Underwater occupation protection system and construction method thereof

Abstract

The invention relates to an underwater occupation protection system. Comprising a multi-layer fan-ring-shaped self-interlocking locking block flexible protection belt, the self-interlocking locking block flexible protection belt comprises a plurality of sets of steel pipe piles arranged in a fan ring shape, protection locking blocks are installed on the sets of steel pipe piles, the protection locking blocks sink into water along the steel pipe piles where the protection locking blocks are located, and the adjacent protection locking blocks are connected in an embedded mode; and the rear space of each layer of self-interlocking locking block flexible protective belt is filled with sand and gravel materials to form an occupation body. The invention further relates to a construction method. The construction method comprises the following steps that S1, preparation is conducted before construction; s2, the workboat is in place and anchored; s3, steel pipe pile driving is carried out; s4, a protective locking block is installed; s5, throwing and filling the sand-gravel materials; and S6, layered backstepping construction is carried out. The access protection system has the characteristic of fabricated construction, can be quickly constructed in a water body to meet the requirements of riverway rescue and the like, and has higher water flow scouring resistance, all-terrain adaptability and higher dynamic stability.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater occupation construction, and in particular relates to an underwater occupation protection system and a construction method thereof. Background Art

[0002] The sealing of river embankment breaches, reinforcement of weak bank slopes, protection of beaches and banks, and repair of river flood sections are important projects to improve river safety. Take the sealing of embankment breaches as an example: when a embankment breaches, a large amount of land is submerged and buildings are destroyed, causing huge losses of life and property to local people. Faced with the severe rescue situation of rapid breaches and strong impact, the rescue investment is large and the efficiency is low due to the conditions of small working surface, inconvenient transportation and long rescue distance. The above-mentioned project is based on the construction of an occupation protection system in the water body. By reasonably constructing an occupation protection system, the purpose of sealing breaches, reinforcing bank slopes and beaches, and repairing river flood sections is achieved. On the other hand, in order to prevent the weakening of the scouring effect of the river on the river channel, the construction of a spur dike orthogonal or oblique to the river bank in the river channel is also an important river regulation project. The spur dike in this scenario is also an important underwater occupation protection system.

[0003] In the existing technology, the emergency rescue construction technology of "redundant configuration and extreme operation" is usually adopted to ensure the construction strength and efficiency. Land rescue machinery mostly uses excavators and loaders for loading, dump trucks for transporting materials, and bulldozers for laying fillers. Rescue boats as water rescue machinery are usually used in transportation, traction, anchoring and auxiliary rescue operations. Specific engineering aspects: In 2000, reinforced gabions were used for the first time in the emergency rescue of Yigong barrier lake to protect the drainage channel, but it was eroded and destroyed after the breach flow began to increase rapidly. Chen Xiaoqing and others proposed a tetrahedral artificial structure to control the flood peak and conducted relevant experimental research. Cai Yaojun, Zhou Zhao and others first proposed the "control after control, not early control, flexible and adaptive" flood control technology route, and developed the flood control technology of wall-mounted gabion string slope protection and flexible mesh chain bottom protection. Indoor and field tests showed that the flood peak reduction rate reached 20%, and a breakthrough in flood control technology was achieved. However, the above technologies are all pre-protection on existing structures, and cannot be dynamically protected according to the rescue progress, and the adaptability is poor.

[0004] In summary, it is necessary to develop and design an underwater intrusion protection system and its construction method to solve the shortcomings of the existing technology. Summary of the invention

[0005] The purpose of the present invention is to provide an underwater intrusion protection system, which has the characteristics of prefabricated construction, can be quickly constructed in water bodies to meet requirements such as river rescue, has stronger resistance to water erosion, and has higher dynamic stability.

[0006] The technical solution adopted by the present invention is: an underwater intrusion protection system, including multiple layers of fan-shaped self-locking block flexible protection belts, each of which is stacked layer by layer to form a stepped structure, the bottom layer of the self-locking block flexible protection belt is located on the mud surface of the bottom of the water, and the top of the top layer of the self-locking block flexible protection belt is exposed from the water surface, the front bottom of the upper layer of the self-locking block flexible protection belt is pressed on the rear top of the lower layer of the self-locking block flexible protection belt to form an overlapping area; the self-locking block flexible protection belt includes multiple groups of steel pipe piles arranged in a fan-shaped ring, and a protection locking block is installed on each group of steel pipe piles and the protection locking block is sunk underwater along the steel pipe piles, and adjacent protection locking blocks are interlocked and connected, and the rear space of each layer of the self-locking block flexible protection belt is filled with sand and gravel to form an intrusion body.

