A self-balancing, self-circulating sinking structure and method for caisson

Abstract

The invention discloses a self-balancing and self-circulating sinking structure and method for a caisson, and belongs to the technical field of caisson construction. The invention provides a plurality of mud storage bins, well wall empty bins and partition wall empty bins. Mud water in the caisson's non-drainage sinking stage is injected into the mud storage bins, and clean water is filtered out through a water-permeable structure for water replenishment during the sinking of the caisson, thereby realizing water recycling. The dead weight of each area of ​​the caisson is adjusted by adjusting the water storage capacity of the well wall empty bins, thereby adjusting the sinking posture of the caisson. At the same time, the invention provides a plurality of air holes on the well wall outside the caisson, and high-pressure air pipes are connected as needed to spray high-pressure air to the outside to assist sinking, thereby avoiding the risk of sudden sinking. The local spraying of high-pressure air can also adjust the sinking posture of the caisson to maintain the balanced sinking of the caisson.

Description

Technical Field

[0001] The invention relates to the technical field of caisson construction, in particular to a caisson self-balancing and self-circulating sinking structure and method. Background Art

[0002] Caisson is a shaft-shaped or rectangular structure. It relies on its own gravity to overcome the frictional resistance of the shaft wall and sinks to the designed elevation. It is then sealed with concrete and filled. Caisson construction methods are widely used in large bridge pier foundation pits, anchor foundations, sewage pumping stations, large equipment foundations, civil air defense shelters, underground passages and other transportation and municipal engineering projects. The caisson sinking method is divided into drainage sinking and non-drainage sinking. In the non-drainage sinking stage, the method of controlling the caisson posture is mainly to adjust the underwater soil excavation depth in different areas. Because it is underwater soil excavation, it is not easy to control accurately. As the sinking depth increases, the friction resistance around the caisson increases, and the difficulty of sinking is gradually increasing. When encountering this kind of problem, air curtain measures are generally used to assist sinking, that is, high-pressure air is pressed into the air pipes pre-buried around the well wall, and sprayed out through the jet holes set in the well wall, and rises along the outer surface of the well wall and overflows to the ground, thereby forming a loose layer of liquefied soil containing gas and water around the well wall. The gas-containing soil layer surrounds the caisson like a curtain, thereby reducing the friction of the well wall and achieving the purpose of assisting sinking. In practice, it is found that this "air curtain" sinking-aiding measure has the risk of sudden sinking, cannot accurately control the amount of sinking, and is prone to construction accidents. In addition, during the current large-scale caisson sinking stage without drainage, the mud water generated must be set up in a sedimentation tank or handled by a mud treatment plant, which is inefficient and costly. Summary of the invention

[0003] In view of the above shortcomings, the present invention develops a self-balancing, self-circulating sinking structure and method for caissons. The structure and method are provided with a number of mud storage bins, well wall empty bins and partition wall empty bins. The mud water in the caisson sinking stage without drainage is injected into the mud storage bins, and the clean water is filtered out through the permeable structure for water replenishment during the sinking of the caisson, thereby realizing the self-circulation of clean water. The deadweight of each area of ​​the caisson is adjusted by adjusting the water storage capacity of the well wall empty bins, thereby adjusting the sinking posture of the caisson. In addition, the structure retains and utilizes the pre-buried tension bolt holes in the concrete pouring of the outer well wall as air holes. When the caisson is in a difficult sinking stage, the clean water in the well wall empty bins is extracted, and the operation is performed in the well wall empty bins, and a local "air curtain" method can be used to assist the sinking.

