Marine mud large caisson segmented sinking method and structure

Abstract

The application provides a large-scale caisson segmented sinking method and structure in marine silt. At least one circle of barrier piles is arranged in the soil outside the caisson position, the barrier piles are overlapped with each other, and a barrier cavity surrounding the outer periphery of the caisson structure is formed. A plurality of support piles are vertically arranged in the soil at the caisson position, and a spacing distance is arranged between the support piles. The caisson structure can be sequentially segmented and sunk according to a predetermined sequence, and the support piles below can be crushed by the weight to stably reach the predetermined depth position during the sinking process of the caisson structure. The barrier cavity surrounding the outer periphery of the caisson structure plays a role of blocking the surrounding environment and water stop curtain, and can avoid problems such as partial sinking, water gushing and mud gushing during the sinking process. The design of the support piles can make the sinking process of the caisson slow and stable, avoid sudden sinking, and the remaining support piles after crushing can also play a supporting role when the caisson reaches the predetermined depth position, thereby avoiding over-sinking of the caisson.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of open caisson construction, in particular to a large open caisson segmented sinking method and structure in marine silt. BACKGROUND

[0002] With the continuous development of economy, the city scale is expanding, and more and more municipal engineering construction projects, open caisson structure is widely used in municipal engineering with its unique advantages. The coastal areas mainly with marine silt geology more and more commonly use open caisson structure as the water intake pump house of sewage treatment plant and water plant, or as the sewage lifting pump station in sewage collection pipe network.

[0003] In the marine flow plastic silt, the open caisson construction is affected by the soil structure itself. Because the shear deformation resistance of the soil around the open caisson is poor, the soil around the open caisson will exert pressure on the lateral side of the open caisson, and it is easy to appear sudden sinking, partial sinking sliding, over-sinking, sinking speed and direction difficult to control and other technical problems. And because of the high water content of the soil, when the open caisson is constructed in the marine flow plastic silt, water and mud are easy to gush in the well.

[0004] In the past, the construction of open caisson mostly adopts the non-draining method sinking, or the foundation reinforcement treatment at the design elevation of the blade foot bottom to overcome the above-mentioned problems. However, under the condition of marine silt, it is difficult to use the suction pump to suck the silt, and the current non-draining method often encounters practical construction difficulties.

[0005] The method of using foundation reinforcement treatment at the blade foot bottom can meet the requirement of bearing capacity after sinking, but it is still easy to appear sudden sinking, partial sinking, water and mud gushing and over-sinking during sinking process. These phenomena in the sinking process of open caisson are still difficult to solve. SUMMARY

[0006] The present application provides a large open caisson segmented sinking method and structure in marine silt, which can reduce the influence of the surrounding environment on the open caisson operation during sinking, and can provide support for the blade foot during the segmented sinking process, stabilize the open caisson structure, and avoid over-sinking or partial sinking. The present application specifically adopts the following technical solutions.

[0007] Firstly, in order to achieve the above-mentioned purpose, a large open caisson segmented sinking method in marine silt is proposed, and the steps include:

[0008] Firstly, at least one circle of blocking piles is arranged in the soil around the open caisson position, and the blocking piles are connected with each other to form a blocking cavity surrounding the outer periphery of the open caisson structure;

[0009] Second step, a plurality of support pile bodies are vertically arranged in the soil body at the caisson position, the bottom end of each support pile body is arranged at the first depth position, a spacing distance is arranged between each support pile body, and the top end of each support pile body is located directly below the caisson cutting edge of the caisson structure;

[0010] Third step, each section of the caisson structure is sunk in a predetermined order, if the sinking of the caisson structure is blocked before reaching the predetermined depth position, the support pile bodies are gradually removed, until all the caisson structures crush the remaining support pile bodies by gravity and reach the predetermined depth position;

[0011] The first depth position is deeper than the predetermined depth position of the first section of the caisson structure.

