Open caisson bottom sealing device and open caisson bottom sealing method

Abstract

The invention belongs to the technical field of underground engineering, and discloses an open caisson bottom sealing device and an open caisson bottom sealing method. The open caisson bottom sealing device comprises a sealing membrane assembly and a grouting channel, the sealing membrane assembly has a sinking state and a pouring state, and when the sealing membrane assembly is in the sinking state, the sealing membrane assembly wraps the inner well wall of an open caisson in a surrounding mode; the sealing membrane assembly can be folded to a pouring state, when the sealing membrane assembly is in the pouring state, one part of the sealing membrane assembly wraps the side wall of the blade foot in a surrounding mode, the other part of the sealing membrane assembly is attached to the excavation face, and a closed pouring face is formed on the excavation face; the grouting channel is arranged on the side wall of the blade foot and used for conveying cement paste between the diaphragm sealing assembly and the side wall of the blade foot. According to the open caisson bottom sealing method, the open caisson bottom sealing device is used, contact between bottom sealing concrete and an excavation face soil layer can be isolated, local weak points are prevented from being formed when the bottom sealing concrete is poured, and the waterproof performance of the blade foot position is greatly improved by injecting cement paste.

Description

Technical Field

[0001] The invention relates to the technical field of underground engineering, and in particular to a caisson bottom sealing device and a caisson bottom sealing method. Background Art

[0002] A caisson is a common shaft-shaped structure in underground engineering, usually used as the foundation of bridge piers or other structures; the basic principle of its sinking is to utilize the deadweight of the shaft and the friction between the shaft wall and the soil layer, and to dig soil inside the shaft so that the shaft gradually sinks in the soil layer.

[0003] After the caisson is sunk, the bottom of the caisson needs to be sealed to improve the stability and safety of the caisson. Before sealing the bottom, the inner wall of the shaft needs to be cleaned to remove the silt and sediment attached to the wall, thereby improving the bonding quality between the bottom seal concrete and the wall. The commonly used method for cleaning the wall is to manually go down to the bottom of the well to clean the wall, but this method has the problems of low cleaning efficiency and insufficient cleaning effect, and there is a certain danger for caissons that need to be cleaned underwater. In addition, the blade foot of the caisson often leaks due to improper sealing, which greatly affects the safety of the caisson.

[0004] Therefore, it is urgent to design a caisson bottom sealing device to solve the above problems existing in the prior art. Summary of the invention

[0005] The object of the present invention is to provide a caisson bottom sealing device and a caisson bottom sealing method, which can greatly improve the waterproof performance of the caisson.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] Caisson bottom sealing device, including:

[0008] A diaphragm assembly, wherein the diaphragm assembly has a sinking state and a casting state. When the diaphragm assembly is in the sinking state, the diaphragm assembly surrounds and covers the inner wall of the caisson;

[0009] The diaphragm assembly can be folded to a casting state under the action of gravity. When the diaphragm assembly is in the casting state, a part of the diaphragm assembly surrounds and covers the side wall of the blade foot, and another part of the diaphragm assembly is attached to the excavation surface, and a closed casting surface is formed on the excavation surface;

[0010] A grouting channel is provided on the side wall of the blade foot, and is used for conveying cement slurry between the diaphragm assembly and the side wall of the blade foot.

[0011] Preferably, the sealing membrane assembly comprises a first sealing membrane and a second sealing membrane, wherein a plurality of the first sealing membranes are arranged along the circumference of the inner well wall, and a plurality of the second sealing membranes are also arranged along the circumference of the inner well wall;

[0012] When the sealing membrane assembly is in a sinking state, the first sealing membrane is close to the inner well wall, a first avoidance space is provided between two adjacent first sealing membranes in the circumferential direction, and the second sealing membrane covers the first avoidance space;

[0013] When the sealing membrane assembly is in a casting state, the second sealing membrane is attached to the excavation surface, and a second avoidance space is formed between two circumferentially adjacent second sealing membranes. The first sealing membrane covers the second avoidance space, and a side of the first sealing membrane facing the wellhead and a side of the second sealing membrane facing the wellhead are spliced ​​to form the casting surface.