[0004] The present invention is implemented through the following technical scheme: a self-balancing, self-circulating sinking structure of a caisson, including a well wall and a partition wall, the well wall is a double-walled concrete wall, including an outer well wall, an inner well wall and a bottom plate, the outer well wall and the inner well wall are concrete walls built in parallel on the bottom plate, forming a hollow well wall structure opening upward, the well wall is connected with multiple partition walls intersecting horizontally and vertically, the partition wall includes a partition wall inner wall, a partition wall outer wall and a partition wall bottom plate, the partition wall inner wall and the partition wall outer wall are concrete walls built in parallel on the partition wall bottom plate, forming a partition wall hollow structure opening upward, the partition wall divides the caisson into multiple sinking areas, characterized in that: multiple groups of well wall hollow structures and mud storage bins are arranged on the well wall, the mud storage bin is arranged at the junction of the well wall and the partition wall, separated from the well wall hollow structure by a concrete wall, and separated from the partition wall hollow structure by a wall panel, and the wall panel is embedded with a permeable structure.

[0005] Preferably, the permeable structure is arranged starting from the bottom of the wall panel, with a group arranged every 2-3 m.

[0006] Preferably, the hollow structure of the well wall also includes an inner partition, which is inserted between the outer well wall and the inner well wall and fixedly connected to the outer well wall, the inner well wall and the bottom plate. The inner partition divides the hollow structure of the well wall into a plurality of empty well walls with openings facing upward.

[0007] Preferably, the hollow partition wall structure also includes a partition wall partition plate, which is inserted between the inner wall and the outer wall of the partition wall and fixedly connected to the inner wall, the outer wall and the partition wall bottom plate of the partition wall, and the partition wall partition plate divides the hollow partition wall structure into a plurality of partition wall empty compartments with openings facing upward.

[0008] Preferably, a plurality of partition walls and partition boards are provided, and partition wall water-permeable structures are arranged at intervals on the partition wall and partition boards, and the partition wall water-permeable structures are embedded in the partition wall and partition boards.

[0009] Preferably, the partition wall water-permeable structure is composed of a metal outer shell and an inner sponge, which is embedded in the partition wall partition. A plurality of holes are drilled on the outer wall of the metal outer shell, with a diameter of 1-3 cm and a hole spacing of 1 cm. The inner sponge is filled inside the metal outer shell, and an outer sponge is wrapped on the metal outer shell, and a temporary film is wrapped on the outer surface of the outer sponge.

[0010] Preferably, the partition wall water-permeable structure is arranged starting from the bottom of the partition wall partition, with a group arranged every 2-3m.

[0011] Preferably, the intersection of the partition walls is a solid wall that separates the hollow structure of the partition walls.

[0012] Preferably, a plurality of air holes are provided on the outer well wall, and the air holes are temporarily blocked with plugs.

[0013] Preferably, the present invention further discloses a self-balancing and self-circulating sinking method for a caisson, comprising any one of the self-balancing and self-circulating sinking structures for a caisson described above, and the specific steps of the self-balancing and self-circulating sinking method for a caisson are as follows:

[0014] S1. Construct steel shell concrete caisson and reinforced concrete caisson. The reinforced concrete caisson is constructed on top of the steel shell concrete caisson and is sunk by drainage method;

[0015] S2. After the steel shell concrete caisson and reinforced concrete caisson are sunk, a self-balancing and self-circulating sinking structure of the caisson is constructed on the reinforced concrete, and the caisson is sunk by the undrainage method;

[0016] S3. During the sinking process, half of the mud storage bins are first filled with mud water extracted from the caisson. The mud water is filtered through the permeable structure and the partition wall permeable structure to become clean water and flow into the adjacent partition wall empty bin. The clean water is extracted by a water pump and added to the sinking area of ​​the caisson for recycling.

[0017] S4. When the caisson continues to sink and the height difference of the caisson wall is maintained within 0.5m, when the bulk dry soil remaining in the mud storage bin after filtering is full, stop adding mud water to the mud storage bin, dig out the bulk dry soil on the upper part of the mud storage bin, and select the other half of the empty mud storage bin to add the mud water extracted from the caisson, and continue to sink using the undrained method;

[0018] S5. When the caisson continues to sink and the height difference of the caisson wall exceeds 0.5m, add clean water to the empty space on the side of the caisson wall with a higher height to restore the caisson to a balanced state;

[0019] S6, repeat operations S3-S5 until the sinking of the caisson is blocked;

[0020] S7. Pump out the clean water in the empty chamber on the well wall to form an operating space;