[0012] Optionally, in the large caisson sinking method in marine silt, the spacing between the central axes of adjacent barrier pile bodies in the first step is not more than the diameter length of the barrier pile body.

[0013] Optionally, in the large caisson sinking method in marine silt, at least two circles of barrier pile bodies are arranged in the soil body around the caisson position in the first step, wherein the barrier pile bodies in the inner circle and the barrier pile bodies in the outer circle are arranged in a staggered manner and are overlapped with each other, forming a vertically sealed barrier cavity side wall structure, and no gap is arranged between the barrier pile bodies.

[0014] Optionally, in the large caisson sinking method in marine silt, the barrier pile body in the first step is a cement mixing pile, which is formed by wet spraying process;

[0015] In the second step, the support pile body is formed by dry spraying process and is arranged in long-short intervals, including long powder mixing pile and short powder mixing pile, wherein:

[0016] The bottom end of the long powder mixing pile is arranged at the first depth position, and the top end of the long powder mixing pile is flush with the ground surface at the caisson position;

[0017] The bottom end of the short powder mixing pile is arranged at the first depth position, and the top end of the short powder mixing pile is arranged at the second depth position below the ground surface at the caisson position;

[0018] The second depth position is higher than the predetermined depth position corresponding to the second section of the caisson structure.

[0019] Optionally, in the large caisson sinking method in marine silt, when the sinking of the caisson structure is blocked before reaching the predetermined depth position in the third step, the support pile bodies are gradually removed symmetrically around the axis of the caisson structure as the center of symmetry.

[0020] To achieve the above object, the present application provides a large-scale caisson sinking structure in marine sludge, comprising:

[0021] a blocking cavity surrounding the outer periphery of the caisson structure and arranged in the soil outside the caisson position;

[0022] supporting piles vertically arranged in the soil at the caisson position, the bottom end of each supporting pile being arranged at a first depth position, and a spacing distance being arranged between each supporting pile, and the top end of each supporting pile being located directly below the caisson cutting edge of the caisson structure.

[0023] Optionally, in the large-scale caisson sinking structure in marine sludge, the side wall of the blocking cavity is formed by a plurality of cement mixing piles connected to each other, and the spacing distance between the central axes of adjacent cement mixing piles is not more than the diameter length of the cement mixing pile.

[0024] Optionally, in the large-scale caisson sinking structure in marine sludge, the cement mixing pile is provided with two inner and outer rings, wherein the cement mixing piles in the inner ring and the cement mixing piles in the outer ring are arranged in a staggered manner and are overlapped between each other, the central connecting line between adjacent cement mixing piles in the inner ring and the outer ring forms an included angle of 30°, 60° or 45°, and the cement mixing piles are overlapped with each other to form a vertically sealed blocking cavity side wall structure, and no gap is arranged between adjacent cement mixing piles.

[0025] Optionally, in the large-scale caisson sinking structure in marine sludge, the supporting pile comprises:

[0026] long powder mixing piles, the bottom end of each long powder mixing pile being arranged at a first depth position, and the top end of each long powder mixing pile being flush with the ground surface at the caisson position;

[0027] short powder mixing piles arranged between adjacent long powder mixing piles, the bottom end of each short powder mixing pile being arranged at a first depth position, and the top end of each short powder mixing pile being arranged at a second depth position below the ground surface at the caisson position;

[0028] wherein the second depth position is higher than a predetermined depth position corresponding to a section of the caisson structure containing the caisson cutting edge structure.

[0029] Optionally, in the large-scale caisson sinking structure in marine sludge, only one ring of long powder mixing piles is arranged at the position directly below the outer wall of the caisson structure between the second depth position and the ground surface at the caisson position;

[0030] each of the long powder mixing piles and / or the short powder mixing piles can be symmetrically removed, so that the caisson structure can crush the remaining long powder mixing piles and / or short powder mixing piles by its own weight to reach the predetermined depth position.

