【作者】 邹颖娴；

【导师】 王社良；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2010， 博士

【摘要】 古塔自传入中国,就开始了与我国文化相融合的过程,它与中国传统建筑形式相结合,经过长时间的发展,已成为我国最具代表性的古代建筑形式之一。纵观我国几千年的古代建筑技术史,古塔的建造技术可以称得上代表了中国古建筑的最高科学和技术成就,它不但记录了当时的历史、材料、技术和工艺,更为中华民族留下了宝贵的历史文化财产,因此说古塔是古代劳动人民智慧的结晶,也是全世界人类宝贵的历史文化遗产。另外,我国的古塔不仅对研究我国古代建筑技术的发展具有极其重要的意义,更是我国古老的历史、文化、艺术、宗教、政治、外交、社会和经济等各方面的活生生的印证,可以说古塔建筑在我国具有不可替代的历史和文化价值。我国现存古塔结构大多都历经的年代久远,遭受的自然灾害和人为损害比较严重,因此,对古塔的保护研究已成为文物保护的重要工作之一。然而,目前针对古塔结构的保护工作多数都是具体问题具体处理,以抢救性的加固方案研究为主,针对古塔结构整体及局部的抗震机理与保护理论等方面研究较少,新材料和高新技术的应用也较少。因此,在我国开展针对古塔结构抗震机理、保护理论以及实用工程应用方法的系统研究,具有重要的社会历史意义和实用价值。本文通过查阅文献资料和现场检测等方法,详细了解了我国广州怀圣寺光塔的历史变化和工程现状,掌握了光塔结构的材料组成、构造形式以及目前的倾斜和裂缝等,同时对光塔结构的动力特性及其在大震和小震作用下的地震反应进行了深入分析,讨论了光塔结构的主要受力特性和抗震保护的关键问题。根据光塔结构的材料特性、构造形式和主要受力特点,分别对光塔进行了大震和小震作用下的抗震可靠性分析。具体方法是,首先根据光塔的工程现状建立光塔样本空间,然后根据光塔在地震作用下的受力特性和灾变特点合理选择抗震可靠度研究的控制截面,确定破坏准则和功能函数,最后对光塔样本空间中的各样本在大震和小震作用下的地震反应分别进行计算,并统计光塔分别在大震、小震作用下的失效概率,从而得出光塔结构的抗震可靠度。提出利用形状记忆合金(SMA)材料相变伪弹性性能,建立SMA阻尼器被动控制系统以提高光塔抗震可靠性的保护方案,并对形状记忆合金丝的相变伪弹性性能进行了试验研究,主要讨论了工作温度、应变幅值以及加载速度等对合金丝力学性能的影响,采用双线形模型对特定工况下合金丝的拉伸试验曲线进行拟合,得到的双线性恢复力模型可作为简化的形状记忆合金材料相变伪弹性恢复力模型,并能够应用于工程结构的理论分析和设计。根据光塔的结构特点和受力特性,设计并制作了2种形状记忆合金阻尼器被动控制系统,同时对其力学性能进行了试验研究。采用双线性模型,对特定工况下阻尼器被动控制系统的试验曲线进行拟合,得到的双线性恢复力模型可以作为简化的形状记忆合金阻尼器被动控制系统的恢复力模型,并能够应用于理论分析和实际工程的抗震加固设计。应用所研制的形状记忆合金阻尼器被动控制系统加固光塔模型结构,并对其进行了模拟地震振动台试验,验证了该被动控制系统有效性。同时,又设计了7种光塔结构的抗震加固方案,并通过对各种加固方案控制效果的分析,选定效果较好的方案作为光塔结构抗震加固的依据。接着,对加固后光塔结构进行了样本抽样,并根据加固后的光塔强度选取控制截面和破坏准则,分别对加固后的光塔结构进行了小震作用下和大震作用下的抗震可靠性分析。通过对光塔原型结构的抗震可靠性分析,找出了其存在多处不同的内部缺陷或薄弱环节,总体的抗震可靠性较差,难以承受地震、飓风等强灾害的袭击,亟需采取加固措施进行抗灾保护。SMA材料具有较好的相变伪弹性性能,利用形状记忆合金丝研制的SMA阻尼器被动控制系统具有很好的消能能力,应用其进行古建筑抗灾保护是一种新方法,具有可明显降低光塔结构的地震反应,大幅度提高光塔结构抗震可靠性等特点,很值得进一步开发和推广应用。文中所得结论不仅可为光塔结构的抗震保护和抗震可靠性研究提供理论依据与技术支持,而且对其它历史建筑的保护和修复也具有一定的参考意义。更多还原

