Under-slung launchinggantry

Theloading-bearing main girder system is situated under the bridge, and outsidemould system sits on the loading-bearing main girder. The main girder systemsits on the platform by outrigger, which are anchored on the pier by the highprecision rolling thread steel. Outside mould template opens with the maingirder transversely or opens transversely singly to avoid the pier whilepassing through the hole. The outrigger can perform an auto forward flip or bythe auxiliary crane. Outside mould system can move longitudinally with maingirder. Its clearance under bridge is large and the height of the bridge pieris generally more than 4m, which has a stronger adaptability for high piers.

Performance and parameters：

Applicable spanand girder weight ；40m/1300t

Applicable heightof the bridge pier: 4m

Applicablelongitudinal gradient: 4%

Applicable curveradius: 1000m

Compared with:

Up-slung launching gantry

1) Double main girder andtwo-span structure, more secure, faster. Applicable to the low pier andclearance under bridge is not demanded. Simple construction, needless todismantle the main girder and outside mould parts;

2) Outside mould system opens and closes transversely,original design and ingenious conception;

3) Transverse movement and hoisting is propelled bythe power, easily and fast;

4) Lifting and opening, closing are controlled by thehydraulic pressure, with steady movement which is secure and reliable. Reducethe labor intensity and upgrade the construction efficiency;

5) All the legs can pass through the wholeautomatically and erect, reducing the investment of auxiliary equipments,reducing the construction cost.

Performance and parameters：

Applicable longitudinal gradient: 2.0%
Applicable curve radius: ≥1500m
Requirements for environment wind pressure:

Maximum allowable wind pressure during shifting: 150N/㎡

Maximum allowable wind pressure during casting: 800N/㎡ ( or to be anchored)
Total power by using the whole machine:About 95kw
Kinetic condition: 4Ac, 380v, 50Hz
Hydraulic system pressure: 32Mpa
Shift speed: 0-1.5m/min
Deflection of main girder: Less than L/700( only considering the deflectioncaused by the concrete loading and internal mould weight)
Via Hole Stability Factor: k>1.5
Transportation condition: meet the limits of railway and highwaytransportation.
Unit Weight: About 530t (without separated mould situated in the support)
Construction cycle: 10 days/span