Underwater gap filling construction method for steel sheet pile ring beam

Abstract

The invention discloses a steel sheet pile ring beam underwater gap filling construction method which comprises the following steps: after steel sheet piles are inserted and driven, sequentially carrying out ring beam gap filling construction on a first ring beam structure, a second ring beam structure, a third ring beam structure and a fourth ring beam structure. The construction method is suitable for underwater gap filling construction of deepwater steel sheet pile ring beams, gap filling treatment of gaps between the first ring beam and the steel sheet pile and gaps between the second ring beam and the steel sheet pile is completed in the mode that operation is conducted while water pumping is conducted, gap filling treatment of gaps between the third ring beam and the steel sheet pile and gaps between the fourth ring beam and the steel sheet pile is completed in the mode of underwater operation, and divers conduct underwater operation; the prefabricated concrete bag is stuffed into the gap between the steel sheet pile and the third ring beam and is hooked and fixed by the reinforcing steel bar, so that the gap between the steel sheet pile and the ring beam is effectively filled, the steel sheet pile and the ring beam are tightly attached, and water and soil pressure can be jointly resisted, and deformation of the steel sheet pile is reduced. And for the gap between the steel sheet piles, a proper mode is correspondingly adopted for gap plugging and leaking stoppage.

Description

Technical Field

[0001] The invention relates to the technical field of cofferdam construction, in particular to an underwater seam plugging construction method for a steel sheet pile ring beam. Background Art

[0002] Cofferdam construction is a common construction method used in bridge engineering to solve the problem of bridge abutment construction. The key to cofferdam construction is water stopping and anti-seepage. In the actual construction process, even the inspected steel sheet piles may have loose locking and curling during the installation process, resulting in water seepage. For this, the method of plugging is usually used to solve this water seepage problem. On the other hand, the ring beam structure is the main structure on the inside of the cofferdam to provide support for the steel sheet piles. During the steel sheet pile insertion process, a large gap may be formed between the steel sheet piles and the ring beam, resulting in the steel sheet piles and the ring beam not being tightly attached, unable to effectively resist the water and soil pressure together, and easily causing the steel sheet piles to be unevenly stressed, deformed, or even damaged. For the construction of deep-water steel sheet pile cofferdams, it is necessary to set up multiple ring beam structures. How to achieve the plugging treatment between the steel sheet piles and the multiple ring beams to ensure that the steel sheet piles and the ring beams are tightly attached and can resist the water and soil pressure together is crucial for the construction of deep-water steel sheet piles. To this end, it is necessary to study and design an underwater plugging construction method that meets the construction requirements of such deep-water steel sheet pile cofferdams. Summary of the invention

[0003] In view of the above problems, the present invention provides a method for underwater seam plugging construction of a steel sheet pile ring beam, comprising the following steps:

[0004] S1, after the steel sheet piles are driven in, the first ring beam, the second ring beam, the third ring beam and the fourth ring beam are placed in the cofferdam, and the ring beam caulking construction is started on the first ring beam structure, the second ring beam structure, the third ring beam structure and the fourth ring beam structure in sequence;

[0005] S2, installing the first ring beam corbel, fixing the first ring beam structure support at the designed elevation position of the first ring beam structure, and performing a caulking treatment on the gap between the steel sheet pile and the first ring beam structure;

[0006] S3, pumping water in the cofferdam to a position lower than the design elevation of the second ring beam structure, installing the second ring beam corbel, supporting and fixing the second ring beam structure at the design elevation of the second ring beam structure, and performing a caulking treatment between the steel sheet pile and the second ring beam structure;

[0007] S4, backwater sand pumping, start pumping sand after the backwater in the cofferdam, and pump sand to a position lower than the design elevation of the third ring beam structure;

[0008] S5, performing a secondary lowering operation on the third ring beam and the fourth ring beam;

