CN105714683A - Installation and dismantling method of high bent cast-in-situ aqueduct suspension type bailey frames - Google Patents

Abstract

The invention relates to a method for installing and dismantling a suspension type Bailey frame of a cast-in-situ aqueduct with a high-bracket frame. The method takes advantage of the high bearing capacity of the bent frame pier body of the main project, uses the top of the pier cap as the supporting surface, and adopts a separately designed suspension support type Bailey frame as the formwork support, and uses a crane to hoist it in place in groups. When the concrete structure of the aqueduct After the construction is completed, when it is necessary to dismantle the Bailey support, install the upper beam, lower joist, wire rope and lifting screw connected to the upper beam and lower joist on the top surface of the concrete structure of the aqueduct in time, and finally remove and lift the Bailey support . Compared with the prior art, the present invention has the characteristics of high safety performance, saving investment, simple scheme, convenient operation, short construction period, etc., and solves the problem that the prior art can carry out tall and large bent structures under unfavorable terrain conditions such as crossing rivers and paddy fields. Deficiencies in the construction of the aqueduct.

Description

Installation and dismantling method of suspended Bailey frame in cast-in-situ aqueduct with high-bracket frame

technical field

The invention relates to a new type of support technology for large-scale high-position cast-in-place beams and slabs in civil engineering, and in particular to a construction method for installing and removing suspension-type Bailey frames based on high-bracket cast-in-situ aqueducts.

Background technique

At present, new support technologies for large-scale cast-in-place beams and slabs in civil engineering include the following:

The steel column support construction method of the Bailey frame: there are many thick steel pipe support systems between the two piers, and ground exploration and special design for the support foundation are required, and heavy foundation preloading must be carried out for the support system. If the support system is unstable, it will seriously affect the quality of the project. In addition, the foundation construction cost of the supporting system is high and the period is long.

The scaffolding construction method of Bailey frame full house scaffolding: similar to steel column support, it is necessary to carry out comprehensive foundation treatment between the two piers. After the steel frame is installed, the preloading is high and there are many connectors, so the quality of the full house frame is difficult to be guaranteed. The construction cost is high and the period is long.

Mobile formwork construction method: The formwork is expensive and can only travel in one direction. In the case of a large amount of work, it is not suitable for simultaneous construction on multiple working faces, which has a serious impact on the construction period.

Prefabricated and large bridge erecting machine installation and construction method: there must be a large prefabricated site, a large beam (aqueduct) transport vehicle, and a large bridge erecting machine, and the complete set of equipment is expensive. At the same time, this construction method is not suitable for aqueduct construction. The aqueduct is different from the box girder, and the top surface of the aqueduct is open, which cannot satisfy the bridge erecting machine to walk on it.

Contents of the invention

Aiming at the above-mentioned problems existing in the prior art, the present invention proposes a construction method based on the installation and removal of the suspension type Bailey frame of the cast-in-situ aqueduct with high bent frames. The pier body of the bent frame of the main project has the advantage of high bearing capacity. The top of the pier cap is used as the supporting surface, and the separately designed suspension support type Bailey frame is used as the formwork support, and it is hoisted in place by groups of cranes. Finally, when it is necessary to remove the Bailey support, install the upper beam, lower joist, steel wire rope connecting the upper beam and lower joist, and lifting high-strength screw on the top of the concrete structure of the aqueduct in time, and finally remove and lift the Bailey support.

To achieve the above object, the present invention adopts the following technical solutions:

A method for installing and dismantling a suspension-type Bailey frame of a cast-in-situ aqueduct with high-brackets, comprising the following steps:

Step 1, install the sand box.

A sand box is placed on the top of the pier cap, and a sand box is set at each end of each piece of Bailey frame. The size of the sand box is the same. bottom on the same level.

Step 2, assemble the Bailey frame and hoist the assembled Bailey frame in place.

