穿斗式木结构抗震机理及抗震加固方法研究

Column and tie timber construction is one of the most commonly used structure type in Chinese history. In southern china area, many existing buildings in rural area and historical buildings were this type, recently, this type of structure is also commonly used to build some public buildings. There were some common failure modes been found after some major earthquake events in past few decades, it is urgent to study its aseismic mechanism and retrofitting methods to guide engineering practice. In order to understand aseismic mechanism and weak link of joint and the structure, quasi-static tests on mortise and tenon connection and column and tie timber construction will be carried out first; Based on experimental investigation, a restoring force model for mortise and tenon connection will be proposed, which will be used to build 3D dynamic non-linear analysis model of Column and tie timber construction, then use verified model to do quantitative seismic performance analysis of structure system. According to the weak link of structure, retrofitting methods by means of self-taping screws, FRP and sheet metal will be proposed, quasi-static tests and numerical simulation technics will be employed to study the suitability of each retrofitting method, finally, suggestions for engineering practice will be raised. This project will be an important advance in terms of understanding the aseismic mechanism and seismic performance of column and tie timber construction, provides fundamental knowledge for solving technical problems in engineering practice, and also accumulate knowledge database to propose building codes.

穿斗式木结构是中国传统建筑中最重要的结构形式之一，南方地区大量的既有建筑及部分新建建筑采用该结构形式。历次地震后发现该类结构存在规律性震害，亟待对其抗震机理及抗震加固方法等问题展开研究，以指导工程实践。本项目拟通过榫卯节点及穿斗式木构架的拟静力试验，对榫卯节点及穿斗式木结构的抗震机理及薄弱环节进行分析；再以试验研究为基础，提出榫卯节点恢复力模型并构建结构体系的非线性动力分析模型，利用模型对该类结构的抗震性能进行数值模拟参数分析；针对结构的抗震薄弱环节，提出采用自攻螺丝、FRP及扁钢等方法对榫卯节点进行加固，改善结构体系的抗震性能，采用试验和数值模拟分析的方法对各种加固方法的适用性进行探讨，最终提出实用指导建议。项目的实施对于认识穿斗式木结构的抗震机理及抗震性能具有重要意义，同时为解决工程实践中出现的技术盲点及难点问题提供重要依据，为相关标准的制定积累基础。

穿斗式木结构是中国传统建筑中最重要的结构形式之一，南方地区大量的既有建筑及部分新建建筑采用该结构形式。历次地震后发现该类结构存在规律性震害，对该类结构的抗震性能还缺乏认识。通过本项目开展的试验研究及理论研究工作，在穿斗式木结构抗震机理、抗震性能及抗震加固措施方面取得了一定的突破和积累。研究发现，该类结构的节点转动刚度低、抗侧刚度低，但不易于发生整体倒塌，通过FRP、扁钢、自攻螺丝等节点加固措施可以部分改善结构的晃动及变形过大的问题，但是效果有限，通过本项目提出的墙体抗震加固技术，可以显著提升穿斗式木结构的刚度及抗震能力。项目的实施对于认识穿斗式木结构的抗震机理及抗震性能具有重要意义，同时为解决工程实践中出现的技术盲点及难点问题提供重要依据，为相关标准的制定积累基础。