Caisson bottom sealing device and caisson bottom sealing method

Abstract

This invention belongs to the field of underground engineering technology and discloses a caisson bottom sealing device and method. The caisson bottom sealing device includes a sealing membrane assembly and a grouting channel. The sealing membrane assembly has a sunken state and a casting state. When in the sunken state, the sealing membrane assembly surrounds and covers the inner wall of the caisson. The sealing membrane assembly can be folded into the casting state. When in the casting state, a portion of the sealing membrane assembly surrounds and covers the cutting edge sidewall, while another portion adheres to the excavation face, forming a closed casting surface on the excavation face. The grouting channel is located on the cutting edge sidewall and is used to deliver cement grout between the sealing membrane assembly and the cutting edge sidewall. Using the above-mentioned caisson bottom sealing device, this method can isolate the bottom sealing concrete from the soil layer of the excavation face, avoiding the formation of local weak points during the pouring of the bottom sealing concrete. Furthermore, by injecting cement grout, the waterproofing performance at the cutting edge position is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of underground engineering technology, and in particular to a caisson bottom sealing device and a caisson bottom sealing method. Background Technology

[0002] Caissons are a common type of shaft-shaped structure in underground engineering, usually used as the foundation for bridge piers or other structures. The basic principle of their sinking is to use the weight of the shaft itself and the friction between the shaft wall and the soil layer, by excavating soil inside the shaft, so that the shaft gradually sinks in the soil layer.

[0003] After the caisson is lowered into the ground, its bottom needs to be sealed to improve its stability and safety. Before sealing the bottom, the inner wall of the caisson needs to be cleaned to remove silt, sediment, and other debris, thereby improving the bonding quality between the sealing concrete and the caisson wall. Currently, the commonly used method for cleaning the caisson wall is to manually descend to the bottom to clean it. However, this method has the problems of low cleaning efficiency and insufficient cleaning effect, and it also poses certain dangers for caissons that require underwater cleaning. In addition, the cutting edge of the caisson often leaks due to improper sealing, which greatly affects the safety of the caisson in use.

[0004] Therefore, there is an urgent need to design a caisson sealing device to solve the above-mentioned problems in the existing technology. Summary of the Invention

[0005] The purpose of this 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 objective, the present invention adopts the following technical solution:

[0007] The caisson bottom sealing device includes:

[0008] A septum membrane assembly, which has a submerged state and a cast-in state, wherein when the septum membrane assembly is in the submerged state, the septum membrane assembly surrounds and covers the inner wall of the caisson;

[0009] The sealing membrane assembly can be folded into a casting state under the action of gravity. When the sealing membrane assembly is in the casting state, a part of the sealing membrane assembly surrounds and covers the side wall of the cutting foot, and another part of the sealing membrane assembly is attached to the excavation surface, forming a closed casting surface on the excavation surface.

[0010] The grouting channel is located on the side wall of the cutting edge and is used to deliver cement grout between the sealing membrane assembly and the side wall of the cutting edge.

[0011] Preferably, the septum assembly includes a first septum and a second septum, wherein a plurality of the first septum are provided along the circumference of the inner well wall, and a plurality of the second septum are also provided along the circumference of the inner well wall;

[0012] When the septum assembly is in a submerged state, the first septum is attached to the inner well wall, and there is a first avoidance space between two adjacent first septums along the circumferential direction, and the second septum covers the first avoidance space;

[0013] When the diaphragm assembly is in the casting state, the second diaphragm is attached to the excavation surface, and a second avoidance space is formed between two adjacent second diaphragms along the circumferential direction. The first diaphragm covers the second avoidance space, and the side of the first diaphragm facing the wellhead and the side of the second diaphragm facing the wellhead are spliced ​​together to form the casting surface.

[0014] Preferably, both the first septum and the second septum have a free end and a fixed end. The fixed end is away from the wellhead and is fixedly disposed on the upper end of the cutting edge. The upper end of the cutting edge is the end of the inner well wall near the side wall of the cutting edge. The free end is close to the wellhead and is detachably connected to the inner well wall.

