Demounting construction method for lock catch steel pipe pile of deepwater cofferdam

Abstract

The invention discloses a deepwater cofferdam lock catch steel pipe pile dismantling construction method, and belongs to the field of deepwater cofferdam lock catch steel pipe pile dismantling construction. 2, cleaning a riverbed; step 3, cutting a lock mouth; 4, reinforcing and connecting the steel pipe piles; fifthly, the inner supports and the surrounding purlins are dismantled; and sixthly, the steel pipe pile is cut and pulled out. The steel pipe piles are temporarily reinforced and connected, so that the safety of operators is ensured, and the risk that the steel pipe piles are unstable in the dismantling process is reduced; the cutting surface is controlled to be 15cm above the bearing platform surface, so that the stability of the bearing platform structure is effectively ensured, and the influence caused by long-time scouring is reduced; the underwater cutting method is simple in equipment, flexible in using method, wide in adaptability, fast in effect, safe and reliable.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of deep water cofferdam lock steel pipe pile dismantling construction, and particularly relates to a deep water cofferdam lock steel pipe pile dismantling construction method. BACKGROUND

[0002] The Huanghe (Yellow River) super-large bridge in Lengkou is located in the territory of Lengkou County, Bayannur City, and Balagong Town, Hangjin Banner, Ordos City, Inner Mongolia Autonomous Region. The main bridge adopts a (102+4*178+102) m steel and concrete hybrid continuous beam, and the main beam is composed of a prestressed concrete box beam and a steel and concrete combined section. The 57# to 63# piers are located in the main channel of the Huanghe River, and the geology mainly includes alluvial clay, silty clay, silt, fine sand, medium sand, coarse gravel sand, fine round gravel, and coarse round gravel soil. According to the geological division, the foundation construction is protected by a lock steel cofferdam. The steel pipe used in the cofferdam is Φ820*14 mm, the lock is of a C-T type, the inside is supported in multiple levels by a section steel and a fabricated steel pipe according to the height of the cofferdam, the cofferdam is excavated to the design elevation, and then the bottom is sealed by using C30 concrete. After the main structure construction is completed, the cofferdam is dismantled in sequence.

[0003] The longest lock steel pipe pile is 26 m, and the longest soil depth is about 23 m. It is particularly important to determine the steel pipe pile dismantling elevation and to smoothly and safely dismantle the steel pipe pile. SUMMARY

[0004] The purpose of the present application is to provide a deep water cofferdam lock steel pipe pile dismantling construction method, which solves the problems of how to determine the steel pipe pile dismantling elevation and how to smoothly and safely dismantle the steel pipe pile.

[0005] To solve the above technical problems, the present application adopts the following technical scheme:

[0006] The present application is a deep water cofferdam lock steel pipe pile dismantling construction method, which comprises the following steps:

[0007] Step one, site preparation: the riverbed elevation is measured on site, and a measurement record table is filled in. The sand soil cleaning height of the riverbed outside the cofferdam is accurately calculated;

[0008] Step two, riverbed cleaning: the riverbed outside the lock steel cofferdam is cleaned downward by using a long-arm excavator. The cleaning is performed to a certain distance upward from the pile cap surface. The local cleaning is performed by using a diver to clean underwater by using a high-pressure water gun to ensure the cutting space;

[0009] Step three, lock cutting: the lock between the steel pipe piles is cut underwater, and the cutting elevation line starts from the pile cap surface;

[0010] Step four, steel pipe pile reinforcement and connection: the steel pipe piles outside the lock steel cofferdam are reinforced and connected one by one to form an integral whole, and the underwater cutting is absolutely safe.

[0011] Step five, inner support and coaming removal: after the reinforcement is completed, the water in the cofferdam is pumped out below the second layer of coaming, and the inner support and steel coaming are removed; after the inner support and steel coaming are removed, the water is returned to the normal water level, and finally the first layer of inner support and steel coaming is removed;

[0012] Step six, steel pipe pile cutting and removal: after the cofferdam support and steel coaming are removed, the steel pipe pile is cut; before the steel pipe pile is cut, the steel pipe is filled with water, and the cutting method is underwater cutting in the pipe by artificial; the cutting height is a suitable height above the pile cap surface; after the steel pipe pile is cut along the cutting line according to a certain order, the reinforcement structure made in step four is cut, the steel pipe pile is pulled out by a pulling machine, and finally transported to the material field.

[0013] Further, in step two, the outer side of the lock cofferdam is cleaned down to 0.5-1m above the pile cap surface.

[0014] Further, in step three, during the cutting process, the lock cutting line is as level as possible.

[0015] Further, in step four, the steel pipe pile is reinforced and connected at the top and a suitable distance below.

[0016] Further, in step four, the steel pipe pile is reinforced and connected at the top and 1-1.5m below.

