Dock entrance cofferdam structure, dry dock system and construction method

Abstract

The invention relates to the technical field of dry dock construction, in particular to a dock entrance cofferdam structure, a dry dock system and a construction method.The cofferdam structure comprises an earth rock cofferdam arranged in a shallow water area, a prefabricated caisson arranged in a deep water area and a dock gate, one end of the earth rock cofferdam is connected with a revetment, and the other end of the earth rock cofferdam is connected with the prefabricated caisson; the end, away from the earth rock cofferdam, of the prefabricated caisson abuts against the dock gate, the end, away from the prefabricated caisson, of the dock gate abuts against the retaining dam, the earth rock cofferdam is used in a shallow water area to reduce the cost, the prefabricated caisson is used in a deep water area to reduce the amount of earth and stones in the deep water area, the cost is reduced, and the ecological influence is relieved. The original dock gate is utilized, normal use of the dock entrance is achieved by opening or closing the dock gate, the requirement for recovery after the dock entrance is widened is met, further, the waterproof curtain blocks the water seepage path of water in the earth rock cofferdam, the waterproof effect of the earth rock cofferdam is improved, and the water stop performance of the cofferdam structure is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of dry dock construction technology, and in particular to a dock entrance cofferdam structure, a dry dock system, and a construction method. Background Technology

[0002] A dry dock is a large work area used for casting large components such as immersed tubes and wind turbine platforms. It is located below the ground on the shore and has a dock opening on the water-facing side to connect with the water area for floating large components. It also has a dock gate, which can drain the water after the dock gate is closed to cast large components.

[0003] When the size of a large component exceeds the dock opening, the dock opening needs to be widened when the large component is shipped out. After the large component is shipped out, the dock opening often needs to be restored. Currently, the common method is to use earth and rock cofferdams to completely seal the widened dock opening. However, since there are deep water areas near the dock opening, the deep water areas need to be filled with a large amount of earth and rock cofferdams, which is costly. In addition, the large amount of earth and rock will also affect the marine ecological environment. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the background art by providing a dock entrance cofferdam structure, a dry dock system, and a construction method.

[0005] In a first aspect, the present invention provides a dock entrance cofferdam structure, comprising an earth-rock cofferdam set in a shallow water area, a prefabricated caisson set in a deep water area, and a dock gate, wherein one end of the earth-rock cofferdam is connected to a revetment, and the other end of the earth-rock cofferdam is connected to the prefabricated caisson. The end of the precast caisson away from the earth-rock cofferdam abuts against the dock gate, and the end of the dock gate away from the precast caisson abuts against the dam. It also includes a water-stopping curtain installed on the earth-rock cofferdam, one end of which is used to connect to the precast caisson, and the other end of which extends to the revetment.

[0006] Preferably, the water-stop curtain includes interlocking piles, and a plurality of the interlocking piles are arranged in a continuous row on the earth-rock cofferdam; High-pressure jet grouting piles are installed between the water-stop curtain and the precast caisson, and the high-pressure jet grouting piles are used to connect the water-stop curtain and the precast caisson.

[0007] Preferably, the precast caisson has a caisson base bed at the bottom, and a first waterstop strip is longitudinally provided at the top of the precast caisson base bed. The first waterstop strip is used to stop the water from entering the bottom of the precast caisson.

[0008] Preferably, it also includes a concrete layer, which is laid on top of the precast caisson and is flush with the top of the earth-rock cofferdam.

[0009] Preferably, it further includes a first vertical water-stop gate, which is disposed at the joint between the precast caisson and the dock gate.

[0010] Preferably, it also includes a second vertical water-stop gate, which is located at the joint between the dock gate and the dam.

[0011] Preferably, the earth-rock cofferdam includes a cofferdam body and a slope protection, the slope protection is laid on both sides of the cofferdam body, and geotextile is also provided between the slope protection and the cofferdam body.