[0015] Preferably, the sealing membrane assembly further includes a flexible membrane, which is fixedly disposed on the upper end of the cutting 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 well sealing device further includes a connecting assembly, which includes an electromagnet and an adsorbent. The electromagnet is disposed on the inner well wall, and the adsorbent is disposed at the free ends of the first sealing membrane and the second sealing membrane.

[0017] The electromagnet can attract the adsorbed object when it is energized.

[0018] Preferably, the caisson sealing device further includes an injection pipe assembly, which is used to pour sealing concrete onto the casting surface when the diaphragm assembly is in the casting state.

[0019] Preferably, the injection pipe assembly includes side injection pipes and a central injection pipe. Multiple side injection pipes are arranged along the circumference of the caisson, with the outlet of the side injection pipe facing the side wall of the cutting edge, and the central injection pipe facing the lowest point of the casting surface.

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

[0021] S1. The septum assembly is wrapped around the inner well wall, and the end of the septum assembly away from the wellhead is fixed to the upper end of the cutting foot. The upper end of the cutting foot is the end of the inner well wall near the side wall of the cutting foot. The end of the septum assembly near the wellhead is connected to the inner well wall.

[0022] S2. Excavate the soil layer to allow the caisson to sink to the specified depth;

[0023] S3. Remove the end of the diaphragm assembly near the wellhead, and fold the diaphragm assembly to the casting state under the action of gravity;

[0024] S4. Pour sealing concrete onto the pouring surface;

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

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

[0027] Water is injected into the grouting channel.

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

[0029] The beneficial effects of this invention are as follows:

[0030] The caisson sealing device provided by this invention includes 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, it surrounds and covers the inner wall of the caisson. Therefore, during the sinking process, it isolates the soil from the inner wall, ensuring that the inner wall is clean and mud-free within the pouring height range of the sealing concrete during sinking. This eliminates the need for manual cleaning of the wall and ensures the bonding quality between the sealing concrete and the inner wall, greatly improving construction efficiency and safety. When the sealing membrane assembly is in the pouring state, it adheres to the excavation... Furthermore, the construction method forms a closed pouring surface on the excavation surface, thus isolating the excavation surface soil from the bottom sealing concrete, avoiding the influence of the excavation surface soil properties on the pouring quality, ensuring the uniformity of the bottom sealing concrete pouring, and thus improving the construction quality. Since there are grouting channels on the cutting edge sidewall, cement slurry can be delivered between the diaphragm assembly and the cutting edge sidewall, thus bonding treatment can be performed at the cutting edge sidewall to form an integral whole with the diaphragm assembly and the bottom sealing concrete on the pouring surface, ensuring the waterproof performance at the cutting edge position of the caisson, thereby greatly improving the safety and reliability of the caisson.

[0031] Using this caisson sealing method, a diaphragm assembly is wrapped around the inner wall of the caisson, thus isolating the inner wall from the soil. This ensures that the inner wall is clean and free of mud within the height range of the sealing concrete pouring during caisson sinking, thereby guaranteeing the quality of the caisson sealing. Because the diaphragm can fold under gravity to the pouring state, in this state, the diaphragm assembly adheres to the excavation surface, thus isolating the sealing concrete from the soil layer of the excavation surface and preventing the formation of local weak points during the pouring of the sealing concrete. Furthermore, because the grouting channel can inject cement grout between the cutting edge sidewall and the diaphragm assembly, the diaphragm assembly and the cutting edge sidewall are connected as a whole, greatly improving the waterproofing performance at the cutting edge location. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the sealing membrane assembly provided in a specific embodiment of the present invention when it is in a submerged state;

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

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

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

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

[0037] In the picture:

[0038] 100-caisson;

[0039] 1-Sealing membrane assembly; 11-First sealing membrane; 12-Second sealing membrane; 13-Second vacancy avoidance; 14-Flexible membrane;

[0040] 2- Grouting channel;

[0041] 3-Connecting components;

[0042] 4-Injection tubing assembly; 41-Side injection tubing; 42-Central injection tubing. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0044] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in 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 into 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 cutting edge sidewall, and another part of the diaphragm assembly 1 is attached to the excavation face, forming a closed casting face on the excavation face. The grouting channel 2 is provided on the cutting edge sidewall and is used to deliver cement slurry between the diaphragm assembly 1 and the cutting edge sidewall.