[0014] Preferably, the first sealing membrane and the second sealing membrane each have a free end and a fixed end, the fixed end is away from the wellhead and fixedly arranged at the upper end of the blade foot, the upper end of the blade foot is the end of the inner well wall close to the side wall of the blade foot, and the free end is close to the wellhead and is detachably connected to the inner well wall.

[0015] Preferably, the sealing membrane assembly further comprises a flexible membrane, wherein the flexible membrane is fixedly disposed on the upper end of the blade foot, and the fixed end of the first sealing membrane and the fixed end of the second sealing membrane are both connected to the flexible membrane.

[0016] Preferably, the caisson bottom sealing device further comprises a connecting assembly, wherein the connecting assembly comprises an electromagnet and an adsorbent, wherein the electromagnet is arranged on the inner well wall, and the adsorbent is arranged on the free ends of the first sealing membrane and the second sealing membrane;

[0017] The electromagnet can adsorb the adsorbent after being energized.

[0018] Preferably, the caisson bottom sealing device further comprises an injection pipe group, and when the sealing membrane assembly is in the casting state, the injection pipe group is used to cast bottom sealing concrete onto the casting surface.

[0019] Preferably, the injection pipe group includes side injection pipes and a central injection pipe, and a plurality of the side injection pipes are arranged along the circumference of the caisson, the outlets of the side injection pipes are arranged opposite to the side walls of the blade foot, and the central injection pipe is arranged opposite to the lowest point of the casting surface.

[0020] The caisson bottom sealing method, using the caisson bottom sealing device, comprises the following steps:

[0021] S1, wrapping the sealing membrane assembly around the inner well wall, and fixing the end of the sealing membrane assembly away from the wellhead to the upper end of the blade foot, the upper end of the blade foot is the end of the inner well wall close to the side wall of the blade foot, and connecting the end of the sealing membrane assembly close to the wellhead to the inner well wall;

[0022] S2, excavating the soil layer to sink the caisson to a specified depth;

[0023] S3, removing the end of the sealing membrane assembly close to the wellhead, so that the sealing membrane assembly is folded to the casting state under the action of gravity;

[0024] S4, pouring bottom sealing concrete onto the casting surface;

[0025] S5. Inject cement slurry into the grouting channel.

[0026] Preferably, before injecting cement slurry into the grouting channel in step S5, the method further includes:

[0027] Water is injected into the grouting channel.

[0028] Preferably, the end of the sealing membrane assembly away from the wellhead is pre-buried in the inner well wall.

[0029] The beneficial effects of the present invention are:

[0030] The caisson bottom sealing device provided by the present invention comprises a sealing membrane assembly and a grouting channel. The sealing membrane assembly has a sinking state and a pouring state. When the sealing membrane assembly is in the sinking state, the sealing membrane assembly surrounds and covers the inner well wall of the caisson. Therefore, during the sinking process of the caisson, it plays a role of isolating the soil from the inner well wall, ensuring that the inner well wall within the pouring height range of the sealing bottom concrete is clean and free of mud when the caisson sinks. The bonding quality of the sealing bottom concrete and the inner well wall can be guaranteed without manual cleaning of the wall, thereby greatly improving the construction efficiency and construction safety. When the sealing membrane assembly is in the pouring state, the sealing membrane assembly is attached to the excavated well. The blade foot side wall is provided with a grouting channel, and the grouting channel can transport cement slurry between the sealing membrane assembly and the blade foot side wall. Therefore, the blade foot side wall can be bonded to form a whole with the blade foot side wall, the sealing membrane assembly and the bottom concrete on the casting surface, thereby ensuring the waterproof performance at the blade foot position of the caisson, thereby greatly improving the safety and reliability of the caisson.

[0031] By using the caisson bottom sealing method, a diaphragm assembly is coated on the inner wall of the caisson, thereby isolating the inner wall from the soil, ensuring that the inner wall within the casting height range of the bottom concrete is clean and free of mud when the caisson sinks, thereby ensuring the bottom sealing quality of the caisson; because the diaphragm membrane can be folded to a casting state under the action of gravity, in this state, the diaphragm membrane assembly is attached to the excavation surface, thereby isolating the bottom concrete from contact with the soil layer of the excavation surface, thereby avoiding the formation of local weak points when casting the bottom concrete; because the grouting channel can inject cement slurry between the side wall of the blade foot and the diaphragm membrane assembly, the diaphragm membrane assembly and the side wall of the blade foot are connected as a whole, thereby greatly improving the waterproof performance at the blade foot position. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of a diaphragm membrane assembly provided by a specific embodiment of the present invention when it is in a sinking state;

