In this paper, the dynamic interaction between soil and a cooling tower is analysed using a hybrid method that combines a finite element method and a boundary element method. The dynamic behavior of the soil half-space is investigated in detail. The effect of soil-structure interaction on the gust responses of draught column-supported hyperbolic cooling towers is estimated, and a comparison is made between these numerical results and their counterparts obtained under a full-scale test.

Dynamic Soil-Structure Interaction Analysis by a Hybrid Method*

The main purpose of this paper is to apply the modified Vlasov foundation model to free vibration analyses of hyperbolic cooling towers resting on elastic foundations. Moreover, the influence of some characteristic parameters such as thickness, height, curvature and throat level on the frequency response of cooling towers on elastic foundations is investigated. For this purpose, a computing tool coded in MATLAB employing open application programming interface feature of SAP2000 to provide two-way data flow during execution is used to perform the analyses of hyperbolic cooling towers with supporting columns over hollow annular rafts founded on elastic subsoil. The circumferential, lateral and extensional natural frequency parameters of cooling towers are presented in tabular and graphical forms to evaluate the effects of the geometric parameters and soil–structure interaction. As far as numerical examples are considered, it can be concluded that the soil–structure interactive behavior of the tower leads to a remarkable decrease in the frequency parameter of the system compared to the fixed based condition. Moreover, the frequency parameters are considerably affected by altering geometrical parameters.

A parametric study for free vibration analysis of hyperbolic cooling towers on elastic foundation using consistent FEM-Vlasov model

A semi-stochastic process model of reliability was established for hyperbolic cooling towers subjected to combined loadings of wind force, self-weight, temperature loading. Effect of the soil-structure interaction on reliability was evaluated. By involving the gust factor, an equivalent static scheme was employed to convert the dynamic model to static model. The TR combination rule was used to consider relations between load responses. An analysis example was made on the 90M cooling tower of Maoming, Guangdong of China. Numerical results show that the design not including interaction turns to be conservative.

Wen-Da Lu

Papers

Static soil-structure interaction analysis by FE-BE coupling method