Connect the hanging terminal bracket to the standard Bailey piece of each Bailey frame (the Bailey frame is composed of Bailey pieces and non-standard terminal brackets), and assemble in groups of three; after the assembly is completed, use a car Hang it in place and place it on the corresponding sand box. Repeat the steps of assembling and hoisting in place until the assembly and hoisting in place of each group is completed.

Step 3, build the construction horseway board.

Hang the steel pipe cross-joist under the upper chord of the Bailey beam. The steel pipe is perpendicular to the upper chord of the Bailey beam. The steel pipe is fixed with ring bolts, and the cross fasteners are used to connect the protective railing poles at both ends of the steel pipe.

Step 4, install the aqueduct bottom template.

The ribs of the bottom formwork of the aqueduct are connected with the upper chord of the Bailey frame by connecting bolts, so that the upper chord of the Bailey frame and the bottom bracket of the bottom formwork of the aqueduct jointly form a straight plane truss structure.

Step 5, remove the Bailey rack.

After the concrete of the aqueduct reaches the design strength, remove the connecting bolts between the bottom formwork of the aqueduct and the Bailey beam, and open the sand discharge door of the sand box to allow the dry sand to flow out. When the beam is separated, remove the outer formwork and bottom formwork of the aqueduct.

Use a translation device to move the Bailey frame out of the bottom of the tank: first place the upper beam on the top of the aqueduct, and then install the lower joist. The upper beam and the lower joist are connected by a steel wire rope and a high-strength screw, and the nuts of the high-strength screw are tightened or loosened. Controls the raising and lowering of the lower joists.

Further, the method also includes the step of erecting a construction ladder on one side of the pier body.

Further, the sand box includes a sand box body, a sand box plug at the top of the sand box body and a sand discharge door at the bottom of the sand box body, and the sand diameter is less than 2mm.

Further, the suspension terminal bracket includes a suspension terminal and non-standard Bailey pieces.

Further, the diameter of the fastening screw described in step 3 is not less than 14mm; a steel pipe cross joist is provided every 60cm, and the thickness of the steel gasket is not less than 5mm; the width of the carriageway is not less than 90cm; the height of the pole is not less than 1.2m.

Further, the diameter of the connecting bolt in step 4 is not less than 16mm.

Further, the hoisting of the combined Bailey beam described in step 5 includes the following steps:

On each lower joist, a square timber is placed directly under the combined Bailey beam, and when hoisting, the square timber is moved under the Bailey frame to be removed. Tighten the bolts on the upper beam to support the group of Baileys. After the hanging end of the Bailey frame leaves the top surface of the sand box, use the jackhammer or a chain hoist to move the upper lifting screw support outwards to move the Bailey beam outwards horizontally. The middle beret is delivered in multiples. Finally, use a crane for vertical lifting. After the hoisting of a group of Bailey beams is completed, the above process is repeated to complete the removal of all Bailey frame composite beams.

Compared with the prior art, the present invention has the following advantages:

(1) The present invention uses a suspension type end, which can increase the upper support function on the basis of the lower support of the existing Bailey beam structure, and can make full use of the narrow space between the pier top surface and the bottom surface of the aqueduct to complete the Bailey support installation of structures.

(2) Compared with the steel column support construction method of the Bailey frame, the present invention does not need to add many thick steel pipe support systems between the two pier bodies, and simultaneously saves the foundation exploration and special design of the support foundation, as well as the heavy support system. The foundation preloading and other processes not only simplifies the construction procedure, shortens the construction period, but also reduces the construction cost.

(3) Compared with the supporting construction method of Bailey frame full hall scaffolding, the present invention does not need to carry out comprehensive foundation treatment between the two pier bodies, does not need to set up full hall frames, and does not need to carry out construction procedures such as preloading, which not only simplifies the process, but also shortens the construction time. The construction period is shortened and the construction cost is reduced.

