CN111335177B - Underwater dry operation construction system and method by bottomless air bag method - Google Patents

Abstract

The present invention provides a bottomless airbag method underwater dry operation construction system and method, the system includes an airbag with an open bottom made of flexible material, an annular airbag bottom made of rigid material, a counterweight pressed on the airbag bottom, a submarine for transporting construction personnel and construction materials, a submarine channel arranged below the annular airbag bottom and connecting the inside and outside of the airbag, an air compressor, a generator and a concrete pump arranged above the water surface, the airbag is located below the water surface, the bottom of the airbag lands on the seabed after leveling construction, the airbag has an inflatable inner cavity for construction operations, an air delivery pipe, a cable and a concrete pump delivery pipe are arranged in the inflatable inner cavity, respectively passing through the airbag and connecting with the air compressor, the electric motor and the concrete pump above the water surface, and the inflatable inner cavity maintains an air inflation pressure that matches the seabed pressure. The present invention can form a waterless working environment at any position underwater, can significantly improve the construction quality, and compared with the cofferdam method construction, its construction cost is low, safe and controllable.

Description

Bottomless airbag method underwater dry operation construction system and method

Technical Field

The invention relates to the technical field of underwater construction, in particular to underwater dry operation construction technology.

Background Art

With the development of social economy, a large number of construction projects need to be constructed underwater, such as the substructure of cross-sea bridges and the foundation of offshore wind turbine stations. At present, the relatively mature underwater construction technologies mainly include underwater concrete pouring by duct method, cofferdam construction, underwater installation and construction of prefabricated components, etc. However, these construction technologies have their own limitations. The most difficult problem to overcome is that with the increase of water depth, the difficulty of construction technology and construction cost will also increase, and the safety risk will also increase.

In order to solve the technical difficulties of deep-water construction, the present invention intends to build a waterless construction working environment under water, so that various construction tasks can be completed in the waterless working environment.

Summary of the invention

The object of the present invention is to provide a system constructed under water for providing a waterless construction working environment.

In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a bottomless airbag method underwater dry construction system, which includes an airbag with an open bottom made of flexible material, an annular airbag bottom made of rigid material, a counterweight pressed on the bottom of the airbag, a submarine for transporting construction personnel and construction materials, a submarine passage arranged below the bottom of the annular airbag and connecting the inside and outside of the airbag, an air compressor, a generator and a concrete pump arranged above the water surface, the airbag is located below the water surface, the bottom of the airbag lands on the seabed after leveling construction, the airbag has an inflatable inner cavity for construction operations, an air supply pipe, a cable and a concrete pumping pipe are arranged in the inflatable inner cavity, which respectively penetrate the airbag and are connected to the air compressor, the electric motor and the concrete pump above the water surface, the inflatable inner cavity maintains an air inflation pressure that matches the seabed pressure, and the inflation pressure is calculated and determined according to the height of the airbag:

_ps ＝K(ρgh+ _P0 )

_ps ——test pressure

P ₀ —— atmospheric pressure

ρ——density of water

g——acceleration due to gravity

h——Height of the airbag

K——Safety factor, K value shall not be less than 1.4.

Preferably, the bottom opening of the airbag has a horizontal annular steel plate, a vertical cylindrical protective wall is arranged on the annular steel plate, the airbag is attached to the inner side of the cylindrical protective wall, and a counterweight is pressed on the outer side of the cylindrical protective wall.

Preferably, a plurality of supporting ribs are provided between the cylindrical protective wall and the annular steel plate.

At the concave position where the seabed is uneven, the airbag bag opening hangs down from under the annular steel plate until it contacts the seabed.

Another object of the present invention is to provide an underwater dry operation construction method.

A bottomless airbag method for underwater dry work construction, which uses any of the bottomless airbag method underwater dry work construction systems described above, and adopts the following steps for construction:

(s1) manufacturing the airbag and the bottom of the airbag;

(s2) Leveling the seabed and excavating submarine passages;

(s3) After the airbag passes the inspection, the wires, air supply pipes, concrete pump pipes and the through-holes of the airbag are sealed and connected, and the airbag is sunk into the seabed according to the predetermined position. After the airbag enters the water, the air inside the airbag must be drained;

(s4) After the airbag sinks to the seabed, check whether the bottom of the airbag falls on the flat seabed plane. When the bottom of the airbag lands in a concave position on the seabed, lower the airbag bag mouth until it contacts the bottom of the seabed, and then install the counterweight above the bottom of the airbag;