[0031] Advantages:

[0032] The application sets at least one circle of barrier piles in the soil outside the caisson position, each barrier pile is overlapped with each other, forming a barrier cavity surrounding the outer periphery of the caisson structure. When a circle of barrier piles forms a vertical sealed barrier cavity side wall structure together, it can block the soil outside the barrier cavity, and the barrier cavity side wall structure can also provide mechanical strength to resist the shear deformation of the outside soil, avoiding the shear force of the outside soil acting on the caisson structure from the inside, so that the caisson structure deviates during the sinking process. The barrier cavity around the outer periphery of the caisson structure also plays a role in reducing the impact on the surrounding environment during the sinking of the caisson and the water stop curtain, which can prevent problems such as water and mud gushing during the sinking process. The application vertically sets a plurality of support piles in the soil at the caisson position, and the top end of each support pile is located directly below the caisson blade foot of the caisson structure, and a spacing distance is provided between each support pile. During use, each section of the caisson structure is sunk in a predetermined order until all the caisson structures are sunk. During the sinking process, the caisson structure can crush the support piles below it by using its own weight, and reach the predetermined depth position stably through the buffer support of the support piles. During the segmented sinking process, the caisson blade foot will crush the support piles below it, and the caisson structure will provide friction and support force by the crushed support column, slowly sinking under the combined action of the crushed support and the surrounding soil structure. The design of the support pile can make the caisson sink slowly and stably during the sinking process, and can solve the problems of sudden sinking and over-sinking during the sinking process of the caisson.

[0033] Further, the barrier piles in the application are overlapped and staggered with each other, making the barrier cavity side wall structure more sealed and providing better water stopping effect. Moreover, the wet spraying process is used to form the concrete, which has high strength after molding, so that the soil can be effectively prevented from acting on the caisson structure from the inside to cause the caisson to deviate.

[0034] Further, the support piles in the application are formed by the dry spraying process, which can reduce the construction cost on the one hand, and on the other hand, the strength of the concrete formed by the dry spraying process is relatively low, which can facilitate the application of force to the support piles during the sinking process of the caisson to crush them under suitable conditions to provide additional resistance to support the caisson structure and provide a buffer before the caisson structure sinks to the predetermined depth position. The crushed support piles are pressed around the lower part of the caisson structure, which can form a supporting surface, which can effectively prevent the caisson structure from over-sinking and improve the stability of the structure by mutual extrusion with the external soil structure.

[0035] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0036] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

[0037] Figure 1 is a structural schematic diagram of a large-scale sinking well segmented sinking structure in marine sludge;

[0038] Figure 2 is a structural schematic diagram of a long powder mixing pile at A-A of the application; Figure 1

[0039] Figure 3 is a structural schematic diagram of a short powder mixing pile at B-B of the application; Figure 1

[0040] In the drawings, 1 represents a barrier pile body; 2 represents a support pile body; 21 represents a long powder mixing pile; 22 represents a short powder mixing pile; 3 represents an outer wall of a sinking well structure; 4 represents a sinking well structure; 41 represents a sinking well blade foot. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present application.

[0042] Those skilled in the art can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art in the field of the present application. It should also be understood that terms such as those defined in a general dictionary should be understood to have meanings consistent with those in the context of the prior art, and should not be interpreted to have idealized or overly formal meanings unless otherwise defined.

[0043] The meaning of "and / or" described in the present application means that each single existence or both existences are included.

[0044] The meaning of "inner, outer" described in the present application means that the direction from the barrier cavity side wall structure to the sinking well structure is inner, and vice versa; and is not a specific limitation on the device mechanism of the present application.

[0045] The meaning of "connection" described in the present application can be direct connection between components or indirect connection between components through other components.

[0046] ​​The "upper and lower" in the present application refers to the direction of the first caisson pointing to the second caisson after all caisson structures reach the predetermined depth, and the opposite direction is the lower direction, which is not a specific limitation of the device mechanism of the present application.

