【作者】 刘晨曦；

【导师】 彭兴黔；

【作者基本信息】 华侨大学 ， 结构工程， 2018， 硕士

【摘要】 福建土楼作为世界上最大的现役夯土民居建筑,夯土墙既是承重结构也是维护结构,夯土墙形成一个承力整体,表现出与其它夯土建筑不同的建筑和结构特点。但随着时间迁移,福建土楼夯土墙的损伤日益严重,损伤原因包括:风雨侵蚀、承载力下降、耐久性、抗震性能等问题,其中,土楼夯土墙结构的抗震性能研究较少,本文对方形土楼的抗震性能进行研究。本文以九盛楼为原型进行了不同墙厚方形土楼的缩尺拟静力试验,从破坏形态、承载能力、变形能力、刚度及其退化曲线、滞回曲线、骨架曲线、耗能性能几方面进行了分析。并依据试验工况利用ABAQUS进行数值模拟,将数值模拟结果与试验结果进行对比,验证模拟的有效性。最后计算了九盛楼的承载力。主要研究内容如下:(1)通过对永定土楼的实地调研,选取具有代表性的方形土楼“九盛楼”为原型,将墙厚作为唯一变量,制作3个缩尺试件,进行拟静力试验研究,试验材料采用自己研发配制的C5混凝土代替夯土材料,通过立方体轴压试验,计算C5混凝土的密度、抗压强度标准值、弹性模量等。通过计算相似比将模型与原型相关联。(2)通过拟静力试验现象及破坏形态分析,得到试件开裂荷载、极限荷载及破坏模式。通过计算试件的抗剪承载力来分析其承载能力;通过计算试件位移延性系数来分析其变形能力;通过计算试件的平均刚度来分析其刚度,并通过Origin拟合了刚度退化指数曲线;通过对滞回曲线和骨架曲线的拟合,以及滞回耗能、等效粘滞阻尼系数的计算,分析其耗能性能。并得出方形土楼夯土墙结构随墙体厚度增加,其承载能力增加、刚度降低、延性降低、滞回耗能量有所增加的变化规律。(3)依据试验工况,通过ABAQUS软件,分别用C5混凝土材料及夯土材料建立试验模型,采用位移加载方式对模型进行低周往复模拟,得到后处理应力云图、滞回曲线及骨架曲线。并从承载力、破坏形态和骨架曲线几方面进行模拟与试验的对比分析,验证模拟的准确性。(4)对九盛楼的抗剪承载力及抗震承载力进行理论计算。更多还原

【Abstract】 Fujian tulou is the largest active rammed residential building in active service.Rammed earth wall is not only the load-bearing structure but also the maintenance structure.The rammed earth wall forms a bearing force as a whole and shows the different construction and structural features with other rammed earth buildings.As time goes on,however,the damage of rammed earth wall in fujian is becoming more and more serious.The causes of damage include many problems such as wind and rain erosion,capacity reduction,durability,seismic performance and so on.Meanwhile,there are few researches on seismic performance of rammed earth wall structure.Therefore,this paper studies the seismic performance of Fujian square Tulou.In this paper,the prototype of Jiusheng building for different thickness has been used to carry out the pseudo-static test of the scale model of the square Tulou.And the failure pattern,bearing capacity,deformation capacity,stiffness and its degradation curve,hysteresis curve,skeleton curve and energy dissipation are analyzed.In addition,based on the test condition,ABAQUS is used for numerical simulation.The numerical simulation results are compared with the experimental results and the validity of the test is verified.Finally,the bearing capacity of Jiusheng building is calculated.The main research contents are listed as below:(1)Through the field survey of Yongding tulou,the paper selects the representative square tulou "Jiusheng building" as the prototype.The wall thickness is used as the only variable to make three scale specimens and the pseudo-static test is carried out.The experimental materials used their own research and development of C5 concrete instead of rammed earth materias.The C5 concrete is tested for the cube axial compression,and the density,the standard value of compressive strength and the elastic modulus are calculated.The model will be associated with the prototype By calculating the similarity ratio.(2)The crack load,ultimate load and failure mode of the specimens are obtained through the analysis of the pseudo-static test and the failure form.The bearing capacity of the specimens is analyzed by calculating the shear bearing capacity of the specimens.The displacement ductility coefficient of the specimen was calculated to analyze its deformation ability.By means of calculating the average stiffness of the specimens,the stiffness and the curve of the stiffness degradation index are obtained through Origin.The energy dissipation performance is analyzed by fitting the hysteresis curve,skeleton curve,the calculation of hysteresis and equivalent viscous damping coefficient.It is concluded that the bearing capacity,deformation ability and energy dissipation of the structure of the square earth wall with the change of wall thickness.(3)Based on the test condition,the test models by using C5 concrete materials and rammed earth materials are established through ABAQUS software.Low-cycle reciprocating simulation of the model is carried out by using displacement loading method,and the post-processing stress cloud graph,hysteresis curve and skeleton curve are obtained.The accuracy of the numerical simulation is verified by comparison of the bearing capacity,the failure mode and the skeleton curve.(4)The theoretical calculation of shear bearing capacity and seismic bearing capacity of jiusheng building is carried out.更多还原