CN101177931B - Erection of gantry type small-cycle traction system on large-span suspension bridge main cable - Google Patents

Abstract

The utility model relates to a gantry type small circulation traction system for a main cable erection of a large-span suspension bridge, which belongs to the technical field of bridge superstructure construction. Set up a cable storage area behind the anchorage A, and install a 60-ton gantry crane and a cable-laying bracket; set up a traction cable revolving wheel behind the anchorage; set up a 25-ton main traction hoist and a balance weight bracket on the side of the anchorage B. The traction cable is connected by a puller at Anchor Anchor, bypasses the hoist drum at B Anchor Anchor, and is inserted through the balance weight bracket and each steering block to form a ring-shaped endless cable. Make a horizontal circular motion to form an independent small circular traction system. The small circulation system has the advantages of high power, large traction force, high construction efficiency and low cost.

Description

Gantry-type Small Circulation Traction System for Main Cable Erection of Long-span Suspension Bridge

technical field

The invention relates to a construction method for a main cable erection of a suspension bridge, and belongs to the technical field of construction of the upper structure of a suspension bridge.

The main cable erection gantry type small circulation traction system uses a double-drum friction hoist to realize the main cable erection through the circular motion. The gantry-type small circulation traction system is suitable for the erection of main cables of suspension bridges with various spans, and has obvious advantages especially in the synchronization of main cable laying and traction.

Background technique

The main cable is the "lifeline" of the suspension bridge, and the erection quality of the main cable is directly related to the construction quality of the suspension bridge.

Usually, the main cables of long-span suspension bridges are erected using a double-wire reciprocating traction system, but the main and auxiliary traction winches of the traction system are arranged on both sides of the main span of the bridge. The phenomenon affects the speed and quality of main cable erection.

Contents of the invention

The object of the present invention is to provide a reliable and continuous main cable traction and erection method for the above deficiencies in the prior art. The invention relates to a method for traction and erection of the main cable of a suspension bridge, which is characterized in that a hoist (11) is used as the power to realize the circular movement of the traction cable through a non-polar circulating traction cable (10) and rotating and guiding wheels, so as to achieve The purpose of pulling and erecting the main cable. The traction system is provided with a balance weight (12), which can automatically adjust the sag of the traction cable (10). The entire traction process of the main cable is relatively smooth, which plays a good role in improving the quality of cable strand erection.

The traction system is mainly composed of: storage cable system, supporting transport system, power circulation system, tensioning and debugging mechanism and other facilities.

1. Cable storage system: a 60t gantry crane (13) and a cable release device (14) with a braking torque motor are provided in the cable storage and release area, and the number of cable reels (24) stored can reach 60 reels.

2, support delivery system: A anchorage cable release area is provided with long and short rubber drums, and a support guide wheel (15) is established at intervals of 8m on the outside of the main cable of the catwalk. Appropriately increase the number of supporting guide wheels or use guide wheel sets at the parts with large height difference and main cable saddle and scatter cable saddle.

3. Power circulation system

3.1 Traction rope (10): It adopts Φ36mm non-rotating steel core wire rope with a total length of about 4800m, which is customized by a professional manufacturer. Among the two ends of the traction rope, one end is connected by a puller (7), and the other end is directly butted to form an endless looping rope.

3.2 Traction cable steering: Horizontal steering is set at A anchorage (11), horizontal and vertical steering is set at B anchorage (14), catwalk door frame (38), AB main tower (12) (13), loose cable saddle ( 23) The buttress is provided with a guide wheel group.

3.3 Puller (7): The puller is a device for connecting the traction cable with the main cable strand, so as to realize the traction and erection of the strand.

3.4 Traction hoist: double-drum friction-type traction hoist with open rope slots. After setting a certain speed by using the frequency converter, the speed of unwinding and unwinding the steel wire rope is constant, and the position of the rope is constant. Step speed change; the measurement and control system is composed of test components such as tension sensors and amplifiers installed on the fixed pulley and the computer, and the traction force and speed changes at each point during the real-time traction process and the total running length of the wire rope are saved at any time through the computer dynamic collection and real-time traction. Print. The relationship between tension and speed can be set according to specific working conditions, and semi-automation under manual intervention can be implemented.

The main technical parameters:

Working effective traction force: 250kN

Traction speed: 5~30m/min stepless speed change

Rope capacity of the receiving drum: 2500m

Reel: double reel, friction type

Drive: The hoist must be able to pull forward and reverse

Braking system: electric or hydraulic automatic brake release

Transmission mode: mechanical or hydraulic

Motor: ~3×380V, FC=100%, 110kW, start with winding series resistance

Control mode: the drum controller is the central controller, and the rotor is connected in series with a resistor to start the speed regulation

4. Tension adjustment mechanism: The cyclic traction system is affected by factors such as temperature changes, elastic deformation and relaxation of traction cables, rear tension of the hoist, changes in erection status, etc., and tension adjustment facilities must be installed. The method of counterweight is adopted.