[0047] Figure 1 The large caisson segmented sinking structure in the marine silt in the present application comprises a barrier cavity surrounding the outer periphery of the caisson structure 4 and arranged in the soil outside the caisson position. The side wall of the barrier cavity is formed by a plurality of cement mixing piles connected to each other, the spacing between the central axes of adjacent cement mixing piles is not more than the diameter length of the cement mixing pile, and a certain space distance is reserved between the inner side of the barrier cavity and the outer wall of the caisson structure, facilitating construction.

[0048] The cement mixing pile is provided with two inner and outer circles, wherein the cement mixing piles in the inner circle and the cement mixing piles in the outer circle are arranged in mutual overlap and staggered, the central connecting line between the four adjacent cement mixing piles in the inner circle and the outer circle forms an included angle of 30° or 60° or 45°, and the cement mixing piles are overlapped to form a vertical sealed barrier cavity side wall structure, and no gap is arranged between adjacent cement mixing piles. The construction risk of piping can be effectively prevented during construction, and the construction safety during caisson sinking construction is improved.

[0049] The present application also provides a support pile 2 below the caisson structure in the barrier cavity. The support pile is vertically arranged in the soil at the caisson position, the bottom end of each support pile is arranged at a first depth position, wherein the first depth position is the same as the bottommost depth position of the cement mixing pile, and the first depth position is deeper than the predetermined depth position of the bottom of the deepest caisson structure 4. A spacing distance is provided between the support piles, and the top end of each support pile is located directly below the caisson blade foot 41 arranged at the bottom of the deepest caisson structure. The second caisson structure is arranged above the first caisson structure at the deepest position. The two caisson structures correspond to their respective predetermined depths to identify the depths corresponding to the bottoms of each caisson structure after sinking in place.

[0050] As Figure 2 , Figure 3As shown, the support pile body can be specifically provided as including: long powder mixing piles 21, the bottom ends of which are all arranged at the first depth position, and the top ends of which are all flush with the ground at the caisson position. Short powder mixing piles 22, which are arranged between two adjacent long powder mixing piles 21, the bottom end of each short powder mixing pile 22 is arranged at the first depth position, and the top end of each short powder mixing pile 22 is arranged at the second depth position below the ground at the caisson position. Wherein, the second depth position is higher than the corresponding predetermined depth position of the caisson structure 4 containing the caisson blade foot 41 structure. Between the second depth position and the ground at the caisson position, only one circle of long powder mixing piles 21 is arranged at the position directly below the outer wall 3 of the caisson structure, which can be crushed by the gravity of the first section caisson structure during the sinking process of the first section caisson structure, and provides a buffer for the first section caisson structure. Between the second depth position and the first depth position, one circle of long powder mixing piles 21 and short powder mixing piles 22 are alternately arranged at the position directly below the outer wall 3 of the caisson structure, which can be crushed by the gravity of the first section caisson structure and the second section caisson structure during the sinking process of the second section caisson structure, while providing a buffer for the upper and lower caisson structures. The long powder mixing piles 21 and / or the short powder mixing piles 22 can be symmetrically chiseled, so that the caisson structure 4 can crush the remaining long powder mixing piles 21 and / or short powder mixing piles 22 by its own weight to reach the predetermined depth position. The same problem can be solved by arranging powder mixing piles or other types of piles with the same length below the caisson blade foot 41, but considering that if the strength of the powder mixing pile is too large and the resistance is too large, the sinking depth of the caisson is not enough, and the number of piles that need to be chiseled is large, the construction difficulty is large, and other columns have high cost, the use of powder mixing piles can control the cost under the premise of the same effect.

