The Application Of Limit Length Of Cable Method In Long-Span Concrete Filled Steel Tubular Arch Bridge's Rib Assembling

Non-bracket and Cable erection is the main erecting arch ribs method of a long span concrete-filled steel-tube(CFST) arch bridge recently,but it requires to adjust the cable force over and over again,which increases the degree of construction difficulty and arch axis linear control trouble,delays the project limit time.Based on the disadvantage of non-bracket and cable erection method,Limit Length of Cable method is put forward,which the cables are stretch-drew to one control condition,and does not demand readjustment during erecting arch ribs.Through establishing the rib's raised height beforehand,the cables'elastic stretching caused by cables'force increasement can adjust the ribs height.So when the arch ribs are joined together,the ribs level can coincide with the design arch axis linear.This method's advantage lies in simple construction,easy operation,and no readjustment,and the practice has proves that this method is a success. Then this paper introduces the method of cable force calculation and the formula of arch axis linear when erecting arch ribs of CFST arch bridge,and develops relevant control program. This paper's aim is to advance construction safety and speed,simplify construction and shorten project limit time.This paper takes recent CFST development condition and the character of design and construction as the point of departure,compares all kinds of construction methods and control methods.then provides Limit Length of Cable method's basic principle and calculation method.Finally,an example of SanMen JianTiao bridge is offered to present the Limit Length of Cable method's application in this bridge in detail,and provides control achievement.