[0033] Figure 2 is a top view of the second diaphragm assembly provided by a specific embodiment of the present invention when it is attached to the excavation surface;

[0034] Figure 3 is a top view of the diaphragm membrane assembly provided by a specific embodiment of the present invention when it is in a casting state;

[0035] Figure 4 is a cross-sectional view of a caisson provided in a specific embodiment of the present invention;

[0036] Figure 5 It is a structural schematic diagram of pouring bottom sealing concrete onto a pouring surface provided by a specific embodiment of the present invention.

[0037] In the figure:

[0038] 100-caisson;

[0039] 1-seal film assembly; 11-first seal film; 12-second seal film; 13-second avoidance space; 14-flexible film;

[0040] 2- Grouting channel;

[0041] 3- Connect components;

[0042] 4-injection tube group; 41-side injection tube; 42-central injection tube. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0044] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0046] In the description of this embodiment, the terms "upper", "lower", "right", "left" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0047] like Figure 1 , Figure 4 as well as Figure 5 As shown, the present invention provides a caisson bottom sealing device, which includes a diaphragm assembly 1 and a grouting channel 2. The diaphragm assembly 1 has a sinking state and a casting state. When the diaphragm assembly 1 is in the sinking state, the diaphragm assembly 1 surrounds and covers the inner wall of the caisson 100; the diaphragm assembly 1 can be folded to the casting state under the action of gravity. When the diaphragm assembly 1 is in the casting state, a part of the diaphragm assembly 1 surrounds and covers the side wall of the blade foot, and the other part of the diaphragm assembly 1 is attached to the excavation surface, and a closed casting surface is formed on the excavation surface; the grouting channel 2 is arranged on the side wall of the blade foot, and the grouting channel 2 is used to transport cement slurry between the diaphragm assembly 1 and the side wall of the blade foot.

[0048] In this embodiment, since the diaphragm assembly 1 surrounds and covers the inner wall of the caisson 100 when it is in the sinking state, it plays a role in isolating the soil from the inner wall during the sinking process of the caisson 100, ensuring that the inner wall within the pouring height range of the bottom concrete of the caisson 100 is clean and free of mud when the caisson 100 sinks, and the bonding quality between the bottom concrete and the inner wall can be guaranteed without manual cleaning of the wall, which greatly improves the construction efficiency and construction safety; since the diaphragm assembly 1 is in the pouring state, the diaphragm assembly 1 is attached to the excavation surface and forms a closed pouring surface on the excavation surface , thus isolating the contact between the excavation surface soil and the bottom concrete, avoiding the influence of the excavation surface soil properties on the pouring quality, ensuring the uniformity of the bottom concrete pouring, and thus improving the construction quality; since the blade foot side wall is provided with a grouting channel 2, the grouting channel 2 can transport cement slurry between the diaphragm assembly 1 and the blade foot side wall, so the blade foot side wall can be bonded to form a whole with the blade foot side wall, the diaphragm assembly 1 and the bottom concrete pouring on the pouring surface, ensuring the waterproof performance at the blade foot position of the caisson, thereby greatly improving the safety and reliability of the caisson 100. It can be understood that when the diaphragm assembly 1 is in a sinking state, the side of the diaphragm assembly 1 facing the inner well wall is attached to the inner well wall, and when the diaphragm assembly 1 is folded under the action of gravity, the side facing the inner well wall is separated from the contact with the inner well wall, and the side away from the inner well wall will rotate downward and finally be attached to the excavation surface.

[0049] Specifically, the grouting channel 2 needs to be reserved when manufacturing the caisson 100. The grouting channel 2 extends upward along the axial direction of the caisson 100 and is connected to the cement grouting equipment on the ground.