[0021] S8. Remove the plugs of the air holes on the outer well wall as needed, connect the high-pressure air pipe, and spray high-pressure air outward through the air holes to form a local air curtain, so that the caisson continues to sink and maintains the balance of the caisson;

[0022] S9. Repeat operations S6-S8 until the caisson is completely sunk.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention provides a plurality of mud storage bins, well wall hollow bins and partition wall hollow bins, and adjusts the deadweight of each area of ​​the caisson by adjusting the water storage capacity of the well wall hollow bins, thereby adjusting the sinking posture of the caisson, so that the caisson can maintain a balanced posture when sinking.

[0025] 2. The present invention arranges multiple groups of permeable structures on the walls of the mud storage bin and the hollow structure of the partition wall, and arranges multiple groups of partition wall permeable structures on the partition wall partitions, so as to quickly filter the mud water injected into the mud storage bin to form clean water, thereby realizing water circulation in the process of sinking the caisson without drainage.

[0026] 3. The present invention is provided with a plurality of air holes on the outer wall of the caisson, and a high-pressure air pipe is connected as needed to spray high-pressure air to the outside to assist sinking. Different from the existing "air curtain" sinking-assisting system, the positions of the air holes in the present invention are random, and they are temporarily blocked with plugs in static state. When the caisson has difficulty in sinking, the plugs are taken out as needed to spray high-pressure air outward, thereby forming a local "air curtain". While assisting sinking, the risk of sudden sinking is avoided. Moreover, the local spraying of high-pressure air can also adjust the sinking posture of the caisson to maintain the balanced sinking of the caisson. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a top view of the overall structure of the present invention;

[0028] Figure 2 A top view of a local structure of the present invention;

[0029] Figure 3 It is a three-dimensional schematic diagram of the hollow structure of the well wall in the present invention;

[0030] Figure 4 It is a three-dimensional schematic diagram of the hollow structure of the partition wall in the present invention;

[0031] Figure 5 It is a schematic cross-sectional view of the partition wall water-permeable structure of the present invention;

[0032] Figure 6 is a schematic cross-sectional view of a wall panel in the present invention;

[0033] Among them: 1. Well wall; 11. Outer well wall; 111. Air holes; 12. Inner well wall; 2. Partition wall; 21. Inner wall of partition wall; 22. Outer wall of partition wall; 3. Hollow structure of well wall; 31. Partition board inside the warehouse; 32 Empty warehouse of well wall; 4. Hollow structure of partition wall; 41. Partition wall partition board; 42 Empty warehouse of partition wall; 5. Mud storage warehouse; 51. Wall panel; 6. Bottom plate; 7. Bottom plate of partition wall; 8. Permeable structure; 9. Permeable structure of partition wall; 91. Metal shell; 92. Inner sponge; 93. Drill hole; 94. Outer sponge; 95. Temporary film. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1-6 The present invention provides a technical solution: a self-balancing, self-circulating sinking structure of a caisson, comprising a well wall 1 and a partition wall 2, wherein the well wall 1 is a double-walled concrete wall, comprising an outer well wall 11, an inner well wall 12 and a bottom plate 6, wherein the outer well wall 11 and the inner well wall 12 are concrete walls constructed in parallel on the bottom plate 6 to form a well wall hollow structure 3 with an opening upward, wherein the well wall 1 is connected with a plurality of partition walls 2 intersecting horizontally and vertically, wherein the partition wall 2 comprises a partition wall inner wall 21, a partition wall outer wall 22 and a partition wall bottom plate 7, wherein the partition wall The inner wall 21 and the outer wall 22 of the partition wall are concrete walls built in parallel on the partition wall bottom plate 7, forming a partition wall hollow structure 4 opening upward, and the partition wall 2 divides the caisson into multiple sinking areas, characterized in that: multiple groups of hollow well wall structures 3 and mud storage bins 5 are arranged on the well wall 1, and the mud storage bins 5 are arranged at the junction of the well wall 1 and the partition wall 2, separated from the hollow well wall structure 3 by a concrete wall, and separated from the hollow partition wall structure 4 by a wall panel 51, and the wall panel 51 is embedded with a permeable structure 8.

