The Life Estimation Of Box Girder Details Of Shanghai Yangtze River Tunnel And Bridge Based On WIM Data

In recent decades, Cable-stayed Bridge become the main stream bridge in the large span bridgeconstruction because of its advantages and built all over the world. However, after a period of time,the fatigue problem of the steel bridge faced is becoming more and more serious.This paper is based on the Shanghai Yangtze River Tunnel and Bridge as the engineeringbackground, Focus on the stress process and fatigue damage degree of the main channel span and twobox girders of The South Tower under the car’s live load. And make the life estimation. The maincontents are as follows:1, Reviewing the present situation of bridge fatigue assessment; Summarizes some problems andthe direction of development of bridge fatigue assessment, and practical significance of bridge fatigueassessment.2, Introduced some methods of fatigue assessment and steps of the fatigue damage and fatiguelife estimation. I dentified the basic thought of fatigue life prediction about box girder details of theShanghai Yangtze River Tunnel and Bridge.3, Brief introduction of weight-in-motion and data acquisition and analysis technology. Andrespectively collected three periods of data of vehicle from the system.2010-07,2011-05,2012-02.And refer to the related auto manual, summarize the vehicle classification standard, with the theory ofequivalent fatigue damage, deduced the actual operation vehicle load spectrum of Shanghai YangtzeRiver Tunnel and Bridge.4, Using the ANSYS software to establish the integral bridge and segmental box girder model,and make the analysis of transient dynamic response for different shaft type vehicle across the wholeprocess. Calculate the detail stress process, and use the discharge of water at the same time, establishthe detail fatigue stress spectrum..5, Reference to the tenth part of British bridge standard BS5400, determine the S-N curve whichcan reflect the detail fatigue performance, combine with “Miner” fatigue cumulative damage rule,make the life estimation for the bridge. Assuming the bridge’s fatigue failure occurs just in the serviceperiod，I estimate the daily traffic flow of these three lanes.6, The results showed that: in the life estimation for main channel span and box girders of TheSouth Tower in three periods of times. Each typical details of stress level is relatively low, they arebellow fatigue limit. The fatigue damage of box girders details is smaller under live load, so it will not cause the fatigue damage of the structure.