[0017] Further, in step four, the steel pipe pile is reinforced and connected by channel steel and I-beam.

[0018] Further, in step six, the cutting height of the steel pipe pile is 10-20cm above the pile cap surface.

[0019] Further, in step six, the diver enters the steel pipe and cuts along the steel pipe wall using underwater oxygen-arc cutting, and near the remaining arc surface of the cofferdam inner side, the diver gets out of the water and cuts the remaining arc surface outside the pipe.

[0020] Further, in step six, the remaining arc surface length when the diver cuts in the steel pipe is 20-30cm.

[0021] Further, in step six, the cutting sequence of the steel pipe pile is cofferdam downstream→cofferdam right side→cofferdam left side→cofferdam upstream.

[0022] Compared with the prior art, the beneficial technical effects of the present application are:

[0023] The steel pipe pile is temporarily reinforced and connected in the application, the safety of the operator is ensured, and the risk of instability of the steel pipe pile in the demolition process is reduced; the cutting surface is controlled to be 15 cm above the bearing platform surface, the stability of the bearing platform structure is effectively ensured, and the influence caused by long-time scouring is reduced; the underwater cutting method is simple in equipment, flexible in use method, wide in adaptability, fast in efficacy, safe and reliable. BRIEF DESCRIPTION OF DRAWINGS

[0024] The application will be further described below in combination with the description of the drawings.

[0025] Figure 1 The process flow chart of the construction method of the application is shown in the figure;

[0026] Figure 2 The first layer plan layout of the steel pipe pile cofferdam of the application is shown in the figure;

[0027] Figure 3 The elevation view of the steel pipe pile cofferdam of the application is shown in the figure;

[0028] Figure 4 The Figure 3 enlarged view of position A in the figure;

[0029] Figure 5 The underwater cutting sequence diagram of the steel pipe pile of the application is shown in the figure.

[0030] Explanation of reference signs: 1, steel pipe pile; 2, channel steel; 3, I-beam; 4, bearing platform. DETAILED DESCRIPTION

[0031] As Figures 1-5 shown in the figure, a deep water cofferdam lock buckle steel pipe pile demolition construction method comprises the following steps:

[0032] Step one, site preparation: measure the riverbed elevation on site, fill in the measurement record table, and accurately calculate the cleaning height of the sand soil on the riverbed surface outside the cofferdam;

[0033] Step two, riverbed cleaning: the height difference between the riverbed surface and the bearing platform surface is about 2-4 m, the geology is mainly fine sand layer, the long-arm excavator is used to clean the riverbed surface outside the lock cofferdam downward, the cleaning is performed to the position 1 m above the bearing platform surface, the local cleaning is not in place, the diver uses the high-pressure water gun to clean underwater, and the cutting space is ensured;

[0034] Step three, lock cutting: the lock between the steel pipe piles is cut underwater, and the cutting line is cut from the bearing platform surface; the lock cutting line is ensured to be located on the same horizontal line as much as possible during the cutting process;

[0035] Step four, steel pipe pile reinforcement connection: to ensure that the steel pipe pile is cut in an absolutely safe state, the top of the steel pipe pile outside the lock steel cofferdam and 1.5 m below are reinforced and connected by 20 channel steel and 20 I-beams, which are connected as a whole to ensure the absolute safety of underwater cutting; (in this step, all I-beams can also be used to reinforce and connect the steel pipe pile)

[0036] Step five, inner support and surrounding purlin removal: after the reinforcement is completed, the water in the cofferdam is pumped out to below the second layer of surrounding purlins, and the inner support and steel surrounding purlins are removed; after the inner support and steel surrounding purlins are removed, the water is returned to the normal water level, and finally the first layer of inner support and steel surrounding purlins are removed;

[0037] Step six, steel pipe pile cutting and removal: after the cofferdam inner support and steel surrounding purlins are removed, the steel pipe pile is cut; before the steel pipe pile is cut, the steel pipe is filled with water, and the cutting method is artificial underwater cutting in the pipe; the cutting height is 15 cm above the pile cap surface; the diver enters the steel pipe and cuts along the steel pipe wall using underwater oxygen-arc cutting, leaving a remaining arc length of about 30 cm (close to the inner side of the cofferdam); the diver gets out of the water and cuts the remaining 30 cm outside the pipe; after the steel pipe pile is completely cut along the cutting line, the two reinforced channel steels and I-beams are cut off using plasma cutting, and the steel pipe pile is pulled out using a pulling machine and transported to the material field on a flat car.

[0038] The cutting sequence is: cofferdam downstream → cofferdam right side → cofferdam left side → cofferdam upstream; specifically, as shown in Figure 5 , the cofferdam downstream is removed from left to right, the cofferdam right side is removed from bottom to top, the cofferdam left side is removed from bottom to top, and the cofferdam upstream is removed from right to left.