[0051] Meanwhile, the application also discloses a large caisson segmented sinking method in marine sludge, and the steps thereof include:

[0052] Firstly, as Figure 1As shown, at least one circle of barrier pile bodies 1 is arranged in the soil outside the caisson position, and each barrier pile body 1 is connected to each other to form a barrier cavity surrounding the outer periphery of the caisson structure. In the specific construction, two circles of barrier pile bodies can be arranged in the soil outside the caisson position, wherein each barrier pile body in the inner circle and each barrier pile body in the outer circle are arranged in a staggered manner and are connected to each other, and each barrier pile body in the same circle is connected to each other to form a vertical sealing barrier cavity side wall structure, and there is no gap between each barrier pile body. The vertical sealing here means that each barrier pile body is connected to each other, which can block and prevent the soil water and mud from flowing into the caisson structure in a horizontal or inclined direction. Considering the strength of the barrier cavity side wall structure, and taking into account the higher processing efficiency, the distance between the central axes of adjacent barrier pile bodies 1 can be set to be not more than the diameter length of the barrier pile body 1, and the barrier pile body is a cement mixing pile which is formed by using the existing wet spraying process.

[0053] The barrier cavity side wall structure composed of two rows of cement mixing piles arranged in a staggered manner outside the caisson can reduce the influence on the surrounding environment when the caisson sinks, and can also play a role of water stop curtain, which can separate water and mud from the caisson structure, and can avoid the problems of water and mud gushing during the sinking process of the caisson. It can also provide strength to resist the shear deformation of the soil outside, and can bear the lateral pressure of the soil around the caisson structure, so as to avoid the soil around the caisson from flowing into the caisson due to gravity and uneven soil density, which can affect the caisson structure inside, and can also avoid the offset of the caisson structure caused by the asymmetric stress of the caisson structure. The barrier cavity side wall structure composed of two rows of cement mixing piles arranged in a staggered manner can bear the lateral pressure of the soil, so that the lateral pressure of the surrounding soil on the caisson structure can be reduced and applied to the caisson structure in a more uniform manner, and therefore, the barrier cavity can effectively prevent the caisson structure from tilting, offsetting and other construction risks. The design of the barrier pile body 1 provides favorable conditions for the construction of the caisson by using the drainage sinking method.

[0054] In the second step, a plurality of support pile bodies 2 are arranged vertically in the soil at the caisson position, the bottom end of each support pile body 2 is arranged at a first depth position, and a spacing distance is arranged between each support pile body, and the top end of each support pile body is located directly below the caisson blade foot 41 of the caisson structure 4. The support pile body is formed by using a dry spraying process, and is arranged in a manner that the long powder mixing pile 21 and the short powder mixing pile 22 are arranged in a staggered manner. The dry spraying process is mainly used because the strength of the concrete formed by the dry spraying process is relatively low, which is convenient for crushing the support pile body during the sinking process of the caisson, and also convenient for providing additional sinking resistance to the caisson structure before the caisson structure sinks to the predetermined depth position, and the support strength of the support pile body can be adjusted by manually removing the support pile body step by step. Here, the dry spraying process with slightly lower forming strength can improve the working efficiency when the support pile body is removed.

[0055] The bottom end of the long powder body stirring pile 21 is arranged at a first depth position, and the top end of the long powder body stirring pile 21 is flush with the ground at the caisson position. The bottom end of the short powder body stirring pile 22 can also be arranged at the first depth position, but the top end of the short powder body stirring pile 22 can be arranged at a second depth position selected by corresponding simulation calculation according to the sinking depth of the first section caisson structure and considering the construction soil support strength. The second depth position is generally arranged to be higher than the predetermined depth position corresponding to the bottom of the second section caisson structure. The long and short powder body stirring piles are arranged opposite to the caisson position of the caisson structure.

[0056] The second section caisson structure specifically refers to another section caisson structure located directly above the first section caisson structure. The two section caisson structures are vertically aligned with each other. The predetermined depth position corresponding to the second section caisson structure is consistent with the depth position of the top end of the first section caisson structure after sinking in place.

