Detachable operating platform and construction method for pipeline welding in shield tunnels

Abstract

The present invention relates to a detachable operating platform and construction method for welding pipelines in a shield tunnel corridor, comprising the following steps: connecting the end points of a steel pipe component by bolts, installing an adjustable self-locking steel belt, providing anti-skid rubber on the outer surface of the pipeline, and sleeve the steel pipe component and the adjustable self-locking steel belt on the outer surface of the pipeline; installing a connecting buckle between two straight steel pipe components at the top of the pipeline, adjusting the adjustable self-locking steel belt to fix the detachable operating platform; and performing pipeline welding in a shield tunnel corridor on the detachable operating platform. The beneficial effects of the present invention are: providing a working platform for pipeline welding construction, ensuring the safety of welding personnel, and being recyclable; connecting the left and right sides of the detachable operating platform by the connecting buckle, thereby improving the strength and safety of the detachable operating platform.

Description

Technical Field

[0001] Aiming at the welding of pipelines in urban pipeline corridor tunnels, the present invention proposes a detachable operating platform and a construction method for welding pipelines in shield pipeline corridor tunnels to ensure personnel safety and construction welding quality. Background Art

[0002] With the rapid development of urban engineering construction, the rational utilization of urban underground space has become increasingly important. To integrate various pipelines within the city and facilitate unified management, urban pipeline corridors and tunnels have emerged. During the construction of urban pipeline corridors and tunnels, pipeline welding is inevitably required, and the quality requirements for pipeline welding are relatively strict.

[0003] However, due to space limitations and pipe shape constraints, there is no suitable operating position for welding the upper portion of the pipe. Furthermore, pipes are often wet and smooth, making welding on top of them very dangerous. During shield tunneling pipeline migration welding, the construction site environment is complex and space is limited. When welding the upper gaps of the pipelines, the operating environment is harsh. Water stains often exist on the pipelines, posing risks such as falls and electric shocks, making welding quality difficult to guarantee. Currently, there are few types of operating platforms for welding the upper gaps of pipelines, with poor adaptability, large overall components, and virtually no disassembly or transfer. Furthermore, there are relatively few construction technologies suitable for welding pipelines within urban pipe corridors. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a detachable operating platform and a construction method for welding pipelines in a shield tunnel.

[0005] This detachable operating platform for pipe welding in a shield tunnel gallery includes steel pipe components, bolts, anti-skid rubber, adjustable self-locking steel belts, and connecting buckles. The steel pipe components include straight steel pipe components and curved steel pipe components. The two curved steel pipe components are symmetrically semicircular. The two curved steel pipe components forming the semicircular arc are set as a group. Multiple groups of curved steel pipe components are arranged on the upper part of the outer surface of the pipeline along the length direction of the pipeline. Anti-skid rubber is provided between the curved steel pipe components and the outer surface of the pipeline. An adjustable self-locking steel belt is provided between the two side ends of each group of curved steel pipe components. The adjustable self-locking steel belt fits the lower part of the outer surface of the pipeline.

[0006] Each curved steel pipe member is connected to a straight steel pipe member at both ends, and the two straight steel pipe members at both ends of each curved steel pipe member are connected to each other to form a right angle; the ends of adjacent steel pipe members in the length direction of the pipeline are connected by straight steel pipe members; all steel pipe members are connected by bolts, and the two straight steel pipe members at the top of the pipeline are connected by connecting clips.

[0007] As a preference, both ends of the steel pipe member are flat, and both ends of the steel pipe member are provided with bolt holes.

[0008] Preferably, all straight steel pipe members in the steel pipe member have the same size.

[0009] Preferably, two steel pipe grooves are symmetrically formed on the bottom of the connecting buckle, the shapes of the steel pipe grooves match those of the straight steel pipe component, and the central angle corresponding to the cross-sectional shape of the steel pipe grooves is greater than 180°.

[0010] As a preferred embodiment, a semicircular groove is further provided between the two steel pipe grooves at the bottom of the connecting buckle.

[0011] Preferably, the connecting buckle is made of ABS plastic.