[0039] The present application is particularly suitable for the lock steel pipe pile removal operation of the Huanghe River super-large bridge in Lengkou; the purpose of the present application is to use a long-arm excavator and a high-pressure water gun to lower the riverbed surface to 1 m above the pile cap surface outside the lock steel cofferdam, and to connect the steel pipe pile as a whole by using two I-beams at the top of the steel pipe pile outside the cofferdam and 1.5 m below; the inner support and surrounding purlins in the lock steel cofferdam are removed from bottom to top, the lock is completely cut off at the design elevation of the pile cap surface using underwater cutting in the cofferdam; the steel pipe pile is cut off and pulled out one by one using artificial underwater cutting in the pipe.

[0040] The above-described embodiments are only preferred modes of the present application and do not limit the scope of the present application; various modifications and improvements to the technical solutions of the present application made by those skilled in the art without departing from the design spirit of the present application shall fall within the protection scope determined by the claims of the present application.

Claims

1. A method for dismantling interlocking steel pipe piles in deep-water cofferdams, characterized in that: Includes the following steps: Step 1, On-site preparation: Measure the riverbed elevation on-site and fill in the measurement record form, accurately calculate the height of sand and soil clearing from the riverbed outside the cofferdam; Step 2, Riverbed clearing: Use a long-arm excavator to clear the riverbed surface on the outside of the lock-lock steel cofferdam downwards, clearing it to a certain distance above the pier surface. For areas that cannot be cleared, divers will use high-pressure water guns to clear them underwater, ensuring sufficient cutting space. Step 3, Interlock Cutting: The interlocks between steel pipe piles are cut underwater, and the cut-off elevation line is cut starting from the pile cap surface; Step 4, Steel Pipe Pile Reinforcement and Connection: Reinforce and connect each steel pipe pile on the outside of the lock-joint steel cofferdam into a whole to ensure absolute safety during underwater cutting; Step 5, Removal of inner supports and walers: After reinforcement is completed, pump the water in the cofferdam to below the second layer of walers, and remove the inner supports and steel walers; after the removal of the inner supports and steel walers, return the water to the normal water level, and finally remove the first layer of inner supports and steel walers. Step Six, Steel Pipe Pile Cutting and Removal: After the internal supports and steel walers of the cofferdam are removed, the steel pipe piles are cut. Before cutting the steel pipe piles, the steel pipes are filled with water. The cutting method is manual underwater cutting inside the pipe. The cutting elevation is a suitable height above the foundation surface. After all the steel pipe piles are cut off along the cutting line in a certain order, the reinforcement structure made in Step Four is cut off. The steel pipe piles are then pulled out using a driving and pulling machine and finally transported to the material yard.

2. The method for dismantling interlocking steel pipe piles in deep-water cofferdams according to claim 1, characterized in that: In step two, the riverbed surface on the outer side of the lock-type steel cofferdam is cleared downwards to a point 0.5 to 1m above the pier surface.

3. The method for dismantling interlocking steel pipe piles in deep-water cofferdams according to claim 1, characterized in that: In step three, during the cutting process, it is important to ensure that the cut lines of the lock are on the same horizontal line as much as possible.

4. The method for dismantling interlocking steel pipe piles in deep-water cofferdams according to claim 1, characterized in that: In step four, reinforcement connections are made at a suitable distance from the top of the steel pipe pile.

5. The method for dismantling deep-water cofferdam interlocking steel pipe piles according to claim 4, characterized in that: In step four, reinforcement connections are made at the top of the steel pipe pile and 1 to 1.5 meters below it.

6. The method for dismantling interlocking steel pipe piles in deep-water cofferdams according to claim 4, characterized in that: In step four, channel steel and I-beams are used to reinforce and connect the steel pipe piles one by one.

7. The method for dismantling interlocking steel pipe piles in deep-water cofferdams according to claim 1, characterized in that: In step six, the steel pipe pile is cut off at an elevation of 10-20cm above the pile cap surface.

8. The method for dismantling interlocking steel pipe piles in deep-water cofferdams according to claim 1, characterized in that: In step six, the diver enters the steel pipe and uses underwater oxygen-arc cutting to cut around the steel pipe wall. A certain length of arc surface remains near the inside of the cofferdam. The diver then comes ashore and cuts the remaining arc surface from the outside of the pipe from the inside of the cofferdam.

9. The method for dismantling interlocking steel pipe piles in deep-water cofferdams according to claim 8, characterized in that: In step six, the remaining arc length when the diver cuts inside the steel pipe is 20-30cm.

10. The method for dismantling interlocking steel pipe piles in deep-water cofferdams according to claim 1, characterized in that: In step six, the cutting sequence of the steel pipe piles is: downstream of the cofferdam → right side of the cofferdam → left side of the cofferdam → upstream of the cofferdam.

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