古建筑木结构柱脚节点受力性能试验研究  

Mechanical property of column footing joint in traditional wooden structure by quasi-static test

作　　者：贺俊筱 王娟[1,2] 杨庆山[2,3] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]北京交通大学结构风工程与城市凤环境北京市重点实验室,北京100044 [3]重庆大学土木工程学院,重庆400044

出　　处：《建筑结构学报》2017年第8期141-149,共9页Journal of Building Structures

基　　金：国家自然科学基金青年科学基金项目(51408038);国家自然科学基金重点项目(51338001);国家科技支撑计划(2015BAK01B02)

摘　　要：在古建筑木结构中,将木柱直接平摆浮搁于础石之上,形成连接上部结构与台基之间的柱脚节点,其只承受压力而不承受拉力。在反复荷载作用下,木柱会沿柱脚边缘转动。为研究柱脚节点在地震、风荷载等作用下的受力性能,参考宋代《营造法式》制作了3个七等材足尺柱脚节点模型。通过低周反复荷载试验对柱脚节点的受力特点、滞回特性、转动刚度、刚度退化、柱脚截面等效半径和柱脚边缘点应变等特性进行研究,并分析了竖向荷载对上述性能的影响。试验结果表明:在反复荷载作用下,柱脚边缘出现受压变形,其转动支点交替变化;滞回曲线呈反Z形,产生捏拢现象;柱脚节点恢复弯矩和柱脚截面等效半径首先随转角增加而增加,而后逐渐趋于稳定;柱脚节点的初始转动刚度较大,随后刚度随转角增加逐渐减小;在反复荷载作用下,柱脚节点产生刚度退化现象,加载过程中,柱脚转动刚度为正值,表明其具有较好地转动性能;柱脚恢复弯矩、转动刚度、边缘点应变随竖向荷载增加明显增加,柱脚截面等效半径随竖向荷载增加而减小;通过试验拟合得到了竖向荷载对恢复弯矩和转动刚度的影响系数。Column is set on the stone base directly in traditional wooden structure, which forms to the very important column footing joint connecting the upper structure and stone base. Column foot transfers compressive force only without any tensile capacity. Columns can rotate around the edge of column foot under cyclic loads. Three 7 ts＇ ai full- scale column footing joint models based on Ying-tsao-fa-shih were established to study mechanical property of column footing joint under cyclic loads, such as earthquake or wind loads. The mechanical property, hysteretic characteristics, rotation stiffness, stiffness degradation law, equivalent radius and strain of edge point of column footing joint were analysed, and the effects of vertical loads on the above performances were also studied. Results show that compression deformation occurs at the edge of column foot, and rotation point of column foot changes from left to right under cyclic loads. Hysteretic curve with a Z-shape has pinching effect. Restoring moment and equivalent radius are increased with increase of rotation angle first and then constant. The stiffness with great initial value is decreased with increase of rotation angle. Stiffness degradation of column foot happens under cyclic loads. The rotation stiffness is positive during loading, which shows it has preferable rotation capability. Restoring moment, rotation stiffness and strain of edge point have a rising trend with the increase of vertical load. On the contrary, the equivalent radius is decreased with the increase of vertical load. The coefficient of vertical load on restoring moment and rotational stiffness were obtained by test results fitting.

关 键 词：古建筑木结构 柱脚节点 拟静力试验 恢复弯矩 转动刚度 等效半径 

分 类 号：TU366.2[建筑科学—结构工程] TU317.1