[0057] The spacing between the above-mentioned support piles 2, the diameter of the support column, the length of the long powder body stirring pile 21 and the length of the short powder body stirring pile 22 can be determined according to the specific construction project. The arrangement depth of each support pile 2 is greater than the sinking depth, and the specific size of the support pile is calculated according to the weight of each section sinking structure, the soil resistance condition and the sinking depth distance.

[0058] The present application arranges one long and one short support pile 2 at the bottom of the caisson blade foot 41. During the sinking process of the sectionally manufactured caisson structure, the limit strength control principle is adopted, and the number of long and short powder body stirring piles is calculated to enable the first section caisson to sink by crushing the powder body stirring pile under its own weight. The second section caisson can continue to sink by crushing the powder body stirring pile under its own weight after symmetrically removing a small amount of powder body stirring pile. When the caisson sinks to the design elevation, the powder body stirring pile under the blade foot can support the caisson to prevent over-sinking.

[0059] Therefore, the present application can sink each section caisson structure 4 to the corresponding depth position in a predetermined order. The first section caisson structure at the bottom is usually provided with a caisson blade foot 41, and the predetermined depth position of the first section caisson structure should be the deepest relative to the predetermined depth positions of other sections. If the strength of the support pile 2 is too high and the caisson structure 4 cannot continue to move downward before sinking to the predetermined depth position, the operator enters the caisson structure to symmetrically remove the support piles step by step. During the removal process, the axis of the caisson structure is taken as the symmetric center, and the support piles are symmetrically removed step by step. Until all caisson structures 4 can crush the remaining support piles under their own weight and reach the predetermined depth position.

[0060] The specific process of the sinking operation of the caisson structure is as follows:

[0061] The first section of the caisson structure with the caisson blade foot 41 is lowered, and the upper part of the long-powder mixing pile 21 is gradually crushed under the action of its own gravity. The long-powder mixing pile 21 is extruded below the caisson blade foot 41, and the crushed long-powder mixing pile 21 is laid on the bottom of the caisson blade foot and wrapped around it, which can interact with the surrounding soil structure to provide buffer support for the sinking of the caisson. Because of the blocking and support of the powder mixing pile, the caisson slowly and stably sinks without sudden sinking during the sinking process. When the first section of the caisson structure continues to sink to near the second depth position, the short-powder mixing pile 22 can contact the caisson blade foot 41, and the caisson continues to sink and is resisted by the short-powder mixing pile 22. When the support resistance of the caisson structure is equivalent to its gravity, the caisson structure stops sinking. Therefore, before construction, the number and interval diameter of the powder mixing pile can be calculated and designed in advance so that the first section of the caisson structure can basically stop sinking after sinking to the second depth position, facilitating the sinking operation of the second section of the caisson structure.

[0062] When the second section of the caisson structure starts to sink, the gravity of the two sections of the caisson structure is superimposed on the lower part of the long-powder mixing pile 21 and the short-powder mixing pile 22 below the second depth position. The two kinds of support piles together provide buffer for the two sections of the caisson structure above. The long-powder mixing pile 21 and the short-powder mixing pile 22 are gradually crushed under the action of the gravity of the two sections of the caisson structure and wrapped around the caisson structure, and the crushed powder mixing pile interacts with the surrounding soil to continue to provide support for the two sections of the caisson structure until the two sections of the caisson structure 4 sink to the respective predetermined depth positions.

[0063] Because the support pile is crushed and can be basically uniformly distributed below the side wall of the caisson structure, the support force it provides can uniformly act on the caisson structure, effectively avoiding partial sinking. The buffer effect of the lower support pile can provide support for the caisson structure in time when sudden sinking occurs, ensuring smooth sinking of the caisson and avoiding sudden sinking.

[0064] During the process of sinking the two sections of the caisson structure 4 to the respective predetermined depth positions, if the sinking is affected by the excessive mechanical strength of the support pile, the operator can enter the inside of the caisson structure and symmetrically dig out the corresponding support pile at the bottom of the caisson structure. The crushed support pile can be basically laid flat below the caisson blade foot and wrapped around the caisson position, which can increase the sinking resistance of the caisson structure and avoid sudden sinking. The remaining support pile after crushing can serve as the bottom foundation of the caisson structure to provide support and avoid over-sinking.