(4) Compared with the construction method of mobile formwork, the present invention solves the problems such as high cost of formwork, only one-way travel, and too long construction period; Large prefabricated sites, large aqueduct transport vehicles, large bridge erecting machines, etc., the whole set of equipment is expensive. At the same time, the construction method of prefabrication and large bridge erecting machines is not suitable for aqueduct construction. Aqueducts are different from box girders in that the top surface of the aqueduct is open. It is not enough for the bridge erecting machine to walk on it. The present invention adopts the installation and dismantling method of the suspended bailey frame, which avoids the restriction of the above-mentioned unfavorable construction conditions.

Description of drawings

Fig. 1 is a schematic diagram of the sand box structure;

Fig. 2 is the schematic diagram of the longitudinal section of the suspended Bailey frame;

Fig. 3 is a schematic diagram of a transverse section of a suspended Bailey frame;

Fig. 4 is a schematic structural diagram of a suspended end bracket;

Fig. 5 is the schematic diagram of setting up the cantilevered construction curb slab;

Fig. 6 is the connection schematic diagram of aqueduct bottom formwork and Bailey beam;

Figure 7 is a schematic diagram of the complete dismantling of the Bailey frame.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

A method for installing and dismantling a suspension-type Bailey frame of a cast-in-situ aqueduct with high-brackets, comprising the following steps:

1. Preparation before construction

(1) Preparation of auxiliary materials

Before the installation and removal of the Bailey bracket, the preparations for the required accessories are done, mainly including: the design and manufacture of the sand box for height adjustment, the design and manufacture of the suspended end bracket, the fixing parts of the cantilevered construction road ( Long bolts with rings) design and manufacture, design and manufacture of aqueduct bottom formwork restraint bolts and gaskets, selection and purchase of upper beams, lower joists, and lifting screws used for dismantling, etc.

The structure of the sand box is shown in Figure 1, including the sand box body, the sand box plug at the top of the sand box body and the sand discharge door at the bottom of the sand box body. The sand boxes should be made in the same size, use fine sand, and screen out particles over 2mm, so that the fine sand can be smoothly discharged from the sand discharge door. The amount of sand loaded in each box needs to pass a compaction test, so that the bottom of the aqueduct after load-bearing is on the same level.

The structure of the suspended end bracket is shown in Figure 4, including the suspended end and non-standard Bailey pieces.

(2) Technical preparation

When selecting and designing Bailey beams, refer to the standard Bailey beam mechanical property table, geometric property table and truss allowable internal force table, so that the combined Bailey frame can meet the requirements of construction load and deflection value. When designing and manufacturing the end support, the shear force and bending moment at the extended end of the upper chord meet the requirements.

Before the Bailey beam is formally hoisted in place, simulate the construction load to verify the deflection value of the overall Bailey beam after loading, find out the difference between the actual value and the theoretical calculation, and take correct correction (or adjustment) measures, such as taking The measure of increasing or reducing the number of Bailey beams and filling the thickness of thin wood boards between the top surface of the aqueduct and the bottom formwork of the aqueduct can make the pre-camber of the aqueduct body meet the design requirements.

(3) Set up a ladder

On the side of the pier body, build a construction ladder for construction workers to go up and down.

2. Install sand box

A sand box is placed on the top of the pier cap, and a sand box is provided at each end of each bailey to support the suspension end and lower the height of the bailey when the formwork is removed.

3. Assemble the Bailey frame and hoist the assembled Bailey frame in place

Connect the suspension-type end bracket to the standard Bailey sheet of each Bailey frame. During the construction process, operate according to the construction technical requirements for steel bridge installation. Three groups are used. After each group is assembled and checked, use a car crane Lift it in place and place it accurately on the corresponding sand box. After the first group is in place, repeat the assembly and hoisting of the next group in place. The schematic diagram after being in place is shown in Figure 2 and Figure 3.