[0048] In this embodiment, when the diaphragm assembly 1 is in the sinking state, it surrounds and covers the inner wall of the caisson 100. Therefore, during the sinking process of the caisson 100, it isolates the soil from the inner wall, ensuring that the inner wall of the caisson 100 is clean and free of mud within the pouring height range of the bottom sealing concrete during sinking. This eliminates the need for manual cleaning of the wall and ensures the bonding quality between the bottom sealing concrete and the inner wall, greatly improving construction efficiency and safety. Furthermore, when the diaphragm assembly 1 is in the pouring state, it adheres to the excavation surface and forms a closed pouring surface on the excavation surface. Therefore, it can isolate the contact between the excavated soil and the bottom sealing concrete, avoiding the influence of the excavated soil properties on the pouring quality, ensuring the uniformity of the bottom sealing concrete pouring, and thus improving the construction quality. Because the cutting edge sidewall is equipped with grouting channels 2, which can deliver cement slurry between the diaphragm assembly 1 and the cutting edge sidewall, it can bond the cutting edge sidewall, forming a unified whole with the diaphragm assembly 1 and the bottom sealing concrete on the pouring surface. This ensures the waterproof performance at the cutting edge position of the caisson, thereby greatly improving the safety and reliability of the caisson 100. It is understandable that when the diaphragm assembly 1 is in the sinking state, the side of the diaphragm assembly 1 facing the inner well wall is against the inner well wall. When the diaphragm assembly 1 folds under gravity, the side facing the inner well wall detaches from the inner well wall, and the side facing away from the inner well wall rotates downwards and eventually adheres to the excavated surface.

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

[0050] The specific structure of the sealing membrane assembly 1 can be configured according to actual needs; for example, such as Figures 1 to 3As shown, the diaphragm assembly 1 includes a first diaphragm 11 and a second diaphragm 12. Multiple first diaphragms 11 are arranged circumferentially along the inner well wall, and multiple second diaphragms 12 are also arranged circumferentially along the inner well wall. When the diaphragm assembly 1 is in the sinking state, the first diaphragms 11 are attached to the inner well wall, and there is a first avoidance space between two adjacent first diaphragms 11 along the circumferential direction. The second diaphragm 12 covers the avoidance space. When the diaphragm assembly 1 is in the casting state, the second diaphragms 12 are attached to the excavation face, and a second avoidance space 13 is formed between two adjacent second diaphragms 12 along the circumferential direction. The first diaphragms 11 cover the second avoidance space 13. The side of the first diaphragm 11 facing the wellhead and the side of the second diaphragm 12 facing the wellhead are spliced ​​together to form the casting surface. Specifically, the first diaphragm 11 is located on the inner layer of the diaphragm assembly 1 near 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 submerged state, since the second diaphragm 12 covers the first avoidance space between two adjacent first diaphragms 11, the first diaphragms 11 and the second diaphragm 12 can together cover the inner well wall. Furthermore, because there is a first avoidance space between two adjacent first diaphragms 11, when the diaphragm assembly 1 folds downwards under gravity, the first avoidance space can provide space to avoid the compression deformation of the first diaphragms 11 during folding, allowing the first diaphragms 11 to... The folding can be completed smoothly under the influence of gravity. Similarly, when the diaphragm assembly 1 is in a sinking state, there is a first avoidance space between two adjacent second diaphragms 12. The purpose is to provide avoidance space for the deformation generated when the second diaphragm 12 is folded downward, so that the second diaphragm 12 can be folded smoothly. Since 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 folded under the action of gravity, the second diaphragm 12 first folds down and adheres to the excavation surface. Then the first diaphragm 11 folds down and covers the second avoidance space 13, thereby splicing together to form a closed casting surface.

