【作者】 郭涛；

【导师】 黄浩； 邓高峰；

【作者基本信息】 重庆大学 ， 工程硕士（建筑与土木工程领域）（专业学位）， 2016， 硕士

【摘要】 中国传统木结构主要分为抬梁式和穿斗式两大类,抬梁式木结构主要分布在我国北方地区,穿斗式木结构以其轻巧而简洁的结构布置成为我国南方木结构民居的主要形式。历次地震后发现穿斗式木结构房屋具有规律性震害特征,如拉榫、折榫、榫头拔出、柱脚过大滑移、结构侧移较大而影响结构的稳定性和整体性等。抬梁式木结构与穿斗式木结构有一些相似性,如连接均为榫卯连接、柱础的处理以及减震、隔震、抗震机理等,但两者之间亦有很多差别,如节点构造、结构布置等,已有研究对抬梁式木结构进行了较为深入的研究,对穿斗式木结构的研究尚不充分,亟待对其抗震机理及抗震性能进行研究。为进一步研究穿斗式木结构的抗震机理、抗震性能、影响抗震性能的主要因素等,本文通过实地调研、查阅文献等确定木构架试件尺寸,为与实际更加相符,选用1:1足尺模型进行试验研究。通过对两榀单层双跨穿斗式木构架试件的水平低周往复荷载试验,获得了穿斗式木构架的荷载—位移滞回曲线、节点的弯矩—转角曲线、穿斗式木构架在水平荷载下的受力特性等试验成果。其主要结论如下:(1)榫卯连接的木构架抗侧刚度较小,P-△二阶效应明显,在对木构架滞回曲线的研究中,竖向荷载所产生的P-△二阶效应的影响是不可忽略的。(2)在同一目标位移控制下的三次循环中,木构架的强度退化主要发生在第二次循环,第三次循环与第二次循环相比,退化幅度较小。(3)木构架的刚度呈现出“先上升后下降”的变化特征,木构架在试验初期节点榫卯之间存在一定的空隙,且柱子是直接浮搁于基础之上,使得整个木构架初始状态下刚度较低,随着位移控制级的增大,木构架刚度逐渐增大,在到达175mm位移控制级后,木构架节点的累积损伤不断增多,木构架的刚度开始缓慢下降。(4)木构架的等效粘滞阻尼系数随着位移控制级的增大逐渐减小,在到达175mm位移控制级后开始基本保持不变,两榀木构架呈现出相同的变化的规律。(5)木构架柱底的滑移量相对于木构架整体变形值较小,且两侧边柱柱底在整个实验过程中并未完全与基础脱离,在对木构架整体进行计算分析的简化模型中可以将柱脚与基础相连位置作铰接处理。(6)两榀木构架节点的弯矩—转角关系具有相似的变化特点,拟合得到了节点弯矩—转角三线型简化模型,对以后的研究和工程应用有一定的参考价值。(7)节点滞回曲线与构架滞回曲线具有相似性和同步性,节点耗能是构架耗能的主要耗能形式。更多还原

【Abstract】 Traditional Chinese timber structure are classically classified into two categories. One is post-and-lintel construction, which commonly used in north china. The other is Chuan-Dou style wood construction which has become the main form of wooden structure houses in southern China because of its lightweight and compact structural arrangement. Types damage of the Chuan-Dou style wood houses, which have been found in the past earthquakes, include the frictional sliding at the column base, the fracture at timber beam end, the pull-out of the tenon from the mortise and lateral displacement and greater influence stability and structural integrity. Post-and-lintel construction has been studied deeply by domestic scholars, while relatively few studies made in Chuan-Dou style wooden structure. There are some similarities, such as mortise-tenon connection, column base connection, shock absorption, seismic mechanism and seismic mechanism, in this two wood structure types. Therefore, the existing research on the Chinese traditional wooden structure has an important reference value on the research Chuan-Dou style wooden structure.To further study the seismic mechanism and seismic performance of the Chuan-Dou timber structure, two full-scale models were built based on extensive investigation of resident houses, related historical documents. Low-cyclic reversed loading tests are conducts on the wood samples, load-displacement hysteresis curve of wood frame, moment-rotation hysteresis curve of mortise-tenon joints and the mechanical characteristics of wood frame under horizontal load are achieved. The main conclusions are as follows:(1)P-△ effect have a great impact on the results of analyzing hysteretic curves, skeleton curves and related behaviors of wood samples, so the P-△ effect of vertical load should be concerned in studying the wood frame.(2)The strength degradation of wood frame mainly occurred in the second cycle in the three cycles at the same displacement stage. Compared to the second cycle, the strength degradation of the third cycle is lower.(3)At initial loading stage, the lateral stiffness for both specimens K1 and K2 are relatively low, which due to the initial gaps of mortise-tenon joints. When applied displacement increased, the lateral stiffness increased simultaneousesly, up to the displacement of 175 mm. After which, the lateral stiffness slightly decreased.(4)The equivalent viscous damping coefficient of wood frame drops off gradually when cyclic amplitude increased and keeps stably after 175 mm, similar variation is presented in the two samples.(5)Compare to the deformation of wood frame, the amount of base slip and pulling up is very little, so we can treated the connection of column base and foundation as a hinge.(6)Moment and rotation relationship of mortise-tenon joints with similar variation have been fitted a three-wire simplified model, which has a guiding significance to the further research and engineering application.(7)The hysteretic curve of the joints and the hysteretic curve of the wood frame are similar and synchronous. The energy dissipation of joints is the main form of energy dissipation of wood frame.更多还原