【Abstract】 The architectural form pagoda combined itself with Chinese cultural as it came to China. After thousand years’development, it became a representative ancient Chinese architectural form. The pagodas recorded the history, materials, architectural technology of ancient china. As the ancient pagodas were the witnesses of our long history, culture, architectural, religions, politics, diplomacy, society and economy, they are very important and irreplaceable in the historic and cultural researches of our country.Most of the pagodas existing in our country are of great age, they suffered serious natural disasters and manmade damages in the long history and most of them were seriously injured. So the researches on protecting those ancient pagodas became an important work of cultural relic preservation.The purpose of this paper was to find out a method to evaluate the seismic reliability of a historic building, and search a feasible and effective method on seismic reinforcement of it.First, a detailed inquiry was made to acquire the changes in its history and the present situation of Guang Minaret in Huaisheng Mosque through reviewing of the literature and field testing. Through the inquiry, the material composition, structural form, bank and crack amount were acquired in detail. Then, the dynamic characteristics and the seismic performance of Guang Minaret in frequently-occurred earthquake and rarely-occurred earthquake was studied in detail through finite element method, and the key point of Minaret’s weighted behavior and seismic protection for it were also discussed.As most historic buildings had worn down by the years and their material strengths were low, the probability that they can work in elastic stage when an earthquake happened was little, and so, the seismic reliability analysis method based on random vibration theory was not fit the historic buildings. So, in this paper, the seismic reliability method based on earthquake resistant design code was applied. This analysis method mainly contains two parts, one is the strength-checking calculation in frequently-occurred earthquake, and the other is the deformation-checking calculation in rarely-occurred earthquake. The seismic reliability of Guang Minaret in frequently-occurred earthquake and rarely-occurred earthquake were separately analyzed according to its material characteristics, the structural form and weighted behavior.The sample space of Guang Minaret was built up according to its present situation; the key section, failure criteria and performance function was defined and the seismic response of each sample was calculated separately and the seismic reliability of Guang Minaret in frequently-occurred earthquake and rarely-occurred earthquake were concluded.Through the seismic reliability analysis of Guang Minaret, it was found that the minaret’s seismic reliability was low and it needed some seismic protection and reinforcement urgently. The protection plan using shape memory alloys to build up a passive seismic response control system for Guang Minaret was suggested in this paper.The passive seismic response control system was designed applying the pseudo-elasticity of shape memory alloys. Some experimental researches were made on the pseudo-elasticity of shape memory alloys, and the impact that working temperature, maximal strain value and loading rate may make on the mechanical properties of shape memory alloys were paid special attention. A data fitting was made on the material tensile test curve under specific working condition applying the bilinear model. The bilinear restoring force model can be used as the simplified pseudo-elasticity restoring force model of shape memory alloys in following theoretical analysis and calculation.Two type shape memory alloy dampers were made according to the minaret’s structural features and weighted characteristics. And some tensile experiment researches were made to acquire the performance data of those dampers. A data fitting was made on the dampers’tensile test curve under specific working condition applying the bilinear model. The bilinear restoring force model can be used as the simplified super-elasticity restoring force model of shape memory alloy dampers in following theoretical analysis and calculation.Seven protecting plans were made for Guang Minaret using the shape memory alloy dampers and the seismic response of reinforced minaret was calculated. Comparing the results of each protecting plans, a most suitable protecting plan was chosen, and according to this reinforcement, the sample space of reinforced minaret was built up. The key section, failure criteria and performance function were chosen for the reinforced minaret and the seismic reliability of Guang Minaret under frequently-occurred earthquake and rarely-occurred earthquake were calculated using Monte-Carlo method.Through the seismic reliability analysis of Guang Minaret, it was known that the seismic reliability was low and there were some internal defects and weak points in the minaret, and it needed some protection urgently or it may not survive a strong natural disaster such as an earthquake or a hurricane. Shape memory alloys were metals with very unique mechanical property, the pseudo-elasticity, and the shape memory alloy dampers had very good energy absorbing capability according to the experimental researches. The protecting plan applying shape memory alloy dampers suggested in this paper was proved to be an effective seismic reinforcement for ancient pagodas. The seismic response of Guang Minaret reduced a lot and the seismic reliability improved obviously with this protecting plan using shape memory alloy dampers.The passive seismic response control system applying shape memory alloy dampers in this paper was proved to be with good energy dissipating effect and can effectively improve the seismic reliability of Guang Minaret, and this reinforce method using shape memory alloys in the ancient pagodas’seismic reinforcement need more developments, spread and exploitations. The conclusions in this paper can not only provide some theory evidence and technical support to the seismic protecting and seismic reliability analysis of Guang Minaret, but also, it can provide references to protecting and repairing of other ancient buildings.更多还原