CN116024904A - Large-span basket arch bridge installation construction method - Google Patents

Abstract

The invention relates to the technical field of basket arch bridges, in particular to a large-span basket arch bridge installation and construction method. The method comprises the following steps: s1, constructing a pier support; s2, installing a main beam bracket; s3, hoisting the main beam; s4, positioning and mounting a main arch bracket; s5, hoisting the main arch; s6, dismantling the main arch support; s7, comprehensively paving bridge deck precast slabs; s8, installing a suspender and performing primary tensioning of the suspender; s9, dismantling a main beam bracket; s10, bridge repair welding and paint repair; s11, pouring joints of bridge deck precast slabs; s12, stretching the suspender last time. The installation construction method provided by the invention can be preferably implemented based on a bracket hoisting method, and the installation construction of the large-span basket arch bridge can be preferably realized by adopting a beam-first and arch-then construction scheme.

Description

Large-span basket arch bridge installation construction method

Technical Field

The invention relates to the technical field of basket arch bridges, in particular to a large-span basket arch bridge installation and construction method.

Background

In the construction of a large-span basket arch bridge, the existing common methods are a bracket method, a swivel construction method and a cable-stayed buckling method. The engineering construction unit generally adopts a corresponding construction method or improves the existing construction method according to the specific requirements of engineering construction projects and the geographical environment where the engineering is located.

At present, no better solution exists for the construction of a large-span prefabricated basket arch bridge.

Disclosure of Invention

The invention provides a large-span basket arch bridge installation and construction method which can overcome certain or some defects in the prior art.

The invention relates to a large-span basket arch bridge installation construction method, which comprises the following steps:

s1, constructing a pier support;

s2, installing a main beam bracket;

s3, hoisting the main beam;

s4, positioning and mounting a main arch bracket;

s5, hoisting the main arch;

s6, dismantling the main arch support;

s7, comprehensively paving bridge deck precast slabs;

s8, installing a suspender and performing primary tensioning of the suspender;

s9, dismantling a main beam bracket;

s10, bridge repair welding and paint repair;

s11, pouring joints of bridge deck precast slabs;

s12, stretching the suspender last time.

Preferably, in S1, after the bridge pier support is constructed, the elevation of the bridge pier support top and the bridge axis are retested.

Preferably, in S2, the main girder brackets are installed from the middle of the bridge body to both sides.

Preferably, in the step S3, the middle section of the main beam is hoisted to two sides in sequence, and in the hoisting process, the assembly between the cross beam and the longitudinal beam of the main beam is completed, and the bridge deck precast slabs are synchronously installed.

Preferably, in S4, positioning and mounting of the arch support are first completed, and then positioning and mounting of the main arch support are performed.

Preferably, in S5, the main arch is symmetrically hoisted from the arch foot section to the arch top section, and the adjacent main arch sections are hoisted and positioned for assembly.

The invention has the beneficial effects that: the installation construction method provided by the invention can be preferably implemented based on a bracket hoisting method, and the installation construction of the large-span basket arch bridge can be preferably realized by adopting a beam-first and arch-then construction scheme.

Drawings

Fig. 1 is a flowchart of a boom installation construction method in embodiment 1.

Fig. 2 is a schematic structural view of the sling cage of example 1.

Fig. 3 is a layout of a hoist in embodiment 1.

Fig. 4 is a layout of the truck suspension in example 1.

Fig. 5 is a layout of an automobile crane in example 1.

Fig. 6 is a schematic diagram of lifting of the sling in example 1.

Fig. 7 is a schematic diagram of the lifting sequence of the sling in example 1.

Fig. 8 is a structural diagram of the tensioning device in example 1.

Detailed Description

For a further understanding of the present invention, the present invention will be described in detail with reference to examples. It is to be understood that the examples are illustrative of the present invention and are not intended to be limiting.

Example 1

The embodiment provides a large-span basket arch bridge installation and construction method, which comprises the following steps:

s1, constructing a pier support;

s2, installing a main beam bracket;

s3, hoisting the main beam;

s4, positioning and mounting a main arch bracket;

s5, hoisting the main arch;

s6, dismantling the main arch support;

s7, comprehensively paving bridge deck precast slabs;

s8, installing a suspender and performing primary tensioning of the suspender;

s9, dismantling a main beam bracket;

s10, bridge repair welding and paint repair;

s11, pouring joints of bridge deck precast slabs;

s12, stretching the suspender last time.