4. Build a construction horseway board

The actual width of the combined Bailey beam can only meet the load-bearing requirements of the structure, and it is necessary to add construction slabs on both sides of the Bailey beam. The steel pipe cross-joist is hoisted under the upper chord of the Bailey beam. The laying method is as follows:

Fix the steel pipe under the upper chord of the Bailey beam with eyebolts. The steel pipe is perpendicular to the upper chord of the Bailey beam. The diameter of the fastening screw is not less than 14mm; the diameter of the fastening screw is not less than 60cm, and the thickness of the steel gasket is not less than 5mm. It is advisable to slip off, and the width of the horse path is not less than 90cm. Use cross fasteners to connect the protective railing poles at both ends of the steel pipe, and the height of the poles should not be less than 1.2m. The sketch is shown in Figure 5.

5. Install the aqueduct bottom formwork

When installing the bottom formwork of the aqueduct, connect its ribs with the upper chord of the Bailey frame, so that the upper chord of the Bailey frame and the bracket of the bottom formwork of the aqueduct form a stable planar truss structure to ensure that the combination does not occur lateral bending. The diameter of the connecting bolts is not less than 16mm. As shown in Figure 6, the diameter of the two bolts and supporting nuts is 16mm; the lower gasket (splint) is 10mm thick, 200mm long, and 140mm wide; the upper gasket (splint) is 10mm thick and 200mm long , 60mm wide.

6. Remove the Bailey Rack

When the concrete of the aqueduct reaches the design strength, remove the connecting bolts between the bottom formwork and the Bailey beam, open the sand discharge door of the sand box, and let the dry sand flow out. Remove the outer formwork and bottom formwork of the aqueduct when it is separated from the Bailey beam. After the removal of the outer mold and the bottom mold is completed, the Bailey frame is removed.

All Bailey racks are located under the aqueduct body, and the Bailey racks are first moved out of the bottom of the tank, and then vertically hoisted to remove them.

The translation device can be lifted and lowered in a small range. When dismantling, the upper beam is first placed on the top of the aqueduct, and then the lower joist is installed. The upper beam and the lower joist are connected by steel wire ropes and high-strength screws. Implement fastening or loosening the nuts of the lifting high-strength screw rod, and the lower joist can be lifted.

On each lower joist, directly under the combined Bailey beams that are planned to be hoisted, place a square log with a thickness of about 10cm. The length of the square wood is greater than the width of the three sets of Bailey frames. When hoisting, move the square timber under the Bailey frame to be removed, fasten the bolts on the upper beam, and lift up the group of Bailey frames. When the hanging end of the Bailey frame leaves the top surface of the adjustment sand box, use Qianjinding (or chain hoist) moves the upper lifting screw support outward, moves the Bailey beam outward horizontally (the middle Bailey frame can be transported in multiple times to meet the hoisting requirements), and then vertically hoist with a crane . When a group of Bailey racks is hoisted, repeat the above process to complete the dismantling of all Bailey racks.

Figure 7 shows the schematic diagram of the entire group of Bailey racks being dismantled.

The method described in the present invention has been successfully applied to the aqueduct construction of the 1# aqueduct crossing the water field and the 2# aqueduct crossing the river in the second phase of Changhua River Daguangba Water Conservancy and Hydropower (irrigation area) Changqian I standard project in Hainan Province from 2009 to 2011. It was successfully implemented in the 33-meter-high bent aqueduct by hanging Bailey frame.

The present invention is not limited to the above-mentioned embodiments, and any obvious improvements or changes made by those skilled in the art to the above-mentioned embodiments will not exceed the concept of the present invention and the scope of protection of the appended claims.