[0050] The specific structure of the diaphragm assembly 1 can be set according to actual needs; for example, Figures 1 to 3As shown, the diaphragm assembly 1 includes a first diaphragm 11 and a second diaphragm 12, and a plurality of first diaphragm 11 are arranged along the circumference of the inner well wall, and a plurality of second diaphragm 12 are also arranged along the circumference of the inner well wall; when the diaphragm assembly 1 is in a sinking state, the first diaphragm 11 is attached to the inner well wall, and a first avoidance space is provided between two circumferentially adjacent first diaphragm membranes 11, and the second diaphragm 12 covers the avoidance space; when the diaphragm assembly 1 is in a casting state, the second diaphragm 12 is attached to the excavation surface, and a second avoidance space 13 is formed between two circumferentially adjacent second diaphragm membranes 12, and the first diaphragm 11 covers the second avoidance space 13, and a side of the first diaphragm 11 facing the wellhead and a side of the second diaphragm 12 facing the wellhead are spliced ​​to form a casting surface. Specifically, the first diaphragm 11 is located on the inner layer of the diaphragm assembly 1 close to the inner well wall, and the second diaphragm 12 is located on the outer layer of the diaphragm assembly 1 away from the inner well wall. When the diaphragm assembly 1 is in a sinking state, since the second diaphragm 12 covers the first avoidance space between the two adjacent first diaphragm films 11, the first diaphragm film 11 and the second diaphragm film 12 can cover the inner well wall together after being combined; and since there is a first avoidance space between the two adjacent first diaphragm films 11, when the diaphragm assembly 1 is folded downward under the action of gravity, the first avoidance space can provide an avoidance space for the extrusion deformation of the first diaphragm film 11 when it is folded, so that the first diaphragm film 11 can It can be folded smoothly under the influence of gravity; similarly, when the diaphragm membrane assembly 1 is in a sinking state, there is also a first avoidance space between two adjacent second diaphragm membranes 12, the purpose of which is to provide an avoidance space for the deformation of the second diaphragm membrane 12 when it is folded downward, so that the second diaphragm membrane 12 can be folded smoothly; since the second diaphragm membrane 12 is located on the outer layer of the diaphragm membrane assembly 1 away from the inner well wall, when the diaphragm membrane assembly 1 is folded under the action of gravity, the second diaphragm membrane 12 is first folded down and abutted against the excavation surface, and then the first diaphragm membrane 11 is folded down again, and the first diaphragm membrane 11 covers the second avoidance space 13, thereby splicing to form a closed casting surface.

[0051] like Figures 1 to 3 As shown, the first diaphragm 11 and the second diaphragm 12 both have a free end and a fixed end, the fixed end is far away from the wellhead and fixedly arranged at the upper end of the blade foot, the upper end of the blade foot is the end of the inner well wall close to the side wall of the blade foot, and the free end is close to the wellhead and detachably connected to the inner well wall; taking the second diaphragm 12 as an example, when the caisson 100 sinks to a specified depth, since the fixed end is fixedly arranged at the upper end of the blade foot, the free end of the second diaphragm 12 can be removed from the inner well wall and can be folded down with the plane where the fixed end is located as the axis under the action of its own gravity, while being attached to the excavation surface, the side wall of the blade foot is covered. In this embodiment, the first diaphragm 11 and the second diaphragm 12 are both made of rubber, have good waterproof performance, and are heavy, and can be smoothly folded to the casting state under the action of their own gravity.

[0052] The shapes of the first sealing membrane 11 and the second sealing membrane 12 can be set according to actual needs, as long as they can ensure complete coverage of the inner well wall and the excavation surface; for example, Figures 1 to 3 As shown, the first diaphragm 11 and the second diaphragm 12 have the same shape, both of which are arc triangles with one side being a straight side, the straight side being fixedly connected to the upper end of the blade foot, the straight sides of two adjacent first diaphragm 11 are connected and the straight sides of two adjacent second diaphragm 12 are connected, the first diaphragm 11 and the second diaphragm 12 are alternately arranged, that is, the first diaphragm 11 and the second diaphragm 12 do not completely overlap in the radial direction of the caisson 100, thereby ensuring that the second diaphragm 12 can cover the first avoidance space between the two adjacent first diaphragm 11, and the first diaphragm 11 can also cover the first avoidance space between the two adjacent second diaphragm 12.

