【作者】 张风亮；

【导师】 赵鸿铁； 薛建阳；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2013， 博士

【摘要】 古建筑木结构由于其独特的结构特性而具有优良的力学性能，使得像山西佛光寺大殿以及五台山南禅寺大殿这些经历千年风吹雨打和多次地震的典型古建筑物依然屹立于中华大地。然而，在漫长的历史岁月中，由于材料的老化、腐朽、虫蛀以及强震、战火、风雨侵蚀等自然力以及人为的破坏，再加上多年来对其保护不够重视、年久失修，使得这些现存古建筑木结构处于结构体系破坏、多种病害缠身、险情不断发展甚至潜伏坍塌的危险状态。因此，作为国家重点文化保护遗产的现存古建筑木结构建筑物，其修缮加固工作变得尤为重要。本文结合汶川地震后对现存古建筑木结构的震害调查，通过系统归纳和分类统计，对古建筑木结构的地基基础、梁柱和枓栱等构件、榫卯节点、整体稳定性以及围护结构在地震作用下的破坏情况及破坏原因、木材性能退化等进行了详细的分析和探讨；并针对结构不同的破坏情况，提出了相应的抗震加固方法。为了掌握古建筑木结构地震作用下的破坏过程及对应的破坏状态，对震后古建筑木结构的破坏程度做出合理的评估，基于燕尾榫柱架和枓栱铺作层低周反复荷载作用下的滞回特性和能量耗散原理，将燕尾榫柱架和枓栱铺作层看做两耗能构件，计算出其在低周反复荷载作用下的“抵抗破坏潜能”；根据古建筑木结构振动台试验，计算出各工况地震作用下每一耗能构件所耗散的能量；基于构件的“抵抗破坏潜能”和各工况下的地震耗能情况建立耗能构件在不同地震作用下的地震破坏评估模型，并借助于能量分配系数找出了各耗能构件破坏状态与整体结构破坏状态之间的关系，从而建立整体结构在不同地震作用下的破坏评估模型。应用该地震破坏评估模型，分别对燕尾榫柱架和枓栱铺作层以及整体结构进行构件地震破坏评估和整体结构地震破坏评估，所得到的破坏系数能较好地反映各构件以及整体结构在不同地震作用下的破坏状态。对按照宋代《营造法式》构造要求制作的古建筑木结构实体加固模型进行模拟振动台试验。选用三条地震波分别对结构模型的柱根、柱头、铺作、乳栿的位移、加速度响应、地震剪力以及榫卯节点的内力进行定量研究，并对结构的破坏形态、动力特性、扭转效应进行定性分析。研究结果表明：柱础的摩擦滑移、半刚性榫卯节点的转动以及枓栱铺作层的滑移使得结构模型地震响应大幅度减小，满足“小震不坏、中震可修、大震不倒”的设计要求；结构模型最大剪力沿高度的分布出现在柱架层或柱础层，并非一定出现在结构的柱础最低层；得出榫卯节点不同工况下的转动弯矩最大值；由于高振型的参与以及质量和刚度不均匀分布，结构模型在400Gal后出现明显的扭转。根据碳纤维布加固古建筑木结构力学性能，基于试验和理论分析，分别得出了能够体现碳纤维布加固古建筑木结构独特受力性能的各关键部位或构件的恢复力特性曲线；用Combine40弹簧单元、Combine39弹簧单元+Combine14弹簧单元以及Combine39弹簧单元简化模拟柱脚与础石间的摩擦滑移特性、半刚性榫卯及枓栱连接，建立整体结构的有限元计算模型。模态分析得出了结构模型的前十阶振型及自振频率。地震响应分析显示，随着地震动强度的增大，结构各层的最大位移值和加速度值逐渐增大，同时各层的动力放大系数越来越小，说明大震时半刚性榫卯连接的减震效果比中震和小震时的减震效果要好。殿堂式古建筑木结构由于其独特的构造特点而具有与现代建筑结构不同的抗震性能，现有的结构动力分析模型对于古建筑木结构不再适用。基于其水平地震作用下的受力性能及动力破坏形态，给出了关键构件的简化分析模型，将柱架简化为“摇摆柱”，将枓栱铺作层简化为“剪弯杆”；根据简化分析模型及整体结构质量分布情况，提出了单层殿堂式古建筑木结构的两质点“摇摆-剪弯”动力分析模型；结合构件试验以及动力学理论推导得到了动力分析模型不同受力状态下各参数的计算方法及适用范围，并与振动台试验结果进行对比。结果表明，提出的动力分析模型可以较好地反映单层殿堂式古建筑木结构在水平地震作用下的动力反应。最后，结合碳纤维布和扁钢加固燕尾榫节点在外荷载作用下的受力破坏性能，并根据试验破坏情况，提出了碳纤维布和扁钢加固古建筑木结构燕尾榫节点的抗弯承载力计算公式，并给出了合理的加固设计建议，为古建筑木结构的修缮加固提供理论依据。更多还原