[0012] In a second aspect, the present invention discloses a dry dock system, comprising a dry dock and a dock entrance cofferdam structure as described in the present invention; The dry dock has a dock entrance, a revetment is provided on one side of the dock entrance, and a water-blocking dam is provided on the other side of the dock entrance. The dock entrance cofferdam structure is located between the revetment and the water-blocking dam.

[0013] In a third aspect, the present invention discloses a construction method for a dock entrance cofferdam structure, used for constructing the dock entrance cofferdam structure described in the present invention, comprising the following steps: S1: Construct the earth-rock cofferdam in the shallow water area, and build the water-stop curtain on the earth-rock cofferdam; S2: Pull the dock gate to the dock entrance, and fill the dock gate with water to set it at the bottom; S3: Construct the caisson foundation in the deep water area, and transport the prefabricated caisson to the top of the prefabricated caisson foundation, and fill the prefabricated caisson with sand to sit on the bottom; S4: High-pressure jet grouting piles are installed between the earth-rock cofferdam and the precast caisson; S5: Perform vertical water-stopping on the precast caisson, the dock gate, the dock gate, and the dam.

[0014] Preferably, step S3 further includes: S31: Construct the caisson foundation in the deep water area and install the first waterstop strip on the top of the caisson foundation; S32: Transport the prefabricated caisson to the designated location, and then fill the prefabricated caisson with sand to set it in place; S33: Perform grouting and water-stopping operations on the caisson foundation bed; S34: The joint area between the precast caisson and the earth-rock cofferdam is filled and compacted.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The cofferdam structure of the present invention adopts a segmented cofferdam structure. An earth-rock cofferdam is set in the shallow water area, with one end connected to the revetment and the other end connected to the prefabricated caisson in the deep water area. The end of the prefabricated caisson away from the earth-rock cofferdam abuts the dock gate, and the other end of the dock gate abuts the dam. The earth-rock cofferdam is used in the shallow water area to reduce costs, and the prefabricated caisson is used in the deep water area to reduce the amount of earth and rock used, thereby reducing costs and mitigating ecological impact. At the same time, the combination of the earth-rock cofferdam, the prefabricated caisson and the dock gate utilizes the original dock gate. By opening or closing the dock gate, the dock can be used normally, meeting the restoration needs after the dock is widened. Furthermore, the water-stop curtain blocks the seepage path of water in the earth-rock cofferdam, improves the waterproof effect of the earth-rock cofferdam and ensures the water-stopping performance of the cofferdam structure.

[0016] 2. The dry dock system of the present invention restores the widened dock opening through a dock opening cofferdam structure, achieving low-cost and low-ecological-impact restoration of the widened dock opening. Furthermore, the cofferdam structure works in conjunction with the revetment and the dam to enable normal opening and closing of the widened dock opening, ensuring the normal use of the dry dock.

[0017] 3. The construction method of the dock entrance cofferdam structure of the present invention involves constructing an earth-rock cofferdam in shallow water and a caisson foundation in deep water, then installing precast caissons on the caisson foundation, and pre-pulling the dock gate to the dock entrance. The precast caissons, earth-rock cofferdam, and dock gate are used as the cofferdam structure to widen the dock entrance. Water-stop strips and water-stop gates are then used to stop the water in the cofferdam structure, thereby improving the water-stopping performance of the cofferdam structure. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the dry dock system of the present invention.

[0019] Figure 2 This is a schematic diagram of an earth-rock cofferdam.

[0020] Figure 3 It is an elevation view of the earth-rock cofferdam and the prefabricated caisson.

[0021] Figure 4 This is a top view of the water-stop curtain and prefabricated caisson.

[0022] Figure 5 This is a top view of the dock gate and prefabricated caissons.

[0023] Figure 6 It is an elevation view of the dock gate and prefabricated caissons.