[0051] like Figures 1 to 3 As shown, both the first diaphragm 11 and the second diaphragm 12 have a free end and a fixed end. The fixed end is away from the wellhead and is fixedly installed on the upper end of the cutting edge. The upper end of the cutting edge is the end of the inner well wall near the side wall of the cutting edge. The free end is near the wellhead and is detachably connected to the inner well wall. Taking the second diaphragm 12 as an example, when the caisson 100 sinks to the specified depth, since the fixed end is fixedly installed on the upper end of the cutting edge, the free end of the second diaphragm 12 can be detached from the inner well wall and folded downwards with the plane of the fixed end as the axis under its own weight, thus covering the side wall of the cutting edge while adhering to the excavation face. In this embodiment, both the first diaphragm 11 and the second diaphragm 12 are made of rubber, have good waterproof performance, and are heavy enough to be easily folded into the casting state under their own weight.

[0052] The shapes of the first sealing diaphragm 11 and the second sealing diaphragm 12 can be set according to actual needs, as long as they can ensure complete coverage of the inner well wall and the excavation face; for example, such as Figures 1 to 3 As shown, the first septum 11 and the second septum 12 have the same shape, both being arc triangles with one straight side. The straight side is fixedly connected to the upper end of the cutting edge. The straight sides of two adjacent first septum 11 are connected, and the straight sides of two adjacent second septum 12 are connected. The first septum 11 and the second septum 12 are staggered, that is, the first septum 11 and the second septum 12 are not completely aligned and overlapped along the radial direction of the caisson 100, thereby ensuring that the second septum 12 can cover the first avoidance space between two adjacent first septum 11, and the first septum 11 can also cover the first avoidance space between two adjacent second septum 12.

[0053] Furthermore, in order to ensure that the first septum 11 and the second septum 12 can be smoothly folded into the casting state, such as... Figure 4 As shown, the septum assembly 1 also includes a flexible membrane 14, which is fixedly disposed on the upper end of the cutting edge. The fixed ends of the first septum 11 and the second septum 12 are both connected to the flexible membrane 14. Specifically, the flexible membrane 14 is a highly flexible polymer membrane made of polyetheretherketone (PEEK), which has good flexibility and extensibility. One end of the flexible membrane 14 is fixedly disposed on the upper end of the cutting edge, and the other end is connected to the first septum 11 and the second septum 12 respectively. It is understood that compared with the first septum 11 and the second septum 12 made of rubber, the flexible membrane 14 has a higher cost and is therefore only used as a connection structure between the septum assembly 1 and the inner well wall.

[0054] Furthermore, such as Figure 1 and Figure 3 As shown, the caisson 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 workers can remove the free ends from the inner well wall after the caisson 100 sinks to a specified depth. For example, the connecting component 3 includes an electromagnet and an adsorbent. The electromagnet is disposed on the inner well wall, and the adsorbent is disposed on the free ends of the first sealing membrane 11 and the second sealing membrane 12. When the electromagnet is energized, it can attract the adsorbent. The adsorbent is disposed on the free ends of the first sealing membrane 11 and the second sealing membrane 12 respectively. The adsorbent can be attracted by the energized electromagnet. Therefore, the workers can remotely control the automatic detachment of the free ends from the ground without going down into the well, saving time and effort.

[0055] To improve the reliability of the connection between the diaphragm assembly 1 and the inner well wall, connection components 3 are also provided on the first diaphragm 11 and the second diaphragm 12 at positions other than the free ends. The specific locations can be selected according to the actual site conditions.

[0056] Furthermore, such as Figure 5 As shown, the caisson sealing device also includes an injection pipe assembly 4. When the diaphragm assembly 1 is in the pouring state, the injection pipe assembly 4 is used to pour sealing concrete onto the pouring surface.

[0057] Specifically, such as Figure 5 As shown, the injection pipe assembly 4 includes side injection pipes 41 and a central injection pipe 42. Multiple side injection pipes 41 are arranged around the circumference of the caisson 100. The outlet of the side injection pipe 41 is set directly opposite the side wall of the cutting edge, and the central injection pipe 42 is set directly opposite the lowest point of the pouring surface. The pouring surface is a concave, pot-shaped arc surface, connected to the side wall of the cutting edge on all four sides. The bottom of the side injection pipe 41 is provided with an injection section facing the side wall of the cutting edge. When pouring the bottom sealing concrete, firstly, a large amount of concrete is poured into the sealing membrane assembly 1 at the side wall of the cutting edge through the side injection pipe 41, so that the sealing membrane assembly 1 adheres to the side wall of the cutting edge under the impact of the concrete, thereby ensuring the waterproof effect at the side wall of the cutting edge. Then, concrete is evenly poured into the pouring surface directly below through the central injection pipe 42.