[0053] Furthermore, in order to ensure that the first sealing film 11 and the second sealing film 12 can be smoothly folded to the casting state, as Figure 4 As shown, the sealing membrane assembly 1 also includes a flexible membrane 14, which is fixedly arranged at the upper end of the blade foot, and the fixed ends of the first sealing membrane 11 and the second sealing membrane 12 are both connected to the flexible membrane 14; specifically, the flexible membrane 14 is a highly flexible polymer membrane made of polyetheretherketone, which has good flexibility and ductility; one end of the flexible membrane 14 is fixedly arranged at the upper end of the blade foot, and the other end is respectively connected to the first sealing membrane 11 and the second sealing membrane 12. It can be understood that compared with the first sealing membrane 11 and the second sealing membrane 12 made of rubber, the use cost of the flexible membrane 14 is higher, so it is only used as a connecting structure between the sealing membrane assembly 1 and the inner well wall.

[0054] Furthermore, if Figure 1 and Figure 3 As shown, the caisson bottom sealing device also includes a connecting component 3, which is used to detachably fix the free ends of the first sealing membrane 11 and the second sealing membrane 12 to the inner well wall, so that the staff can remove the free ends from the inner well wall after the caisson 100 sinks to a specified depth; illustratively, the connecting component 3 includes an electromagnet and an adsorbent, the electromagnet is arranged on the inner well wall, and the adsorbent is arranged on the free ends of the first sealing membrane 11 and the second sealing membrane 12; the electromagnet can adsorb the adsorbent after being energized, and the adsorbent is respectively arranged at the free ends of the first sealing membrane 11 and the second sealing membrane 12, and the adsorbent can be adsorbed by the energized electromagnet, so the staff can realize the automatic detachment of the free ends by remote control on the ground, without the need to go down to the well for operation, saving time and effort.

[0055] In order to improve the reliability of the connection between the sealing membrane assembly 1 and the inner well wall, connecting components 3 are also provided at other positions of the first sealing membrane 11 and the second sealing membrane 12 except the free ends. The specific setting positions can be selected according to the actual situation on site.

[0056] Furthermore, if Figure 5 As shown, the caisson bottom sealing device also includes an injection pipe group 4. When the sealing membrane assembly 1 is in a casting state, the injection pipe group 4 is used to cast the bottom sealing concrete onto the casting surface.

[0057] Specifically, Figure 5 As shown, the injection pipe group 4 includes a side injection pipe 41 and a central injection pipe 42. A plurality of side injection pipes 41 are arranged along the circumference of the caisson 100. The outlet of the side injection pipe 41 is arranged opposite to the side wall of the blade foot, and the central injection pipe 42 is arranged opposite to the lowest point of the casting surface; the casting surface is a concave pot-bottom-shaped arc surface, which is connected to the side wall of the blade foot on all sides. The bottom of the side injection pipe 41 is provided with an injection section facing the side wall of the blade foot. When pouring the bottom sealing concrete, firstly, a large amount of concrete is poured onto the sealing membrane assembly 1 at the side wall of the blade foot through the side injection pipe 41, so that the sealing membrane assembly 1 fits onto the side wall of the blade foot under the impact of concrete, thereby ensuring the waterproof effect at the side wall of the blade foot; then, concrete is evenly poured onto the casting surface directly below through the central injection pipe 42.

[0058] This embodiment also provides a caisson bottom sealing method, using the above-mentioned caisson bottom sealing device, comprising the following steps:

[0059] S1. Wrap the sealing membrane assembly 1 around the inner well wall, and fix the end of the sealing membrane assembly 1 away from the wellhead to the upper end of the blade foot. The upper end of the blade foot is the end of the inner well wall close to the side wall of the blade foot. Connect the end of the sealing membrane assembly 1 close to the wellhead to the inner well wall.

[0060] S2. Excavate the soil layer to sink the caisson 100 to a specified depth. Since the diaphragm assembly 1 is coated on the inner well wall, the diaphragm assembly 1 can isolate the soil from the inner well wall during the sinking of the caisson 100, so as to ensure that the inner well wall is clean and free of mud during the excavation and sinking process.

[0061] S3. Remove the end of the diaphragm assembly 1 close to the wellhead, so that the diaphragm assembly 1 is folded to the casting state under the action of gravity; after the diaphragm assembly 1 is in the casting state, the diaphragm assembly 1 covers the excavation surface and forms a closed casting surface, thereby isolating the contact between the excavation surface soil and the bottom concrete, avoiding the influence of the excavation surface soil properties on the casting quality, ensuring the uniformity and consistency of the bottom concrete casting, and thus improving the construction quality.

