阅读说明：本技术 一种可回收负压贯入式沉井结构及施工方法 (Recyclable negative pressure injection type open caisson structure and construction method ) 是由 王冲冲 刘光磊 张雷刚 赵欣宇 杨宝森 侯文诗 于 2021-09-30 设计创作，主要内容包括：本发明公开一种可回收负压贯入式沉井结构及施工方法,应用于土木工程水下结构施工领域,为方便水下结构施工而发明,所述负压贯入式沉井结构包括下部沉井、上部助沉结构、中部橡胶垫层、顶部抽水口,下部沉井与上部助沉结构通过法兰连接。所述施工方法为：当沉井安装过程中受到阻力无法继续下沉时,将助沉结构通过法兰连接安装在沉井的顶部；利用抽水机从助沉结构设置的抽水口上抽取密闭空间内的水体,密闭空间内形成负压,下部沉井在大气压的作用下将继续下沉；用抽水机向其内部注水,沉井将在水压作用下向上拔出。本发明适合需要水下施工、无大型打桩船及运输船、工期要求严格、工程造价有限的项目。(The invention discloses a recoverable negative pressure injection type open caisson structure and a construction method, which are applied to the field of civil engineering underwater structure construction and are invented for facilitating underwater structure construction. The construction method comprises the following steps: when the sinking well cannot sink continuously due to resistance in the installation process, the sinking-assisting structure is connected and installed at the top of the sinking well through a flange; a water pump is used for pumping water in the closed space from a water pumping port arranged on the sinking-assisting structure, negative pressure is formed in the closed space, and the lower open caisson continues to sink under the action of atmospheric pressure; the water pump is used for injecting water into the open caisson, and the open caisson is pulled out upwards under the action of water pressure. The invention is suitable for projects which need underwater construction, have no large-scale piling ships and transport ships, have strict construction period requirements and have limited construction cost.)

1. A recoverable negative pressure injection type open caisson structure and a construction method are characterized in that: the open caisson structure comprises a lower open caisson, an upper sinking-assisting structure, a middle rubber cushion layer and a top water pumping port; the lower open caisson is connected with the upper sinking-assisting structure through a flange, and a flexible rubber cushion layer is arranged in the middle of the lower open caisson; the top water pumping ports are symmetrically arranged.

2. The structure and construction method of a recoverable negative pressure penetration type open caisson according to claim 1, wherein the structure comprises: the lower open caisson is a cylindrical structure with two open ends and closed periphery, is made of steel, has a wedge-shaped lower end and a flange structure at the upper end, and is connected with the upper sinking-assisting structure.

3. The structure and construction method of a recoverable negative pressure penetration type open caisson according to claim 1, wherein the structure comprises: the sinking-assisting structure is a cylindrical structure with a closed upper end and an open lower end and is made of steel, the lower end of the sinking-assisting structure is provided with a flange connector and is connected with the lower sunk well, and the upper end of the sinking-assisting structure is provided with two symmetrically distributed water pumping ports.

4. The structure and construction method of a recoverable negative pressure penetration type open caisson according to claim 1, wherein the structure comprises: a rubber cushion layer is arranged between the upper sinking assisting structure and the lower sinking well and made of flexible materials, so that the inside of the structure is in a closed state, and a closed space is formed among the soil body, the sinking well and the sinking assisting structure.

5. The structure and construction method of a recoverable negative pressure penetration type open caisson according to claim 1, wherein the structure comprises: the closed end of the sedimentation assisting structure is provided with symmetrically distributed water pumping ports, the number of the water pumping ports is freely set according to formation conditions and mechanical equipment, and the water pumping ports are uniformly distributed.

6. A recoverable negative pressure injection type open caisson structure and a construction method are characterized in that the construction method comprises the following steps:

the method comprises the following steps: the open caisson begins to sink along the soil layer under the action of self gravity, the verticality of the open caisson is strictly controlled in the process, when the sinking penetration resistance of the open caisson during sinking is balanced with the self gravity of the open caisson, the open caisson does not sink any more, and the self-weight sinking penetration stage is completed;

step two: the open caisson structure is taken as a base, the sinking-assisting structure is arranged on the open caisson structure, the open caisson and the sinking-assisting structure are connected by a rubber cushion layer, the sealing performance of the open caisson structure is ensured, and a sealed space is formed among the open caisson, the sinking-assisting structure and the soil body;

step three: connecting a water pump with the open caisson sinking-assisting structure, starting the water pump, and pumping water in the open caisson to form negative pressure in the open caisson;

step four: the open caisson continues to cut soil bodies to sink under the action of negative pressure, after the open caisson sinks to a preset position, the water pump is removed, the upper sinking-assisting structure is removed, and the next construction operation is started inside the open caisson;

step five: after the construction operation is finished, the sinking-assisting structure is connected with the lower sunk well through the flange again, after the air tightness is confirmed, water is injected into the sunk well through the water pump, the sunk well starts floating under the action of internal water pressure and buoyancy, and the sunk well is recycled in cooperation with the crane ship.

