Large Span Continuous Rigid Frame Bridge Prestress Loss Monitoring Research During Construction

With the development of national economy and the development of traffic facilities, largespan bridge construction has entered a new period of development. Prestressed concretecontinuous rigid frame bridge is a combination of continuous beam bridge and T rigid framebridge, because of good mechanical properties, low cost, large span, construction, smalldeformation, expansion joints, ride comfort, low maintenance costs, seismic capacity and otheradvantages,so it becomes the main bridge of highway bridge and city bridge,and using thecontinuous rigid frame bridge is the inevitable trend of the development of. large span concretebeam bridge. For prestressed concrete structure, prestress loss influences the establishment ofeffective prestress, thereby affecting the entire component and the whole performance of thestructure.Effective prestress calculation is not accurate, overestimated the component ofeffective prestress will pose a security risk; considering the effective prestress is too low togive full play to the actual role of the prestress. So how to determine the value of prestress lossin prestressed concrete structure design is an important content.This paper adopts a direct method for measuring steel beam prestress loss, by embeddingthe magnetic flux sensor and anchor cable dynamometer, directly measures the steel stress invarious positions, in order to study the regularity of prestressed loss during construction.Selecting web beam, roof beam and folded beam test based on the project, measuringprestress losses of test steel during the construction of value, comparatively analysising thetheoretical calculation analysis,and come to some conclusion.Finally, the software of MIDAS/Civil simulates the steel beam loss of prestress in construction phase, extracts simulation data,analyzes the difference among simulation data, calculated values and measured values,Explores the feasibility and the reference value of the software simulation during theconstruction of prestressed loss.