[0009] S6, pump water out of the cofferdam, install the third ring beam corbel, lower the third ring beam to the designed elevation, and then perform underwater caulking between the steel sheet pile and the third ring beam. Divers work underwater to fill the prefabricated concrete bags into the gap between the steel sheet pile and the third ring beam, and fix them with steel bars;

[0010] S7, backwater excavation, excavation work after backwater in the cofferdam;

[0011] S8, lower the fourth ring beam for the second time, install the fourth ring beam corbel underwater, lower the fourth ring beam to the designed elevation and perform underwater caulking treatment, and divers work underwater to fill the prefabricated concrete bags into the gap between the steel sheet piles and the fourth ring beam, and fix them with steel bar hooks.

[0012] As a further explanation of the present invention, the method for sealing the seams of the first ring beam structure and the second ring beam structure is:

[0013] S201, first assemble the formwork and fix the threaded steel bars according to the site dimensions;

[0014] S202, tying the ring beam and the steel sheet piles in a clockwise order;

[0015] S203, pouring concrete into the gaps.

[0016] Furthermore, the underwater seam plugging treatment method for the third ring beam structure and the fourth ring beam structure is:

[0017] S801, prefabricate and process concrete bags in advance;

[0018] S802, after the third ring beam corbel or the fourth ring beam corbel is welded, the third ring beam or the fourth ring beam is hung by a winch and slowly lowered to its designed elevation position, and supported by the corresponding third ring beam corbel or the fourth ring beam corbel;

[0019] S803, divers perform underwater operations to seal gaps between the steel sheet piles and the third ring beam structure or the fourth ring beam structure using the concrete bags.

[0020] Furthermore, the first ring beam corbel, the second ring beam corbel, the third ring beam corbel and the fourth ring beam corbel all include short corbels and long corbels, and I45 I-beams are used as corbel profiles.

[0021] Furthermore, in the step S4, the water levels inside and outside the cofferdam are kept consistent during the sand pumping process.

[0022] Furthermore, in step S7, the water level inside and outside the cofferdam is kept consistent during the excavation operation.

[0023] Furthermore, during the pumping operation in the cofferdam, if there is water leakage from the steel sheet piles, the gaps between the steel sheet piles are plugged.

[0024] Furthermore, the plugging operation includes:

[0025] S901, for small gaps, use slats, cotton wool or hemp wool to plug the gaps between the steel sheet piles to stop leakage;

[0026] S202: For wider gaps, use hemp rope mixed with butter to plug the gaps and stop leakage;

[0027] S203, after mixing graded coarse sand, sawdust and cement, a plugging duct is set on the outside of the steel sheet pile above the leak; the plugging mixture is lowered through the plugging duct to the top where the leak needs to be plugged, and the coarse sand, sawdust, cement, etc. are sucked into the gaps in the locking mouths of the leaking steel sheet piles to fill them tightly and plug the gaps.

[0028] Furthermore, during the pumping operation inside the cofferdam, if the cofferdam is severely deformed, pumping should be stopped and the cause should be found out.

[0029] Beneficial effects of the present invention:

[0030] The construction method of the present invention is suitable for underwater plugging of deepwater steel sheet pile ring beams. The plugging of the gaps between the first and second ring beams and the steel sheet piles is completed by pumping water while working, and the plugging of the gaps between the third and fourth ring beams and the steel sheet piles is completed by underwater working, so as to effectively fill the gaps between the steel sheet piles and the ring beams, so that the steel sheet piles and the ring beams are tightly attached to each other, and can jointly resist the water and soil pressure, and basically ensure that the steel sheet piles are not deformed. For the gaps between the steel sheet piles, a suitable method is used to plug the gaps and stop leakage, so as to achieve water stopping and anti-seepage of the cofferdam. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the arrangement of a steel sheet pile cofferdam and a ring beam according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the arrangement of long and short corbels according to an embodiment of the present invention;

[0033] Figure 3 It is a schematic diagram of the sand pumping principle of an embodiment of the present invention.

