Testing And Strengthening Analysis For The Coal Transporting Trestle Of A Thermal Power Plant

The electric power system is a city’s lifeline engineering, which plays an important rolein the development of the society and people’s life. The coal needed in electric powergeneration is transferred trestle, and the trestle acts as a bridge between coal bunker andboiler, its security ensures the whole power generation system works regularly. While withthe expansion of installed capacity which leads to the increase of traffic volume and span ofthe trestle, it need a stricter requirement for structure design of the trestle. Transport vehiclepose a threat to the trestle, if it is hit by vehicles, the trestle will be badly damaged,which leadto a breakoff of coal transportation,and it makes the power generation system paralysis. Tominimize the loss, it demands that the trestle is restored at a short time. A economic andscientific solution plays an important role for the study and application of trestlestrengthening measures.This paper is based on a project of a damaged coal transporting trestle hit by vehicle.Inthe process of consulting original design materials and measuring in accident spot, securityevaluation is taken in accordance with national relevant codes,the collected data include thedeformation of handrail,deformation of castellated beam,the strength and crack width ofbracket concrete.Finite element analysis is done to simulate the process of the collision,ABAQUSsoftware is used to build collision model,several steps are to make,including the selection ofelement tye,the found of material properties,mesh generation, the found of faying surface,thesimulation of vehicle,the definition of collision time and initial velocity.etc..The model needto be simplified rationally,concise rational collision model makes the analysis result in objectivity.The main work of this finite element simulation is about the analysis of force anddeformation for the damaged castellated beam and the analysis of force for bracket with itscracked concrete,the result shows that large displacement happens to the beam,with itsbottom flange yielding, stiffener yielding and the concrete of the bracket cracks, reinforcingbars yield. Compared with the scene of the accident, it proves that the model is scientific,theresult of the simulation is identical with the scene.Reinforcement scheme of the castellated beam and the bracket is put forward accordingto the result of the analysis,the result indicates that large deformation occurs to the castellatedbeam,stress distribution and stress value of the beam show that its bottom flange isyielding,so does it to stiffener,stress distribution and stress value of bracket surface show thatthe concrete is crashed,the reinforced bar is yielding,stress distribution and stress value ofreinforced bar show that main bars are not yielding but part of stirrups.Based on thisresult,strengthening measures are put forward,it as follows:identical beam is to replaced;forthe bracket,embedded bar and yielded stirrups is to replaced,strengthened with the enclosuresteel method is used to restore the bracket. The process of the analysis and strengtheningmeasure serve a reference to similar projects.