[0007] Preferably, two longitudinally penetrating mounting holes are provided on the protective locking block, and the number of steel pipe piles corresponding to each protective locking block is two and the two steel pipe piles are respectively located in the two mounting holes of the protective locking block.

[0008] Preferably, the protective locking block is a hollow high-strength plastic locking block, a filling hole for injecting filler into the inner cavity is provided on the top of the protective locking block, and a sealing buckle cover is provided on the filling hole.

[0009] Preferably, the width of the overlapping area is equal to 15-30% of the width of the protective locking block.

[0010] Preferably, the lower end of the steel pipe pile passes through the unstable soil layer of the bottom mud surface and is driven into the bearing layer, and the depth of the driving into the bearing layer is equal to 1 / 3 to 1 / 2 of the pile length of the steel pipe pile.

[0011] Preferably, the underwater intrusion protection system is a spur dike, which is perpendicular or oblique to the river bank and extends into the river channel, or the underwater intrusion protection system is located on the inner side of the breach on the river bank and closes the breach.

[0012] Another object of the present invention is to provide a construction method for an underwater intrusion protection system.

[0013] The technical solution adopted by the present invention is: a construction method of an underwater intrusion protection system, based on an amphibious rescue ship, comprising the following steps: Step S1, preparation before construction, mapping the river terrain, water depth, flow velocity and geological conditions, determining the pile layout parameters of the occupation protection system, checking the stability of the construction area and clearing obstacles to ensure that the construction ship can dock safely; Step S2, the construction ship is positioned and anchored. The amphibious rescue ship sails to the designated construction area, starts the autonomous anchoring system to fix the hull, and uses the positioning pile trolley of the construction ship to adjust the level of the hull; Step S3, steel pipe pile driving, using the GPS system and underwater depth sounder carried by the amphibious rescue ship to confirm the pile position coordinates and depth, using the pile positioning trolley of the construction ship to adjust the hull posture to ensure the verticality of the pile, and using the pile driving device of the construction ship to drive the steel pipe pile according to the pile spacing and burial depth required by the design; Step S4, installing the protective lock block, installing the protective lock block on the injected steel pipe pile, injecting filler into the protective lock block and sealing it, the protective lock block naturally sinks along the steel pipe pile where it is located by gravity, and the completely sunken protective lock blocks are sequentially connected and embedded underwater to form a self-embedded flexible protection belt as a continuous anti-collision barrier; Step S5, filling sand and gravel into the occupied area. Sand and gravel are filled behind the formed self-interlocking block flexible protection belt to form an occupied layer. The filling order is gradually filled from the outside to the center of the river channel. The sand and gravel layer after filling is compacted to ensure the density of the occupied layer. Step S6, layered retreat construction, after completing the construction of the first layer, the amphibious rescue ship is retreated and moved, and steps S2 to S5 are repeated to complete the construction of the upper layers until the top elevation of the uppermost occupation layer exceeds the water surface height. Each occupation layer constitutes an occupation body, and each interlocking block flexible protection belt and the occupation body constitute an underwater occupation protection system.

[0014] Preferably, in step S2, the horizontality of the amphibious rescue ship is controlled within 5 mm; in step S3, the verticality of the steel pipe pile is re-measured every 2 m depth to ensure that the inclination rate is <1% and the deviation between the injection position of the steel pipe pile and the designed pile position is <10 cm; in step S4, the filler injected into the protective lock block is gravel and / or water, and the density of the filled protective lock block is >1200 kg / m 3 .

[0015] The advantages and positive effects of the present invention are: The present invention provides an underwater intrusion protection system, wherein a multi-layer self-embedded locking block flexible protection belt constitutes an anti-scouring barrier, which withstands the impact of water flow and can be further embedded to form a stable structure, and the anti-scouring barrier can better resist the scouring effect of water flow, so the constructed underwater intrusion protection system has strong overall stability and is not easy to collapse. The self-embedded locking block flexible protection belt is composed of a plurality of sequentially embedded protection locking blocks and uses steel pipe piles as a skeleton, so the underwater intrusion protection system has the structural characteristics of an assembled type and can be quickly constructed on site to meet requirements such as river rescue. On the other hand, when the underwater intrusion protection system encounters the problem of river bottom scouring, the overall structure will also decline accordingly, and the problem of overall collapse of the masonry structure intrusion system due to local settlement will not occur, so it has higher dynamic stability in the water body. The steel pipe piles and protection locking blocks of the underwater intrusion protection system can also be disassembled, recycled and reused to reduce the waste of resources.