[0034] Drawing reference numerals: steel sheet pile 1 , first ring beam structure 2 , second ring beam structure 3 , third ring beam structure 4 , fourth ring beam structure 5 , corbel 6 , short corbel 601 , long corbel 602 , casing 7 . DETAILED DESCRIPTION

[0035] Example:

[0036] The following is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0037] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0038] See attached Figure 1 As shown, a method for underwater seam plugging construction of a steel sheet pile ring beam of the present invention comprises the following steps:

[0039] S1, after the steel sheet piles are driven in, the first ring beam, the second ring beam, the third ring beam and the fourth ring beam are placed in the cofferdam, and the ring beam caulking construction is started on the first ring beam structure, the second ring beam structure, the third ring beam structure and the fourth ring beam structure in sequence.

[0040] S2, installing the first ring beam corbel, fixing the first ring beam structure support at the designed elevation position of the first ring beam structure, and performing a sealing treatment between the steel sheet pile and the first ring beam structure, wherein the specific sealing treatment method comprises the following steps:

[0041] S201, first assemble the formwork and fix the threaded steel bars according to the site dimensions;

[0042] S202, tying the ring beam and the steel sheet piles in a clockwise order;

[0043] S203, pouring concrete into the gaps.

[0044] After the caulking treatment, the gap between the steel sheet pile and the first ring beam formed due to the insertion of the steel sheet pile is effectively filled, so that the steel sheet pile and the ring beam are tightly attached and can jointly resist water and soil pressure.

[0045] As shown in the attached drawings, the first ring beam corbel of this embodiment includes a short corbel and a long corbel, and specifically uses I45 I-beam as the corbel profile, which is welded and fixed on the steel sheet pile of the cofferdam at intervals to prevent the first ring beam from falling down due to its own weight, and ensure that the steel sheet pile and the ring beam are jointly stressed to resist water and soil pressure. During actual installation, try to align the support rod of the first ring beam corbel with the center of gravity of the ring beam to ensure its functional role.

[0046] S3, pump water in the cofferdam to a position lower than the design elevation of the second ring beam structure, install the second ring beam corbel, fix the second ring beam structure support at the design elevation of the second ring beam structure, and caulk the gap between the steel sheet pile and the second ring beam structure. This pumping is also the first pumping of the cofferdam, which is for the subsequent installation of the corbels and caulk of the second ring beam. For example, in this embodiment, as shown in the attached drawings, the design elevation of the second ring beam structure is +7.5m. In order to be able to install the corbels and caulk the gaps normally after pumping, the waterline in the cofferdam during this pumping is at an elevation of +6m. The installation of the second ring beam corbel and the caulk of the second ring beam structure after pumping are the same as the caulk of the first ring beam corbel and the first ring beam structure, so they will not be repeated.

[0047] S4, backwater sand pumping, after the water in the cofferdam is backed up, sand pumping begins, and the sand is pumped to a position lower than the design elevation of the third ring beam structure. The purpose of this sand pumping is to enable the third ring beam to be lowered and installed to its design elevation. For example, in this embodiment, as shown in the attached figure, the design elevation of the third ring beam structure is +4.5m. Therefore, during the actual construction process, the backwater in the cofferdam is pumped to an elevation of +2.5m, and the elevation of the sand pumping is controlled from +2.5m to +2.0m. Long-arm excavator + high-pressure water pump + grab machine can be used to excavate sand in the cofferdam. The excavated sand and gravel and the sand and gravel dug up by the grab bucket are placed in a slag box, and then after the slag box is full, it is transported to a slag disposal point 14KM away by a transport vehicle. For the sand that cannot be excavated, a high-pressure water pump is used to pump the sand and discharge it to the ship. The specific principle is shown in the figure below. During the sand pumping process, the connecting pipe valve is opened to keep the water level inside and outside the cofferdam consistent.

