Study On The Influence Of Safety Reserve Of Bazhong Dongmen Low Tower Cable-stayed Bridge's Construction Error

At present,the extradosed cable-stayed bridge has become one of the main bridge construction in our country,the construction method for cast-in-place cantilever.In the construction process will be subject to the influence of many factors,construction error factor to produce more,main construction error of bridge structure safety reserves occur constantly changing,in order to let the structure by force characteristics to meet the design requirements and specifications,in the construction control construction error and according to the field test data to determine the structure safety storage of seems particularly important.In this paper,the main consideration of the construction error of the construction stage of the elevation error,cable force error,temporary consolidation or not.In the error analysis to bridge five section(pier 1# small mileage 1/2 section,pier 1# mileage 1/4 section,pier 2# small mileage 1/4 section,1# pier high mileage of 1/2 section,cross cross section)for control section carried out the following studies:(1)using MIDAS civil to establish the whole bridge finite theory of the original model,the extracted control section stress and bearing capacity,tower bottom stress value and tower displacement.(2)the monitoring in each segment of the beam at the end of the actual elevation(other model data were as the theoretical value)model,extraction control section of the stress and bearing capacity,tower bottom should force and pylon deviation,and limit state under stress and bearing capacity for comparing the actual target under high error margin of safety.(3)the use of monitoring actual cables of cable force(other model data were as the theoretical value)model,extraction control section of the stress and bearing capacity,tower bottom stress,and tower displacement,and limit state under stress and bearing capacity for comparing the actual cable force error margin of safety.(4)establish temporary consolidation of full bridge model(other model data were as the theoretical value)extraction control section of the stress and bearing capacity,tower bottom should force and pylon deviation,and limit state under stress and load-carrying capacity obtains the temporary consolidation prior to the termination of the margin of safety.After the temporary consolidation is released,the theoretical model is calculated.It is concluded that the safety of the bridge is the most unfavorable to the temporary consolidation.When the temporary consolidation is relieved,the error of the cable force is greatly influenced the safety of the bridge structure.