[0012] The construction method of the detachable operating platform for pipe welding in a shield tunnel gallery comprises the following steps:

[0013] Step 1: Connect the ends of the steel pipe component with bolts, install adjustable self-locking steel belts, set anti-slip rubber on the outer surface of the pipe, and put the steel pipe component and the adjustable self-locking steel belt on the outer surface of the pipe;

[0014] Step 2: Install the connecting clips between the two straight steel pipe components at the top of the pipeline, and connect the connecting clips to the steel pipe components on both sides of the top of the pipeline; adjust the adjustable self-locking steel belt to fix the detachable operating platform on the top of the pipeline;

[0015] Step 3: Weld the pipes in the shield tunnel corridor on the detachable operating platform. After welding, adjust the adjustable self-locking steel belt, dismantle the detachable operating platform, and recycle the steel pipe components and the adjustable self-locking steel belt.

[0016] Preferably, in step one, the ends of the interconnected steel pipe members overlap, bolts pass through the bolt holes of the interconnected ends of the steel pipe members, and both ends of the bolts are tightened by nuts.

[0017] The beneficial effects of the present invention are:

[0018] 1) The present invention proposes a detachable operating platform located above the pipeline in the shield tunnel corridor, and increases the friction between the steel pipe component and the pipeline through anti-slip rubber, providing a working platform for pipeline welding construction, ensuring the safety of welding personnel, and ensuring the quality of pipeline welding.

[0019] 2) The detachable operating platform for pipe welding in the tunnel of the pipe gallery proposed in the present invention is constructed of steel pipe components. The straight steel pipe components have uniform sizes, a simple manufacturing process, and are easy to install. After the welding operation is completed, it can be disassembled on site. The disassembly process is simple and the storage is convenient, and it can be recycled.

[0020] 3) The detachable operating platform for pipe welding in the pipe gallery tunnel proposed in the present invention is provided with an adjustable self-locking steel belt. The detachable operating platform is fastened to the top of the pipe by adjusting the adjustable self-locking steel belt, and is easy to adjust so that the operating platform structure can adapt to different pipe welding conditions.

[0021] 4) The present invention provides a connecting buckle in the center of the detachable operating platform, and connects the left and right sides of the detachable operating platform through the connecting buckle, thereby improving the strength and safety of the detachable operating platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a cross-sectional view of the safe operating platform;

[0023] Figure 2 It is a top view of the safe operating platform;

[0024] Figure 3 Schematic diagram of the cross-sectional shape of the connecting buckle;

[0025] Figure 4 is a schematic diagram of the processing and finishing of butt welding of pipes with unequal inner wall sizes and unequal thicknesses (where Figure 4a This is the groove processing and finishing diagram for butt-jointed pipes of unequal thickness with inner wall size difference less than or equal to 10mm. Figure 4b This is the groove processing and finishing diagram for butt-jointed pipes of unequal thickness with an inner wall size difference greater than 10mm. Figure 4c Correction diagram for thinning with unequal inner wall dimensions);

[0026] Figure 5 is a schematic diagram of the processing and finishing of butt welding of pipes with unequal outer wall sizes and unequal thicknesses (where Figure 5a This is the groove processing and finishing diagram for butt-jointed pipes of unequal thickness with an outer wall size difference of less than or equal to 10mm. Figure 5b (Diagram showing beveling processing and finishing for butt-jointed pipes of unequal thickness with an outer wall dimension difference greater than 10mm);

[0027] Figure 6 This is a schematic diagram of the processing and finishing of unequal thickness butt welding pipes with unequal inner and outer wall dimensions.

[0028] Description of the accompanying drawings: steel pipe component 1, bolt 2, anti-slip rubber 3, adjustable self-locking steel belt 4, pipe 5, connecting buckle 6. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the following examples. The following examples are provided only to facilitate understanding of the present invention. It should be noted that, without departing from the principles of the present invention, it is possible for a person skilled in the art to make various modifications to the present invention, and such improvements and modifications fall within the scope of the claims of the present invention.

