Seismic Behavior of Turbine-Generator Foundation under Strong Earthquake Action in Different Directions

Dong An,Tie-Jun Qu

doi:10.1155/2018/2506264

Abstract

In order to study seismic behavior of half-speed turbine-generator foundation under horizontal earthquake loading in different directions, the 1/10 scaled model was designed and fabricated. The rigid foundation of half-speed turbine-generator sets can be seen as a complex space frame system. The tests were conducted under eight earthquake waves in two directions separately. The loading directions were along the axis of longitudinal and transverse. The seismic response of displacement and story drift was investigated by a pseudodynamic test. The hysteresis behavior and crack propagation were analyzed. From the research, it is shown that the maximum displacement of the foundation under the earthquake of intensity 7 is 15.20 mm (longitudinal), basically in the range of elastic deformation. The seismic response of earthquake input in different directions is obviously different. Under the same earthquake input, the seismic displacement along the axis of longitudinal is larger than that of transverse. Under the rarely earthquake of intensity 8, the foundation still keeps good working condition. The maximum elastic-plastic story drift is 1/191 under the limit value 1/50 provided in the Code for Seismic Design of Buildings. The deformation capacity of the structure meets the requirements of the current seismic design code of China.

Highlights

As a special industrial structure, experimental research should be carried out in addition to theoretical methods for seismic response analysis. e experimental study on seismic performance of the foundation structure of half-speed turbine generator can be carried out, and the weak parts of the foundation under strong earthquake action can be further grasped for reference to the seismic safety design of the T-G foundation. e T-G foundation is a complex space system; the seismic performance, especially under strong earthquake, has not been adequately studied in China, or for this kind of structure system and the development of norms or standards, so we need to conduct experimental studies on this kind of structure system
In order to study the seismic behavior of T-G foundation, under strong earthquake action in different directions, the 1/10 scaled model was designed and fabricated according to similarity theory; pseudodynamic tests were carried out in two directions, respectively. e hysteretic curve of displacement and force, seismic response, including velocity, acceleration, and displacement, and crack propagation determine the seismic demand of T-G foundation and determine whether the T-G foundation meets the requirements of the Code for Seismic Design of Buildings (GB50011-2010) [11]
Displacement Response. e high-precision displacement sensors (LVDT) were laid out on the structure model to control the displacement of the pseudodynamic test and measurement plate

Summary

Introduction

Once it is destroyed in earthquake, the turbine-generator foundation (hereinafter referred to as the “T-G foundation”) will cause serious disasters. e structure of the foundation is complex, the section size of the beam and column in frame foundation is large, and the operating platform is subjected to huge equipment weight. e T-G foundation can be approximately regarded as a single-layer reinforced concrete frame structure with a single span and a longitudinal span of 6 spans. e section size of the concrete component is between 2 and 4 meters, and the height is about 30 meters. e frame sets two intermediate platforms at different elevations of the lower end of the generator, and the plate thickness is about 0.5 meters. ese intermediate platforms are arranged in the span of the two ends and are not connected with each other. As a special industrial structure, experimental research should be carried out in addition to theoretical methods for seismic response analysis. E experimental study on seismic performance of the foundation structure of half-speed turbine generator can be carried out, and the weak parts of the foundation under strong earthquake action can be further grasped for reference to the seismic safety design of the T-G foundation. A pseudodynamic test of 1251 MW steam-turbine-generator foundation was carried out under intensity 7 frequently and rarely earthquake [2]. In order to study the seismic behavior of T-G foundation, under strong earthquake action in different directions, the 1/10 scaled model was designed and fabricated according to similarity theory; pseudodynamic tests were carried out in two directions, respectively. In order to study the seismic behavior of T-G foundation, under strong earthquake action in different directions, the 1/10 scaled model was designed and fabricated according to similarity theory; pseudodynamic tests were carried out in two directions, respectively. e hysteretic curve of displacement and force, seismic response, including velocity, acceleration, and displacement, and crack propagation determine the seismic demand of T-G foundation and determine whether the T-G foundation meets the requirements of the Code for Seismic Design of Buildings (GB50011-2010) [11]

Test Situation

Test Scheme

Seismic Response

Conclusions