In S1 of this embodiment, after the bridge pier support is constructed, retest is performed on the elevation of the top of the bridge pier support and the bridge axis.

In S2 of this embodiment, the main girder brackets are installed from the middle of the bridge body to both sides.

In S3 of this embodiment, the middle section of the main beam is hoisted to two sides in sequence, and in the hoisting process, the assembly between the girder and the girder is completed, and the bridge deck precast slabs are synchronously installed.

In S4 of this embodiment, positioning and mounting of the arch support are first completed, and then positioning and mounting of the main arch support are performed.

In S5 of this embodiment, the main arch is symmetrically hoisted from the arch foot section to the arch top section, and the adjacent main arch sections are assembled after being hoisted and positioned.

The installation construction method provided by the embodiment can be preferably implemented based on a bracket hoisting method, and the installation construction of the large-span basket arch bridge can be preferably realized by adopting a construction scheme of girder-first and arch-later.

In this embodiment, the bridge deck system can be installed and erected first, then the main arch rib is installed, the prefabricated slab is installed after the arch rib bracket is removed, then the sling is installed, and after the cable force and the cable shape are accurately adjusted, the bridge deck system bracket is removed.

As shown in fig. 1, S8 of the present embodiment has the steps of:

step S81, performing preparation work before construction, wherein the preparation work comprises checking the angle of the embedded pipe and the spacing between the earplates, and producing matched suspenders according to the specification of an arch bridge;

step S82, the hanger rod is installed, which mainly comprises the following steps:

step S821, lifting the suspender to the corresponding position of the arch rib;

step S822, penetrating the suspender through the tower end embedded pipe through a preset hole at the arch rib by a winch, and installing a tower end nut;

s823, installing a pin shaft at the lower end of the suspender;

s83, installing arch end tensioning equipment, debugging and checking, then symmetrically tensioning in batches according to requirements, and tightening a fixed nut after tensioning to a design cable force;

step S84, repeating the step S83 until tensioning of all the suspenders is completed;

and step S85, performing protection treatment on the anchor according to design requirements.

In the embodiment, the hoisting rod is hoisted by adopting the hoisting machine, compared with a hoisting mode by a crane, the hoisting machine is more convenient to install and set, the hoisting machine can be more simply and conveniently fixed at the bridge deck, compared with the large volume of the crane, the space occupied by the bridge deck is smaller, the hoisting machine is more convenient to use, and the interference to the construction at the bridge deck caused by the overlarge volume is avoided; thereby the constructor has made things convenient for the construction of bridge floor, simultaneously, through adopting the hoist mode of hoist engine, the cost of having still preferred reduction has practiced thrift economy.

The specific operation steps are as follows:

(1) Determining the construction period of a main line:

construction preparation, boom installation, tensioning, cable adjustment, boom protection and construction ending.

(2) Other procedures are as follows: the construction platform, the lifting rod transport, the lifting rod installation, the tensioning and the tensioning equipment transport.

(3) The transverse connection is enhanced, the coordination work with each main bridge construction unit is well performed, and the construction land, the construction channel, the construction platform and the large-scale carrying equipment are reasonably used.

And rechecking the angle of the embedded pipe and the spacing of the lug plates by a steel structure team, and blanking to produce the suspender according to the actual length.

Arch end construction platform

A suspension cage suspension point and a safety rope are arranged on the vault, and fig. 2 is a schematic diagram of a sling suspension cage, and the under-arch construction building suspension cage required for construction is prepared to be in place. The main body is formed by taking 25 # angle steel with the length of 70 meters and the length of 6 70 centimeters as the bottom.

The main equipment arranged on the deck comprises: the device comprises an automobile crane (the layout of the automobile crane is shown in fig. 4 and 5), a winch, a hoist and a guiding system, a tensioning jack, an oil pump and an assembly.

In order to ensure convenient operation and accurate control of procedures such as hanging the boom on the arch and hanging the beam end, a winch with good condition is selected as a winch of important construction equipment, and a pulley is arranged on each winch. According to the weight of the rope body, the hoisting machine is installed and arranged in the safety guarantee coefficient by the boom.

