CN111795625B - Method and device for protecting shock waves in water of blasting excavation of seabed foundation pit - Google Patents

Abstract

The invention discloses a method and device for protecting shock waves in water by blasting and excavating a submarine foundation pit, comprising: (1) determining the position of the protection device according to the size of the foundation pit; (2) making a flexible protective wall, including a protective panel, a protective steel mesh, springs and Connecting parts, protective panels include open-cell polyurethane foam panels, neoprene interlayers and air interlayers; (3) Install protective devices, including flexible protective walls, bottom section steel, perforated steel pipes and high-pressure gas pipes, and the lower part of the flexible protective wall is connected to the bottom Section steel, the outer side of the bottom section steel is connected with a perforated steel pipe, and the perforated steel pipe is connected to the high-pressure air pipe, and the flexible protective wall is tied into a whole with a rope; (4) Inflate to form a bubble curtain. The invention combines the flexible protective wall and the bubble curtain, which can effectively reduce the shock wave in the water near the blasting area, and protect the construction personnel, marine organisms, the surrounding aquatic environment and underwater structures; at the same time, the shock wave is absorbed by the protective panel. , reduce the shock wave reflection and protect the foundation pit.

Description

A method and device for protecting shock waves in water by blasting and excavating a submarine foundation pit

technical field

The invention relates to the technical field of engineering blasting, in particular to a method and device for protecting shock waves in water during blasting and excavation of a submarine foundation pit.

Background technique

In recent years, the blasting and excavation technology of submarine foundation pits has been widely used in offshore wind power, bridges and other construction projects. The water shock wave generated during blasting construction will inevitably cause harm to construction personnel, marine organisms, surrounding aquatic environment and underwater structures.

In the protection of shock waves in water, the methods currently used are: bubble curtain technology and setting up explosion-proof walls. Bubble curtain technology is to form a continuously rising and dense bubble curtain by introducing high-pressure gas between the blasting area and the protected object, and use the sudden change of wave impedance between the media to hinder the propagation of shock waves in water; but for the elimination of short-range underwater blasting shock waves The protective effect is not obvious. The explosion-proof wall relies on the concept of strength, ductility and energy absorption of the structure to resist explosion-proof loads; however, due to its large size, high construction cost, and complicated construction, it is difficult to popularize it on a large scale.

"A bubble curtain device" disclosed in Chinese patent CN 201826334 U includes an air compressor and a launch tube arranged on the suspension device, and the peak clipping rate is between 42.9% and 97.3%. However, the single bubble curtain device has a limited clipping effect due to the rising and spreading of bubbles. To achieve a certain effect, multiple high-power air compressors are required to act at the same time, and the energy consumption is relatively high. The "underwater shock wave protection device" disclosed in Chinese patent CN 107883824A includes laminated bamboo rafts and counterweights bound by bamboo tubes with a moisture content of more than 40%. The natural airtight airbags in each bamboo tube are used to form a gas barrier, and the dielectric waves pass through them. The sudden change in impedance impedes shock wave propagation. However, the device is bulky and difficult to construct, and is not suitable for large-scale use, and may cause the bamboo tube to rupture during the protection process, thereby causing secondary harm.

The above scheme is generally set up for specific stationary protection objects, but there is still a threat to the safety of marine organisms and construction personnel; and the reflection of the shock wave after encountering the bubble curtain or ordinary protective wall is likely to cause unfavorable effects to the foundation pit after the excavation is completed. influences.

Therefore, the present invention proposes an underwater shock wave protection method which is set in a near blasting area and can significantly reduce the influence of underwater shock waves.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a method for protecting shock waves in water by blasting and excavating seabed foundation pits, which utilizes the combination of protective partition and bubble curtain technology to combine double protection to eliminate waves in the near blasting area and reduce the impact of underwater shock waves on the surrounding water environment and construction. At the same time, it can effectively absorb shock waves, reduce reflections, and protect the stability of the foundation pit.

The method for protecting the shock wave in the underwater foundation pit blasting and excavation provided by the method of the present invention comprises the following steps:

(1) Determine the arrangement position of the protective device according to the plane size of the foundation pit. The protective device is arranged so that its covering diameter is 2-10m larger than that of the foundation pit on a plane, and it is an area from the top of the covering layer to the water surface on a vertical plane.

