What’s the fabrication process of bridge girder launcher?
a. the bridge girder launcher mainly uses Q235B steels: the butt welds of cover board and web board, the outer lead weld of cover board and web board adopts Lincoln weld, other welds use CO2 gas shielded welding; welding material: welding rod of Lincoln weld
launching gantry
H08A, and HJ431; welding rod of CO2 gas shielded welding: ER50-6; the electrode of tack welding uses J422 when the machine is assembled. The 100% ultrasonic inspection should be done for butt welding, the acceptance standard is GB11345-89, and the grade of welding quality is I grade; the welds between cover board and web board adopt melt thru weld, the 100% ultrasonic inspection is done after welded, and I grade is qualified. All of T joints do X-ray detection, the acceptance standard is GB3323-87, and the grade of welding quality is II grade.
b, sand-blasting should be done after the welding is finished, and the derusting grade is Sa2.5; the casting wheel need to do
annealing treatment; the NC cutting machine is demanded to cut the steel plate which thickness exceeds 10mm; CNC boring machine is used to process the wheel holes of traveling wheels; the press is used to install the bearing.
c. The paint should be the special paint for engineering machinery, the first layer of outer surface is epoxy zinc-rich primer, the middle layer is epoxy cloud iron paint, and the last two layers is polyurethane paint. The total thickness of paint shouldn’t less than 125μm, and the deviation of right and left is 5μm.
What are the composition of bridge girder launcher?
Launching Gantry
Walking bridge girder launcher is made up of main girder, lifting trolley, front legs, middle legs, rear legs, rear bracket ,electrical system and hydraulic system etc.
The protective measures for the electrical system of the MSS
Bridge Girder Launcher
The movable support system (MSS) is a large-scale construction equipment. The necessary protective measures for the electrical system not only improve the construction safety, but also guarantee the personnel security.
Check the accident-prone points of the launching gantry
Bridge Girder Launcher
In order to effectively prevent, control and eliminate the damages by the sudden accidents happening in the bridge-erection process, reduce the losses by the accidents to the large extent, maintain the social and enterprise business interest, protect the personnel and property security, we should develop a series of management measures aiming to the possible incidents.
The types and characteristics of launching gantry in China
1, The types
a, According to different construction methods, it consists of the field-casting and field segmental assembly.
b, It divides into the movable supporting system and movable standing system in light of carrying the mould plate or not. For the movable supporting system, we cast the concrete girder on site. However the movable standing system is to assemble the pre-cast segmental concrete girder on the machine.
c, It consists of the upstroke movable supporting system and downstroke movable supporting system according to the piers position.
Nowadays the upstroke movable supporting system is the most popular one.
660T Downstroke MSS Bridge Creating Machine
Downstroke Movable Support System
1, The applicable scope and purpose
MSS30/660 Bridge Creating Machine is designed for meeting the demands of 30m continuous concrete box-girder construction. It is a bridge construction machine whose construction method is that installing on the piers and field casting. The main characteristics are high rigid for main girder, convenient bracing installation, variable piers.
How to install bridge girder launcher safely?
Bridge Girder Launcher
1. Organization measure
Set up safety leading group headed by general manager. Group leader and group members
2. Safety training measure to install the boundary beam
A. in accordance with related rule formulates safe operation implementing regulations. Have a safety technology disclosure to construction personnel and
Carry out safety education
B. Organize constructor to have a safety technology training and assessment before installing girders. Therein, for special type of constructor, they must be employed with the certificate, for all who participate in installing the boundary beam and access to the worksite; it is needed to wear safety protective equipment.
How to operate the bridge girder launcher?
Bridge Girder Erection Machine
The bridge girder launcher which generally have four construction steps to erect one girder: feed-in girder, bundle girder, lift girder and drop girder is designed and manufactured by ZZHZ. (1)Feed-in girder 1.Before feeding-in girder, check rear part support of bridge construction machine to avoid excessive subsidence at rear part of the machine when feeding-in girder 2.As transporting girder, there should have someone to pay attention to support to avoid colliding with bridge construction machine. And there should have someone to be responsible for operating girder transporter 3.As transporting girder, it is forbidden to have workers standing on rear part of the girder or scaffold floor to avoid falling objects hurting someone 4.When bridge construction machine begins to feed girder, the girder transporter should push in the girder slowly. At the meantime, appoint someone to watch it so that the girder will not collide with transporter or bridge construction machine
The classification of launching gantry
Launching Gantry
It is a bridge construction machinery which moves along the pre-laying rails to erect the concrete girders. Because of its high efficiency, its design principle has been considered fully in the designing process of the China Railway Bridge Girder. It owns the large body and has exceeded the railway transportation limit, so it must be dismantled while delivering. After arriving at the construction site, we will assemble and install before it’s been put into practice.
HZQ Launching Gantry Integrating Carrying and Erecting Functions
Launching Gantry
ZZHZ is a professional manufacturer of hoisting machinery, the main products include all kinds of launching gantry, gantry crane which are widely used in the highway construction projects. The honeycomb girder launching gantry made by our company is welded by the honeycomb steel plate and triangular web plate. The overall shape is triangle. Compared with the box girder, it owns the characteristics of lower gravity center, light weight, safe and good wind-resistance. Compared with the truss girder, it owns wide welding contact surface and the suffered force is even. When the truss girder suffers the force, the load-bearing points are the channel steel welding points and easy to mechanical deformation. Therefore, the honeycomb girder owns the characteristics of light deflection and high rigid intensity. The connection method between the two girders is the pin-connecting. While assembling the machine, just entering the six steel pins is enough. In this way the assembly period is short. Usually it only takes a week to install the whole set of launching gantry.