[0048] S5, the third ring beam and the fourth ring beam are lowered for a second time, so that the third ring beam is lowered to the designed elevation position of the third ring beam structure, and the fourth ring beam is lowered to the ground sand layer. In the actual construction process, after the sand in the cofferdam is pumped to an elevation of +2.5m, the fourth ring beam is lowered first, and then the third ring beam is lowered to an elevation of +4.5m.

[0049] The steps for lowering the fourth ring beam include: Step 1: Divers fix the lowering hook; Step 2: Raise it by about 10cm through the winch, unweld the hanging point on the steel casing, and then lower the ring beam to the sand pumping elevation; Step 3: After the fourth ring beam lands on the sand surface, the diver releases the lowering hook. For the third ring beam, the same method is used to lower it to the elevation of +4.5m, but when it is lowered to the elevation of +4.5m, the hook is not released, and the hook is released after the water is pumped out and the third ring beam corbel is installed.

[0050] S6, pump water in the cofferdam to a position lower than the design elevation of the third ring beam structure, install the third ring beam bracket, fix the third ring beam structure support at the design elevation of the third ring beam structure, and perform underwater caulking treatment between the steel sheet pile and the third ring beam structure. This pumping is the second pumping of the cofferdam, and the purpose is to install the third ring beam bracket and caulking the gap between the third ring beam and the steel sheet pile. The pumping process is the same as the first pumping process, except that the waterline position of this pumping is at an elevation of +4m. After pumping, the third ring beam bracket is installed in time. After the third ring beam bracket is installed, the hook of the winch is released, and then the gap between the third ring beam structure and the steel sheet pile is caulked underwater. Divers work underwater to stuff the prefabricated concrete bags into the gap between the steel sheet pile and the third ring beam, and use steel bars to hook and fix them.

[0051] S7, backwater excavation, excavation work is carried out after the backwater in the cofferdam, and the excavation is carried out to a position lower than the design elevation of the fourth ring beam structure. After the third ring beam is installed and the fourth ring beam is suspended and stabilized, the backwater in the cofferdam is returned, and excavation is continued to a position with an elevation of -0.74m, and the fourth inner ring beam is lowered, and preparations are made to lower the fourth ring beam. The specific construction steps include:

[0052] Step 1: Open the connecting valve and return water to the inside of the steel sheet pile as high as possible above the water surface on the outside.

[0053] Step 2: Continue to use high-pressure air pump + long-arm excavator + long-arm grab to continue excavating to an elevation of -0.74m.

[0054] When digging sand in the foundation pit, it is necessary to check whether the flatness of the bottom of the foundation pit and the siltation around the steel sheet piles meet the technical requirements:

[0055] 1) Check whether the dead corners around the steel sheet piles and at each corner are clean;

[0056] 2) During the excavation process, the bottom elevation of the foundation pit is measured at the pre-arranged measuring points with a measuring rope to ensure that there is no excessive over-excavation or under-excavation of the foundation pit;

[0057] 3) Ensure that the water level inside and outside the cofferdam is level during the excavation of the foundation pit, observe the deformation of the steel sheet piles and the water level inside and outside the cofferdam. If the steel sheet piles are found to be deformed too much, the excavation of the foundation pit should be stopped immediately, and construction can only be continued after the problem is solved.

[0058] S8, install the fourth ring beam corbel, lower the fourth ring beam and support and fix it at the designed elevation position of the fourth ring beam structure, and perform underwater caulking treatment between the steel sheet piles and the fourth ring beam structure. In this embodiment, when the underwater excavation reaches the elevation position of -0.74m, the fourth ring beam is lowered underwater to ensure that the fourth ring beam is lowered to the designed elevation position. In the actual construction process, 4 winches are used to cooperate in lowering the ring beam. After the lowering is completed, the fourth ring beam is hung on the steel sheet piles, and then the divers use concrete bags underwater to perform underwater caulking construction. The specific process includes:

[0059] Step 1: When excavation reaches the -0.74m position, prepare the concrete bags in advance.