7. The structure and construction method of claim 6, wherein the recovery process comprises injecting water into the caisson by a water pump, and the caisson is recovered by a crane ship under the combined action of internal water pressure and buoyancy.

Technical Field

The invention relates to a recoverable negative pressure injection type open caisson structure and a construction method, which are applied to the field of civil engineering underwater structure construction.

Background

As water engineering projects become more and more, the foundation portion of the building needs to be constructed underwater. However, underwater construction is extremely inconvenient and even impossible. Open caisson is most commonly used as a building envelope for underwater construction. The open caisson is a well cylindrical structure, is excavated in the well, is sunk to a designed elevation after overcoming the frictional resistance of the well wall by self gravity or a pile driver, and is generally used as a containment device during the construction of pier foundation pits, sewage pump stations, shield assembled wells, underground driveways and station hydraulic foundations. The invention enables the open caisson to sink under the action of negative pressure by improving the open caisson structure and the construction process, does not need a large-scale piling ship and a large self-weight of the structure, reduces the construction cost and shortens the construction period at the same time.

The existing open caisson construction method is roughly divided into two types, one is a large-diameter steel open caisson which is driven into a preset elevation by a large-scale pile driver. The method needs large-scale piling machinery, and has high construction technical requirement and great construction difficulty; the other is a large-diameter reinforced concrete open caisson, and soil is dug in the open caisson to ensure that the open caisson sinks under the action of self gravity. The method needs large concrete amount, needs to be prefabricated on shore, is transported to a construction site by a large carrying ship during construction, has long construction period and high construction cost, and is easy to cause drifting sand to cause inclination or difficult sinking of the open caisson during construction.

In view of the above-mentioned drawbacks of the conventional open caisson structure and construction method, there is a need to further improve the construction method of the underwater structure and foundation, and a recoverable negative pressure penetration open caisson structure and a corresponding construction method are provided to solve the above-mentioned problems.

Disclosure of Invention

The invention aims to provide a recyclable negative pressure injection type open caisson structure and a construction method, and aims to solve the problems that underwater construction is needed, a large-sized piling ship and a large-sized transport ship are not needed, the construction period requirement is strict, and the construction cost is limited.

In order to achieve the purpose, the invention adopts the following technical scheme:

a recoverable negative pressure injection type open caisson structure and a construction method are characterized by comprising the following steps:

the method comprises the following steps: the open caisson begins to sink and penetrate along the soil layer under the action of self gravity, the verticality of the open caisson is strictly controlled in the process, when the sinking penetration resistance of the open caisson during sinking is balanced with the self gravity of the open caisson, the open caisson does not sink any more, and the self-weight sinking penetration stage is finished;

step two: the open caisson structure is taken as a base, the open caisson structure with the closed top and the open bottom is arranged on the open caisson structure, the open caisson and the open caisson structure are connected by a rubber gasket layer, the tightness of the open caisson structure is ensured, and a closed space is formed among the open caisson structure, the open caisson structure and the soil body;

step three: connecting a water pump with a water pumping port on the open caisson sinking assisting structure, starting the water pump, and pumping water in the open caisson to form negative pressure in the open caisson;

step four: the open caisson continues to cut the soil body to sink under the action of negative pressure, and the open caisson is ensured to be in a vertical state all the time in the sinking process;

step five: after the open caisson continues to sink to a preset position, removing the water pump, and dismantling the upper sinking-assisting structure, so that the next construction operation can be started in the open caisson;

step six: after the construction operation is finished, the sinking-assisting structure is connected with the lower sunk well through the flange again, after the air tightness is confirmed, water is injected into the sunk well through the water pump, the sunk well floats upwards under the action of internal water pressure and buoyancy, and the sunk well is matched with the crane ship to finish recycling of the sunk well.

Furthermore, the negative pressure injection type open caisson is formed by combining a lower open caisson, an upper sinking assisting structure, a middle rubber cushion layer and a water pumping port.

Furthermore, the lower open caisson is a cylindrical structure with two open ends and closed periphery, is usually made of steel or reinforced concrete, has a wedge-shaped end part, can reduce the tip resistance applied when the open caisson sinks, and has a flange structure at the other end, which can be connected with the upper sinking-assisting structure.

Furthermore, the sinking-assisting structure is a cylindrical structure with one closed end and the other open end, is usually made of steel or reinforced concrete, the other end of the sinking-assisting structure is made into a flange interface and can be connected with a lower sunk well, and the other end of the sinking-assisting structure is provided with two symmetrically distributed (a plurality of) water pumping ports according to engineering requirements

Furthermore, a rubber cushion layer is arranged between the upper sinking-assisting structure and the lower sinking well, so that the air tightness of the whole structure is ensured, and a closed space is formed among the soil body, the sinking well and the sinking-assisting structure.

Furthermore, the closed end of the sinking-assisting structure is provided with symmetrically distributed water pumping ports, the number of the water pumping ports can be freely set according to sinking resistance and mechanical equipment, and the water pumping ports are uniformly distributed.

Furthermore, the recovery process is through water pumper to its inside water injection, with inside the open caisson is squeezed into to outside water, the open caisson under the combined action of inside water pressure and buoyancy, the recovery of cooperation crane ship completion open caisson.