【Abstract】 The good mechanical properties of Chinese ancient timber structure, due to itsunique structural characteristics, makes the existing ancient timber structures such asShanxi Buddha temple hall and Wutai mountain south temple hall still stand to the earthafter experiencing thousands of rains, winds and earthquakes. However, in the endlesshistory years, because of material ageing and many kinds of damages like earthquake,most of the ancient buildings are in the perilous state of damaging, risk escalating evenpotential collapse. Therefore, repair reinforcement work of ancient timber structuresregarded as the fruit of ancient culture becomes more and more important.Combined with the earthquake damage survey to the ancient timber structures afterWenchuan earthquake, it took detailed analysis and discussion under the effects ofearthquake damage to the ancient timber structures in terms of foundation, componentsuch as beams and columns, mortise-tenon joints, overall stability and buildingenvelope through summing up and classification and statistical methods; And inallusion to different structure damages, it put forward the corresponding seismicstrengthening methods.In order to investigate the failure process and corresponding failure mode of theancient timber structure so as to be able to make a reasonable evaluation of the damagedegree of the ancient timber structure after earthquakes, the ‘potential ofdestruction-resistance’ of the two energy-consuming components under low reversedcyclic loading was calculated based on the hysteretic behavior and energy dissipationprinciple of the dovetail column-frame and arches brackets under the low reversedcyclic loading. The dissipated energy of each energy-consuming component undervarious earthquake conditions was calculated based on the results of the shaking tabletest of ancient timber structure. The model for seismic damage evaluation of the two energy-consuming components was established on the basis of the ‘potential ofdestruction-resisting’ and dissipated energy. The relationship of the failure modebetween energy-consuming components and overall structure was found by means ofthe energy distribution coefficient. The model for seismic damage evaluation of theoverall structure under the various earthquake conditions was also developed. With thederived model of seismic damage evaluation, the energy-consuming components andthe overall structure can be evaluated separately; the resulting failure coefficient canbetter reflect the failure mode of each component and the overall structure under variousearthquake conditions.A shaking table test of a model of an ancient timber structure，constructedaccording to the Fabrication Methods of Song dynasty and strengthened with CFRP，was conducted． Quantitative analyses were performed for the displacement andacceleration response of the root，the head of column，Shop Aung，Ru Fu，theearthquake shear of structure and the internal force tenon-mortise node，failure pattern，dynamic property，and torsional effect．The study showed that the friction-sliding ofpedestal，rotation of semi-rigid tenon-mortise node and sliding of Shop Aung greatlydecreased the dynamic response of the structure，and met the design requirements of nodamage under frequent earthquakes，repairable under moderate earthquakes and nocollapse under rare earthquakes．Maximal shear force of the structure distributed alongthe height appeared in the column frame layer or the pedestal，and the maximal bendingmoment of tenon-mortise node under different conditions was also obtained．Due to theparticipation of high vibration model and non-uniform distribution of mass andstiffness，there was obvious twist beyond400Gal．According to the mechanical properties of ancient timber structure, its restoringforce characteristic curves of the key position and components were got based on thetest and theoretical analysis, and the plinth, mortise-tenon joint and the Arches bracketwere simulated with Combine40, Combine39+Combine14, Combine39of large scalefinite numerical simulation software ANSYS, and the finite element model wereestablished. The first ten order of the structural nature frequency and mode shapes wereobtained by the modal analysis. Seismic response simulation results show that themaximal displacement and acceleration increases with the increasing of intensity, theseismic amplification coefficient gradually decrease, which indicates that the shockabsorption effect of semi-rigid connection mortise-tenon in major earthquake is better than that in moderate earthquake and minor earthquake.The monolayer hall-style ancient timber structure，due to its unique constructionfeatures，the seismic behavior is different from modern buildings．The existing dynamicanalysis model of structure is no longer suitable for ancient timber structure Based onits mechanical behavior and dynamic failure mode under the horizontal earthquakeaction，the equivalent models of the key members of which the column frame wassimplified as‘rocking column’and the bucket arches was simplified as ‘shear-bendingmember’were put forward．According to the equivalent models and mass distribution ofthe whole structure，‘rocking-shear-bending’ dynamic analysis model for monolayerhall-style ancient timber structure was proposed，the analysis method and applicationrange of each parameter based on component test and theoretical derivation of dynamicswere obtained．The results of analysis model were compared with experimentalresults．It is found that the test results agree with analysis results，which shows that theproposed dynamic analysis model can reflect the dynamic response of the monolayerhall-style ancient timber structure under the horizontal seismic action．At last, the flexural capacity equations of mortise-tenon joint strengthened withCFRP and steel flat were proposed combined with damaged performance ofstrengthened joints, and the reasonable strengthening design method was also proposed,which would provide theoretical basis to the reinforcement of ancient timber structure.更多还原