[0065] Thus, the application can adopt the ultimate strength control principle, and better solve the technical problems such as sudden sinking, partial sinking, piping and over-sinking and the like in the sinking process of a large-scale sinking well in a marine flow plastic silt by arranging the powder mixing piles in long and short intervals under the blade feet of the sinking well.

[0066] 1. A barrier pile body is additionally arranged outside the sinking well to form a water stop curtain, so as to avoid water and mud gushing and partial sinking;

[0067] 2. The powder mixing piles arranged in long and short intervals are additionally arranged at the blade feet or the bottom of the partition wall to control the sinking speed of the sinking well;

[0068] 3. The sinking well is sunk in sections, the first section of the sinking well is sunk by crushing the support piles by the self-weight, the second section of the sinking well is sunk by symmetrically removing a small amount of support piles, and the sinking process is stable and controllable;

[0069] 4. When the sinking well is sunk to the design elevation, the powder mixing piles at the bottom of the blade feet can support and stop the sinking at the bottom.

[0070] The above is only an embodiment of the application, which is described in detail, but it should not be understood as a limitation on the scope of the patent. It should be noted that, for those skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are all within the scope of protection of the application.

Claims

1. A method for segmented sinking of large caissons in marine silt, characterized by the following steps: include: The first step is to set at least one ring of retaining piles (1) in the soil around the caisson location, and the retaining piles (1) are connected to each other to form a retaining cavity surrounding the caisson structure. The second step is to vertically install several support piles (2) in the soil at the location of the caisson. The bottom of each support pile is located at the first depth position. There is a gap between each support pile, and the top of each support pile is located directly below the caisson cutting edge (41) of the caisson structure (4). The third step is to sink each section of the caisson structure (4) in a predetermined order. If the caisson structure (4) is blocked before sinking to the predetermined depth, the supporting piles are gradually removed until the entire caisson structure (4) crushes the remaining supporting piles by its own weight and reaches the predetermined depth. The first depth position is deeper than the predetermined depth position of the first section of the caisson structure (4); The supporting pile body includes: The bottom of the long powder mixing pile (21) is set at the first depth position, and the top of the pile is flush with the ground at the caisson position. Short powder mixing piles (22) are set between two adjacent long powder mixing piles (21). The bottom end of each short powder mixing pile (22) is set at the first depth position, and the top end of each short powder mixing pile (22) is set at the second depth position below the ground at the caisson position. The second depth position is higher than the predetermined depth position corresponding to a section of caisson structure (4) containing the caisson cutting edge (41) structure; Between the second depth position and the caisson position, only one ring of the long powder mixing piles (21) is set at the position directly below the outer wall (3) of the caisson structure. During the sinking of the first section of the caisson structure, it can be crushed by the gravity of the first section of the caisson structure, providing a buffer for the first section of the caisson structure. Between the second depth position and the first depth position, a ring of long powder mixing piles (21) and short powder mixing piles (22) are alternately arranged directly below the outer wall (3) of the caisson structure. During the process of the second section of the caisson structure continuing to sink, they can be crushed by the gravity of the first section of the caisson structure and the second section of the caisson structure, while providing a buffer for the upper and lower sections of the caisson structure. The long powder mixing pile (21) and / or the short powder mixing pile (22) can be symmetrically removed so that the caisson structure (4) can crush the remaining long powder mixing pile (21) and / or short powder mixing pile (22) by its own weight and thus reach the predetermined depth position.

2. The method for segmented sinking of large caissons in marine silt as described in claim 1, characterized in that, In the first step, the distance between the central axes of each adjacent retaining pile (1) shall not exceed the diameter length of the retaining pile (1).