[0016] The construction method of the present invention is based on an amphibious rescue ship, which gives full play to the characteristics of the amphibious rescue ship, such as flexible mobility and rich configuration (including positioning system, anchoring system, piling device, etc.), and thus has all-terrain adaptability. By giving full play to the amphibious rescue ship's amphibious and land maneuverability, it does not require external lifting equipment and is suitable for construction in narrow waters and complex traffic conditions. The adopted layered retreat construction technology has the following advantages: 1. Layered implementation can avoid excessive stress on the overall structure of the occupied system and reduce the risk of being washed away during construction; 2. Under the condition of bottom bearing force, the higher the occupied system is, the greater the upper torque is. Starting from the bottom layer, the construction difficulty can be greatly reduced; 3. The flexible anti-scouring barrier can better adapt to the underwater terrain, effectively achieve airtightness, and reduce the flow rate; 4. The layer-by-layer stacking process can effectively increase the weight of the bottom protection body, thereby improving the compactness of the contact surface and reducing water scouring; 5. The retreat layer pile structure can effectively improve the overall stress of the occupied protection system, improve the uniformity and self-stability of the stress of the protection body, and avoid the collapse of the occupied system due to excessive local stress; 6. The slope structure of the layered retreat flexible lock block protection body can effectively reduce the shear force of the bearing piles and avoid the instability of the vertical protection structure due to excessive passive earth pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the top view of the structure of the intrusion protection system of the present invention, that is, a plan layout diagram; Figure 2 It is a schematic diagram of the cross-sectional structure of the intrusion protection system of the present invention; Figure 3 yes Figure 1 A schematic diagram of the top view of the structure of the middle protective lock block; Figure 4 This is a schematic diagram of the overhead structure when the occupation protection system is in the form of a spur dike; Figure 5 It is a schematic diagram of the overhead structure when the intrusion protection system is used to seal the breach.

[0018] In the figure: 1. Steel pipe piles; 2. Protective lock blocks; 3. Occupied body; 4. Overlapping area; 5. River bank; 6. Breach. DETAILED DESCRIPTION

[0019] In order to further understand the content, features and effects of the present invention, the following embodiments are given to explain in detail.

[0020] See also Figure 1 and Figure 2The underwater intrusion protection system of the present invention comprises a plurality of fan-shaped self-interlocking block flexible protection belts, each of which is stacked layer by layer to form a stepped structure, the bottom layer of the self-interlocking block flexible protection belt is located on the bottom mud surface, the top of the top layer of the self-interlocking block flexible protection belt is exposed from the water surface, the front bottom of the upper layer of the self-interlocking block flexible protection belt is pressed on the rear top of the lower layer of the self-interlocking block flexible protection belt and forms an overlapping area 4. The rear space of each layer of the self-interlocking block flexible protection belt is filled with sand and gravel to form an intrusion body 3, and the respective interlocking block flexible protection belts arranged in a stepped shape in front together constitute the anti-scouring barrier of the intrusion body 3, and the scouring effect of the water flow is mainly applied to the anti-scouring barrier, so that the underwater intrusion protection system has a stronger ability to resist water flow scouring and is not easy to collapse after construction.

[0021] The self-locking block flexible protection belt includes multiple groups of steel pipe piles 1 arranged in a fan-shaped ring shape. A protection locking block 2 is installed on each group of steel pipe piles 1 and the protection locking block 2 is sunk underwater along the steel pipe piles 1 where it is located. Adjacent protection locking blocks 2 are interlocked and connected. The injected steel pipe piles 1 serve as the skeleton of the self-locking block flexible protection belt. Under the action of water flow pressure, the protection locking blocks 2 of the underwater self-locking block flexible protection belt tend to gather toward the center, thereby making the self-locking block flexible protection belt more compact and improving the structural strength. The steel pipe piles 1 are made of Q235B steel, and the length is customized according to the designed water depth, generally 8 to 15 meters.

[0022] Figure 3 A typical structural style of the protective lock block 2 is given in the figure. It can be seen that when the protective lock blocks 2 are Z-shaped and are sequentially spliced ​​and interlocked to form a fan-shaped self-interlocking block flexible protection belt, the front of the next protective lock block 2 overlaps the rear of the previous protective lock block 2 to form an interlocking connection. Since the adjacent protective lock blocks 2 in the circumferential direction are not rigidly fixed, the "self-interlocking block flexible protection belt" is flexible. The stepped anti-collision barrier composed of multiple layers of self-interlocking block flexible protection belts is also flexible. Since the protective lock blocks 2 are prefabricated and installed layer by layer on site, the underwater intrusion protection system has the structural characteristics of an assembled type, which can shorten the construction period.