(2) Make flexible protective walls, including protective panels, protective steel meshes, springs and connectors. The protective panel comprises a layer of open-cell polyurethane foam panels, two layers of neoprene rubber spacers and a layer of air spacer layers, and the layers are tightly connected. Both sides of the protective panel are connected with the protective steel mesh through springs, the protective steel mesh has a supporting function, and the vibration of the protective panel drives the compression of the spring to absorb part of the energy; the upper and lower sides of the protective steel mesh are connected with steel bars. The parts are used for the interconnection between the bottom section steel and the flexible protective wall and each flexible protective wall.

The open-cell polyurethane foam panel is located on the wave-facing side, in a "wavy" shape, with a thickness of 10-20mm, a wave amplitude of 5-10mm, and a wavelength-to-amplitude ratio of 2-5, which can absorb shock waves and consume part of the energy. The air spacer is sandwiched between the two layers of neoprene spacer and is closely connected with the open-cell polyurethane foam panel. The edge of the porous polyurethane foam panel is treated with rubber for waterproofing. The thickness of the front neoprene rubber layer located on the side of the air partition near the foundation pit is 20-30mm, and the thickness of the rear neoprene rubber layer located on the outermost side is 10-15mm. . The neoprene barrier is the primary material that dissipates shock wave energy. The protective panel can effectively absorb shock waves, consume energy, and prevent shock waves from propagating to the outside.

The length of each flexible protective wall is 5-12m, and the height is related to the water depth, which is 5-30m.

(3) Install a protective device, the protective device includes a flexible protective wall, a bottom section steel, a steel pipe with holes and a high-pressure gas pipe. The bottom section steel is located at the bottom of the flexible protective wall, and serves as a counterweight and also plays a positioning role. The perforated steel pipe is connected to the outside of the bottom section steel, and has the same length and the same number as the bottom section steel; one end of the perforated steel pipe is blocked, and the other end is connected to the high-pressure gas pipe, which is communicated with the air compressor to form bubbles Curtain device.

The flexible protective wall is formed by tying the flexible protective wall at intervals with connecting ropes. The connecting ropes are ordinary ropes. The entire protective device is bound once every 3-6m from the bottom to the top, and each binding is 2-3 circles, which plays a role of fixing and supporting; Adjacent steel mesh can be connected with steel wire to form a whole.

The overall structure of the protective device consists of 6-10 flexible protective walls and the same number of bottom section steel and perforated steel pipes.

(4) Inflate to form a bubble curtain. The perforated steel pipe is inflated from the high-pressure gas pipe to form a dense bubble curtain that rises steadily.

The present invention also provides a shock wave protection device in underwater foundation pit blasting and excavation, comprising a flexible protective wall, a bottom section steel, and a bubble curtain device, wherein the bubble curtain device includes an air compressor, a perforated steel pipe and a high-pressure gas pipe. The wall includes a protective panel, a protective reinforcement mesh, springs and connectors, the protective panel includes a layer of open-cell polyurethane foam panel, two layers of neoprene rubber spacer and an air spacer, the protective panel is on both sides by springs Connected to the protective steel mesh, the entire flexible protective wall is followed from outside to inside by protective steel mesh, spring, neoprene interlayer, air interlayer, neoprene interlayer, open-cell polyurethane foam panel, spring and protective steel mesh. The layers are tightly connected, and each node of the protective steel mesh is connected with a spring, and the upper and lower sides of the protective steel mesh are connected with steel connecting pieces, which are respectively used between the bottom section steel and the flexible protective wall and each flexible The interconnection between the protective walls, the perforated steel pipe is connected to the outside of the bottom section steel, and has the same length and the same number as the bottom section steel, one end of the perforated steel pipe is blocked, and the other end is connected to the high-pressure gas pipe. Connected with the air compressor, the flexible protective wall is arranged in a circle around the foundation pit, and each block is connected with a connecting rope, which can be disassembled and reused after use.

In the above-mentioned underwater shock wave protection device for blasting and excavation of a submarine foundation pit, the open-cell polyurethane foam panel is located on the wave-facing side and is "wave-shaped".