Claims (7)

1. the cast-in-place aqueduct suspension type Bailey bracket of high framed bent is installed and method for dismounting, it is characterised in that said method comprising the steps of:

Step 1, installs sandbox:

Placing sandbox at pier cap top, set a sandbox at the two ends of every Bailey bracket, sandbox in the same size, the sand loading amount of sandbox obtains through compaction test and calculating, and makes after load-bearing the end of Bailey bracket in same level；

Step 2, assembled Bailey bracket by the Bailey bracket hoisted in position after assembly:

Suspension type end head bracket is connected on the standard beret truss of every Pin Bailey bracket, carries out assembly with three Pin for one group；Assembly adopts truck crane hoisted in position after completing, and is placed in above corresponding sandbox；Repeat described assembly and hoisted in position step, until completing assembly and the hoisted in position of each group；

Step 3, erection construction packway plate:

Hanging bed steel pipe cross girders below the top boom of Bailey beam, steel pipe is vertical with the top boom of Bailey beam, adopts the fixing steel pipe of hanging-ring type bolt, adopts cruciform fastening for falsework to connect guard rail vertical rod at steel pipe two ends；

Step 4, installs aqueduct end template:

Adopt connecting bolt the rib of aqueduct end template and Bailey bracket top boom to be linked together, make the top boom of Bailey bracket and the lower supporter of aqueduct end template be collectively forming straight truss structural；

Step 5, removes Bailey bracket；

After aqueduct concrete reaches design strength, remove the connecting bolt of aqueduct end template and Bailey beam, open the sand discharge door of sandbox, making dry sand flow out, sandbox crest level uniformly declines, and Bailey beam frame declines simultaneously, when template separates with Bailey beam, remove aqueduct external mold and bed die；

Adopt translating device that Bailey bracket is translated out bottom land: entablature is first placed in aqueduct top, then lower joist is installed；Entablature and lower joist are connected by steel wire rope and high-strength bolt；The lifting of lower joist is controlled by fastening or loosening the nut lifting high-strength bolt.

2. the cast-in-place aqueduct suspension type Bailey bracket of high framed bent according to claim 1 is installed and method for dismounting, it is characterised in that described method is additionally included in the step of pier shaft side erection construction cat ladder.

3. the cast-in-place aqueduct suspension type Bailey bracket of high framed bent according to claim 1 is installed and method for dismounting, it is characterised in that described sandbox includes sandbox body, is positioned at the sandbox plug of sandbox bodies top and is positioned at the sediment outflow door of sandbox body bottom portion, and sand footpath is less than 2mm.

4. the cast-in-place aqueduct suspension type Bailey bracket of high framed bent according to claim 1 is installed and method for dismounting, it is characterised in that described suspension type end head bracket includes hanging termination and non-standard beret truss.

5. the cast-in-place aqueduct suspension type Bailey bracket of high framed bent according to claim 1 is installed and method for dismounting, it is characterised in that described in step 3, fastening screw diameter is not less than 14mm；One steel pipe cross girders of every 60cm, steel plate washer thickness is not less than 5mm；Packway width is not less than 90cm；Vertical rod is highly not less than 1.2m.

6. the cast-in-place aqueduct suspension type Bailey bracket of high framed bent according to claim 1 is installed and method for dismounting, it is characterised in that described in step 4, connecting bolt diameter is not less than 16mm.

7. the cast-in-place aqueduct suspension type Bailey bracket of high framed bent according to claim 1 is installed and method for dismounting, it is characterised in that the lifting combining Bailey beam described in step 5 comprises the following steps:

On every lower joist, just lay a lumps of wood to below combination Bailey beam, during lifting, the described lumps of wood is moved to below the Bailey bracket that will remove；Bolt on fastening entablature, holds up this group Bailey bracket；After sandbox end face is left in the suspension termination of Bailey bracket, use a thousand pieces of gold top or chain block to be displaced outwardly lifting screw bearing above, Bailey beam is moved horizontally outward；Middle Bailey bracket is transported several times；Crane is finally used to carry out vertical lifting；One group of Bailey beam repeats above-mentioned operation after having lifted, and completes the dismounting of all Bailey bracket combination beams.