Experimental Study And Time-history Response Analysis On Seismic Behavior Of Steel Frame-bent Of The Large-scale Thermal Power Plant

Thermal power plant belongs to life line engineering for its vital importance toour daily life. The most common structure for its main plant in China is frame-bentstructure. The failure mechanism and seismic performance of the frame-bent structurehas been the focus of researches on thermal power plants. In recent years, with theintroduction of large capacity units, steel frame-bent structure has become the mostfavorable structure in the construction of the main plant of large scale thermal powerplants. All its advantages-flexible layout, high strength, light weight, fast constructionand good seismic performance make it quite suitable for earthquake resistance area.However, as researches on seismic performance of the steel frame-bent structure inChina is still on an exploratory stage, there are no specified regulations on seismicdesign in related standards yet. Therefore, the study on seismic performance of steelframe-bent structure has its great significance.Conducting pseudo-dynamic test and pseudo-static test on a1:10scale model ofthree-span single steel frame-bent, load-displacement hysteretic curve, skeleton curve,deformation, stiffness degradation and plastic hinge distribution of the model structureare studied in this paper. The hysteretic curve being fairly full shows that this structurehas a strong seismic capacity. At the time of destruction of box bent, the displacementductility index of the overall structure is2.6, which is significantly low, indicting thedeficiency of structural deformation capacity. Both the inter-story drift angle and theoverall drift angle of the steel frame-bent keep within the specification limits, meetingthe "Three Standards" of seismic resistance. The steel frame-bent has a stabile bearingcapacity and its stiffness degradation is not obvious. And the section stiffness of Coal scuttle beam is relatively high. It shows a “strong beam and weak column” symptomon this floor. The plastic hinge exists inside the column.Taking the steel frame-bent of the main plant of thermal power plants as theprototype and using SAP2000to carry out the Time-history Response Analysis on itsstructure, we get a perfect result that it is in good agreement with the experimentalresult. On this basis, the dynamic characteristics of this kind of structures, frameworkand bent internal force distribution, impact of the split-level on the corresponding floorcolumn shear distribution, quality of coal scuttle layer and impact of the unevenstiffness distribution to the seismic performance are studied.Tests and the result of finite element analysis provide a theoretical basis for theseismic design of steel frame-bent structure, and it also could be used as a referenceand provide basic data for the formulation of the relevant industry regulations.