In the above-mentioned underwater shock wave protection device for blasting and excavating a submarine foundation pit, the air spacer is sandwiched between the two layers of neoprene spacer, and is closely connected with the open-cell polyurethane foam panel, and the air spacer welcomes waves. The side surfaces are tapered and rubberized for water repellency at the edges of the open-cell polyurethane foam panels.

The above-mentioned shock wave protection device for blasting and excavating underwater foundation pits has a thickness of 10-20 mm, a wave amplitude of 5-10 mm, and a wavelength-to-amplitude ratio of 2-5.

In the above-mentioned blasting and excavation water shock wave protection device for a submarine foundation pit, the thickness of the air barrier is 10-20mm, and the thickness of the front neoprene rubber barrier located on the side of the air barrier near the foundation pit is 20-30mm, The outermost rear neoprene compartment is 10-15mm thick.

The above-mentioned shock wave protection device for underwater foundation pit blasting and excavation, the length of each flexible protective wall is 5-12m, the height is 5-30m related to the water depth, and the overall structure of the protective device is composed of 6-10 flexible protective walls. It is composed of the same number of bottom section steel and perforated steel pipe, and the perforated steel pipe is connected to the air compressor through the high-pressure gas pipe.

In the above-mentioned underwater shock wave protection device for blasting and excavation of a submarine foundation pit, the flexible protective walls are bound together by connecting ropes at intervals to form a whole. The connecting ropes are ordinary ropes, and the entire protective device is bound from bottom to top at intervals of 3-6m, 2-3 circles at a time, to play a role of fixing and supporting; it can also be used to connect adjacent steel meshes with steel wires to form them. overall.

The above-mentioned underwater shock wave protection device for blasting and excavating a submarine foundation pit is used for the protection of marine organisms and construction personnel moving in the water and the protection of the foundation pit.

The beneficial effects of the shock wave protection method in the underwater foundation pit blasting excavation provided by the present invention are:

(1) The present invention proposes a dual protection method combining bubble curtains and protective partitions, which can effectively absorb shock waves and consume their energy in the near blasting area. At the same time, the wave-absorbing effect of the flexible protective wall structure is used to reduce the reflection of the shock wave and better protect the excavation foundation pit from the damage of the shock wave reflection.

(2) The polyurethane foam material on the surface of the protective panel has a similar wave impedance to the water medium, which can absorb shock waves well. The opening material can enhance the reflection and refraction of shock waves in the holes, and enhance the loss of shock waves. The surface is designed to be "wave-shaped" "The absorption area is enlarged, and at the same time, tiny particles can be added in the polyurethane foam to strengthen the scattering of the incident wave to consume the energy of the shock wave; in addition to preventing the shock wave from propagating outward, the air barrier can also generate large deformation to consume the shock wave through resonance. The energy, whose surface is designed to be tapered, enhances the reflection and refraction of the shock wave to increase energy dissipation, and is absorbed again in the neoprene barrier and polyurethane foam layer. Neoprene, as the main wave absorbing material, is a viscoelastic polymer material like polyurethane foam. It is resistant to water pressure, corrosion resistance, has high elasticity and certain tensile strength, and the neoprene layer has higher internal friction and shock wave incidence. Afterwards, due to the damping effect, it quickly attenuates and is converted into heat energy to dissipate. At the same time, the neoprene rubber has a closed cell structure, which can strengthen the reflection, refraction and scattering of the shock wave propagating in it, and effectively weaken the shock wave in water.

(3) The protective panel is fixed between the two steel meshes by the spring. When the flexible protective panel is deformed by the shock wave, it can drive the spring to compress and deform, consume part of the energy, and effectively reduce the shock wave.

(4) The protective devices used in the method of the present invention mainly include: protective panels, steel meshes, springs, connectors, bottom profiles, air compressors, perforated steel pipes and high-pressure air pipes, etc. During use, the devices are constructed and installed It is flexible and convenient, some devices can be reused, and the cost is low; the protective panel can be rolled up to save space, facilitate transportation and storage, and is suitable for large-scale promotion.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a shock wave protection device in the underwater foundation pit blasting and excavation according to the present invention.