The sling hoisting equipment comprises a winch, a steel wire rope, beam end guide points, arch end guide points and the like, two 3T winches are respectively arranged on bridge decks on two sides, the steel wire rope enters an arch from a reserved hole of a bridge deck arch rib, temporary hoisting points are arranged in the arch through the welding angle guide of each diaphragm, the steel wire rope penetrates through a cable guide pipe, a steel wire rope traction system is arranged, and the sling hoisting equipment is shown in combination with fig. 3:

z1, the hanging point is arranged in an arch end anchor box, a hoist steel wire rope hanging counter-force point is arranged right above an arch end anchor pad plate by utilizing the anchor box, a steel wire rope with the diameter of phi 15.6mm is adopted as the steel wire rope, and the load of 4 tons can be borne maximally by the crane;

the Z2 and 3T windlass is arranged at the bridge abutment position of two banks and is temporarily fixed so as to avoid accidents in the hoisting operation process;

z3, winding the steel wire rope, winding around the temporary lifting point on the arch, putting the steel wire rope to the outlet of the cable guide pipe at the arch end after passing through the cable guide pipe right below, and additionally arranging 2 chain blocks with 2 tons beside;

and Z4, finishing the installation of the hoisting equipment.

Through the steps, the hoisting performance of the hoisting machine on the boom is enhanced, so that the stability of the hoisting machine in hoisting the boom is improved.

According to the requirement of a design drawing on the cable force of a lifting rod, a YCW200 jack is selected as a jack, the requirement of 170 tons of the maximum cable force is met, tensioning control is carried out according to a symmetrical principle, a double-suspender structure is adopted, 4 points are symmetrically and synchronously tensioned, 8 jacks and 8 oil pumps and 8 sets of tensioning tools are adopted for matching combination, the oil pumps can be arranged on a bridge deck in the tensioning process, an oil pipe enters an arch rib through a temporary manhole and is connected with the jack, the arch rib is in tensioning communication with bridge deck operators through interphones, and the jack and the tensioning tools are mainly matched with a chain block through manpower when moving in the arch rib, so that the space of the jack and the tools is small in the arch rib, the potential safety hazard is large, and special attention is required.

The heaviest in the tensioning tool and equipment is a jack, when the jack moves from the arch foot to the vault, auxiliary traction is needed by using a chain block, and the auxiliary manual hole is hung at the manhole position of the arch rib partition plate by using the chain block; the equipment and the tooling can be put into the arch rib in advance when the arch rib is hung to be heavy, so that one-time carrying is reduced.

Main construction method of suspender

Treatment of cable ducts

The outer diameter of the anchor head of the suspender is smaller than the inner diameter of the cable sleeve, so that position deviation is very easy to occur during the installation of the suspender, thereby causing damage to the outer screw teeth of the anchor head and the PE protective sleeve of the suspender, and the arch rib end cable sleeve is comprehensively inspected before the installation of the suspender, so that welding slag, burrs and the like in the cable sleeve are flattened and polished.

Beam end ear plate treatment

And checking the position, angle and aperture of the beam end lug plate.

Suspension cable upper end anchor head hoist (suspension cable hoist schematic view is shown in figure 6)

G1, slowly putting down a connecting device of a winch traction hoisting system, firmly connecting with an anchor head at the upper end of a sling, and releasing a hoop on the sling;

g2, starting a winch, slowly pulling an upper anchor head to the position of an embedded pipe of an anchor box under an arch, and adjusting the direction of the anchor head at the upper end of a sling by a worker on a construction platform and centering so as to smoothly pass through the embedded pipe to reach a transverse arch rib plate;

and G3, continuing to lift, lifting the upper anchor head to a design position, screwing the upper end nut, and temporarily anchoring the upper anchor head of the sling.

G4, boom installation procedure, in which the boom is installed from the abutment to the midspan side (a suspension cable hoisting procedure is schematically shown in fig. 7).

Through the construction process in this embodiment, the hoisting of the anchor head at the upper end of the sling can be realized better.

The anchor head at the lower end of the sling is installed

(1) And arranging a winch and a pulley according to the position of the suspender.

(2) An auxiliary clamp is arranged at the tail end of the suspender, and a hoist is used for pulling the suspender fork lug to be close to the lug plate. The beam surface staff adjusts the fork lug position and angle through the cooperation of chain block, inserts the round pin axle when the position is suitable.

Boom tensioning arrangement

According to the requirement of a design drawing on the cable force of the lifting rod, a YCW100 lifting jack is selected as the lifting jack, the requirement of 170 tons of the maximum cable force is met, the lifting control is carried out according to a symmetrical principle, the lifting jack is of a double-lifting-rod structure, 4 points are symmetrically and synchronously tensioned, 16 lifting jacks, 8 oil pumps and 8 sets of tensioning tools are adopted for matching combination, the oil pumps can be arranged on a bridge deck in the tensioning process by using ZB4-500, the lifting jacks are the heaviest of the tensioning tools and equipment, and the lifting jacks are used or manually installed.