[0024] Marked in the image: 1- Earth and rock cofferdam, 11-Dam body, 12-Slope protection 2-Precast caisson, 3-Water-stop curtain, 31-Interlocking post, 4-High-pressure jet grouting piles, 5-Ceiling foundation bed, 6-First waterstop strip, 7- First vertical water-stop gate, 8-Second vertical water-stop gate, 9-Second water stop strip, 10-Riverbank Protection 20-Dock Gate, 30-Dam, 40-Concrete layer, 50 - Reserved grouting pipe, 100-Dry Dock 101-Dock. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0026] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0027] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," "parallel," and "coaxial" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, parallel, or coaxial. Slight tilt or deviation is permissible, as long as it does not affect the normal function of the relevant component. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal; a slight tilt is acceptable. "Coaxial" means that two components are set as coaxially as possible, allowing them to move coaxially or approximately coaxially when their relative positions change. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," "parallel," or "coaxial" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present invention.

[0028] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0029] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0030] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0031] Example 1 like Figures 1-4 As shown, this embodiment discloses a dock gate cofferdam structure, including an earth-rock cofferdam 1 set in the shallow water area, a prefabricated caisson 2 set in the deep water area, and a dock gate 20. One end of the earth-rock cofferdam 1 is connected to the revetment 10, and the other end of the earth-rock cofferdam 1 is connected to the prefabricated caisson 2. The end of the precast caisson 2 away from the earth-rock cofferdam 1 abuts against the dock gate 20, and the end of the dock gate 20 away from the precast caisson 2 abuts against the dam 30. It also includes a water-stop curtain 3 installed on the earth-rock cofferdam 1. One end of the water-stop curtain 3 is used to connect with the precast caisson 2, and the other end of the water-stop curtain 3 extends to the revetment 10.

[0032] The cofferdam structure of this embodiment adopts a segmented cofferdam structure. In the shallow water area, an earth-rock cofferdam 1 is set up, with one end connected to the revetment 10 and the other end connected to the prefabricated caisson 2 in the deep water area. The end of the prefabricated caisson away from the earth-rock cofferdam abuts against the dock gate 20, and the other end of the dock gate abuts against the water-retaining dam 30. The earth-rock cofferdam 1 is used in the shallow water area to reduce costs, while the prefabricated caisson 2 is used in the deep water area to reduce the amount of earth and rock used, thereby reducing costs and mitigating ecological impact. At the same time, the combination of the earth-rock cofferdam 1, the prefabricated caisson 2, and the dock gate 20 utilizes the original dock gate 20. By opening or closing the dock gate 20, the dock can be used normally, meeting the restoration needs after the dock widening. Furthermore, the water-stop curtain blocks the seepage path of water in the earth-rock cofferdam 1, improves the waterproof effect of the earth-rock cofferdam 1, and ensures the water-stopping performance of the cofferdam structure.

[0033] In one or more implementations, such as Figure 4 As shown, the water-stop curtain 3 includes interlocking piles 31, and multiple interlocking piles 31 are arranged in a continuous row on the earth-rock cofferdam 1. A high-pressure jet grouting pile 4 is installed between the water-stop curtain 3 and the precast caisson 2. The high-pressure jet grouting pile 4 is used to connect the water-stop curtain 3 and the precast caisson 2.

[0034] The interlocking piles 31 are arranged in a continuous row to form a water-stopping curtain 3, which enhances the water-stopping ability of the earth-rock cofferdam 1. At the same time, the high-pressure jet grouting piles 4 fill the gap between the water-stopping curtain 3 and the precast caisson 2 to form a sealed connection, further blocking the seepage channel. Specifically, leakage is prone to occur at the connection between the water-stop curtain 3 and the precast caisson 2, affecting the overall reliability of the water-stopping mechanism. High-pressure jet grouting piles 4 are used to seal the connection between the water-stop curtain 3 and the precast caisson 2. In this implementation, the high-pressure jet grouting piles 4 are embedded in the precast caisson 2 and the interlocking piles 31 near the precast caisson 2. Figure 4 This is to achieve waterproofing at the connection between the water-stop curtain 3 and the precast caisson 2.

[0035] In one or more implementations, such as Figure 3 As shown, the precast caisson 2 has a caisson base bed 5 at the bottom, and a first waterstop strip 6 is longitudinally provided on the top of the caisson base bed 5. The first waterstop strip 6 is used to stop the water at the bottom of the precast caisson 2.