3. The method for segmented sinking of large caissons in marine silt as described in claim 2, characterized in that, In the first step, at least two rings of retaining piles are installed in the soil surrounding the caisson location. The retaining piles in the inner ring overlap and are staggered with the retaining piles in the outer ring to form a vertically sealed retaining cavity sidewall structure. There are no gaps between the retaining piles.

4. The method for segmented sinking of large caissons in marine silt as described in claim 1, characterized in that, In the first step, the retaining pile body is a cement mixing pile, which is formed by wet spraying process. In the second step, the supporting piles are formed by dry spraying and mixing, and are arranged at long and short intervals, including long powder mixing piles (21) and short powder mixing piles (22), wherein: The bottom of each of the long powder mixing piles (21) is located at the first depth position, and the top of each of the long powder mixing piles (21) is flush with the ground at the location of the caisson. The bottom of the short powder mixing pile (22) is set at the first depth position, and the top of the short powder mixing pile (22) is set at the second depth position below the ground at the caisson position; The second depth position is higher than the predetermined depth position corresponding to the second section caisson structure (4).

5. The method for segmented sinking of large caissons in marine silt as described in claim 4, characterized in that, In the third step, when the caisson structure (4) is obstructed before sinking to the predetermined depth, the supporting piles are gradually and symmetrically removed with the axis of the caisson structure as the center of symmetry.

6. A segmented sinking structure for large caissons in marine silt, characterized in that, For performing the method according to any one of claims 1-5, the structure includes: The baffle cavity surrounds the outer periphery of the caisson structure (4) and is set in the soil surrounding the caisson location; The supporting piles are vertically set in the soil at the caisson location. The bottom of each supporting pile is set at the first depth position. There is a gap between each supporting pile, and the top of each supporting pile is located directly below the caisson cutting edge (41) of the caisson structure (4). The supporting pile body includes: The bottom of the long powder mixing pile (21) is set at the first depth position, and the top of the pile is flush with the ground at the caisson position. Short powder mixing piles (22) are set between two adjacent long powder mixing piles (21). The bottom end of each short powder mixing pile (22) is set at the first depth position, and the top end of each short powder mixing pile (22) is set at the second depth position below the ground at the caisson position. The second depth position is higher than the predetermined depth position corresponding to a section of caisson structure (4) containing the caisson cutting edge (41) structure; Between the second depth position and the caisson position, only one ring of the long powder mixing piles (21) is set at the position directly below the outer wall (3) of the caisson structure. During the sinking of the first section of the caisson structure, it can be crushed by the gravity of the first section of the caisson structure, providing a buffer for the first section of the caisson structure. Between the second depth position and the first depth position, a ring of long powder mixing piles (21) and short powder mixing piles (22) are alternately arranged directly below the outer wall (3) of the caisson structure. During the process of the second section of the caisson structure continuing to sink, they can be crushed by the gravity of the first section of the caisson structure and the second section of the caisson structure, while providing a buffer for the upper and lower sections of the caisson structure. The long powder mixing pile (21) and / or the short powder mixing pile (22) can be symmetrically removed so that the caisson structure (4) can crush the remaining long powder mixing pile (21) and / or short powder mixing pile (22) by its own weight and thus reach the predetermined depth position.

7. The segmented sinking structure for large caissons in marine silt as described in claim 6, characterized in that, The sidewall of the partition cavity is formed by connecting multiple cement mixing piles, and the distance between the central axes of adjacent cement mixing piles does not exceed the diameter of the cement mixing pile.

8. The segmented sinking structure for large caissons in marine silt as described in claim 7, characterized in that, The cement mixing piles are arranged in two concentric rings, with the cement mixing piles in the inner ring overlapping and staggered with those in the outer ring. The center lines connecting the four adjacent cement mixing piles in the inner and outer rings form an angle of 30°, 60°, or 45°. The cement mixing piles overlap to form a vertically sealed partition cavity sidewall structure, and there are no gaps between adjacent cement mixing piles.

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