The recoverable negative pressure injection type open caisson structure and the construction method can solve the problems that underwater construction is needed, a large piling ship and a transport ship do not exist, the construction period requirement is strict, and the construction cost is limited. During construction, negative pressure is formed by pumping water in the open caisson, the open caisson sinks to a preset position under the action of the negative pressure, the construction speed is high, and the construction period is greatly shortened.

The invention has the following advantages:

1. the invention adopts a suction mode to install the open caisson, only needs two water-gas dual-purpose water pumps, can be repeatedly used, and has the advantages of low cost, simple construction procedure and short construction period compared with the prior art.

2. The invention mainly extracts water and gas in the closed space, the open caisson can sink under the pressure of atmospheric pressure, the suction is large, the sinking speed is controllable, and compared with the gravity open caisson, the open caisson has no condition that the open caisson cannot sink or sinks suddenly when being blocked.

3. The open caisson tip is wedge-shaped, and under the action of suction, the open caisson tip punctures the soil body and is tightly attached to the soil body, so that the condition that piping or the soil body enters the well cannot occur.

4. The gravity of the open caisson has little influence on the sinking resistance, so the open caisson has lighter weight and lower cost.

Drawings

Fig. 1 is a schematic view of a retrievable penetrating caisson structure of the present invention.

Fig. 2 is a schematic diagram of the open caisson and auxiliary sinking structure of the invention.

Fig. 3 is a schematic view illustrating a construction process of the retrievable penetration type open caisson structure according to the present invention.

Reference numerals: 1-open caisson, 2-sinking-assisting structure, 3-flange interface, 4-water pumping port, 5-water pump and 6-rubber cushion layer.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the invention to these embodiments. It will be appreciated by those skilled in the art that the present invention encompasses all alternatives, modifications and equivalents as may be included within the scope of the claims.

As shown in fig. 1, a recoverable negative pressure penetration type open caisson structure comprises a recoverable open caisson structure with a negative pressure penetration type sinking-assisting structure, wherein the construction method comprises the following steps:

the method comprises the following steps: the open caisson (1) is firstly installed along the soil layer in a penetration mode under the action of self gravity, the verticality of the open caisson is strictly controlled in the process, when penetration resistance of the open caisson during sinking is balanced with the self gravity of the open caisson, the open caisson does not sink any more, and the self-weight penetration stage is completed.

Step two: the open caisson structure is characterized in that the open caisson (1) structure is used as a base, the open-top sinking-assisting structure (2) is arranged on the open caisson structure, the open caisson and the sinking-assisting structure are connected through a rubber cushion layer (6), the airtightness of the open caisson is guaranteed, and an airtight space is formed among the open caisson, the sinking-assisting structure and a soil body.

Step three: connect water pumper (5) with open caisson help heavy structure (2), start the water pumper, extract the inside water of open caisson, make the inside negative pressure that forms of open caisson.

Step four: the open caisson continues to cut soil body to sink under the action of negative pressure, and the open caisson is ensured to be in a vertical state all the time in the sinking process.

Step five: and after the open caisson continues to sink to a preset position, removing the water pump, and dismantling the upper sinking-assisting structure, so that the next construction operation can be started in the open caisson.

Step six: after the construction operation is finished, the sinking-assisting structure is connected with the flange (3) for the lower sinking well again, after the air tightness is confirmed, water is injected into the sinking well by a water pump, the sinking well starts floating under the action of internal water pressure and buoyancy, and the sinking well is matched with a crane ship to finish recycling of the sinking well.

As shown in figure 1, the recoverable negative pressure injection type open caisson structure is formed by connecting a lower open caisson (1) and an auxiliary sinking structure (2) through a flange interface (3), and a flexible rubber cushion layer (6) is arranged in the middle to ensure the air tightness of the interior of the open caisson structure.

As shown in fig. 2, the end part of the open caisson is wedge-shaped, so that the end part resistance in the sinking process can be reduced; the sinking assisting structure is a cylindrical structure with a closed top and an open bottom, two symmetrical water outlets are arranged at the top, and the water body in the closed space is extracted by connecting a water pump and the water outlets in the construction process.

As shown in fig. 3, the installation process of the recoverable negative pressure penetration type open caisson structure is that the open caisson is installed under the action of gravity first, and when the open caisson does not sink any more; the method comprises the following steps that a sinking-assisting structure (2) with a closed top and an open bottom is installed at the top of an open caisson through a flange connector (3), a water body in a closed space is extracted from a water pumping port arranged in the sinking-assisting structure through a water pump (5), negative pressure is formed in the closed space, the lower open caisson continues to sink under the action of atmospheric pressure until the lower open caisson reaches a preset position, and the sinking-assisting structure on the upper portion of the open caisson can be disassembled, so that construction operation can be completed in the lower open caisson; and after construction is finished, the open caisson and the sinking-assisting structure (2) are reconnected, water is injected into the open caisson by a water pump (5), the open caisson is upwards pulled out under the action of water pressure, and the recovery of the open caisson is realized by matching with a crane ship.