[0036] Specifically, the water-permeable structure 8 is arranged starting from the bottom of the wall panel 51, with a group arranged every 2 meters.

[0037] Specifically, the hollow structure 3 of the well wall also includes an inner partition 31, which is inserted between the outer well wall 11 and the inner well wall 12, and is fixedly connected to the outer well wall 11, the inner well wall 12 and the bottom plate 6. The inner partition 31 divides the hollow structure 3 of the well wall into a plurality of well wall empty compartments 32 with openings facing upward.

[0038] Specifically, the partition wall hollow structure 4 also includes a partition wall partition plate 41, which is inserted between the partition wall inner wall 21 and the partition wall outer wall 22, and is fixedly connected to the partition wall inner wall 21, the partition wall outer wall 22 and the partition wall bottom plate 7. The partition wall partition plate 41 divides the partition wall hollow structure 4 into a plurality of partition wall empty compartments 42 with openings facing upward.

[0039] Specifically, a plurality of partition walls and partition boards 41 are provided, and partition wall water-permeable structures 9 are spaced apart on the partition wall and partition boards 41 , and the partition wall water-permeable structures 9 are embedded in the partition wall and partition boards 41 .

[0040] Specifically, the partition wall water-permeable structure 9 is composed of a metal shell 91 and an inner sponge 92, which is embedded in the partition wall partition 41. A plurality of drill holes 93 are opened on the outer wall of the metal shell 91. The diameter of the drill holes 93 is 2 cm and the hole spacing is 1 cm. The inner sponge 92 is filled in the metal shell 91, and an outer sponge 94 is wrapped on the metal shell 91. A temporary film 95 is wrapped on the outer surface of the outer sponge 94.

[0041] Specifically, the partition wall water-permeable structure 9 is arranged starting from the bottom of the partition wall partition plate 41, and a group is arranged every 3m.

[0042] Specifically, the intersection of the partition walls 2 is a solid wall that separates the hollow structure 4 of the partition walls.

[0043] Specifically, a plurality of air holes 111 are provided on the outer well wall 11, and the air holes 111 are temporarily blocked with plugs.

[0044] Specifically, the present invention further discloses a self-balancing and self-circulating sinking method for a caisson, comprising any one of the self-balancing and self-circulating sinking structures for a caisson described above, and the specific steps of the self-balancing and self-circulating sinking method for a caisson are as follows:

[0045] S1. Construct steel shell concrete caisson and reinforced concrete caisson. The reinforced concrete caisson is constructed on top of the steel shell concrete caisson and is sunk by drainage method;

[0046] S2. After the steel shell concrete caisson and the reinforced concrete caisson are sunk, a self-balancing and self-circulating sinking structure of the caisson is constructed on the reinforced concrete caisson, and the caisson is sunk by the non-drainage method;

[0047] S3, during the sinking process, firstly fill half of the mud storage bins 5 with mud water extracted from the caisson, and the mud water is filtered into clean water through the permeable structures 8 and 9 and flows into the adjacent partition wall empty bin 42, and the clean water is extracted by a water pump and added to the sinking area of ​​the caisson for recycling;

[0048] S4, when the caisson continues to sink and the height difference of the caisson wall is maintained within 0.5m, when the bulk dry soil remaining in the mud storage bin 5 after filtering is full, stop adding mud water to the mud storage bin 5, dig out the bulk dry soil on the upper part of the mud storage bin 5, and select the other half of the empty mud storage bin 5 to add the mud water extracted from the caisson, and continue to sink using the undrained method;

[0049] S5. When the caisson continues to sink and the height difference of the caisson wall exceeds 0.5m, clean water is added to the empty chamber 32 on the side of the caisson wall with a higher height to restore the caisson to a balanced state;

[0050] S6, repeat operations S3-S5 until the sinking of the caisson is blocked;

[0051] S7, pump out the clean water in the empty chamber 32 of the well wall to form a workable space;

[0052] S8, remove the plug of the air hole 111 on the outer well wall 11 as needed, connect the high-pressure air pipe, and spray high-pressure air outward through the air hole 111 to form a local air curtain, so that the caisson continues to sink and maintains the balance of the caisson;

[0053] S9. Repeat operations S6-S8 until the caisson is completely sunk.

