| Prestressed concrete continuous rigid-frame bridge is a type of beam bridge with long span capacity.This type of bridge is very popular because of cantilever pouring construction method,comfortable driving,long span with high pier,and appropriate engineering cost.The span of prestressed concrete continuous rigid-frame bridge has increased continuously,and the span has broken through 300 m.Learning from the experience of populization,several damages are found universally in prestressed concrete continuous rigid-frame bridges.The main damage is concrete crack,although the bridges are designed by the conception of fully prestress concrete.The other damage is the vertical deflection at mid-span of the main girder will be increasing continuously with time going on.And the vertical prestress can not reach the requirement of design and even fails sometimes.Based on the above,the bridge damages are classified,summarized and analyzed in this thesis.An actual long-span continuous rigid frame bridge is taken as example for damage analysis and strengthening design.The work of this thesis is shown as follows:Firstly,the history and tendency of the long-span continuous rigid frame bridge at home and abroad is summarized.Secondly,the common bridge damages are classified,and the corresponding reasons are analyzed by using typical bridge engineering examples including the secondary navigational Channel of the Humen Bridge,the Huangshi Yangtze River Highway Bridge,and the Yellow River Bridge at Sanmenxia.Thirdly,the thesis proposes the analysis procedure,technological route and the implementation steps fordamage evaluation of PC continuous rigid frame bridge.A continuous rigid frame bridge with span of 160 m is taken as example to illustrate the procedure and conclusion.Fourthly,based on summarization of the strengthening for this type of bridge,the reinforcement method is put forward for the above example.This thesis puts forward the damage analysis method and the corresponding process for PC continuous rigid frame bridge;and based on this,a reinforcement design scheme is proposed.Which can be used as a universal method for damage analysis of similar bridge.It also can be used as reference for bridge damage evaluation as well. |