[0030] As an example, Figures 1 to 3 As shown, a detachable operating platform for pipe welding in a shield tunnel corridor comprises a steel pipe member 1, bolts 2, anti-slip rubber 3, an adjustable self-locking steel band 4, and a connecting buckle 6. The steel pipe member 1 comprises a straight steel pipe member and a curved steel pipe member. Both ends of the steel pipe member 1 are flat and have bolt holes at both ends. The two curved steel pipe members are symmetrically arranged in a semicircular arc shape. The two curved steel pipe members forming the semicircular arc shape are arranged as a group. Multiple groups of curved steel pipe members are arranged along the length of the pipe 5 on the upper half of the outer surface of the pipe 5. Anti-slip rubber 3 is provided between the curved steel pipe members and the outer surface of the pipe 5 to increase friction between the curved steel pipe members and the pipe 5, improving safety. An adjustable self-locking steel band 4 is provided between the two ends of each group of curved steel pipe members. The adjustable self-locking steel band 4 is attached to the lower half of the outer surface of the pipe 5 and is used to adjust the tightness of the connection between the detachable operating platform and the pipe 5. This makes it suitable for welding pipes 5 with different degrees of slipperiness and facilitates disassembly.

[0031] Each curved steel pipe member is connected to a straight steel pipe member at both ends, and the two straight steel pipe members at both ends of each curved steel pipe member are connected to each other to form a right angle; the ends of adjacent steel pipe members 1 in the length direction of the pipeline 5 are connected by straight steel pipe members; the sizes of all straight steel pipe members in the steel pipe members 1 are the same. All steel pipe members 1 are connected by bolts 2, and the two straight steel pipe members at the top of the pipeline 5 are connected by connecting clips 6. The connecting clips 6 are made of ABS plastic material, and two steel pipe grooves are symmetrically opened at the bottom. The shapes of the steel pipe grooves and the straight steel pipe members match, and the central angle corresponding to the cross-sectional shape of the steel pipe grooves is greater than 180°, so that more than half of the circumference of the straight steel pipe member is stuck in the connecting clip 6. The connecting clip 6 bears the horizontal tensile force, so that the two straight steel pipe members at the top of the pipeline 5 are connected to each other. A semicircular groove is also provided between the two steel pipe grooves at the bottom of the connecting clip 6 to provide deformation and prevent the connecting clip 6 from breaking under stress.

[0032] The construction method of a detachable operating platform for pipe welding in a shield tunnel corridor based on such an operating platform comprises the following steps:

[0033] Step 1: Install the operating platform: Connect the ends of the steel pipe components 1 with bolts 2. The flat ends of the interconnected steel pipe components 1 overlap, and the bolt holes at the ends are also located on the same axis to form through holes for the bolts 2. The bolts 2 pass through the bolt holes that are connected to each other at the ends of the steel pipe components 1. Both ends of the bolts 2 are tightened with nuts to form a solid frame structure for the steel pipe components 1. Install the adjustable self-locking steel belt 4, set the anti-slip rubber 3 on the outer surface of the pipe 5, and put the steel pipe component 1 and the adjustable self-locking steel belt 4 on the outer surface of the pipe 5.

[0034] Step 2: Install the connecting buckle 6 between the two straight steel pipe members at the top of the pipe 5 to connect the steel pipe members 1 on both sides of the top of the pipe 5; adjust the adjustable self-locking steel belt 4 until the operating platform is fixed on the top of the pipe 5 without sliding;

[0035] Step 3: Weld the pipe 5 in the shield tunnel gallery on the operating platform; specifically, it includes pipe and welding material preparation and inspection - groove inspection and external treatment, assembly and matching, joint inspection, welding, cleaning and marking, appearance inspection, and non-destructive testing;

[0036] All steel pipe welding grooves are V-shaped, and the welds are circular butt welds. The steel pipes used are available in six diameters: DN350, DN400, DN600, DN750, and DN800, and are made of Q235 steel. Arc welding carbon steel electrodes are E4315 and J427, with diameters of ￠3.2mm and ￠4.0mm, respectively. Their quality must comply with the E4315 specifications in the "Carbon Steel Welding Rods" standard, GBT5117-1995. All steel pipes and electrodes must be accompanied by a material quality certificate and factory approval certificate.

[0037] The welding equipment and tools used include: a DC arc welder, a welding rod drying oven, a welding rod heat preservation tube, an angle grinder, a wire brush, a slag hammer, a flat shovel, a hand hammer, a steel stamp, and gas cutting equipment and tools. The welding machine must be equipped with an ammeter and a voltmeter; the drying oven should have temperature and time control devices to ensure accurate metering readings and flexible and reliable adjustment. The welding equipment used in the project must meet the process requirements. The welding machine should have sensitive adjustment and accurate parameter indication. Any abnormalities should be promptly reported to the relevant personnel for repair or replacement. Operations with faulty equipment are prohibited.