[0062] S4, pouring bottom sealing concrete onto the casting surface;

[0063] S5. Inject cement slurry into the grouting channel 2. The cement slurry can bond the blade foot side wall and the diaphragm assembly 1 to form a whole, thereby improving the waterproof performance at the blade foot position; specifically, the cement slurry uses high-strength cement slurry.

[0064] By using the caisson bottom sealing method, the inner wall of the caisson 100 is covered with a sealing membrane assembly 1, thereby isolating the inner wall from the soil, ensuring that the inner wall within the casting height range of the bottom concrete is clean and free of mud when the caisson 100 sinks, thereby ensuring the bottom sealing quality of the caisson 100; because the sealing membrane can be folded to a casting state under the action of gravity, in this state, the sealing membrane assembly 1 is attached to the excavation surface, thereby isolating the bottom concrete from contact with the soil layer of the excavation surface, avoiding the formation of local weak points when pouring the bottom concrete; because the grouting channel 2 can inject cement slurry between the blade foot side wall and the sealing membrane assembly 1, the sealing membrane assembly 1 and the blade foot side wall are connected as a whole, thereby greatly improving the waterproof performance at the blade foot position.

[0065] Specifically, the diaphragm assembly 1 includes a first diaphragm 11 and a second diaphragm 12, the first diaphragm 11 is located on the inner layer of the diaphragm assembly 1 close to the inner well wall, and the second diaphragm 12 is located on the outer layer of the diaphragm assembly 1 away from the inner well wall; the first diaphragm 11 and the second diaphragm 12 both have a free end and a fixed end, the fixed ends of the first diaphragm 11 and the second diaphragm 12 are both fixedly arranged on the upper end of the blade foot, the upper end of the blade foot is the end of the inner well wall close to the side wall of the blade foot, and the free ends of both can be detachably connected to the inner well wall ; During the sinking process of the caisson 100, the sealing membrane assembly 1 is in a sinking state. When the caisson 100 sinks to the specified depth, the free end of the second sealing membrane 12 is first removed from the inner well wall, and the second sealing membrane 12 is flipped downward under the action of gravity to be close to the excavation surface and the side wall of the blade foot; then the free end of the first sealing membrane 11 is removed from the inner well wall, and the first sealing membrane 11 is folded downward under the action of gravity to cover the second avoidance space 13, thereby completely covering the side wall of the blade foot and the excavation surface.

[0066] Furthermore, before injecting cement slurry into the grouting channel 2 in step S5, it also includes: injecting water into the grouting channel 2 to fully flush the impurities on the blade foot side wall and the sealing membrane assembly 1 toward the blade foot side wall, ensuring that there are no local weak points on the blade foot side wall that affect the adhesion of cement slurry, thereby ensuring the waterproof performance of the blade foot.

[0067] Specifically, the grouting channel 2 is arranged on the side wall of the blade foot near the top, and a plurality of grouting channels 2 are evenly arranged along the circumference, thereby ensuring sufficient flushing of the side wall of the blade foot.

[0068] Furthermore, in order to improve the connection strength between the sealing membrane assembly 1 and the caisson 100, the end of the sealing membrane assembly 1 away from the wellhead is pre-buried in the inner well wall. In this embodiment, the sealing membrane assembly 1 also includes a flexible membrane 14, and the fixed ends of the first sealing membrane 11 and the second sealing membrane 12 are both connected to the flexible membrane 14, and the flexible membrane 14 is buried at the upper end of the blade foot; the flexible membrane 14 is pre-placed in the mold for making the caisson 100 when making the caisson 100, and then the caisson 100 is cast and formed.

[0069] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A caisson bottom sealing device, characterized in that: include: A sealing membrane assembly (1), wherein the sealing membrane assembly (1) has a sinking state and a casting state. When the sealing membrane assembly (1) is in the sinking state, the sealing membrane assembly (1) surrounds and covers the inner wall of the caisson (100); The diaphragm assembly (1) can be folded to a casting state under the action of gravity. When the diaphragm assembly (1) is in the casting state, a portion of the diaphragm assembly (1) surrounds and covers the side wall of the blade foot, and another portion of the diaphragm assembly (1) adheres to the excavation surface, thereby forming a closed casting surface on the excavation surface. A grouting channel (2), wherein the grouting channel (2) is arranged on the side wall of the blade foot, and the grouting channel (2) is used to transport cement slurry between the diaphragm assembly (1) and the side wall of the blade foot.

