RC-加气混凝土砌块组合墙加固框架结构抗震性能与设计方法

In recent years, study on the new overall seismic reinforcement method for the frame structure has been important research topic in structural engineering field since the anti-seismic ability of many frame structures was substandard due to damage by the earthquake, the seismic fortification intensity adjustment or the seismic fortification criterion adjustment. Based on the previous research about RC-aerated concrete block composite wall, the overall seismic reinforcement method for frame structure using RC-aerated concrete block composite wall is proposed and researched. In this project, we aim to (1) investigate seismic performance and failure mechanism of frame strengthening by composite walls using the model test; (2) propose the lateral stiffness reduction coefficient of the wall by analysis stiffness degradation law, and discuss horizontal shear distribution law between the frame and the composite wall and the calculating method of the shear bearing capacity; (3) establish elastic stiffness model of the frame strengthening by the composite wall, based on the test results and the composite material mechanics theory, and explore the practical design method about frame structure strengthening by composite walls of RC-autoclaved aerated concrete blocks. As a result, a financially viable frame structure overall seismic reinforcement method will be provide, which could be applied in most city and town of our country.

研究震后受损、因设防烈度调整或设防分类标准调整而导致抗震能力不足的框架结构的整体抗震加固方法，已成为当前结构工程领域的一个重要研究课题。本项目在RC-加气混凝土砌块组合墙研究成果的基础上，提出并研究RC-加气混凝土砌块组合墙加固框架结构的整体抗震加固方法，结合试验研究、数值模拟与理论分析，重点解决以下关键问题：（1）通过模型试验，研究RC-加气混凝土砌块组合墙加固框架的抗震性能及破坏机制；（2）分析RC-加气混凝土砌块组合墙的刚度退化规律并提出其侧向刚度折减系数，探讨组合墙加固框架的剪力分配率及受剪承载力计算方法；（3）基于试验结果及复合材料力学理论，提出组合墙加固框架的弹性刚度模型，初步建立RC-加气混凝土砌块组合墙加固框架结构的实用设计方法。本项目旨在揭示组合墙加固框架后两者的协同工作机理，为我国城镇地区量大面广的普通框架结构提供一种经济实用、效果明显的整体抗震加固方法。

针对震后受损框架结构、因设防烈度调整或设防分类标准调整而导致抗震能力不足的框架结构，本项目提出并研究采用RC-加气混凝土砌块组合墙加固框架结构的整体抗震加固方法，主要研究内容及研究结果如下：（1）RC-加气混凝土砌块组合墙加固未损框架、震损框架的抗震性能：试验表明，对于组合墙加固未损框架，加固后构件整体承载力、抗侧刚度较原框架有较大幅度提高；对于组合墙加固震损框架，加固后承载力较震损框架有较大幅度提高，其各个阶段承担水平荷载的能力及等效抗侧刚度均能够恢复至原未损框架水平。在前期加固试验基础上，继续进行了置换加气混凝土砌块法加固震损组合墙及震损框架-组合墙的抗震性能试验，为组合墙加固未损框架的震后二次加固提供试验数据。（2）RC-加气混凝土砌块组合墙加固框架弹性刚度计算模型研究：考虑组合墙的框格构造特点及填充砌块布置方式的影响，依据复合材料学理论建立了组合墙的弹性抗侧刚度计算模型；采用构件刚度叠加法并引入组合墙与框架相互作用影响系数，建立了组合墙加固未损框架的弹性抗剪刚度、抗弯刚度及等效抗侧刚度计算模型，相互作用影响系数反映了组合墙框格布置形式等因素对加固构件弹性刚度的影响。（3）RC-加气混凝土砌块组合墙加固框架受剪承载力计算方法研究：基于水平薄弱层破坏准则并考虑填充砌块布置方式的影响，提出了组合墙加固未损框架的受剪承载力计算方法；对于震损框架，引入损伤折减系数以量化震损框架承载力降低效应。理论计算与有限元模拟对比表明，等效弹性刚度模型及承载力计算公式具有较好的计算精度，能够满足工程要求。（4）RC-加气混凝土砌块组合墙加固框架实用设计方法研究：讨论了组合墙加固框架结构自振周期及水平地震作用的简化计算方法，确定了加固结构层间位移角限值的确定原则，最后给出了组合墙加固框架结构的基本设计步骤，为RC-加气混凝土砌块组合墙加固框架结构技术的进一步研究及应用提供依据。