藏式古建筑石墙体力学性能及残损机理研究

The construction technology of stone masonry wall of Tibetan ancient architecture is very different from other places, and a large number of buildings which using traditional process are very common in Tibet's historic architecture, but the current method of calculation and security identification in masonry structure are not suitable for these buildings. In this project, the mechanics behavior of Tibetan stone masonry wall is researched, and the influence of Tibet regional unique masonry crafts which including thick wall, interdigitate shape of stone, gravel caulking et al on mechanical performance of walls is obtained, the working mechanism and failure criterion of pressure-bearing, shear and seismic of Tibetan stone masonry wall are formed, as well the existing theory of masonry structure mechanics analysis and calculation methods are enriched. Based on this, the damage types and mechanism of stone masonry wall of Tibetan ancient architecture are systematic analyzed, which provides some theoretical reference for performance evaluation, reinforcement and maintenance or reinstatement works. Finally, the maintenance modes based on intuitive feel and experiences in the past will be changed, and the reliable calculation on the bearing capacity of stone masonry wall of Tibetan traditional architecture and the quantitative safety assessment of structure will be achieved.

西藏古建筑石墙体工艺与其他地方有很大差异，这些采用传统工艺的建筑在西藏的文物建筑中十分常见，而现行的砌体结构计算方法及安全鉴定不能完全适用于这些建筑。本项目拟对藏式石墙体开展基本的力学性能研究，获得厚墙、“收分”、块石犬牙交错状、碎石填缝等西藏地域独有的组砌工艺对墙体受力性能的影响规律，形成藏式石墙体承压、抗剪及抗震工作机理及破坏准则，丰富现有砌体结构力学分析理论及计算方法。在此基础上，系统分析藏式古建筑石墙体主要残损类型及机理，为藏式古建筑性能评估、维修加固及原状恢复提供理论参考，以期改变过去凭直观感觉和经验进行维修的方式，实现对藏式传统建筑石墙体承载力可靠计算及既有结构量化安全评估。

西藏古建筑石墙体的砌筑工艺因地方不同而有很大差异，现行砌体结构计算方法和安全鉴定规程均不适用于这类毛石墙体建筑。本项在青藏高原系统收集了传统藏式石砌建筑的相关信息，获得了藏式石墙体的砌筑工艺、建造特征和使用现状，分析了藏式石墙体的传力特征和变形性能，统计分析了石墙体传统建造方法的优缺点；对历次地震中藏式石墙体的地震破坏特征进行了统计分析，分析了传统藏式石墙体的抗震机理。基于实地调研结果，开展了不同砌筑工艺藏式石墙体的承压试验研究，获得了不同砌筑方式下石墙体的抗压承载能力和受压破坏特征，改进了藏式石墙体抗压承载力计算公式；开展了不同竖向压力作用下藏式石墙体的抗剪承载能力试验研究，观察了不同竖向压力下石墙体的水平抗剪承载能力和破坏特征，结合试验结果和摩阻理论推导出了石墙体的抗剪承载力计算公式；对藏式石墙体进行了抗震性能试验研究，分析了不同竖向压力下，藏式石墙体的耗能性能和承载能力。最后，采用图像处理法，结合灰色关联理论，建立不规则毛石块体形状参数与石墙体地震破坏特征的关系，对量化藏式毛石墙体的几何指标影响抗震破坏机理进行了探索，初步确定了较为可信的量化藏式石墙体承载能力和毛石块体形状参数的方法，为日后进一步建立全面评价藏式毛石墙体的承载能力和地震破坏机理提供了依据。