延性交错桁架结构抗震性能及设计对策

In order to solve the scientific problem about the poor seismic performance of staggered truss frame system, reference research results of the special truss frame structure, introduce the concept of special staggered truss structure, by means of theoretical analysis, experimental research and numerical simulation methods, seismic performance and seismic design criterion of special staggered truss frame system is studied;seismic behaivour of special staggered truss frame system are studied by cyclic loading test and vibrating table test and the collapse mechanism of the special staggered truss frame system are explorated; influncing factors about the seismic behaviors of special staggered truss frame system are studied by finite element analysis, and the static and dynamic reduced analysis model are established; based on the experimental and theoretical research results, proposed the reasonable structural system of the construction measures and aseismic design criterion. The project which explore the seismic performance of the special staggered truss system and reveal the structure seismic performance and failure mechanism has important scientific significance, for expansion the application of the staggered truss system in china lays a theoretical foundation, which has important application value in engineering.

针对交错桁架结构体系抗震性能差的科学问题，结合延性桁框架结构的研究成果，提出延性交错桁架结构的概念，采用试验研究和数值模拟相结合的方法，对延性交错桁架结构的抗震性能及抗震设计方法进行研究；通过低周反复加载试验研究延性交错桁架结构的抗震性能，探索延性交错桁架结构的破坏机理；通过有限元分析研究影响延性交错桁架结构体系抗震性能的因素，建立延性交错桁架结构静力及动力简化分析模型；基于试验及理论研究成果，提出该结构体系合理的构造措施及抗震设计方法。本项目对延性交错桁架结构体系抗震性能的探索及揭示该结构体系破坏机理具有重要的科学意义，为扩大交错桁架结构体系在我国的应用范围奠定理论基础，具有重要的工程应用价值。

本研究针对交错桁架钢框架结构抗震性能差的特点，提出延性交错桁架钢框架结构的概念：将桁架跨中空腹节间设计为延性区段，在罕遇地震作用下，延性区段进入塑性耗能，结构其余部分保持弹性，从而改善该结构的抗震性能。采用理论和试验相结合的方法，（1）提出延性交错桁架钢框架的概念并给出基于能量法和基于静力平衡法的抗震设计方法；（2）对3个1/3普通交错桁架及3个1/3延性交错桁架钢框架单榀桁架进行往复荷载作用下的抗震性能试验研究；（3）对9个双槽钢组合截面延性区段足尺试件在往复弯矩作用下的抗震性能进行试验研究；（4）对延性交错桁架钢框架结构及其延性区段进行抗震性能的有限元分析。通过以上研究，发现：（1）提出的基于能量法和静力平衡法的抗震设计方法在不改变用钢量的基础上能有效提高该结构的抗震性能；（2）延性区段的截面形式影响该结构的抗震性能；（3）合理的延性区段设计是延性交错桁架钢框架结构抗震设计的关键；（4）基于开源软件openSees的有限元软件可准确模拟该结构在地震作用下的性能，可为实际工程进行该结构的抗震性能分析所采用。