论文部分内容阅读
基于增量动力分析法,对高耸钢筋混凝土烟囱结构的抗倒塌性能进行了概率性分析,得到了结构的侧向倒塌地震易损性曲线,定量评价了烟囱结构的抗倒塌能力和抗倒塌安全储备。为了探讨土-结构相互作用对烟囱结构倒塌能力的影响,提出了适用于烟囱结构的土体-基础-上部结构共同工作的整体非线性有限元分析模型。研究表明:在7度罕遇地震(PGA=0.22 g)下,该烟囱结构发生倒塌的概率几乎为0%,能够满足规范规定的“大震不倒”的要求。不考虑土-结构相互作用与考虑土-结构相互作用的结构平均抗倒塌能力分别为PGA=2.16 g和PGA=1.34 g,相应的结构倒塌安全储备系数分别为9.82和6.09。两种情况下,虽然烟囱结构的抗倒塌安全储备都比较大,但是土-结构相互作用显著削弱了结构的抗倒塌能力,其降低幅度达38%,因此,对于高耸钢筋混凝土烟囱,在进行抗地震倒塌分析时必须考虑土-结构相互作用。该文的研究结果可为烟囱抗震设计和地震风险评估提供理论依据。
Based on the incremental dynamic analysis method, the collapse resistance of the towering reinforced concrete chimney structure is probabilistically analyzed, the vulnerability curve of the lateral collapse of the structure is obtained, and the anti-collapse ability and anti-collapse safety reserve of the chimney structure are quantitatively evaluated . In order to investigate the effect of soil-structure interaction on the collapse ability of the chimney structure, an overall nonlinear finite element analysis model for the soil-foundation-superstructure work together for the chimney structure is proposed. The results show that under the severe earthquake of 7 degrees (PGA = 0.22 g), the probability of collapse of the chimney structure is almost 0%, which can meet the requirements of the code “no earthquake”. The average collapse resistance of structures without considering soil-structure interaction and considering soil-structure interaction are respectively PGA = 2.16 g and PGA = 1.34 g, and the corresponding structural collapse safety reserve coefficients are 9.82 and 6.09, respectively. In both cases, although the safety of the chimney structures is relatively large, the soil-structure interaction significantly weakens the collapse resistance of the structure, which is reduced by 38%. Therefore, for the towering reinforced concrete chimney, Earthquake analysis must consider the soil-structure interaction. The results of this paper can provide a theoretical basis for seismic design of chimneys and seismic risk assessment.