FIG. 2 is a schematic top-view structural diagram of a shock wave protection device in water for blasting and excavating a submarine foundation pit according to the present invention.

FIG. 3 is a schematic structural diagram of a flexible protective wall.

Figure 4 is an exploded schematic diagram of the flexible protective wall.

In the figure, 1—flexible protective wall; 2—section steel at the bottom; 3—perforated steel pipe; 4—high pressure gas pipe; 5—protective panel; 6—reinforced mesh; 7—spring; 8—connector; 9—polyurethane foam panel; 10—Neoprene rubber spacer; 11—Air spacer.

Detailed ways

The method of the present invention will be further described in detail below through examples and in conjunction with the accompanying drawings.

Example 1

A shock wave protection device in underwater foundation pit blasting and excavation, the protection device includes a flexible protective wall 1, a bottom section steel 2, and a bubble curtain device, and the bubble curtain device includes an air compressor, a perforated steel pipe 3 and a high-pressure gas pipe 4. The flexible protective wall 1 includes a protective panel 5, a protective steel mesh 6, a spring 7 and a connector 8, the protective panel 5 includes a layer of open-cell polyurethane foam panel 9, two layers of neoprene rubber spacers 10 and an air spacer layer 11. Both sides of the protective panel 5 are connected to the protective steel mesh 6 through springs 7, and the entire flexible protective wall 1 is followed by the protective steel mesh 6, spring 7, neoprene interlayer 10, and air interlayer 11 from outside to inside. , neoprene interlayer 10, open-cell polyurethane foam panel 9, spring 7 and protective steel mesh 6, the layers are tightly connected, and each node of the protective steel mesh 6 is connected with a spring 7, the protective steel The upper and lower sides of the net 6 are connected with steel bar connectors 8, which are respectively used for the interconnection between the bottom section steel 2 and the flexible protective wall 1 and between each flexible protective wall 1. The perforated steel pipe 3 is connected to the bottom section steel. 2 outside, and the length and quantity are the same as the bottom section steel 2, one end of the perforated steel pipe 3 is blocked, the other end is connected to the high-pressure gas pipe 4, the high-pressure gas pipe is communicated with the air compressor, and the flexible protective wall 1 surrounds the foundation pit One turn, detachably connected together.

Further, in the above-mentioned underwater shock wave protection device for subsea foundation pit blasting and excavation, the open-cell polyurethane foam panel 9 is located on the wave-facing side, that is, facing the shock wave, in a "wave shape".

Further, in the above-mentioned blasting and excavation water shock wave protection device for a submarine foundation pit, the air spacer 11 is sandwiched between the two-layer neoprene spacer layers 10, and is closely connected with the open-cell polyurethane foam panel 9, so The wave-facing side surface of the air barrier 11 is tapered, and the edge of the open-cell polyurethane foam panel 9 is treated with rubber for waterproofing.

Further, in the above-mentioned underwater shock wave protection device for blasting and excavating a submarine foundation pit, the thickness of the open-cell polyurethane foam panel 9 is 10-20 mm, the wave amplitude is 5-10 mm, and the wavelength-to-amplitude ratio is 2-5.

Further, in the above-mentioned blasting and excavation water shock wave protection device for a submarine foundation pit, the thickness of the air barrier 11 is 10-20 mm, and the thickness of the front neoprene barrier located on the side of the air barrier by the foundation pit is thick. 20-30mm, the outermost rear neoprene compartment is 10-15mm thick.

Further, in the above-mentioned blasting and excavation water shock wave protection device of a submarine foundation pit, the length of each described flexible protective wall 1 is 5-12m, the height is related to the water depth, and is 5-30m, and the overall structure of the protection device is 6-10 m. It is composed of a flexible protective wall 1 and the same number of bottom section steel 2 and steel pipe 3 with holes.

Further, in the above-mentioned underwater shock wave protection device for blasting and excavation of a submarine foundation pit, the flexible protective walls 1 are bound together by connecting ropes at intervals to form a whole. The connecting ropes are ordinary ropes, and the adjacent flexible protective walls are tied at intervals of 3-6m from bottom to top, and 2-3 circles are tied each time to play the role of fixing and supporting; steel wires can also be used to connect adjacent steel bars The net makes it whole.