[0036] Waterproofing is achieved between the precast caisson 2 and the caisson foundation 5 by setting a first waterstop strip 6 on the top of the caisson foundation 5.

[0037] In optional implementations, such as Figure 3 As shown, it also includes a concrete layer 40, which is laid on top of the precast caisson 2 and is flush with the top of the earth-rock cofferdam 1.

[0038] By setting a 40mm concrete layer, the top of the cofferdam is made smooth, avoiding stress concentration caused by height differences, improving the overall structural stability, and providing a flat foundation for subsequent equipment passage or operation, thus improving construction convenience.

[0039] In one or more implementations, such as Figure 5 , Figure 6 As shown, it also includes a first vertical water-stop gate 7, which is installed at the joint between the precast caisson 2 and the dock gate 20.

[0040] The first vertical water-stop gate 7 is used to waterproof the joint between the precast caisson 2 and the dock gate 20, thereby improving the water-stopping performance between the precast caisson 2 and the dock gate 20.

[0041] Furthermore, it also includes a second vertical water-stop gate 8, which is located at the joint between the dock gate 20 and the dam 30.

[0042] The second vertical water-stop gate 8 is used to waterproof the joint between the dock gate 20 and the dam 30, thereby improving the water-stopping performance between the dock gate 20 and the dam 30.

[0043] In one or more implementations, such as Figure 1 As shown, the earth-rock cofferdam 1 includes a dam body 11 and a slope protection 12. The slope protection 12 is laid on both sides of the dam body 11, and geotextile is also installed between the slope protection 12 and the dam body 11.

[0044] The slope protection 12 and the geotextile work together to resist water erosion, protect the structure of the dam body 11, and extend the service life of the earth-rock cofferdam 1. At the same time, the geotextile enhances the bonding force between the slope protection 12 and the dam body 11, and improves the deformation resistance and stability of the earth-rock cofferdam 1.

[0045] Furthermore, it also includes reserved grouting pipes 50 installed on the weir body 11. Multiple reserved grouting pipes 50 are arranged at intervals along the length of the water-stop curtain 3, and the reserved grouting pipes 50 are located on the water-facing side of the water-stop curtain 3.

[0046] Grout is injected into the weir body 11 through the reserved grouting pipe 50 to solidify the soil on the water-facing side of the water-stop curtain 3, thereby further enhancing the waterproofing effect of the water-stop curtain 3.

[0047] Example 2 like Figure 1 As shown, based on Embodiment 1, this embodiment discloses a dry dock system, including a dry dock 100 and the dock entrance cofferdam structure described in Embodiment 1; The dry dock 100 has a dock entrance 101, a bank protection 10 on one side of the dock entrance 101, and a water-blocking dam 30 on the other side of the dock entrance 101. The dock entrance cofferdam structure is located between the bank protection 10 and the water-blocking dam 30.

[0048] The dry dock system in this embodiment restores the widened dock opening through a dock opening cofferdam structure, achieving low-cost and low-ecological-impact restoration of the widened dock opening. Furthermore, the cofferdam structure works in conjunction with the revetment 10 and the dam 30 to enable normal opening and closing of the widened dock opening, ensuring the normal use of the dry dock 100.

[0049] Example 3 like Figures 1-6 As shown, based on Example 1, this example discloses a construction method for a dock entrance cofferdam structure, used for constructing the dock entrance cofferdam structure described in Example 1, including the following steps: S1: As Figure 2 As shown, an earth-rock cofferdam 1 is constructed in the shallow water area, and then a water-stop curtain 3 is constructed on the earth-rock cofferdam 1. Before construction begins, the location of the precast caisson 2 is calculated in advance, and fixed buoys are marked in the shallow water area. Then, bulldozers and excavators are used on land to throw soil and rocks into the sea to form an earth-rock cofferdam 1. Large pieces of slope protection stones and geotextile are thrown on both sides of the earth-rock cofferdam 1 to reduce the impact of waves. Then, a reinforced concrete guide wall is constructed on the top of the earth-rock cofferdam 1. After the guide wall is completed, the interlocking piles 31 are constructed. The design diameter of the interlocking piles 31 is 1.2m, with an overlap of 0.3m between piles, and a minimum penetration of 0.5m into the intact moderately weathered rock surface. After the construction of the interlocking piles 31 is completed, the positions of the interlocking piles that need to be connected to the high-pressure jet grouting piles 4 are marked.

