摘要
在古建筑木结构中,木柱常常直接浮搁于础石上。在地震、风等反复荷载作用下,木柱会出现"摇摆"现象。木柱作为整体结构的主要承重部分,其在摇摆状态下受力性能对整体结构的稳定性和整体性有着重要的影响。为研究木柱在摇摆状态下的受力性能,该文首先提出摇摆运动机理,通过理论分析得到柱脚抬升判定条件;其次,参考《营造法式》制作了七等材木柱模型,通过低周反复荷载试验验证了柱脚抬升判定条件的正确性,研究了木柱的变形特征、柱头荷载位移滞回曲线、骨架曲线、抗侧能力、刚度退化规律等特性。试验结果表明:在反复荷载作用下,木柱出现摇摆现象,柱脚与础石接触部位存在木材受压变形。当柱头位移达到10 mm时,柱脚出现一侧抬升一侧受压现象。加载过程中,柱脚未滑移;木柱荷载位移滞回曲线呈S形,具有一定的捏拢效应;木柱初始抗侧刚度最大,其抗侧能力随柱头位移增大而逐渐减弱;在柱头位移达到60 mm之前,刚度退化较明显,随后刚度退化现象减弱。
Columns were often set on the stone base directly in traditional timber structure. ＇Rocking＇ might occur to the column under repeated loads, such as seismic or wind loads. The column was the main load bearing part of the whole structure. The mechanical behavior of the column during rocking in traditional timber structure had great effect on the stability and integrity of the whole structure. To study the mechanical behavior of the column during rocking, the motion principle of column rocking is obtained and the lifting judgement condition of the column foot is proposed by theoretical analysis firstly. Then, the 7 ts＇ai full-scale column model based on 〈Ying-tsao-fa-shih〉 is produced to verify the lifting judgement condition and study deformation characteristic, hysteretic curve of load and displacement, skeleton curve, lateral resistant ability and stiffness degradation law of column by quasi static test. The results show that ＇rocking＇ occurs to the column and compression deformation happens to the column foot under repeated loads. Lifting at one side and compression at other side occurs at the column foot after the horizontal displacement at the column head up to 10 ram. During loading, there is no slipping at the column foot; Hysteresis curve of load and displacement with an S-shaped has a pinch effect; the original lateral stiffness of the column is largest and the lateral resistant ability decreases with the increase of lateral displacement. The degradation phenomenon of stiffness is obvious before the displacement reaches 60mm, after which it is weaken.
出处
《工程力学》
EI
CSCD
北大核心
2017年第11期50-58,共9页
Engineering Mechanics
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)
国家科技支撑计划项目(2015BAK01B02)
高等学校学科创新引智计划项目(B13002)
北京市自然科学基金重点项目(8151003)
关键词
古建筑木结构
柱摇摆
受力性能
摩擦滑移
抬升
拟静力试验
traditional timber structure
column rocking
mechanical behavior
frictional sliding
lifting
quasi static test