(s5) inflating the inner cavity of the airbag;

(s6) Construction personnel and materials enter the airbag through the submarine channel for construction. Large materials that cannot be loaded into the submarine are sunk into the submarine channel through ropes and then pulled into the airbag cavity through ropes. During the construction process, air must be continuously supplied to the airbag to ensure that the air inside the airbag is fresh;

(s7) Construction workers are carrying out basic construction inside the airbag;

(s8) After the foundation construction is completed, the airbag is floated up to the predetermined height for the pier body construction. A working platform is first set up at the bottom of the airbag to close the bottom opening of the airbag, and a scaffolding for the working platform is set up. The entrance and exit for construction personnel and construction materials are reserved on the scaffolding;

(s9) According to the effective space of the airbag, the floating height of the airbag is adjusted every time a section of pier body concrete is poured, until the pier body is constructed above the water surface and the airbag is removed.

The inflation pressure of step (s5) is calculated and determined based on the height of the airbag:

_ps ＝K(ρgh+ _P0 )

_ps ——test pressure

P ₀ —— atmospheric pressure

ρ——density of water

g——acceleration due to gravity

h——Height of the airbag

K——Safety factor, K value is not less than 1.4,

After inflation is completed, the inflation volume needs to be recorded as the control inflation volume v of the airbag underwater.

The inflation in step (s5) should be carried out in steps, according to the controlled inflation volume v obtained from the airtightness experiment, and in the steps of 0.3v-0.6v-0.9v-1.0v. After each inflation step, check the state of the airbag to see if there is any kink or leakage in the airbag.

Before the floating airbag in step (s8), install the seabed anchor first, effectively connect the anchor and the airbag, reserve anchor steel bars on the foundation in advance, anchor the airbag on the foundation, and after the anchor connection is completed, remove part of the counterweight to allow the airbag to slowly float to a predetermined height.

The weight is calculated based on the volume of the airbag:

G——Counterweight

m——the overall mass of the airbag and bottom steel plate

v - the volume of the airbag when it is filled with air

ρ——density of water

ρ′——density of the counterweight

K——Safety factor, where the K value is not less than 1.4.

When the water depth exceeds 20m, construction workers inside the inner capsule wear decompression respirators.

The advantage of the present invention is that a waterless working environment can be formed at any position underwater, which can significantly improve the quality of the project. Compared with the cofferdam construction method, the construction cost is low and the safety is controllable.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic elevation view of the installation of the airbag on the leveled seabed.

FIG. 2 is a schematic elevation view of the installation of the airbag on a seabed that is not completely flat.

FIG. 3 is a schematic elevation view of the pier construction after the airbag floats up.

FIG. 4 is a schematic diagram of the airbag bottom structure.

FIG. 5 is a cross-sectional view taken along line A-A in FIG. 4 .

Figure 6 is a physical principle diagram.

Among them, airbag 101, working platform 102, counterweight 103, anchor 104, concrete pumping pipe 105, wire 106, air pipe 107, light 108, material hauling rope 109, air compressor 110, generator 111, concrete pump 112, airbag bottom 113, annular steel plate 114, cylindrical wall 115, supporting rib 116, submarine channel 117, material 200

DETAILED DESCRIPTION

The physical principles involved in the design and implementation of the present invention are shown in FIG6 .

Put the cup upside down in water (the bottom of the cup does not need to be sealed). Under the action of water pressure, the air in the cup cannot escape, thus forming a waterless environment in the cup.

According to the liquid pressure calculation formula, p = ρgh, the gas pressure inside the cup is p = ρgH + P ₀ (P ₀ is the atmospheric pressure). The gas pressure inside the cup is equal everywhere, so it can be seen that the pressure at any point on the outer wall of the cup is less than the pressure on the inner wall of the cup. Therefore, it is considered to use flexible materials to sink into the water and fill the inside with air to form a waterless construction working environment.

The buoyancy of the cup is equal to the gravity of the water displaced by the cup. During construction, the larger the volume of the air bag formed, the greater the buoyancy it will experience, so it is necessary to solve the anchoring measures of the air bag in the water.

As shown in Figures 1 to 5, a bottomless airbag method underwater dry construction system of the present invention includes an airbag 101 with an open bottom made of flexible rubber material, an annular airbag bottom 113 made of steel plate, a counterweight 103 pressed on the airbag bottom, a submarine for transporting construction personnel and construction materials, a submarine channel 117 arranged below the annular airbag bottom and connecting the inside and outside of the airbag, an air compressor 110, a generator 111 and a concrete pump 112 arranged above the water surface.