[0050] S2: Pull the dock gate 20 to the dock entrance, and then fill the dock gate 20 with water to allow it to settle on the bottom; During the process, divers installed the second waterstop strip 9 at the bottom of the dock gate 20 using underwater-cured epoxy resin. After the second waterstop strip 9 was installed, the dock gate 20 was reinstalled. Figure 6 , The installation process of dock gate 20 is as follows: ① Dock gate 20 is equipped with cables, ② Dock gate 20 is dewatered and floated, ③ Dock gate 20 is hoisted to the dock entrance, ④ Dock gate 20 is filled with water and sits on the bottom.

[0051] S3: Construct the caisson foundation 5 in deep water. Transport the precast caisson 2 to the top of the precast caisson foundation 5, and then fill the caisson 2 with sand to set it in place. Figure 3 , Specifically, the following steps are included: S31: Construct the caisson foundation 5 in the deep water area and install the first waterstop strip 6 on the top of the caisson foundation 5; Among them, flat barges and excavators were used to fill the caisson foundation bed 5 with small-sized crushed stones, with the crushed stones ranging from 8cm to 20cm. After reaching the design elevation of the caisson foundation bed 5, a group of divers were dispatched to cooperate with a leveling vessel to level the caisson foundation bed 5. The leveling range extended to 0.5 meters from the toe of the precast caisson 2, with a crushed stone thickness of 0.4m to 1.6m and a leveling top elevation of -12.8m.

[0052] Then, the caisson foundation 5 is covered with geotextile. The geotextile overlap is connected by sewing and binding with underwater tying. The overlap length is not less than 1 meter. The geotextile laying length at the toe position of the precast caisson 2 on the top surface of the caisson foundation 5 is not less than 2 meters. Sandbags are placed around the caisson foundation 5 to seal it. At the same time, continuous water-stop rubber strips and local connection water-stop rubber strips are pre-embedded on the foundation at the connection position between the precast caisson 2 and the dock gate 20 to prevent grout leakage during the subsequent grouting foundation construction.

[0053] S32: Transport the precast caisson 2 to the designated location, and then fill the precast caisson 2 with sand to set it in place; The process involves lifting the prefabricated caisson and transporting it to a designated location by tugboat. Once at the designated location, sand is poured into the prefabricated caisson 2, allowing it to sit on the pre-completed caisson foundation 5. During the sitting process, divers observe underwater and adjust the position of the prefabricated caisson 2 in real time to ensure better contact between the prefabricated caisson 2 and the second waterstop strip 9 at the top of the caisson foundation 5.

[0054] S33: Perform grouting and water-stopping operations on caisson foundation bed 5; Among them, the bottom of the precast caisson 2 adopts the grouting and water-stopping operation. The grouting and hole making of the caisson foundation bed 5 is carried out by hammering the riprap of the caisson foundation bed 5. The grouting pipe tip adopts the drop-out tip, and the tip is connected to the grouting pipe by rivets. The mortar is pressed into the gap of the riprap of the grouting foundation bed through the mortar pump, grouting pipe and grouting pipe. During the construction process, divers are specially assigned to assist in the grout leakage inspection and follow the construction sequence of low to high.

[0055] S34: Continue to use bulldozers to fill the joint area between the precast caisson 2 and the earth-rock cofferdam 1 and compact it with a road roller.