2. The caisson bottom sealing device according to claim 1, characterized in that: The sealing membrane assembly (1) comprises a first sealing membrane (11) and a second sealing membrane (12), wherein a plurality of the first sealing membranes (11) are arranged along the circumference of the inner well wall, and a plurality of the second sealing membranes (12) are also arranged along the circumference of the inner well wall; When the sealing membrane assembly (1) is in a sinking state, the first sealing membrane (11) is in contact with the inner well wall, a first avoidance space is provided between two circumferentially adjacent first sealing membranes (11), and the second sealing membrane (12) covers the first avoidance space; When the sealing membrane assembly (1) is in a casting state, the second sealing membrane (12) is attached to the excavation surface, and a second avoidance space (13) is formed between two circumferentially adjacent second sealing membranes (12). The first sealing membrane (11) covers the second avoidance space (13), and a side of the first sealing membrane (11) facing the wellhead and a side of the second sealing membrane (12) facing the wellhead are spliced ​​to form the casting surface.

3. The caisson bottom sealing device according to claim 2, characterized in that: The first sealing membrane (11) and the second sealing membrane (12) both have a free end and a fixed end, the fixed end is away from the wellhead and fixedly arranged at the upper end of the blade foot, the upper end of the blade foot is the end of the inner well wall close to the side wall of the blade foot, and the free end is close to the wellhead and is detachably connected to the inner well wall.

4. The caisson bottom sealing device according to claim 3, characterized in that: The sealing membrane assembly (1) further comprises a flexible membrane (14), wherein the flexible membrane (14) is fixedly arranged at the upper end of the blade foot, and the fixed end of the first sealing membrane (11) and the fixed end of the second sealing membrane (12) are both connected to the flexible membrane (14).

5. The caisson bottom sealing device according to claim 3, characterized in that: The caisson bottom sealing device further comprises a connecting assembly (3), wherein the connecting assembly (3) comprises an electromagnet and an adsorbent, wherein the electromagnet is arranged on the inner well wall, and the adsorbent is arranged on the free ends of the first sealing membrane (11) and the second sealing membrane (12); The electromagnet can adsorb the adsorbent after being energized.

6. The caisson bottom sealing device according to claim 1, characterized in that: The caisson bottom sealing device also includes an injection pipe group (4). When the diaphragm assembly (1) is in the casting state, the injection pipe group (4) is used to cast bottom sealing concrete onto the casting surface.

7. The caisson bottom sealing device according to claim 6, characterized in that: The injection pipe group (4) comprises a side injection pipe (41) and a central injection pipe (42), wherein a plurality of the side injection pipes (41) are arranged along the circumference of the caisson (100), the outlet of the side injection pipe (41) is arranged opposite to the side wall of the blade foot, and the central injection pipe (42) is arranged opposite to the lowest point of the casting surface.

8. A method for sealing the bottom of a caisson, using the caisson bottom sealing device according to any one of claims 1 to 7, comprising the following steps: S1, wrapping the sealing membrane assembly (1) around the inner well wall, and fixing the end of the sealing membrane assembly (1) away from the wellhead to the upper end of the blade foot, the upper end of the blade foot is the end of the inner well wall close to the side wall of the blade foot, and connecting the end of the sealing membrane assembly (1) close to the wellhead to the inner well wall; S2, excavating the soil layer to sink the caisson (100) to a specified depth; S3, removing the end of the sealing membrane assembly (1) close to the wellhead, so that the sealing membrane assembly (1) is folded to the casting state under the action of gravity; S4, pouring bottom sealing concrete onto the casting surface; S5. Inject cement slurry into the grouting channel (2).

9. The method for sealing the bottom of a caisson according to claim 8, characterized in that: Before injecting cement slurry into the grouting channel (2) in step S5, the method further comprises: Water is injected into the grouting channel (2).

10. The method for sealing the bottom of a caisson according to claim 8, characterized in that: The end of the sealing membrane assembly (1) away from the wellhead is pre-buried in the inner well wall.

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