不同场地考虑土-结构相互作用的井塔地震反应

Seismic response of shaft tower considering soil-structure interaction in different sites

摘要:

为研究Ⅱ、Ⅲ类场地下土与结构（井塔和井筒）相互作用对井塔抗震分析的影响,采用理论分析和数值分析两种方法,系统研究不考虑土-结构相互作用、Ⅱ类及Ⅲ类场地下考虑土-结构相互作用对井塔地震动力反应的影响,提出并建立体系在时域内的理论运动方程,利用MATLAB语言编制Runge-Kutta法的求解程序,结合有限元软件建立体系的数值分析模型。以某钢筋混凝土剪力墙结构井塔为例,得出Ⅱ、Ⅲ类场地下考虑体系相互作用对井塔地震反应的影响规律。结果表明:建立的理论分析模型与数值分析模型吻合较好,对应理论解与数值解的最大差值为9.8%,验证了彼此的准确性；Ⅱ、Ⅲ类场地下3条地震波地震反应平均放大系数分别为1.8、2.4倍。工程设计中,Ⅱ、Ⅲ类场地下应该考虑土-结构相互作用对井塔抗震分析的影响,并且土体越软,土-结构相互作用对井塔抗震分析的影响越大。

Abstract:

In view of the relationship between the soil-structure interaction (shaft tower and well bore) and the seismic analysis of shaft tower in Ⅱ and Ⅲ sites, the influence on the seismic response of shaft tower with or without considering the soil-structure interaction in Ⅱ and Ⅲ sites was systematically studied by means of theoretical analysis and numerical analysis. The theoretical equation of motion in time domain was proposed and established, and the solution was presented with Runge-Kutta method and programmed using MATLAB language. Combined with finite element software, the numerical analysis model of the system was established. Taking the shaft tower of a reinforced concrete shear wall structure as an example, the influence on the seismic response of the shaft tower was obtained considering the system interaction under the conditions of Ⅱ and Ⅲ sites. Results show that the theoretical analysis model was in good agreement with the numerical analysis model, and the maximum difference between the theoretical solution and the numerical solution was 9.8%, which verifies the accuracy of the two models. The average amplification factors of the seismic response of three seismic waves under the conditions of Ⅱ and Ⅲ sites were 1.8 and 2.4 times respectively. In engineering design, the influence of soil-structure interaction on the seismic analysis of shaft towers should be considered under the conditions of Ⅱ and Ⅲ sites; the softer the soil is, the greater the influence of soil-structure interaction on the seismic analysis of the shaft tower is.