[0060] Step 2: After the fourth ring beam corbel is welded, four winches are used to hang the fourth ring beam and then slowly lower it to its designed elevation.

[0061] Step 3: Have divers fill the gaps between the steel sheet piles and the fourth ring beam with concrete bags.

[0062] The construction method of the present invention is suitable for underwater seam plugging construction of deep-water steel sheet pile ring beams. The seam plugging treatment of the gaps between the first and second ring beams and the steel sheet piles is completed by pumping water while working, and the seam plugging treatment of the gaps between the third and fourth ring beams and the steel sheet piles is completed by underwater operations, so as to achieve the effect of effectively filling the gaps between the steel sheet piles and the ring beams, so that the steel sheet piles and the ring beams are tightly attached to each other and can jointly resist water and soil pressure.

[0063] On the other hand, there may be gaps between the steel sheet piles, which may cause the cofferdam to leak. Therefore, during the pumping operation in the cofferdam, if there is a steel sheet pile leak, the gaps between the steel sheet piles should be plugged. For the gaps between the steel sheet piles, appropriate methods should be used to plug the gaps and achieve water-stopping and anti-seepage of the cofferdam. During the pumping operation in the cofferdam, if there is a serious deformation of the cofferdam, stop pumping and find out the cause.

[0064] Specifically, for the gaps between the steel sheet piles, if serious water leakage is found during the pumping process, the part below the riverbed in the cofferdam is sealed with glass glue, plugging agent such as Leak-proof King on the inside. The use of Leak-proof King: First, chisel the leaking point or leaking seam into a vertical trumpet shape with a large bottom and a small top, and clean up the debris; put one kilogram of quick plugging agent into the pot, add 0.3-0.33 kilograms of water, and quickly mix it into a slurry. When it is below 10℃, stir it with 30-40℃ water; put the mixed plugging cement on your hand, and when you feel that the cement is hot and slightly hard, quickly press it in the direction of the leak, and continue for a certain period of time before letting go. Generally, the water can be blocked within a few minutes; after blocking the water, in order to ensure the surface is flat, the surface is then plastered with expansion mortar prepared with expansion cement. When the gap is large, it can be blocked by welding steel plates or plugging wooden tips.

[0065] At the outer leakage position above the cofferdam riverbed, the following measures can be taken:

[0066] S901, for small gaps, use slats, cotton wool or hemp wool to plug the gaps between the steel sheet piles to stop leakage;

[0067] S202: For wider gaps, use hemp rope mixed with butter to plug the gaps and stop leakage;

[0068] S203, after mixing graded coarse sand, sawdust and cement, a plugging duct is set on the outside of the steel sheet pile above the leak; the plugging mixture is lowered through the plugging duct to the top where the leak needs to be plugged, and the coarse sand, sawdust, cement, etc. are sucked into the gaps in the locking mouths of the leaking steel sheet piles to fill them tightly and plug the gaps.

[0069] The above only describes the preferred embodiments of the present invention, but it cannot be understood as limiting the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to be changed. In short, all changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.