Description of drawings

Figure 1a, Figure 1b: Front view and top view of the overall layout of the gantry-type small circulation

Figure 2: Elevation layout of A anchorage cable laying area

Fig. 3a, Fig. 3b: Top view and front view of B anchor traction area and tensioning debugging mechanism layout

Figure 4: Tower Top Layout

Figure 5: Layout of catwalk door frame and door frame guide wheel

In the figure: 1- cable release area, 2- traction area, 3- mast support cable, 4- tower top steering, 5- catwalk mast and guide wheel, 6- main cable strand, 7- puller, 8- Catwalk, 9-cable support roller, 10-traction cable, 11-A anchorage, 12-A main tower, 13-B main tower, 14-B anchorage, 15-25t hoist, 16-balance weight, 17 -60t monorail gantry crane, 18-cable laying device, 19-roller, 20-traction cable slewing bracket and pulley, 21-8t hoist, 22-pier gantry guide wheel group, 23-scattering saddle, 24-cable reel , 25- catwalk load-bearing cable, 26- pier gantry, 27- counterweight bracket, 28- steering pulley, 29- gantry supporting cable saddle, 30- tower top gantry, 31- guide wheel group, 32- handrail Cable saddle, 33-catwalk load-bearing cable saddle, 34-handrail cable, 35-pull-down device, 36-main cable saddle, 37-reaction frame, 38-catwalk door frame, 39-catwalk door frame guide wheel.

Detailed ways

The overall construction and erection plan: the erection of the main cable adopts the PPWS construction method, that is, the cable reel (24) is installed on the cable-laying support behind the A anchorage, the anchor head is drawn out from the cable reel, and the anchor head is fixed on the dragging head through the anchor head frame. The puller (7) is connected with the traction cable (10), and the 25t traction hoist (15) arranged on the downstream side of the B anchorage (14) drives the circular traction cable (10) to move forward, and the strands are pulled from A Anchor anchorage (11) drags along catwalk towards B anchorage anchorage (14), pulls a bundle at a time, and cable strand falls on the supporting guide wheel arranged along catwalk. During the traction process, the torsion, bending and loose deformation of the cable strands should be corrected in time. After the cable strands are dragged in place, the anchor heads at both ends are temporarily fixed on the anchor rods respectively, these steel wires are twisted to a parallel state, and the lifting and traversing are carried out at each saddle to shape and straighten the strands, and put them into the saddle Reserved seat. The anchor heads at both ends are introduced to the anchoring position of the anchor frame by the introduction device. After the sag is adjusted, it is locked at the saddle, and the anchor span is adjusted by adjusting the tension of the strands. After the erection of a single strand is completed, the traction hoist drives the circular traction cable to move in reverse, and the puller is returned from the B anchorage to the A anchorage, and the next strand is erected.

The overall construction layout of the gantry-type small circulation traction system for main cable erection: set up a cable storage area behind the A anchorage, install a 60-ton gantry crane (17) and a cable release bracket; set up a traction cable rotary bracket and a pulley ( 20); A 25 tons of traction hoist (15) and counterweight support (27) are established at B anchorage downstream side. The traction cable (10) is composed of 2 Φ36 steel wire ropes, which are connected by the puller (7) at the A anchorage (11), bypass the hoist drum at the B anchor, pass through the balance weight bracket (27) and each steering and guide pulley Connected to form a ring-shaped endless cable, through the horizontal circular movement of the traction drive and the mast block and guide wheel group, an independent small circular traction system is formed to meet the needs of erecting the main cable.

Claims (3)

1. the small-cycle traction system that sets up of large-span suspension bridge main cable, comprise that main rope deposits cable system, system is transported in supporting, power circulation system, tensioning debugging mechanism, it is characterized in that drag cable walks around two reels of a friction-type hoist engine, by the balance weight support with respectively turn to, socket connection behind the leading block, form horizontal ring-type endless cable, under the traction drive effect, around two reel friction-type hoist engines, the balance weight support, angle pulley, cat road door frame guide wheel, the cat head guide wheel group, supporting door frame guide wheel group, drag cable rotary support pulley is done the horizontal cyclic motion.

2. the small-cycle traction system that sets up of main rope of suspension bridge according to claim 1, it is characterized in that: be connected with on the electrodeless drag cable of ring-type and pull device, pull device and be connected with main push-towing rope, moving of drag cable can drive the same moved further of main cable strand.

3. the small-cycle traction system that sets up of main rope of suspension bridge according to claim 1, it is characterized in that: the drive unit of the electrodeless drag cable of ring-type is a two reel friction-type hoist engine.

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