Example 2

An offshore wind power pile foundation blasting excavation project is located in a near-coastal area, with a water depth of 30m and a covering thickness of 10-30m. According to the engineering requirements, after the mechanical excavation of the pilot well, the wind power pile foundation pit with a diameter of 8m is excavated by blasting under the covering layer, and the foundation pit is 15m deep into the rock foundation. As shown in Figure 1 to Figure 4, the concrete steps of the blasting and excavation water shock wave protection method of the submarine foundation pit are as follows:

(1) Determine the arrangement position of the protective device according to the plane size of the foundation pit. In this project, the diameter of the foundation pit is 8m, and the diameter of the protection area is 2m larger than the diameter of the foundation pit on the plane, taking 10m, as shown in Figure 2; on the vertical surface, it is the area from the top of the covering layer to the water surface, as Figure 1.

(2) Making a flexible protective wall 1, including a protective panel 5, a protective steel mesh 6, a spring 7 and a connector 8, as shown in FIG. 4 . The protective panel 5 includes a layer of open-cell polyurethane foam panel 9 , two layers of neoprene rubber spacers 10 and a layer of air spacer layers 11 , and the layers are tightly connected, as shown in FIG. 3 . Both sides of the protective panel 5 are connected to the protective steel mesh 6 through springs 7, and the protective steel mesh 6 has a supporting function. The vibration of the protective panel 5 drives the compression of the spring 7 to absorb part of the energy; Reinforcing bar connectors 8 are connected on both sides, which are respectively used for the mutual connection between the bottom section steel 2 and the flexible protective wall 1 and each flexible protective wall 1 .

The open-cell polyurethane foam panel 9 is located on the wave-facing side, in a "wavy" shape, with a thickness of 15 mm, a wave amplitude of 5 mm, and a wavelength-to-amplitude ratio of 4, which can absorb shock waves and consume part of the energy. The air spacer 11 is sandwiched between the two layers of neoprene spacer 10, and is closely connected with the open-cell polyurethane foam panel 9. The air spacer 11 is tapered, with a thickness of 15mm, and is in the open-cell polyurethane foam panel 9. The edge of the foam panel 9 is treated with rubber for waterproofing, the front neoprene interlayer 9 located on the side of the air interlayer 11 close to the foundation pit is 30mm thick, and the rear neoprene interlayer 9 located on the outermost side is 10mm thick; Effectively absorb shock waves, consume energy, and prevent shock waves from propagating to the outside. Each flexible protective wall 1 is 10m long and 30m high.

(3) Install protective devices, including flexible protective walls 1 , bottom section steel 2 , and a bubble curtain device, which includes an air compressor, a perforated steel pipe 3 and a high-pressure gas pipe 4 . The bottom section steel 2 is located at the bottom of the flexible protective wall 1, and serves as a counterweight and also plays a positioning role. The perforated steel pipe 3 is connected to the outside of the bottom section steel 2, and has the same length and the same number as the bottom section steel 2; one end of the perforated steel pipe 3 is blocked, and the other end is connected to the high-pressure gas pipe 4, which is connected to the air pressure. machine connection.

The flexible protective wall 1 is formed as a whole by tying the flexible protective wall 1 with connecting ropes at intervals. The connecting ropes are ordinary ropes. The adjacent flexible protective walls are bound once every 5m from the bottom to the top, and each binding is 2-3 circles to play the role of fixing and supporting. ; Can also use steel wire to connect adjacent steel mesh to form a whole.

The overall structure of the protective device consists of 6 flexible protective walls 1 and the same number of bottom section steel 2 and steel pipe 3 with holes.

(4) Inflate to form a bubble curtain. The perforated steel pipe 3 is inflated from the high-pressure gas pipe 4 to form a dense bubble curtain that rises steadily.

It should be noted that the technologies not described in detail in the present invention all adopt the prior art.

The above-mentioned embodiments are only examples to illustrate the technical solutions of the present invention. The underwater anti-explosion protection device based on shock wave reflection and energy dissipation involved in the present invention is not limited to the structures described in the above embodiments, but is subject to the scope defined by the claims. Any modifications or additions or equivalent substitutions made by those skilled in the art of the present invention on the basis of this embodiment fall within the scope of protection claimed by the present invention.