Claims

1. A method for underwater seam plugging construction of a steel sheet pile ring beam, characterized in that: The following steps are involved: S1, after the steel sheet piles are driven in, the first ring beam, the second ring beam, the third ring beam and the fourth ring beam are placed in the cofferdam, and the ring beam caulking construction is started on the first ring beam structure, the second ring beam structure, the third ring beam structure and the fourth ring beam structure in sequence; S2, installing the first ring beam corbel, fixing the first ring beam structure support at the designed elevation position of the first ring beam structure, and performing a caulking treatment on the gap between the steel sheet pile and the first ring beam structure; S3, pumping water in the cofferdam to a position lower than the design elevation of the second ring beam structure, installing the second ring beam corbel, supporting and fixing the second ring beam structure at the design elevation of the second ring beam structure, and performing a caulking treatment between the steel sheet pile and the second ring beam structure; S4, backwater sand pumping, start pumping sand after the backwater in the cofferdam, and pump sand to a position lower than the design elevation of the third ring beam structure; S5, performing a secondary lowering operation on the third ring beam and the fourth ring beam; S6, pump water out of the cofferdam, install the third ring beam corbel, lower the third ring beam to the designed elevation, and then perform underwater caulking between the steel sheet pile and the third ring beam. Divers work underwater to fill the prefabricated concrete bags into the gap between the steel sheet pile and the third ring beam, and fix them with steel bars; S7, backwater excavation, excavation work after backwater in the cofferdam; S8, lower the fourth ring beam for the second time, install the fourth ring beam corbel underwater, lower the fourth ring beam to the designed elevation and perform underwater caulking treatment, and divers work underwater to fill the prefabricated concrete bags into the gap between the steel sheet piles and the fourth ring beam, and fix them with steel bar hooks.

2. The underwater seam plugging construction method of the steel sheet pile ring beam according to claim 1 is characterized by: The method for sealing the seams of the first ring beam structure and the second ring beam structure is as follows: S201, first assemble the formwork and fix the threaded steel bars according to the site dimensions; S202, tying the ring beam and the steel sheet piles in a clockwise order; S203, pouring concrete into the gaps.

3. The underwater seam plugging construction method of the steel sheet pile ring beam according to claim 1 is characterized by: The underwater seam plugging treatment method for the third ring beam structure and the fourth ring beam structure is: S801, prefabricate and process concrete bags in advance; S802, after the third ring beam corbel or the fourth ring beam corbel is welded, the third ring beam or the fourth ring beam is hung by a winch and slowly lowered to its designed elevation position, and supported by the corresponding third ring beam corbel or the fourth ring beam corbel; S803, divers perform underwater operations to seal gaps between the steel sheet piles and the third ring beam structure or the fourth ring beam structure using the concrete bags.

4. The underwater seam plugging construction method of the steel sheet pile ring beam according to claim 1 is characterized by: The first ring beam corbel, the second ring beam corbel, the third ring beam corbel and the fourth ring beam corbel all include short corbels and long corbels, and I45 I-beams are used as corbel profiles.

5. The underwater seam plugging construction method of the steel sheet pile ring beam according to claim 1 is characterized by: In step S4, the water levels inside and outside the cofferdam are kept consistent during the sand pumping process.

6. The underwater seam plugging construction method of the steel sheet pile ring beam according to claim 1 is characterized by: In step S7, the water level inside and outside the cofferdam is kept consistent during the excavation operation.

7. The underwater seam plugging construction method of the steel sheet pile ring beam according to claim 1 is characterized by: During the pumping operation in the cofferdam, if there is leakage from the steel sheet piles, the gaps between the steel sheet piles should be plugged.

8. The underwater seam plugging construction method of the steel sheet pile ring beam according to claim 7 is characterized by: The plugging operation includes: S901, for small gaps, use slats, cotton wool or hemp wool to plug the gaps between the steel sheet piles to stop leakage; S202: For wider gaps, use hemp rope mixed with butter to plug the gaps and stop leakage; S203, after mixing graded coarse sand, sawdust and cement, a plugging duct is set on the outside of the steel sheet pile above the leak; the plugging mixture is lowered through the plugging duct to the top where the leak needs to be plugged, and the coarse sand, sawdust, cement, etc. are sucked into the gaps in the locking mouths of the leaking steel sheet piles to fill them tightly and plug the gaps.

9. The underwater seam plugging construction method of the steel sheet pile ring beam according to claim 1 is characterized by: During the pumping operation inside the cofferdam, if there is serious deformation of the cofferdam, stop pumping and find out the cause.

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