[0058] This embodiment also provides a method for sealing the bottom of a caisson, using the aforementioned caisson sealing device, including the following steps:

[0059] S1. Wrap the septum assembly 1 around the inner well wall and fix the end of the septum assembly 1 away from the wellhead to the upper end of the cutting foot. The upper end of the cutting foot is the end of the inner well wall near the side wall of the cutting foot. Connect the end of the septum assembly 1 near the wellhead to the inner well wall.

[0060] S2. Excavate the soil layer to sink the caisson 100 to the specified depth. Since the diaphragm assembly 1 covers 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 near the wellhead, and fold the diaphragm assembly 1 into the pouring state under gravity. After the diaphragm assembly 1 is in the pouring state, the diaphragm assembly 1 covers the excavation surface and forms a closed pouring surface, which can isolate the contact between the excavation surface soil and the bottom sealing concrete, avoid the influence of the excavation surface soil properties on the pouring quality, ensure the uniformity of the bottom sealing concrete pouring, and thus improve the construction quality.

[0062] S4. Pour the bottom sealing concrete onto the pouring surface;

[0063] S5. Inject cement grout into the grouting channel 2. The cement grout can bond the side wall of the cutting edge and the sealing membrane assembly 1 to form a whole, thereby improving the waterproof performance at the cutting edge position. Specifically, high-strength cement grout is used.

[0064] Using this caisson sealing method, by covering the inner wall of the caisson 100 with a sealing membrane assembly 1, the contact between the inner wall and the soil is isolated, ensuring that the inner wall of the caisson 100 is clean and free of mud within the range of the bottom sealing concrete pouring height during sinking, thus guaranteeing the sealing quality of the caisson 100. Since the sealing membrane can fold into the pouring state under gravity, in this state, the sealing membrane assembly 1 is attached to the excavation surface, thereby isolating the bottom sealing concrete from the soil layer of the excavation surface and avoiding the formation of local weak points when pouring the bottom sealing concrete. Since the grouting channel 2 can inject cement grout between the cutting edge sidewall and the sealing membrane assembly 1, the sealing membrane assembly 1 is connected to the cutting edge sidewall as a whole, greatly improving the waterproof performance at the cutting edge position.

[0065] Specifically, the septum assembly 1 includes a first septum 11 and a second septum 12. The first septum 11 is located on the inner layer of the septum assembly 1 near the inner well wall, and the second septum 12 is located on the outer layer of the septum assembly 1 away from the inner well wall. Both the first septum 11 and the second septum 12 have a free end and a fixed end. The fixed ends of both the first septum 11 and the second septum 12 are fixedly disposed on the upper end of the cutting edge, which is the end of the inner well wall near the side wall of the cutting edge. Both free ends can be detachably connected to the inner well wall. During the sinking of the caisson 100, the diaphragm assembly 1 is in a sinking state. When the caisson 100 sinks to the designated depth, the free end of the second diaphragm 12 is first removed from the inner wall of the caisson. Under the action of gravity, the second diaphragm 12 flips downward to adhere to the excavation face and the cutting edge sidewall. Then, the free end of the first diaphragm 11 is removed from the inner wall of the caisson. Under the action of gravity, the first diaphragm 11 folds downward to cover the second avoidance space 13, thereby completely covering the cutting edge sidewall and the excavation face.

[0066] Furthermore, before injecting cement slurry into the grouting channel 2 in step S5, water is injected into the grouting channel 2 to fully flush away impurities on the sidewall of the cutting edge and the sealing membrane assembly 1 facing the cutting edge, ensuring that there are no local weak points on the sidewall of the cutting edge that would affect the bonding of the cement slurry, thereby ensuring the waterproof performance at the cutting edge.

[0067] Specifically, the grouting channel 2 is located on the side wall of the cutting edge near the top, and multiple grouting channels 2 are evenly arranged along the circumference to ensure sufficient scouring of the side wall of the cutting edge.