Claims (5)

1. A method for protecting shock waves in water of blasting excavation of a seabed foundation pit is characterized by comprising the following steps: (1) determining the arrangement position of the protective device according to the plane size of the foundation pit; (2) manufacturing a flexible protection wall, wherein the flexible protection wall comprises a protection panel, a protection reinforcing mesh, a spring and a connecting piece, and the protection panel comprises an open-cell polyurethane foam panel, a chloroprene rubber interlayer and an air interlayer; the whole flexible protection wall sequentially comprises a protection reinforcing mesh, a spring, a rear chloroprene rubber interlayer, an air interlayer, a front chloroprene rubber interlayer, an open-cell polyurethane foam panel, a spring and a protection reinforcing mesh from outside to inside; the open-cell polyurethane foam panel is positioned on the wave-facing side and is in a wave shape; (3) the installation protection device comprises a flexible protection wall, bottom section steel, a steel pipe with holes and a high-pressure air pipe, wherein the lower part of the flexible protection wall is connected with the bottom section steel, the outer side of the bottom section steel is connected with the steel pipe with holes, the steel pipe with holes is communicated with the high-pressure air pipe, the high-pressure air pipe is communicated with an air compressor, and the flexible protection wall is integrally bound by using a rope; (4) inflating to form a bubble curtain;

wherein, the arrangement position of the protective device in the step (1) is that the diameter of the covering layer on the plane is 2-10m larger than that of the foundation pit, and the vertical plane is the area from the top of the covering layer to the water surface;

the protective panel in the step (2) comprises a layer of open-cell polyurethane foam panel, two layers of chloroprene rubber interlayers and an air interlayer, wherein the layers are tightly connected; both sides of the protection panel are connected with a protection reinforcing mesh through springs, and the upper side and the lower side of the protection reinforcing mesh are connected with connecting pieces;

wherein the thickness of the open-cell polyurethane foam panel is 10-20mm, the wave amplitude is 5-10mm, and the wave length-amplitude ratio is 2-5; the air interlayer is clamped between the two layers of chloroprene rubber interlayers and is tightly connected with the open-pore polyurethane foam panel, the surface of the wave-facing side of the air interlayer is conical and has the thickness of 10-20mm, rubber is used for waterproof treatment at the edge of the open-pore polyurethane foam panel, the thickness of the front chloroprene rubber interlayer positioned at the side of the air interlayer close to the foundation pit is 20-30mm, and the thickness of the rear chloroprene rubber interlayer positioned at the outermost side is 10-15 mm; each flexible protective wall is 5-12m in length and 5-30m in height relative to water depth.

2. The method for protecting the shock wave in the excavation water by the blasting of the seabed foundation pit according to claim 1, wherein: and (4) the bottom section steel in the step (3) is positioned at the bottom of the flexible protection wall and connected with the flexible protection wall through a connecting piece, and the length of the bottom section steel is 5-12 m.

3. The method for protecting the shock wave in the excavation water by the blasting of the seabed foundation pit according to claim 1, wherein: the steel pipes with holes in the step (3) are connected to the outer side of the bottom section steel, and are consistent in length and number with the bottom section steel; one end of the steel pipe with the hole is plugged, and the other end of the steel pipe with the hole is communicated with the high-pressure air pipe.

4. The method for protecting the shock wave in the excavation water by the blasting of the seabed foundation pit according to claim 1, wherein: wherein, the ropes in the step (3) are steel wires or common ropes, and are bound once every 3-6m from the outer side of the flexible protective wall from bottom to top, and the binding is carried out for 2-3 circles each time; or connecting adjacent protective reinforcing meshes by steel wires to form the whole protective panels; the whole protection device consists of 6-10 flexible protection walls, bottom section steel and steel pipes with holes, wherein the bottom section steel and the steel pipes are the same in number.

5. The method for protecting the shock wave in the excavation water by the blasting of the seabed foundation pit according to claim 1, wherein: and (4) inflating the perforated steel pipe through the high-pressure air pipe by using the air compressor to form a dense bubble curtain which stably rises.

Images