Tensioning system

In order to ensure that the stress of the suspenders meets the design requirement, the tension error of each suspender in construction is not more than +/-2%, each suspender after bridging is not more than +/-1%, the tensioning is strictly controlled according to the process, and the following items are required to be provided before construction:

1. the boom installation control tension force is provided to the installation construction unit in the form of a monitoring instruction by the monitoring unit;

2. under the action of the tension force of the boom installation control, the relative displacement (or deformation) of the boom anchoring point is calculated, namely the vertical displacement of the lower end anchoring point and the vertical displacement of the upper anchoring point in the vertical plane where the boom is positioned are temporarily given by a monitoring unit;

3. the relevant physical parameters of the corresponding section of the girder are generally determined according to design;

4. the boom cable body geometric and physical parameters are provided by the boom product supplier.

Tensioning process

Boom tensioning process description: according to the structure of the suspender, the adjusting device of the suspender is arranged between the lower end fork lug and the lower anchor head, so that a tension mode of the shoulder pole is needed, two jacks and a pull rod are used for synchronous tension, the pull rod and the jack are arranged in parallel with the axial center line of the suspender, the adjusting connecting device of the suspender is loosened by the upper shoulder pole beam and the lower shoulder pole beam (shown in a structural diagram 8) in the loading process of the jack, and then tension and tension of the suspender are realized by screwing and screwing the connecting sleeve of the suspender adjusting device, and the length of the suspender can be adjusted by rotating the adjusting sleeve while pulling.

The device comprises the following components:

lower shoulder pole beam: is temporarily connected and fixed with the lower fork ear of the suspender. Upper shoulder pole beam: is temporarily connected and fixed with the lower anchor head of the suspender. Temporary pull rod: and full threads, wherein two ends respectively penetrate through the lower shoulder pole beam and the upper shoulder pole beam and are temporarily fixed by nuts. And (3) a jack: and loading the load, and pulling the suspender downwards to the design position or loosening to the design position through the pull rod.

Tensioning procedure

And in the tensioning process, the synchronous tensioning is performed according to the tensioning sequence given by the monitoring unit, and the asynchronous tension difference value of the synchronous tensioning does not exceed the design specified value. The synchronization difference of the jacks is not more than the minimum cell of the oil meter reading, and the median error of the cable force is less than +/-2%.

1. The suspension rod is tensioned twice, firstly, the cable body is pre-tensioned and formally tensioned when the cable is hung, and finally, the full-bridge suspension rod inhaul cable is supplemented or released according to the linear and actually measured cable force after the secondary constant load loading is completed. In this embodiment, through carrying out tensioning twice to the jib, the tensioning degree of lifting jib that can be preferred to the better assurance jib has further promoted the stability of arched bridge to the lifting capacity of bridge floor.

2. After receiving the design tensioning instruction, converting the tension value on the instruction into an oil pressure reading value on each group of tensioning equipment according to a regression equation on a jack calibration book, giving the tensioning operation instruction to a responsible person of each group of tensioning equipment in a written form, and substituting the attention items;

3. the stretching sequence is stretched from the middle to the two sides.

In this embodiment, through setting up the stretch-draw order to stretch-draw from the centre towards both sides, can make every jib homoenergetic stretch-draw the bridge floor that can be preferred to the better lifting effect of jib to the bridge floor has been promoted, simultaneously with stretch-draw order setting up to stretch-draw from the centre towards both sides, also make constructor can be under construction simultaneously from arch bridge center department to both ends, avoided appearing disturbing when the construction, promoted the efficiency of construction to the arch bridge.

Tensioning process

(1) The oil pipes of the oil pump and the jack are connected, whether the precision pressure gauge is consistent with the jack is checked, and before tensioning, the precision pressure gauge can move for two strokes under the condition of no load, so that the jack is ensured to have no problem during tensioning;

(2) the tensioning jack and the oil pressure gauge must be calibrated before tensioning;

(3) starting an oil pump, and synchronously grading, balancing and slowly loading the lifting rods according to tensioning instructions, wherein a grading tensioning program is as follows: 0→0.3σ→0.6σ→0.8σ→1.0σ; in the tensioning process, the boom cable slowly rises, and simultaneously, the boom cable nut is screwed up;

(4) when the design and monitoring requirements are met, the oil pressure is stabilized, and then the nut is screwed so that the nut and the anchor backing plate are fully combined. Finally, oil pressure is removed, oil return, shutdown and power failure are carried out, and tensioning work is completed;

(5) and in the tensioning process, the cable force measurement work of each cable is completed by matching with a detection unit.

