Study On Construction Technology Of The Superstructure Of The Yellow River Bridge Of Jishi Gorge Hydroelectric Power Station

This thesis relies on the project of the Yellow River bridge external highway of Jishi Gorge hydroelectric power station funded by upper reaches of the Yellow River hydroelectric development limited liability company. The paper mainly studied the key constructing technologies to the long span continuous rigid frame bridge under the complicated condition, and this thesis carried out the detailed treatise and study for the constructing technique of 0~# section, the design and constructing technique of the light hang-basket, the constructing technique of the continuous rigid frame beam, the spot constructing technique of the section in beside span, the technique of the closure section, the constructing technique of the three- direction prestressed concrete box beam with changing cross section, the line form control technique of the long-span continuous rigid frame bridge and etc. It can be as reference to constructing of the same kind of bridges.The paper consists of four chaoters totally. The emphasis parts are chapter two and chapter three. The chapter three is the most important part.Chapter 1 mainly introduced the development,the structure characteristic,the constructing technology of the superstructure,the development trend of continuous rigid frame bridge and the main contents of the paper. Continuous rigid frame bridge is a kind of bridge structure form that is widely used in railroad and highway in recent decades. It is welcome by the reasonable strains and stresses, the beautiful configuration, the low protecting expenses etc. With the development and progress of the design, the constructing craft and material, the long span continuous rigid frame bridge usually has been designed to the three-direction prestressed concrete box beam with changing cross section. The span has been developed up to several hundred meters now.The main method for constructing continuous rigid frame bridge is cantilevered construction method. That is cantilevered concreting method in sections or cantilevered assembling method from the top of pier. The Yellow River bridge external highway of Jishi Gorge hydroelectric power station is located at the lower reaches of the dam of Jishi Gorge hydroelectric power station over the Yellow River. The left bank connects with the external highway of Jish Gorge hydroelectric power station ,and the right bank connects with the highway along the Yellow River. The bridge is 75 m high. Through the comprehensive comparison of the technique and the economy, the bridge span is adopted to 1×32 m simple bearing bridge +(96+168 +96) m prestressed concrete continuousrigid frame bridge.Chapter 2 carried out summarize for the constructing technique of 0~# section, the design and constructing technique of the light hang-basket, the constructing technique of the continuous rigid frame beam, the spot constructing technique of the section in beside span, the technique of the closure section and etc. The constructing technology of 0~# section is one of the key constructing technologies of the superstructure of continuous rigid frame bridge, the general design is a thin wall structure of space, the volume is big, the structure is complicated, the common reinforcing steel bar and prestressed reinforce is densely, and the construction is most difficult. The hang-basket is divided into four kinds of the joist type( including flat string type without balance weighty, rhombus, and the bow string type...etc),slant pulling type (including triangle and prestressed slant pulling type),steel type and admixture type ;it is divided into three kinds of the press-heavy type ,the solid type and half press heavy and solid type according to anti-capsizal type; it is divided into two kinds of once walk and twice walk according to walk type; it is divided into three kinds of the roll over type , the glide type and sectional type according to move way. The main craft work for cantilevered constructing continuous rigid frame bridge by the hang-basket is infusing 0~# section - installing thehang-basket - infusing 1~# section - the hang-basket move forward,adjust- infusing the next beam section; completing cantilevered construction in turn; toring down the hang basket; closing the beam section. Chapter 3《STUDY ON CONSTRUCTION TECHNOLOGY OF THE SUPERSTRUCTURE OF THE YELLOW RIVER BRIDGE OF JISHI GORGE HYDROELECTRIC POWER STATION)) is the hardcore of the paper. this thesis carried out the detailed treatise for the general project situation of the Yellow River, the constructing technique of 0~# section, the design and constructing technique of the light hang-basket, the constructing technique of the long-span continuous rigid frame beam, the spot constructing technique of the section in beside span, the technique of the closure section, the constructing technique of the three-direction prestressed concrete box beam with changing cross section, the line form control technique of the long-span continuous rigid frame bridge and etc. The main method for constructing continuous rigid frame bridge is cantilevered construction method of the light rhombus hang-basket, infused concrete is sent by infusing-pump, the span of thebeam is long, there are many sections in cantilevered construction, the weight is big, the time is long, the work condition changes much, the influence factor is many, how guarantee high accuracy of construction, the bridge line form of the end realization design, attain the expectation to be subjected to the dint appearance, is one of the key techniques of the bridge's construction. the 0~# section adopts to the infusing project two times, cantilevered construction of continuous rigid frame bridge is to hang bottom template, outside template to the hang-basket, form cantilevered construction operation flat, colligate reinforcing steel bar successively, install prestressed pipeline, install inner template, infuse concrete construction in turn. When the concrete attains 80% design strength and satisfies 3 days period, pull prestressed work, then move the hang-basket forward and complete infusing grout work, thus become a construction circulation. Pulling prestressed reinforcing steel bar and infusing grout of vertical is behind lengthways after half month and a month.Chapter 4 is the summary of the paper, the key constructing technologies to the long span continuous rigid frame bridge under the complicated condition relies on the project of the Yellow River bridge external highway of Jishi Gorge hydroelectric power station, It can be as reference to constructing of the same kind of bridges.