[0068] Furthermore, to improve the connection strength between the septum assembly 1 and the caisson 100, the end of the septum assembly 1 furthest from the wellhead is pre-embedded in the inner well wall. In this embodiment, the septum assembly 1 also includes a flexible membrane 14, the fixed ends of the first septum 11 and the second septum 12 are both connected to the flexible membrane 14, and the flexible membrane 14 is embedded at the upper end of the cutting edge; the flexible membrane 14 is pre-placed in the mold for making the caisson 100 during the fabrication of the caisson 100, and then the caisson 100 is cast into shape.

[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 implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A caisson bottom sealing device, characterized in that, include: The septum assembly (1) has a sunken state and a casting state. When the septum assembly (1) is in the sunken state, the septum assembly (1) surrounds and covers the inner wall of the caisson (100). The sealing membrane assembly (1) can be folded into a casting state under the action of gravity. When the sealing membrane assembly (1) is in the casting state, a part of the sealing membrane assembly (1) surrounds and covers the side wall of the cutting foot, and another part of the sealing membrane assembly (1) is attached to the excavation surface, forming a closed casting surface on the excavation surface. Grouting channel (2), which is located on the side wall of the cutting edge, is used to deliver cement slurry between the sealing membrane assembly (1) and the side wall of the cutting edge.

2. The caisson bottom sealing device according to claim 1, characterized in that, The septum assembly (1) includes a first septum (11) and a second septum (12). Multiple first septums (11) are provided along the circumference of the inner well wall, and multiple second septums (12) are also provided along the circumference of the inner well wall. When the septum assembly (1) is in a submerged state, the first septum (11) is attached to the inner well wall, and there is a first avoidance space between two adjacent first septums (11) along the circumferential direction, and the second septum (12) covers the first avoidance space; When the septum assembly (1) is in the casting state, the second septum (12) is attached to the excavation surface, and a second avoidance space (13) is formed between two adjacent second septums (12) in the circumferential direction. The first septum (11) covers the second avoidance space (13). The side of the first septum (11) facing the wellhead and the side of the second septum (12) facing the wellhead are spliced ​​together to form the casting surface.

3. The caisson bottom sealing device according to claim 2, characterized in that, Both the first septum (11) and the second septum (12) have a free end and a fixed end. The fixed end is away from the wellhead and is fixedly disposed on the upper end of the cutting foot. The upper end of the cutting foot is the end of the inner well wall near the side wall of the cutting foot. 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 includes a flexible membrane (14), which is fixedly disposed on the upper end of the blade foot. 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 well sealing device further includes a connecting component (3), which includes an electromagnet and an adsorbent. The electromagnet is disposed on the inner well wall, and the adsorbent is disposed on the free ends of the first sealing membrane (11) and the second sealing membrane (12). The electromagnet can attract the adsorbed object when it is energized.

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

7. The caisson bottom sealing device according to claim 6, characterized in that, The injection pipe assembly (4) includes a side injection pipe (41) and a central injection pipe (42). Multiple side injection pipes (41) are arranged along the circumference of the caisson (100). The outlet of the side injection pipe (41) is set directly opposite the side wall of the cutting edge. The central injection pipe (42) is set directly opposite the lowest point of the casting surface.

8. A method for sealing the bottom of a caisson, using the caisson sealing device as described in any one of claims 1-7, comprising the following steps: S1. The septum assembly (1) is wrapped around the inner well wall, and the end of the septum assembly (1) away from the wellhead is fixed to the upper end of the cutting foot. The upper end of the cutting foot is the end of the inner well wall near the side wall of the cutting foot. The end of the septum assembly (1) near the wellhead is connected to the inner well wall. S2. Excavate the soil layer to sink the caisson (100) to the specified depth; S3. Remove the end of the septum assembly (1) near the wellhead and fold the septum assembly (1) back to the casting state under the action of gravity. S4. Pour sealing concrete onto the pouring surface; S5. Inject cement grout 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 grout into the grouting channel (2) in step S5, the following steps are also included: 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 diaphragm assembly (1) away from the wellhead is pre-embedded in the inner well wall.

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