What is THQ900t Bridge Girder Launcher for Tunnels?

1. Range of application and purpose

ZZHZ develops THQ900 bridge girder launcher for tunnels and THY900B girder transporter to solve construction technical problems below:

a. High speed railway bridges and tunnels are connected frequently

b. The bridge girder launcher and girder transporter need to smoothly pass the tunnel to install girders

THQ900 bridge girder launcher in tunnels and THY900B girder transporter can meet the demand to install double track whole span box girder32m, 24m, 20m for passenger special line, as well as meet the demand of span shift, tunnel entrance and exit 6m abutment and erecting curved bridge.

2. Main features and advantages:

a. construct bridge connected with tunnel, reduce cost of dismounting many times

b. four fixed points lifting precast girders with balanced lifting capacity ensure the safety of concrete box girder and lifting system structure. Slight longitudinal and lateral movement of lifting system can realize accurate positioning as installing box girder

c. launching nose and bridge girder launcher do a cooperative work to cross piers longitudinally, featuring easy operation, safe and reliable

d. can realize span shift installation and curved bridge erection, tyred girder transporter can directly carry the bridge girder launcher to transfer sites and pass the tunnels

e. matched with the launching nose, lifting trolley and auxiliary overhead crane, the bridge girder launcher can install the first and last girders as well as girders for tunnel entrance and exit.

 

3. Design basis

The product design is in accordance with relevant provisions of new national codes and standards, it mainly has:

?crane design specifications??GB/T 3811-2008?

?construction equipment research technical conditions for Beijing-Shanghai passenger special line?

?general purpose gantry cranes?(GB/T14406-2010)

?steel structure design codes??GB 50017-2003?

?steel structure construction and acceptance specifications??GB 50205-2001?

?wire rope with important purpose?(GB 8918-2006)

?electrical device installation project construction and acceptance specifications?

( GB50256-96)

?hydraulic system general technical specification?(GB 3766-2001)

?railway engineering construction safety technical procedures(Book One)??TB10401.1-2003?

?bolts, boults and double-screw bolts with fasteners mechanical character?

?GB 3098.1-2010?

 

4. Main design requirements

Lifting steel wire rope safety factor:???????? n?6

Boom stretch stress safety factor:?????????? n?6

Structural strength calculation safety factor:?? n?1.5

Institutions transmission parts safety factor:????? n?1.5

Factor of safety against overturning???????????? n?1.5

Electrical equipment and wiring insulation class should be in accordance with that insulation class of construction ministry and related electrical equipment, protection level should reach: electrical machinery IP54, other electrical equipment IP65 or above.

Crane utilization grade: U0

Crane utilization condition: Q3

Crane working level:????? A3

Crane institutions working level:? M4

Bottom deflection of main girder:? S/700

5. Main craftsmanship

a. the product mainly chooses Q345C steel; weld joint and outboard main angle weld joint of cover plate and web is of union melt welding, other weld joints adopt CO2 gas shielded welding; welding material selection: solder wire for union melt welding H10Mn2 matched with HJ350; solder wire for CO2 gas shielded welding ER50-6; welding rod for tack welding in the assembling process E5015. butt-jointed seam has a 100% ultrasonic flaw detection, inspection and acceptance standard GB11345-89, weld joint quality grade I; penetration weld between cover plate and web, 100% ultrasonic flaw detection will proceed, I grade qualified, all T type joints have a X-ray flaw deflection, inspection and acceptance standard: GB3323-87, welding joint quality grade: Level II.

b. It demands a derusting by sandblast, derusting grade Sa2.5; casting travelling wheel is demanded a annealing heat treatment; CNC cutting machine is used for steel plate with thickness>10mm; spot facing work for travelling wheel demands to use NC boring machine; press machine must be used to install bearings; special paint for engineering machinery is necessary, outside surface is epoxy zinc rich primer, in the middle epoxy micaceous iron paint, at the? end polyurethane paint, overall thickness of paint film ?125?m, deviation

between left and right is 5?m

 

6. Steps to install girders

Super-sized crane should make a plan to choose proper crane and crawler crane before installation, choose experienced installation personnel and lifting workers. Installation steps are as follows:

a. choose main lifting equipment according to the weight of the components

b. on the ground assemble and check main girder, connection beam, the end bracket platform and handrail

c. assemble and check front support leg and cantilever beam on the ground

d. assemble and check bottom launching nose

e. assemble and check auxiliary support leg

f. assemble and check C type support leg

g. assemble and check launching nose crane on the ground

h. assemble and check rear support on the ground

i. assemble and check lifting trolley and auxiliary trolley

j. install front support leg and fix the wind cable

k. install the 3^rd section and 4^th section of the rear support leg with truck crane on the assembled main girder, then put 2 lifting trolleys on the main girder and install the cantilever beam at front of main girder

l. two truck cranes lift assembled parts in steps k, assemble with C type leg and rear support leg, at the same time tighten the bolts connected with front support leg.

m. lift front support leg, auxiliary support leg and launching nose crane to assemble and check, fix the wind cable

n. assemble auxiliary trolley, auxiliary support leg, bottom launching nose and fix the launching nose support leg

o. assemble other auxiliary parts

 

7. Test methods after installation

After installation, it is required to check physical dimension, verticality, levelness, deflection and other items as below:

7.1 wheel distance deviation: S < 10mm

7.2 upper arch degrees of assembled main girder: AF=?0.9/1000?1.4/1000?S

7.3 main girder diagonal deviation (D1-D2) ?5mm

7.4 main girder side deflection: AFP?S/2000

7.5 trolley rail distance difference:

at the end of the rail ?2mm, at the middle of the rail K?7mm;

height difference at trolley rail connections: not more than 1mm

lateral displacement: not more than 1mm

7.6 high strength bolts connection should be in accordance with design and acceptance codes for steel structure high strength bolts connection

 

8. Operational approach, personnel requirement and attentions?

It is forbidden to use gantry crane in the bad weather conditions such heavy wind, mist, rain and snow

It is not allowed to operate the machine with the wind force grade

>7, related protection measures should be made to ensure the stability of the equipment with the wind force grade > 11

Night working should be in accordance with safe construction rules, in the working region and passageway proper lightning should be provided to better visibility and ensure construction safety

Keep travelling rail smooth, straight without barrier

Operators are demanded a professional training and a special equipment operation license

 

9. Disassemble and transfer the bridge girder launcher

The bridge girder launcher can transfer sites in a short distance with its own power. For long distance or passing tunnels, simply disassemble the bridge girder launcher, the transporter can carry it to change working places.

a. lift main lifting equipment according to the weight of components

b. fold up front support leg and rear support leg

c. carrying telescopic institutions of the girder transporter enter into and is fixed with the bridge girder launcher

d. disassemble connection bolts between upper section and lower section of C type support leg, the whole machine descends 2.5m

e. disassemble lifting trolley

f. disassemble C type leg travelling mechanism and jack it, C type leg rotates 90?backward

g. lift launching nose

h. transfer sites or pass tunnels