[0023] Two longitudinally penetrating mounting holes are provided on the protection locking block 2. Each protection locking block 2 corresponds to two steel pipe piles 1, and the two steel pipe piles 1 are respectively located in the two mounting holes of the protection locking block 2. Therefore, the steel pipe piles 1 are used as supports and guides for the protection locking block 2. When the steel pipe piles 1 are pre-installed, their position accuracy needs to be ensured. After that, the protection locking block 2 is installed on the steel pipe pile 1 to form a self-embedded locking block flexible protection belt.

[0024] In this embodiment, the protective lock block 2 is a hollow high-strength plastic lock block (high-strength polyethylene PE or polypropylene PP or ASA / PC material). A filling hole for injecting fillers into the inner cavity is provided at the top of the protective lock block 2, and a sealing buckle cover is provided on the filling hole. The hollow plastic protective lock block 2 is easy to prefabricate and reduces the processing and transportation costs of consumables. By placing fillers inside, the specific gravity of the protective lock block 2 is increased, so that the protective lock block 2 can sink smoothly in the water and resist floating. Of course, it is conceivable that the protective lock block 2 can also be a prefabricated concrete lock block. In this case, the concrete lock block that sinks underwater along the steel pipe pile 1 forms the aforementioned self-embedded lock block flexible protection belt.

[0025] In this embodiment, the width of the overlapping area 4 is equal to 15-30% of the width of the protective locking block 2. By pressing the protective locking block 2 of the upper layer of the self-locking block flexible protective belt onto the protective locking block 2 of the lower layer of the self-locking block flexible protective belt, the overall structural stability of the underwater intrusion protection system can be improved.

[0026] In the present embodiment, the lower end of the steel pipe pile 1 passes through the unstable soil layer of the underwater mud surface and is driven into the bearing layer. The depth of the driving into the bearing layer is equal to 1 / 3 to 1 / 2 of the pile length of the steel pipe pile 1. In this way, the lower part of the steel pipe pile 1 can have a stable bonding relationship with the bearing layer of the underwater mud surface. Therefore, during the existence period of the water intrusion protection system after construction, the steel pipe pile 1 will not lose its anchoring effect and cause instability.

[0027] Figure 4 and Figure 5 Two typical styles of the underwater intrusion protection system are given, which are applied in different scenarios: See also Figure 4 The underwater intrusion protection system is a spur dike, which is perpendicular or oblique to the river bank 5 ( Figure 4 The spur dam is also called "diverting dam", which is a river regulation structure that extends into the river at right angles or diagonally to the river bank. There are different lengths of spur dams. The long ones deflect the axis of the water flow and move it toward the opposite bank, playing the role of diverting the flow. The short ones play the role of partially adjusting the water flow and protecting the river bank. The bank protection project composed of spur dams can control the flow and protect the embankment. It also has the functions of narrowing the riverbed, blocking the fork and filling the beach. Figure 4 As shown in the figure, the anti-scouring barrier of this underwater intrusion protection system (i.e., spur dike) is located at the dam head and is subject to the scouring effect of the water flow.

[0028] See also Figure 5 The water intrusion protection system is located on the inner side of the breach 6 on the river bank 5 and closes the breach 6. In the flood control and rescue application scenario where a breach 6 occurs on the river bank and needs to be blocked, the water intrusion protection system is constructed on the inner side of the breach to block the breach.

[0029] The construction method for constructing the aforementioned underwater occupation protection system is based on the construction of amphibious rescue ships. The amphibious rescue ships are existing facilities. The ships themselves have the ability to move amphibiously. They are equipped with a positioning system (GPS) and an underwater monitoring system, an anchoring system, a pile driving device (pile clamps, pile hammers, etc.), etc. Auxiliary devices include a positioning pile trolley, a lock block installation device (lock block clamps and mechanical arms), and a water injection / filling system. This construction method gives full play to the characteristics of amphibious rescue ships.