[0054] In the present invention, at the beginning stage of construction, the inner and outer well walls are cast with concrete formwork, and the inner and outer formworks are pulled against each other by tie rods. In order to facilitate the removal of the tie rods, a sleeve is arranged in the formwork, and in the process of erecting the outer well wall, a sleeve with an internal thread is used. After the outer well wall is cast and the maintenance is completed, the sleeve of the outer well wall is not sealed with cement mortar, but is temporarily sealed with a plug, which forms a reserved air hole.

[0055] Entering the caisson sinking stage, the drainage method is used in the first stage. When the steel shell concrete caisson and the first section of the reinforced concrete caisson are all sunk into the soil, the undrainage method is used for sinking. At this time, a low-pressure water pump is required to continuously supply water to the caisson to maintain the head pressure in the caisson, and then the air suction machine is started to absorb the mud in the caisson. At this time, due to underwater soil excavation, it is easy for the outer height difference to be too large when the caisson sinks, and the caisson tilts. Therefore, water is added to the empty bin of the well wall to increase the deadweight of the caisson near this area, so that the area can sink and the caisson as a whole returns to a balanced state. At the same time, through the operation of the permeable structure in the mud storage bin and the partition wall empty bin, clean water is filtered out to the adjacent partition wall empty bin, and then the water pump is used to extract clean water and supply it to the caisson to realize the clean water circulation.

[0056] When the caisson maintains balance, extract the mud water in the sinking area, and then continuously dig out the dry mud and sand in the mud storage bin to allow the caisson to continue sinking, and repeat the operation. The caisson continues to sink, and the friction around it further increases until the above solution can no longer assist sinking. Remove the temporary plug on the air hole as needed, connect the high-pressure air pump, and spray high-pressure air to the outside to form a local "air curtain" to reduce local friction and assist the sinking of the caisson. It should be noted that the reason for the formation of a local "air curtain" is that the conventional "air curtain" sprays high-pressure air to all the peripheries of the caisson. Although this effect is good, there is a risk of sudden sinking, and the control of the sinking amount is not precise enough. In our practice, we can increase the number of air jets from the air holes one by one, which can not only avoid sudden sinking, but also effectively control the local sinking amount of the caisson, so that the caisson can maintain a balanced sinking.

