到了2个构件的骨架曲线、刚度退化曲线、等效粘滞阻尼系数、变形模式等内容;同时,通过将试验结果与国内相关研究成果进行对比分析,发现施加预应力对CLT结构整体刚度、耗能能力等有较大提升;相比于预应力-木组合结构组装于钢底梁上,预应力-木组合结构组装在混凝土底梁上在一定程度上减少了钢节点的使用,缩小了两者之间的刚度差,使得混凝土底梁情况下构件屈服荷载、屈服位移以及最大承载力方面有一定的提升。

Orthogonal glued wood(CLT)is an artificial green material suitable for building industrialization.It has the characteristics of prefabrication,renewable,light weight,but high strength and stiffness,and has good environmental effects.If prestress can be added to the cross-laminated timber foundation,the mechanical performance of the composite structure will be further improved.This paper conducts experimental research on orthogonal glued wood concrete structures with prestressed steel strands under various operating conditions.Considering two different initial tensioning forces of prestressed steel strands and two different cross-sectional dimensions of members,two groups of full scale CLT shear wall members were designed for pseudo static reciprocating loading,and the skeleton curves,stiffness degradation curves,equivalent viscous damping coefficients,deformation modes,and influencing factors of the two groups of members were obtained;By comparing and analyzing the test results with relevant domestic research results,it is found that applying prestress significantly improves the overall stiffness and energy dissipation capacity of CLT structures;Compared with prestressed steel wood composite structures,prestressed concrete wood structures reduce the use of steel joints to a certain extent,resulting in a certain improvement in yield load,yield displacement,and maximum bearing capacity.