[0030] Traditional ships are difficult to load and unload, and need to be equipped with large-scale lifting equipment and special large-scale transport vehicles, and have high requirements for lifting sites. However, amphibious rescue ships have the functions of autonomous launching and landing, self-loading and self-unloading, self-anchoring, and self-navigation. They can operate amphibiously in all operation modes, and do not require large-scale lifting equipment for loading and unloading. If the site is small and the traffic conditions are poor, it can automatically move to a wide area without having to consider problems such as running aground due to shallow water or mudflats. It has strong mobility, convenience and flexibility, and has unique mobility both on land and water. In particular, river embankment flood control and rescue are characterized by long flood control dam lines, complex transportation conditions, and limited rescue operation sites. It is particularly suitable to use amphibious rescue ships with strong applicability, strong mobility, and powerful functions for rescue. Traditional ship anchoring usually uses anchor cables to anchor on the shore or in the water. Amphibious rescue ships use an autonomous anchoring system. Operational shifting does not require auxiliary ships, winches or cables. It is automatically stabilized by two front stabilizers and two tiltable rear stabilizers. The rescue ship equipped with a positioning pile trolley can also be moved forward, backward, left and right by the trolley, reducing the number of times the anchor is moved continuously, effectively shortening the construction time.

[0031] The construction method of the water intrusion protection system includes the following steps: Step S1, preparation before construction, surveying and mapping the river terrain, water depth, flow velocity and geological conditions, determining the pile layout parameters of the entry protection system, checking the stability of the construction area and clearing obstacles to ensure that the construction ship can dock safely.

[0032] Step S2, the construction ship is positioned and anchored. The amphibious rescue ship sails to the designated construction area, starts the autonomous anchoring system to fix the hull, and uses the positioning pile trolley of the construction ship to adjust the level of the hull; In this step, the hull levelness of the amphibious rescue ship is controlled within 5 mm.

[0033] Step S3, steel pipe piles 1 are driven, using the GPS system and underwater depth sounder carried by the amphibious rescue ship to confirm the pile position coordinates and depth, using the pile positioning trolley of the construction ship to adjust the hull posture to ensure the verticality of the pile, and using the pile driving device of the construction ship to drive the steel pipe piles 1 according to the pile spacing and burial depth required by the design; In this step, the verticality of the steel pipe pile 1 is remeasured every time the steel pipe pile 1 is driven at a depth of 2 m to ensure that the inclination rate is less than 1% and the deviation value between the driving position of the steel pipe pile 1 and the designed pile position is less than 10 cm.

[0034] Step S4, installing the protective locking block 2, installing the protective locking block 2 on the injected steel pipe pile 1, injecting filler into the protective locking block 2 and sealing it, the protective locking block 2 naturally sinks along the steel pipe pile 1 where it is located by gravity, and the completely sunken protective locking blocks 2 are sequentially interlocked and connected underwater to form a self-interlocking block flexible protection belt as a continuous anti-collision barrier; In this step, the protective lock block 2 can be carried by the amphibious rescue ship itself or by a flatbed trailer to the side of the construction ship. In this step, the filler injected into the protective lock block 2 is gravel (sand and gravel with a particle size of 5 to 20 cm) and / or water. The density of the filled protective lock block 2 is greater than 1200 kg / m 3 .

[0035] Step S5, filling sand and gravel into the occupied area. Sand and gravel are filled behind the formed self-interlocking block flexible protection belt to form an occupied layer. The filling order is gradually filled from the outside to the center of the river channel. The sand and gravel layer after filling is compacted to ensure the density of the occupied layer. In this step, an excavator or a suction dredger is used to dump graded sand and gravel behind the flexible protection belt of the self-interlocking blocks.

[0036] Step S6, layered retreat construction, after completing the construction of the first layer, the amphibious rescue ship is retreated and moved, and steps S2 to S5 are repeated to complete the construction of each layer above, until the top elevation of the uppermost occupation layer exceeds the water surface height, each occupation layer constitutes an occupation body 3, and each interlocking block flexible protection belt and the occupation body 3 constitute an underwater occupation protection system; In this step, "moving the ship backward" means moving the ship toward the river bank 5, and the top elevation of the uppermost occupying layer may exceed the water surface by 1m.