4. After the hanger rod of one cable number is tensioned, carefully checking and recording, confirming that the tensioning equipment can be disassembled at the back without errors, and installing and tensioning the next cable number.

Boom cable-adjusting construction

The tuning rope may need to be phased and distributed after the boom is installed. The cable adjusting part and the cable controlling force are provided by a monitoring unit, the super-tension cable is released, and the cable force is insufficient to be supplemented.

Anti-corrosion operation

After tensioning, coating the inner surface of the anchor cup with slow release paste of 250-300um; the surface of the exposed steel parts at the end parts of the anchor cup, the anchor ring and the anchor backing plate is coated with the slow release paste of 250-300 mu m, then the slow release tape is wrapped, the overlapping rate is 50%, and finally the steel parts are coated with the external protective agent for 2 times.

Through the anticorrosive operation in this embodiment, can carry out anticorrosive treatment to the ground tackle effectively to the life of ground tackle that promotes that can be better.

Shock absorber installation

Built-in shock absorbers generally include shock absorbers, metal rings, wedges, tie rods, nuts, spring washers, and the like. When the shock absorber is installed, the shock absorber is firstly pushed into the embedded pipe in a flat mode, the movable wedge block is installed on the fixed wedge block, the shock absorber rubber is enabled to expand along the radial direction through pushing the shock absorber wedge block, so that the suspender is wedged, and meanwhile, the shock absorber also achieves the fixing effect.

The self-made suspension cage is adopted as an installation platform of the shock absorber, and the suspension cage is welded by using No. 5 angle steel. A temporary hanging point is welded above a cable number to be installed, then the phi 16 steel wire rope and a hoist are used for hanging a hanging cage, and a chain hoist is used for adjusting the height of the hanging cage so as to facilitate construction operation. The temporary welding hanging point puts down a phi 16 steel wire rope to bolt the hanging cage so as to prevent accidents.

The cage platform is considered to be installed and suspended using a truck crane.

It is to be understood that, based on one or several embodiments provided herein, those skilled in the art may combine, split, reorganize, etc. the embodiments of the present application to obtain other embodiments, which do not exceed the protection scope of the present application.

The invention and its embodiments have been described above by way of illustration and not limitation, and the examples are merely illustrative of embodiments of the invention and the actual construction is not limited thereto. Therefore, if one of ordinary skill in the art is informed by this disclosure, the structural mode and the embodiments similar to the technical scheme are not creatively designed without departing from the gist of the present invention.

Claims (6)

1. The installation and construction method of the large-span basket arch bridge comprises the following steps:

s1, constructing a pier support;

s2, installing a main beam bracket;

s3, hoisting the main beam;

s4, positioning and mounting a main arch bracket;

s5, hoisting the main arch;

s6, dismantling the main arch support;

s7, comprehensively paving bridge deck precast slabs;

s8, installing a suspender and performing primary tensioning of the suspender;

s9, dismantling a main beam bracket;

s10, bridge repair welding and paint repair;

s11, pouring joints of bridge deck precast slabs;

s12, stretching the suspender last time.

2. The method for installing and constructing the large-span basket arch bridge according to claim 1, wherein the method comprises the following steps: s1, retesting the elevation of the top of the bridge pier support and the axis of the bridge after the bridge pier support is constructed.

3. The method for installing and constructing the large-span basket arch bridge according to claim 1, wherein the method comprises the following steps: s2, the main beam supports are arranged from the middle part of the bridge body to two sides.

4. The method for installing and constructing the large-span basket arch bridge according to claim 1, wherein the method comprises the following steps: and S3, hoisting the middle section of the main beam to two sides in sequence, and completing assembly between the cross beam and the longitudinal beam of the main beam in the hoisting process, and synchronously installing bridge deck precast slabs.

5. The method for installing and constructing the large-span basket arch bridge according to claim 1, wherein the method comprises the following steps: and S4, firstly, positioning and mounting of the arch support, and then, positioning and mounting of the main arch support.

6. The method for installing and constructing the large-span basket arch bridge according to claim 1, wherein the method comprises the following steps: and S5, symmetrically hoisting the main arch from the arch foot section to the arch top section, and assembling after hoisting and positioning the adjacent main arch sections.

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