The airbag 101 is located under the water surface. The airbag has an inflatable inner cavity for construction operations. An air delivery pipe 107, a cable 106 and a concrete pumping pipe 105 are respectively inserted through the airbag and connected to an air compressor 110, an electric motor 111 and a concrete pump 112 above the water surface. The inflatable inner cavity maintains an air inflation pressure that matches the seabed pressure. The inflation pressure is calculated and determined according to the height of the airbag:

_ps ＝K(ρgh+ _P0 )

_ps ——test pressure

P ₀ —— atmospheric pressure

ρ——density of water

g——acceleration due to gravity

h——Height of the airbag

K——Safety factor, K value shall not be less than 1.4.

The bottom opening 113 of the airbag lands on the seabed after leveling. As shown in FIG4 , the bottom opening of the airbag has a horizontal annular steel plate 114, on which a vertical cylindrical protective wall 115 is arranged. The airbag is attached to the inner side of the cylindrical protective wall, and a counterweight is pressed on the outer side of the cylindrical protective wall. A plurality of supporting ribs 116 are arranged between the cylindrical protective wall and the annular steel plate.

The underwater dry operation construction method of the present invention is implemented according to the following steps:

(s1) Making the airbag and the bottom of the airbag. In order to ensure that the bottom of the airbag has a fixed shape and facilitate the positioning of the airbag on the seabed, the bottom of the airbag is made of steel and the airbag is made of rubber with good airtightness.

(s2) When constructing the pedestal foundation on the seabed, it is necessary to first level the seabed to ensure that the bottom of the airbag falls on a horizontal plane, and to dig a submarine passage in advance to facilitate the entry and exit of personnel and materials.

(s3) Before launching the airbag, check the air tightness and pressure bearing capacity of the airbag, and verify the tensile strength of the airbag. The air tightness inspection method of the airbag is to seal the bottom of the airbag, and then inflate it for air tightness test. When the airbag is in water, the outer wall of the airbag is subjected to water pressure, and the inner wall of the airbag is subjected to air pressure. The pressures will offset each other, and only the top surface of the airbag is subjected to the largest pressure difference. Therefore, the inflation pressure is calculated and determined according to the height of the airbag:

_ps ＝K(ρgh+ _P0 )

_ps ——test pressure

P ₀ —— atmospheric pressure

ρ——density of water

g——acceleration due to gravity

h——Height of the airbag

K——Safety factor, K value is not less than 1.4,

After inflation is completed, the inflation volume needs to be recorded as the airbag's underwater control inflation volume v. After inflation is completed, the air pressure inside the airbag should be tested every 30 minutes. The observation time should not be less than 3 hours. The pressure change value per hour should not be greater than _0.1ps to be qualified.

Since the airbag is subject to the upward buoyancy of water in the water, the outer wall of the airbag is subjected to tension. The tensile strength of the airbag is calculated as:

2πRdσ _s ≥K(ρVg-mg)

R——Center radius of the airbag bottom

d——airbag wall thickness

σ _s ——Controlled tensile stress of airbag material

ρ——density of water

V - the volume of the airbag when it is filled with air

g——acceleration due to gravity

K——Safety factor, not less than 1.4

m——the mass of the airbag

After the airbag is tested and qualified, the wires, air pipes, concrete pump pipes and other facilities are sealed and connected to the penetration ports, and the pipelines are protected. After the inspection is correct, it is sunk into the seabed according to the predetermined position. To ensure the smooth sinking of the airbag, the air inside the airbag must be drained after entering the water, and the airbag must not be scratched or pressed by the bottom steel plate.

(s4) After the airbag sinks to the seabed, check whether the airbag is pressed by the bottom steel plate and whether the bottom of the airbag falls on the flat seabed plane, as shown in Figure 1.

At the concave position where the seabed is uneven, the airbag opening is lowered from the bottom of the annular steel plate until it contacts the seabed, as shown in Figure 2. Then, a counterweight is installed above the bottom opening of the airbag;

The weight is calculated based on the volume of the airbag:

G——Counterweight

m——the overall mass of the airbag and bottom steel plate

v - the volume of the airbag when it is filled with air

ρ——density of water

ρ′——density of the counterweight

K——Safety factor, where the K value is not less than 1.4.

