【作者】 李凯；

【导师】 张荫；

【作者基本信息】 西安建筑科技大学 ， 岩土工程， 2017， 硕士

【摘要】 塔是我国古代建筑的重要组成部分,融合了中外建筑艺术的精华。我国现存古砖塔数量巨大,具有极其重要的文化艺术价值,因而古砖塔的保护具有极其重要的意义。同时我国也是一个地震频发的国家,地震造成古塔既有损伤累积而导致结构破坏。因此古塔的地震损伤模式是研究古塔地震破坏的关键所在。本文以陕西蒲城崇寿寺砖塔为研究对象,引入损伤演化的概念,表征该塔材料性能劣化,分析地震作用下结构的损伤特性;并进行了兴教寺玄奘塔振动台试验,依据试验结果研究了砖塔地震损伤机制。具体工作如下:(1)在环境激励下进行了崇寿寺塔的原位动力测试试验,得到了该塔的基本动力特性,并应用ABAQUS软件建立结构的数值模型,参照动力特性的测试结果确定结构等效计算参数及楼层刚度损伤率,分析了古塔结构的宏观损伤,识别结果显示的分布规律与现场调研结果一致。(2)基于砌体结构损伤本构模型,确定损伤参数,并将损伤模型引入崇寿寺塔数值计算中,按不同烈度输入地震波,计算结构在不同设防烈度下损伤参数的变化规律,探讨空筒式古塔损伤演化规律。结果表明,地震作用下空筒式砖塔结构破坏主要由受拉引起损伤累积造成,结构底部与中部楼层为损伤破坏显著区域。(3)制作了兴教寺玄奘塔1/8比例模型,并进行了振动台试验,分析了两次白噪声、7度单向和三向EL-Centro波输入时模型的反应,研究了实心结构砖塔的损伤演化规律。结果表明,该砖塔的破坏也是由于受拉损伤积累引起的,结构首层或空心层为薄弱层,是结构损伤起始区域。(4)参照试验模型,建立数值模型。对数值模型按方向不同,分别输入7度单向和三向EL-Centro波。将试验和数值模拟的弹性阶段和弹塑性阶段的试验现象和数据分别进行对比,结果表明:在弹性阶段,数值模型的位移、加速度和基本频率都与试验模型符合良好;在弹塑性阶段,数值模型的宏观损伤规律,及加速度曲线的FFT变换曲线都与试验模型符合良好,说明该数值模型是可靠的。更多还原

【Abstract】 Masonry pagoda is an important constituent of the ancient architecture of China,which combined with foreign and Chinese traditional culture.Because of the large quantity and extremely high cultural value,it is very important to protect our masonry pagodas.At the same time,seismic activity happens frequently in China.Earthquakes will accumulate the masonry pagoda`s damage,resulting in structural damage.So,the seismic damage mechanism of the masonry pagoda is the key to studying the seismic damage of the structure.This paper takes Chongshousi Pagoda in Pucheng County,Shaanxi Provincen as the research object.Introducing the concept of damage evolution to characterize the material properties of the deterioration of the material properties in the structure of the pagoda.So as to analyze the damage characteristics of the structure under the action of earthquake,and carry out the Xingjiao temple’s Pagoda’s shaking table test.Specific work is as follows:(1)The basic dynamic test of the pagoda are obtained and the dynamic characteristics of the pagoda are calculated by ABAQUS software.According to the test results of the dynamic characteristics,the equivalent calculation parameters and the stiffness damage rate of the floor are determined.The macroscopic damage of the pagoda structure is analyzed.The distribution of the identification results is consistent with the results of the field investigation.(2)A damage evolution model is introduced into the numerical model of the pagoda,which is based on the damage constitutive model of masonry structures.According to the different intensity of the seismic waves inputted,the change rue of the damage parameters of the structure under different fortification intensity were calculated and the damage evolution law of the empty cylinder pagoda were explored.The results show that the damage of the hollow brick structure under earthquake is mainly caused by the accumulation of damage caused by tension.The floor at the bottom and the middle of the structure is a significant area of damage.(3)A 1/8 scale model of Xingjiao Temple’s Pagoda was made and a shaking table test was carried out.The experimental data were analyzed and the damage evolution law of the solid structure was studied.The results show that,the damage of this pagoda is also caused by the accumulation of tension damage,The first layer of the structure or the hollow layer is the weak layer,which is the starting region of the structural damage.(4)With reference to the test model,a numerical model is established.For the numerical model,enter the 7-degree EL-Centro wave in different directions.The elastic phase and the elastic-plastic phase of the experiment and numerical simulation are compared respectively.The results show that,in the elastic phase,the displacement,acceleration and basic frequency of the numerical model are in good agreement with the experimental model.In the elastoplastic stage,the macroscopic damage law of the numerical model and the FFT curve of the acceleration curve are in good agreement with the experimental model.Indicating that the numerical model is reliable.更多还原