Hangingbasket is the main equipment for cantilever construction, which can be dividedinto four categories according to the form structure: Truss type (includingflat chord without balance heavy style, diamond, triangle, bowstring type,etc.), cable-stayed (including triangular cable-stayed and prestressedcable-stayed), steel type and hybrid type.
Hanging basket’smain components: the main truss, suspension system, anchoring system, walkingsystem, and template system.
Features of our hanging basket: Lightweight, simple structure, strong and stable, moving forward, assembling anddisassembling easily, with strong reusability, small deformation afterreceiving force. There is enough space under the hanging basket, which canprovide a larger space for construction, helps the reinforced templateconstruction operation.
Characteristics of hanging cast cradle construction
(1) The bracket is not required, sothat does not substantially affect the bridge traffic during the construction.
(2) Thehanging basket has simple structure and low cost, pouring concrete section bysection without heavy lifting equipment.
(3) Thereare two parallel operation surfaces for each pier; several piers can realizethe construction in the same time without disturbing each other, so the speedis higher.
(4) Thefollowing tasks in each cantilever unit beam segment: formwork, lashing, pipe location, pouringconcrete, prestressed tension, injection of mortar, etc, can be realized insidethe hanging basket. We can design the top gate and health equipment for thehanging basket. The construction is affected less by temperature, whichguarantees the continuity and quality of construction.
(5) Because of the repetitive tasksaccording to the unit of segment, the construction workers can quickly masterthe skills, so that the efficiency is higher, and it is easy to control andmanage the construction.
(6) Because of the pouring segment bysegment, we can design the girder as variable height girder, which makes thebridge more beautiful, in the same time, it can also reduce the weight of thegirder.
The low tower cable-stayed bridge of Port Da Zheng is ofthree-span prestressed twin-tower and single-cable plane. The main girder is ofthe curved girder prestressed reinforced concrete wide-box structure. The maintower is of lateral tilt concrete structure. The span combination is: 90+165+90=345m.It is the first low tower cable-stayed bridge of lateral bending tower withflat curve. The main girder uses single-box with five chambers’ cross-section,and is the continuous box girder of variable cross-section with three-spanprestressed reinforced concrete. The width of box top is of 34m, and of boxbottom is of 17.499m—21.542m, the width of flange cantilever plate is of 4.5m,the height of girder in the box girder roots is of 7m, the height of girder inthe end of girder and the middle of span is of 3.5m, the girder bottom variesaccording to 2 parabolas. The super big hanging basket of the low towercable-stayed bridge of Port Da Zheng consists of five systems: load-bearingsystem, suspension system, bottom mold system, side-mold system and limitsystem. According to the characteristics of single-box and five chambers,inclined web, lateral slope (About 3%) in the top and bottom, and super widebridge surface, designed the cantilever construction hanging basket as: themain truss is separate in the upper part, the bottom and side template isintegral in the lower part. The width of hanging basket’s top surface is of 34m,the biggest segment of basket is of 4.5m，where the weight of concrete is of about430t，and thehanging basket’s self-weight is of 150t.
The Nan-GuangHigh-Speed Bridge of Lan-Yu Railway locates in Laojun Town, Gaoping District,Nanchong City. The length is of 388.56m. The pier 3#、4#、5#、6# uses the continuousgirder of （40+56+40）m, which crosses the Nan-Guang Highway. Nan-GuangHighway is of two-way and four-lane, with 2-meter –wide buffer zone in themiddle, the pavement width is of 24.5m, the designed speed for vehicles is of 120km/h.The upper span section locates in the Laojun Highway Bridge of Nan-GuangHighway, where the traffic is large.
The super bigbridge of Tai Zi River of Ha-Da passenger line, the length of which is of 23.71367km,the span DK329 is the cable continuous girder, the superstructure of which is （40+64+40）m,using the cantilever pouring method. There are three existing railway lines onthe 226# and 227#；Shen-Da uplink anddownlink line, and Zhang-Tai line. The trains of 100 tons of cargo orpassengers pass on these three lines every day and night. The existing lines’mileage is K340+795, the skew angle is about 45 degrees. The main piers of 226#and 227# sit on the two sides of railway, the heights of which are 13.5m、12.5m. The difficulty in construction, thetransport safety and construction safety pressure is big.