The counterweight must be effectively connected and fixed to the airbag to prevent the airbag from becoming unstable due to water flow or wave force.

(s5) After the counterweight is installed, check whether the airbag is pressed or scratched during the installation process. After the inspection is correct, inflate the airbag. Inflation should be carried out step by step. According to the controlled inflation volume v obtained from the air tightness test, follow the steps of 0.3v-0.6v-0.9v-1.0v. After each inflation step, check the status of the airbag to see if there is any kink in the airbag, whether the airbag is leaking, and whether the airbag is stable.

(s6) Construction workers and materials enter the airbag through the submarine channel for construction. Large materials that cannot be loaded into the submarine are sunk into the submarine channel through ropes and then pulled into the airbag cavity through ropes. During the construction process, air must be continuously supplied to the airbag to ensure that the air inside the airbag is fresh; at least one generator and air compressor should be kept as a spare to prevent power outages and air shortages in the airbag in the event of a malfunction.

(s7) Construction workers are carrying out foundation construction inside the airbag; when the water depth exceeds 20m, the air pressure inside the airbag exceeds 3 atmospheres, and workers must wear decompression respirators and the working time shall not exceed 2 hours. When encountering emergencies, workers should be sent out in time for treatment.

(s8) After the foundation construction is completed, the floating airbag is raised to the predetermined height of the pier body construction to prepare for the pier column construction. Before the floating airbag, first install the seabed anchor, effectively connect the anchor and the airbag, reserve anchor steel bars on the foundation of the pedestal in advance, anchor the airbag on the foundation of the pedestal, and after the anchor connection is completed, remove part of the counterweight to allow the airbag to slowly float to the predetermined height, as shown in Figure 3. Set a working platform 102 at the bottom of the airbag to close the bottom opening of the airbag, set up a working platform scaffolding, and reserve entrances and exits for construction personnel and construction materials on the scaffolding;

(s9) According to the effective space of the airbag, the floating height of the airbag is adjusted every time a section of pier body concrete is poured, until the pier body is constructed above the water surface and the airbag is removed.

(s10) When the top of the airbag emerges from the water, the buoyancy of the airbag gradually decreases, while the impact of waves and currents gradually increases. To ensure the stability of the airbag, some counterweights need to be removed in a timely manner. The removal of the counterweights needs to be carried out in a strictly symmetrical order to prevent the airbag from becoming unstable. Each time a counterweight is removed, the airbag floats up until all counterweights are removed. In the process of removing the counterweights and adjusting the airbag to float up, the tension of the anchor must be verified to prevent the cable from breaking.

After the pier body concrete is constructed above the water surface, the scaffolding and pipeline equipment in the airbag are removed, and the air supply pipe is removed last to prevent accidents caused by the collapse of the airbag. After loosening the cable, the air supply is stopped, and the airbag is lifted by a crane and placed in the designated position, and the anchor is removed to complete the removal of the airbag.

During implementation, an emergency escape capsule is prepared inside the airbag, and workers are given education and training as well as emergency drills to allow them to escape quickly in the event of an emergency.

It should not be used when the river flow rate is too high. We should find a way to build a dam downstream of the construction area to reduce the water flow rate in the construction area before using the air bag method.

Claims (9)

1. The underwater dry operation construction method of the bottomless air bag method is characterized in that a bottomless air bag method underwater dry operation construction system is used for construction, the bottomless air bag method underwater dry operation construction system is composed of an air bag with an open lower part, an annular air bag bottom opening, a counterweight, a submarine channel, an air compressor, a generator and a concrete pump, wherein the air bag is made of flexible materials, the annular air bag bottom opening is made of rigid materials, the counterweight is pressed on the air bag bottom opening, the submarine is used for conveying constructors and construction materials, the submarine channel is arranged below the annular air bag bottom opening and is communicated with the inside and the outside of the air bag, the air compressor, the generator and the concrete pump are arranged above the water surface, the air bag bottom opening is landed on a seabed after leveling construction, an air inflation cavity is formed in the air bag, an air supply pipe, a cable and a pumping pipe are respectively penetrated through the air bag and are connected with an air compressor, a motor and a concrete pump above the water surface, the air inflation pressure matched with the submarine pressure is maintained in the air inflation cavity, and the inflation pressure is determined according to calculation of the height of the air bag:

p_s＝K(ρgh+P₀)

p _s -test pressure

P ₀ atmospheric pressure

Ρ -density of water

G-gravity acceleration

H-height of air bag

K is a safety coefficient, and the K value is not less than 1.4;