Claims

1. An underwater intrusion protection system, characterized by: The invention comprises a plurality of fan-shaped self-interlocking block flexible protection belts, wherein the respective interlocking block flexible protection belts are stacked layer by layer to form a stepped structure, wherein the bottom layer of the self-interlocking block flexible protection belt is located on the mud surface of the bottom of the water, and the top layer of the self-interlocking block flexible protection belt is exposed from the water surface, and the front bottom of the upper layer of the self-interlocking block flexible protection belt is pressed on the rear top of the lower layer of the self-interlocking block flexible protection belt to form an overlapping area (4); the self-interlocking block flexible protection belt comprises a plurality of groups of steel pipe piles (1) arranged in a fan-shaped ring shape, wherein a protection locking block (2) is installed on each group of steel pipe piles (1) and the protection locking block (2) is sunk underwater along the steel pipe piles (1) where it is located, and adjacent protection locking blocks (2) are interlocked and connected, and the rear space of each layer of the self-interlocking block flexible protection belt is filled with sand and gravel to form an entry body (3).

2. The underwater intrusion protection system according to claim 1, characterized in that: Two longitudinally penetrating mounting holes are provided on the protection locking block (2); the number of steel pipe piles (1) corresponding to each protection locking block (2) is two, and the two steel pipe piles (1) are respectively located in the two mounting holes of the protection locking block (2).

3. The underwater intrusion protection system according to claim 2, characterized in that: The protective lock block (2) is a hollow high-strength plastic lock block. A filling hole for injecting a filler into the inner cavity is provided at the top of the protective lock block (2), and a sealing buckle cover is provided on the filling hole.

4. The underwater intrusion protection system according to claim 3, characterized in that: The width of the overlapping area (4) is equal to 15-30% of the width of the protective locking block (2).

5. The underwater intrusion protection system according to claim 4, characterized in that: The lower end of the steel pipe pile (1) passes through the unstable soil layer of the bottom mud surface and is driven into the bearing layer. The depth of the driving into the bearing layer is equal to 1 / 3 to 1 / 2 of the pile length of the steel pipe pile (1).

6. The underwater intrusion protection system according to claim 5, characterized in that: The underwater intrusion protection system is a spur dike, which is perpendicular or oblique to the river bank (5) and extends into the river channel, or the underwater intrusion protection system is located on the inner side of the breach (6) on the river bank (5) and closes the breach (6).

7. The construction method of the underwater intrusion protection system according to claim 6, characterized in that: Based on the amphibious rescue ship, the following steps are included: Step S1, preparation before construction, mapping the river terrain, water depth, flow velocity and geological conditions, determining the pile layout parameters of the occupation protection system, checking the stability of the construction area and clearing obstacles to ensure that the construction ship can dock safely; Step S2, the construction ship is positioned and anchored. The amphibious rescue ship sails to the designated construction area, starts the autonomous anchoring system to fix the hull, and uses the positioning pile trolley of the construction ship to adjust the level of the hull; Step S3, steel pipe piles (1) are driven, using the GPS system and underwater depth sounder carried by the amphibious rescue ship to confirm the pile position coordinates and depth, using the pile positioning trolley of the construction ship to adjust the ship's posture to ensure the verticality of the piles, and using the pile driving device of the construction ship to drive the steel pipe piles (1) according to the pile spacing and burial depth required by the design; Step S4, installing the protective locking block (2), installing the protective locking block (2) on the injected steel pipe pile (1), injecting filler into the protective locking block (2) and sealing it, so that the protective locking block (2) naturally sinks along the steel pipe pile (1) where it is located by gravity, and the completely sunken protective locking blocks (2) are sequentially connected and embedded underwater to form a self-embedded flexible protection belt as a continuous anti-collision barrier; Step S5, filling sand and gravel into the occupied area. Sand and gravel are filled behind the formed self-interlocking block flexible protection belt to form an occupied layer. The filling order is gradually filled from the outside to the center of the river channel. The sand and gravel layer after filling is compacted to ensure the density of the occupied layer. Step S6, layered retreat construction, after completing the construction of the first layer, the amphibious rescue ship is retreated and moved, and steps S2 to S5 are repeated to complete the construction of the upper layers until the top elevation of the uppermost entry layer exceeds the water surface height, and each entry layer constitutes an entry body (3), and each interlocking block flexible protection belt and the entry body constitute an underwater entry protection system.

8. The construction method according to claim 7, characterized in that: step S2 In step S3, the horizontality of the amphibious rescue ship is controlled within 5 mm; in step S4, the verticality of the steel pipe pile (1) is re-measured every time the steel pipe pile (1) is driven at a depth of 2 m, ensuring that the inclination rate is less than 1%, and the deviation between the driven position of the steel pipe pile (1) and the designed pile position is less than 10 cm; in step S5, the filler injected into the protective lock block (2) is gravel and / or water, and the density of the filled protective lock block (2) is greater than 1200 kg / m 3 .

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