[0056] The first waterstop strip 6 and the grouting and water-stopping operation of the foundation bed provide double protection for the bottom sealing of the precast caisson 2, completely solving the problem of water seepage at the bottom of the precast caisson 2. The joint area is filled and compacted to enhance the connection strength between the precast caisson 2 and the earth-rock cofferdam 1, improve the overall structural stability, and avoid leakage or deformation caused by loosening at the joint.

[0057] S4: High-pressure jet grouting piles 4 are installed at the contact surface between the earth-rock cofferdam 1 and the precast caisson 2, such as... Figure 3 , Figure 4 ; Prepare two high-pressure jet grouting machines and two pilot hole drilling machines in advance, keep the equipment in good working order, and prepare the specific slurry ratio in advance. The team members should be in place. High-pressure jet grouting piles 4 are used for water stoppage between the earth-rock cofferdam 1 and the precast caisson 2. First, a drilling rig is used for pilot drilling, with PVC casing used for follow-up protection. The length of the PVC casing is equal to the thickness of the riprap layer. After pilot drilling, a rotary high-pressure jet grouting machine is used to construct the high-pressure jet grouting piles 4. The designed diameter of the high-pressure jet grouting piles 4 is 1.2m, and the spacing between the piles is 0.9m. The piles are required to penetrate at least 0.5m into the intact moderately weathered rock surface. At the connection point between the water-stop curtain 3 and the precast caisson 2, two high-pressure jet grouting piles 4 are used in parallel for interlocking water stoppage. The high-pressure jet grouting piles 4 are embedded in the precast caisson 2 and the interlocking piles 31 to form a water-stop seal.

[0058] S5: Perform vertical waterstopping on the precast caisson 2 and dock gate 20, such as... Figure 6 ; The first vertical water-stop gate 7 is used for water-stopping. The first vertical water-stop gate 7 is set at the joint between the precast caisson 2 and the dock gate 20. Before the first vertical water-stop gate 7 is first laid, underwater construction is required and the top surface of the corresponding foundation bed needs to be leveled with concrete for a second time. The process involves using lifting equipment to hoist and install the first vertical water-stop gate 7, allowing the gate to slowly and steadily sink. While maintaining its sinking position, the pressure marks on the sealing strip are checked to confirm that the position is correct and there are no abnormalities. Then, the lifting lugs pre-installed on the first vertical water-stop gate 7 are used to tighten the first vertical water-stop gate 7, ensuring that the water-stop strip on the first vertical water-stop gate 7 is tightly attached to the dock gate 20. At the same time, water is pumped out from the inside of the dock gate 20, and the difference in water level between the inside and outside is used to further tighten the first vertical water-stop gate 7 in the opposite direction, achieving the water-stopping effect. Vertical water stoppage was carried out at the dock gate 20 and the dam 30; Water is stopped by a second vertical water-stop gate 8, which is located at the joint between the pre-dock gate 20 and the dam 30. The process involves using lifting equipment to hoist and install the second vertical water-stop gate 8, allowing it to slowly and steadily sink. While maintaining its sinking position, the pressure marks on the sealing strip are checked to confirm that the position is correct and there are no abnormalities. Then, the second vertical water-stop gate 8 is tightened using the pre-installed lifting lugs, ensuring that the water-stop strip on the second vertical water-stop gate 8 is tightly attached to the dock gate 20. Simultaneously, water is pumped out from the inside of the dock gate 20, using the difference in water levels to further compress the reverse second water-stop gate 7, achieving the water-stopping effect.