The construction method comprises the following steps:

(s 1) manufacturing an air bag and an air bag bottom opening;

(s 2) leveling the seabed and excavating a submarine channel;

(s 3) after the air bag is detected to be qualified, the electric wire, the air supply pipe, the concrete pump pipe and the through opening of the air bag are connected in a sealing mode, the air bag is sunk into the seabed according to a preset position, and air in the air bag is drained after the air bag is immersed in water;

(s 4) after the air bag is sunk into the seabed, checking whether the bottom opening of the air bag falls on a flat seabed plane, lowering the air bag opening to be in contact with the bottom of the seabed when the bottom opening of the air bag is landed on the sunken position of the seabed, and then installing a counterweight above the bottom opening of the air bag;

(s 5) inflating the balloon lumen;

(s 6) constructors and materials enter the air bag through the submarine channel to construct, large materials which cannot be filled into the submarine sink into the submarine channel through the rope and then are pulled to the inner cavity of the air bag through the rope, and in the construction process, air is continuously supplied to the air bag to ensure that the air in the air bag is fresh;

(s 7) the constructor performs foundation construction inside the air bag;

(s 8) after the foundation construction is completed, floating the air bag to a preset height for pier body construction, firstly arranging a working platform at the bottom opening of the air bag, erecting a working platform scaffold, and reserving a constructor and a construction material access port on the scaffold;

(s 9) according to the effective space of the air bag, adjusting the floating height of one section of the air bag when one section of pier body concrete is poured until the pier body is constructed above the water surface, and dismantling the air bag;

And (s 10) after the top end of the air bag is exposed out of the water surface, removing part of the counter weight, removing the counter weight strictly according to the symmetrical removing sequence, removing the counter weight once, floating the air bag once until all the counter weight is removed, removing the scaffold and pipeline equipment in the air bag after pier body concrete is constructed above the water surface, finally removing the air supply pipe, stopping air supply after loosening a cable, lifting the air bag to a designated position by adopting a crane, removing the ground anchor, and completing the removal of the air bag.

2. The method according to claim 1, characterized in that: the bottom opening of the air bag is provided with a horizontal annular steel plate, the annular steel plate is provided with a vertical cylindrical protecting wall, the air bag is attached to the inner side of the cylindrical protecting wall, and the outer side of the cylindrical protecting wall is pressed with a counterweight.

3. The method according to claim 2, characterized in that: a plurality of supporting rib plates are arranged between the cylindrical protective wall and the annular steel plate.

4. The method according to claim 2, characterized in that: at the concave position of the uneven seabed, the air bag port sags from the lower part of the annular steel plate to be in contact with the seabed.

5. The method according to claim 1, characterized in that: the inflation pressure in the step (s 5) is determined according to the height calculation of the air bag:

p_s＝K(ρgh+P₀)

p _s -test pressure

P ₀ atmospheric pressure

Ρ -density of water

G-gravity acceleration

H-height of air bag

K is a safety coefficient, the K value is not less than 1.4,

After the inflation is completed, the inflation quantity needs to be recorded and used as the controlled inflation quantity v of the air bag under water.

6. The method according to claim 1, characterized in that: the inflation in the step (s 5) is carried out step by step, the inflation quantity v is controlled according to the air tightness experiment, the inflation is carried out according to the steps of 0.3v-0.6v-0.9v-1.0v, and after each step of inflation is completed, the state of the air bag is checked, and whether kinking and air leakage conditions exist in the air bag are checked.

7. The method according to claim 1, characterized in that: and (s 8) before the air bag is floated, installing a submarine ground anchor, effectively connecting the ground anchor with the air bag, reserving an anchor reinforcing steel bar on a bearing platform foundation in advance, anchoring the air bag on the bearing platform foundation, and removing part of the counterweight after the air bag is anchored and connected, so that the air bag slowly floats to a preset height.

8. The method according to claim 1, characterized in that: the balance weight is determined according to the volume calculation of the air bag:

g-counterweight

M-integral mass of air bag and bottom mouth steel plate

V-volume of balloon after filling with air

Ρ -density of water

Ρ' —density of counterweight

K is a safety coefficient, wherein the K value is not less than 1.4.

9. The method according to claim 1, characterized in that: when the water depth exceeds 20m, the constructor inside the inner bag wears the decompression respirator.