[0038] Before formal welding, welding preparation is carried out. This project uses groove welding, and the groove form is V-shaped groove, the groove angle is 55~60°, the blunt edge thickness is 0~3mm, and the gap is 0~3mm. Before the weldments are assembled and before welding, impurities, dirt, and thorns on the welding surface, the groove and its inner and outer surfaces within 20mm should be cleaned, and there should be no defects such as cracks, interlayers, processing damage, slag, etc.

[0039] Before welding, the welding rods must be dried to remove moisture. J427 welding rods should be dried in a baking oven at 350-400°C for at least one hour before use, or according to the manufacturer's recommended baking specifications. After drying, the welding rods should be kept warm in a 100-150°C incubator and removed as needed. Once used, welding rods should be placed in an insulated container and not on the floor to prevent contamination and moisture absorption.

[0040] Welding rods should be baked according to the instructions before use and should not be left exposed.

[0041] When butt welds are assembled for pipes or fittings, the misalignment of the inner walls should not exceed 10% of the thickness of the joint base material and should not be greater than 2mm.

[0042] When butt welding parts of different thickness, the end face of the thin part should be located inside the end face of the thick part. When the misalignment of the inner wall or the outer wall is greater than 3mm, the thickness should be adjusted according to Figure 4 to Figure 6 The processing and finishing diagram of the unequal thickness butt pipe welding is shown in the figure. Figure 4c As shown in the figure, when thinning the thicker side of butt-jointed pipes with unequal inner wall sizes, the length of the thinned section should be 1.5 times the thickness of the thinner pipe.

[0043] The welding construction process mainly includes three important processes: assembly, welding and inspection. The next process can be carried out only after the current process meets the requirements. Otherwise, the construction of the next process is prohibited. During welding construction, relevant professionals strictly control each welding process.

[0044] The number of welding rods to be used at a time shall not exceed the number of welds per weld, and the welding rods shall not be baked more than twice. When receiving welding rods, welders shall carefully check whether the coating of the welding rods is damaged or detached. Welding rods with detached or damaged coatings shall not be used in engineering welding.

[0045] After the joints are aligned and inspected, spot welding is performed on the interfaces. Spot welding is performed by welders and other types of workers are not allowed to do spot welding. The spot welding process and welding materials are the same as those for formal welding. The spot welding length is determined as follows: for pipes with a diameter greater than or equal to 1.6m, it is about 100mm; for pipes with a diameter less than 1.6m, it is about 80mm. Spot welding should be evenly distributed and the length should not exceed 400mm. After spot welding, the quality of each point should be checked. Any that do not meet the requirements should be immediately removed and re-spot welded.

[0046] Arc welding is performed by two people in pairs, in layers. Reasonable welding methods and sequences should be adopted during welding. The arc should not be struck or the test current applied on the surface of the parent material outside the groove. The arc should also be prevented from damaging the parent material. When striking and ending the arc, the reflow method should be used to fill the arc crater to prevent incomplete penetration, craters, and cracks. Short arc welding should be used to facilitate penetration and good fusion. The joints of multi-layer welds should be staggered. The thickness of a single layer of arc welding should not exceed the diameter of the electrode used plus 2 mm. The swing width of a single weld should not exceed 5 times the diameter of the electrode used. Special attention should be paid to the quality of the joints and arc ending during welding. When ending the arc, the molten pool should be filled, and the joints should be staggered, with the staggered amount of each joint greater than 30 mm. For the bottom weld, a ￠2.5 mm electrode should be used, with a higher current, to ensure penetration of the root. Each weld should be completed in one pass whenever possible.

