Evaluation Method Of The Prestressed Concrete Bridge Service Performance Based On The Section Stress Status

PC bridge has rapid development nowadays and becomes the main type bridge of our country.But there are many problems appeared in the operation of the PC bridges.Such as: prestressing force lossing,cracks on the beam,deflection on the middle of span. These problems have directly influenced the durability and safety of the bridge. At present the research of the service performance of the PC bridge with prestressing lossing is less.The article combined with "the research on effective prestressing force detection technology of prestressing force tendons", which is the sub-research of the constructive science and technology item of the westward traffic-"the research on prestressing force detection technology on large-span and moderate-span concrete bridges". Basing on the section stess status, use the stress release method to obtain the section stess status.By calculating the prestressing force and eccentricity of testing section, evaluate the service performance of PC bridge.By single-point stress release method and "stess immobility point" we can get the section stess status of the structure with single-layer prestressing tendon. Using linear function fitting method we can get the section stess status of the structure with multi-layer prestressing tendon. According to the pre-and post cracking structure give the different method of calculating the prestressing force.By studing the distribution law along the way of the prestressing force of moment,give the limit testing section forecast method to forecast the prestressing force along the way of different prestressing system. It is on the real engineering of a prestressed concrete continuous T-beam bridge,using the Evaluation method to evaluate the service performance in different prestressing loss case.The article useing existing detecting method, put forward a set of method to evaluate the service performance of the PC bridge.This set of method can provide reference for the service performance Evaluation of similar bridges.