[0059] The construction method of the dock entrance cofferdam structure in this embodiment involves constructing an earth-rock cofferdam 1 in shallow water and a caisson foundation 5 in deep water. Then, a precast caisson 2 is installed on the caisson foundation 5, and the dock gate 20 is pre-pulled to the dock entrance. The precast caisson 2, earth-rock cofferdam 1, and dock gate 20 serve as the cofferdam structure to widen the dock entrance. Water-stop strips and water-stop gates are used to stop the water in the cofferdam structure, thereby improving the water-stopping performance of the cofferdam structure.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cofferdam structure for a dock entrance, characterized in that, It includes an earth-rock cofferdam (1) set in the shallow water area, a prefabricated caisson (2) set in the deep water area and a dock gate (20). One end of the earth-rock cofferdam (1) is connected to the revetment (10), and the other end of the earth-rock cofferdam (1) is connected to the prefabricated caisson (2). The end of the precast caisson (2) away from the earth-rock cofferdam (1) abuts against the dock gate (20), and the end of the dock gate (20) away from the precast caisson (2) abuts against the dam (30); It also includes a water-stop curtain (3) installed on the earth-rock cofferdam (1), one end of which is used to connect to the precast caisson (2), and the other end of which extends to the revetment (10).

2. The cofferdam structure at the dock entrance according to claim 1, characterized in that, The water-stop curtain (3) includes interlocking piles (31), and multiple interlocking piles (31) are arranged in a continuous row on the earth-rock cofferdam (1); High-pressure jet grouting piles (4) are installed between the water-stop curtain (3) and the precast caisson (2), and the high-pressure jet grouting piles (4) are used to connect the water-stop curtain (3) and the precast caisson (2).

3. The cofferdam structure at the dock entrance according to claim 1, characterized in that, The precast caisson (2) has a caisson base bed (5) at the bottom and a first waterstop strip (6) is provided longitudinally at the top of the precast caisson base bed (5). The first waterstop strip (6) is used to stop the water at the bottom of the precast caisson (2).

4. The cofferdam structure at the dock entrance according to claim 1, characterized in that, It also includes a concrete layer (40), which is laid on top of the precast caisson (2) and is flush with the top of the earth-rock cofferdam (1).

5. A cofferdam structure for a dock entrance according to claim 1, characterized in that, It also includes a first vertical water-stop gate (7), which is located at the joint between the precast caisson (2) and the dock gate (20).

6. A cofferdam structure for a dock entrance according to claim 1, characterized in that, It also includes a second vertical water-stop gate (8), which is located at the joint between the dock gate (20) and the dam (30).

7. A cofferdam structure for a dock entrance according to claim 1, characterized in that, The earth-rock cofferdam (1) includes a dam body (11) and a slope protection (12). The slope protection (12) is laid on both sides of the dam body (11), and geotextile is also provided between the slope protection (12) and the dam body (11).

8. A dry docking system, characterized in that, Includes a dry dock (100) and a dock entrance cofferdam structure as described in any one of claims 1-7; The dry dock (100) has a dock entrance (101), a bank protection (10) is provided on one side of the dock entrance (101), and a water-blocking dam (30) is provided on the other side of the dock entrance (101). The dock entrance cofferdam structure is located between the bank protection (10) and the water-blocking dam (30).

9. A construction method for a dock entrance cofferdam structure, characterized in that, The method for constructing the dock cofferdam structure as described in any one of claims 1-7 includes the following steps: S1: Construct the earth-rock cofferdam (1) in the shallow water area and construct the water-stop curtain (3) on the earth-rock cofferdam (1). S2: Pull the dock gate (20) to the dock entrance, and fill the dock gate (20) with water to sit on the bottom; S3: The caisson foundation (5) is constructed in the deep water area, and the precast caisson (2) is transported to the top of the precast caisson foundation (5), and the precast caisson (2) is filled with sand to sit on the bottom; S4: High-pressure jet grouting piles (4) are installed between the earth-rock cofferdam (1) and the precast caisson (2). S5: Perform vertical water-stopping on the precast caisson (2), the dock gate (20), the dock gate (20), and the dam.

10. A construction method for a dock entrance cofferdam structure according to claim 9, characterized in that, Step S3 also includes: S31: Construct the caisson foundation (5) and install the first waterstop strip (6) on the top of the caisson foundation (5); S32: Transport the precast caisson (2) to the designated location, and then fill the precast caisson (2) with sand to set it in place; S33: Perform grouting and water-stopping operations on the caisson foundation bed (5); S34: The joint area between the precast caisson (2) and the earth-rock cofferdam (1) is filled and compacted.

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