[0047] When welding tack welds, the same welding process as the main project welding should be used. The length, thickness, and spacing of the tack welds should be determined to prevent cracking during the main welding process. When tack welding composite steel, the tack welds should be welded within the groove of the base metal, and the same welding consumables as the base metal should be used. The fixtures used to weld to the base metal should be made of the same material or the same type and type as the base metal, and the welding consumables should be the same or the same type as the base metal. The base metal should not be damaged when the fixtures are removed. After removal, the weld scar should be verified to be free of cracks, and any remaining weld marks should be ground and trimmed flush with the base metal surface. During welding, after each layer, the flux coating and spatter should be cleaned and carefully inspected for defects. If any defects are found, they must be removed before proceeding to the next layer. The joints and arc terminations of multi-layer and multi-pass welds should be staggered by 30-50 mm. Carbon steel and low-alloy steel welding consumables should not be used for welding composite base metal, transition layer welds, or composite welds. When welding the transition layer, it is advisable to use a small welding line energy. Before welding the composite layer, the spatter that falls on the surface of the composite layer groove should be cleaned up.

[0048] After welding is completed, loosen the adjustable self-locking steel belt 4, remove the connecting buckle 6, and separate the steel pipe components 1 on both sides of the top of the connecting pipe 5; finally, remove the bolt 2 to complete the recovery of the steel pipe component 1 and the adjustable self-locking steel belt 4.

Claims

1. A detachable operating platform for pipe welding in a shield tunnel gallery, characterized in that: include: A steel pipe component (1), a bolt (2), an anti-skid rubber (3), an adjustable self-locking steel belt (4) and a connecting buckle (6); the steel pipe component (1) includes a straight steel pipe component and a curved steel pipe component, the two curved steel pipe components are symmetrical in the left and right and are semicircular, and the two curved steel pipe components forming the semicircular are set as a group, and multiple groups of curved steel pipe components are arranged on the upper part of the outer surface of the pipeline (5) along the length direction of the pipeline (5), and the anti-skid rubber (3) is provided between the curved steel pipe components and the outer surface of the pipeline (5); an adjustable self-locking steel belt (4) is provided between the two side ends of each group of curved steel pipe components, and the adjustable self-locking steel belt (4) is in contact with the lower part of the outer surface of the pipeline (5); Each of the two ends of the curved steel pipe member is connected to a straight steel pipe member, and the two straight steel pipe members at the two ends of each curved steel pipe member are connected to each other to form a right angle; the ends of the adjacent steel pipe members (1) in the length direction of the pipeline (5) are connected by straight steel pipe members; all the steel pipe members (1) are connected by bolts (2), and the two straight steel pipe members at the top of the pipeline (5) are connected by connecting buckles (6); The bottom of the connecting buckle (6) is symmetrically provided with two steel pipe grooves, the shapes of the steel pipe grooves and the straight steel pipe component match, and the central angle corresponding to the cross-sectional shape of the steel pipe grooves is greater than 180°; A semicircular groove is further provided between the two steel pipe grooves at the bottom of the connecting buckle (6); both ends of the steel pipe component (1) are flat, and both ends of the steel pipe component (1) are provided with bolt holes.

2. The detachable operating platform for pipe welding in a shield tunnel gallery according to claim 1 is characterized in that: All straight steel pipe members in the steel pipe member (1) have the same size.

3. The detachable operating platform for pipe welding in a shield tunnel gallery according to claim 1 is characterized in that: The connecting buckle (6) is made of ABS plastic.

4. The construction method of a detachable operating platform for pipeline welding in a shield tunnel gallery according to claim 1, characterized in that: The following steps are involved: Step 1: Connect the ends of the steel pipe component (1) with bolts (2), install an adjustable self-locking steel belt (4), set anti-slip rubber (3) on the outer surface of the pipe (5), and cover the steel pipe component (1) and the adjustable self-locking steel belt (4) on the outer surface of the pipe (5); Step 2: Install a connecting buckle (6) between the two straight steel pipe components at the top of the pipeline (5), and connect the connecting buckle (6) to the steel pipe components (1) on both sides of the top of the pipeline (5); adjust the adjustable self-locking steel belt (4) to fix the detachable operating platform on the top of the pipeline (5); Step 3: welding the pipes in the shield tunnel corridor on the detachable operating platform, adjusting the adjustable self-locking steel belt (4) after welding, disassembling the detachable operating platform, and recovering the steel pipe component (1) and the adjustable self-locking steel belt (4).

5. The construction method of a detachable operating platform for pipeline welding in a shield tunnel according to claim 4 is characterized in that: In step 1, the ends of the interconnected steel pipe members (1) overlap, the bolts (2) pass through the bolt holes of the interconnected ends of the steel pipe members (1), and both ends of the bolts (2) are tightened by nuts.

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