[0057] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A self-balancing, self-circulating sinking structure of a caisson, comprising a caisson wall (1) and a partition wall (2), wherein the caisson wall (1) is a double-walled concrete wall, comprising an outer caisson wall (11), an inner caisson wall (12) and a bottom plate (6), wherein the outer caisson wall (11) and the inner caisson wall (12) are concrete walls constructed in parallel on the bottom plate (6), forming a hollow caisson wall structure (3) opening upward, wherein the caisson wall (1) is internally connected with a plurality of partition walls (2) intersecting in the horizontal and vertical directions, wherein the partition wall (2) comprises a partition wall inner wall (21), a partition wall outer wall (22) and a partition wall bottom plate (7), wherein the partition wall inner wall (21) and the partition wall outer wall (22) are concrete walls constructed in parallel on the partition wall bottom plate (7), forming a partition wall hollow structure (4) opening upward, wherein the partition wall (2) divides the caisson into a plurality of sinking areas, characterized in that: The well wall (1) is provided with a plurality of groups of well wall hollow structures (3) and mud storage bins (5); the mud storage bins (5) are provided at the junction of the well wall (1) and the partition wall (2), and are separated from the well wall hollow structures (3) by a concrete wall, and are separated from the partition wall hollow structures (4) by a wall panel (51); and the wall panel (51) is provided with a water-permeable structure (8) embedded therein; The hollow well wall structure (3) further comprises an inner compartment partition (31), wherein the inner compartment partition (31) is inserted between the outer well wall (11) and the inner well wall (12), and is fixedly connected to the outer well wall (11), the inner well wall (12) and the bottom plate (6), and the inner compartment partition (31) divides the hollow well wall structure (3) into a plurality of well wall hollow compartments (32) with openings facing upwards; The partition wall hollow structure (4) further comprises a partition wall partition plate (41), wherein the partition wall partition plate (41) is inserted between the partition wall inner wall (21) and the partition wall outer wall (22), and is fixedly connected to the partition wall inner wall (21), the partition wall outer wall (22) and the partition wall bottom plate (7), and the partition wall partition plate (41) divides the partition wall hollow structure (4) into a plurality of partition wall hollow compartments (42) with openings facing upwards; A plurality of partition walls and partition plates (41) are provided, and partition wall water-permeable structures (9) are provided at intervals on the partition walls and partition plates (41), and the partition wall water-permeable structures (9) are embedded in the partition wall and partition plates (41); The partition wall water-permeable structure (9) is composed of a metal shell (91) and an inner sponge (92), which is embedded in the partition wall partition (41). A plurality of holes (93) are drilled on the outer wall of the metal shell (91). The inner sponge (92) is filled in the metal shell (91). An outer sponge (94) is wrapped on the metal shell (91), and a temporary film (95) is wrapped on the outer surface of the outer sponge (94).

2. The self-balancing, self-circulating sinking structure of a caisson according to claim 1 is characterized by: The water-permeable structures (8) are arranged starting from the bottom of the wall panel (51), with one group arranged every 2-3 m.

3. The self-balancing, self-circulating sinking structure of a caisson according to claim 1 is characterized by: The diameter of the drill holes (93) is 1-3 cm, and the hole spacing is 1 cm.

4. The self-balancing, self-circulating sinking structure of a caisson according to claim 1 is characterized by: The partition wall water-permeable structure (9) is arranged starting from the bottom of the partition wall partition plate (41), with one group arranged every 2-3 m.

5. The self-balancing and self-circulating sinking structure of caisson according to claim 1 is characterized in that: The intersection of the partition walls (2) is a solid wall that separates the hollow partition wall structure (4).

6. The self-balancing, self-circulating sinking structure of caisson according to claim 1 is characterized by: The outer well wall (11) is provided with a plurality of air holes (111), and the air holes (111) are temporarily blocked with plugs.

7. A self-balancing and self-circulating sinking method for a caisson, comprising a self-balancing and self-circulating sinking structure for a caisson as claimed in any one of claims 1 to 6, wherein the specific steps of the self-balancing and self-circulating sinking method for a caisson are as follows: S1. Construct steel shell concrete caisson and reinforced concrete caisson. The reinforced concrete caisson is constructed on top of the steel shell concrete caisson and is sunk by drainage method; S2. After the steel shell concrete caisson and the reinforced concrete caisson are sunk, a self-balancing and self-circulating sinking structure of the caisson is constructed on the reinforced concrete caisson, and the caisson is sunk by the non-drainage method; S3. During the sinking process, half of the mud storage bins (5) are first filled with mud water extracted from the caisson. The mud water is filtered through the permeable structure (8) and the partition wall permeable structure (9) to become clean water, which flows into the adjacent partition wall empty bin (42). The clean water is extracted by a water pump and added to the sinking area of ​​the caisson for recycling. S4, when the caisson continues to sink and the height difference of the caisson wall is maintained within 0.5 m, when the mud storage bin (5) is full of loose dry soil remaining after filtering, stop filling the mud storage bin (5), dig out the loose dry soil on the upper part of the mud storage bin (5), and select the other half of the empty mud storage bin (5) to fill with mud water extracted from the caisson, and continue to sink using the undrained method; S5. When the caisson continues to sink and the height difference of the caisson wall exceeds 0.5 m, clean water is added to the empty chamber (32) on the side of the caisson wall with a higher height to restore the caisson to a balanced state; S6, repeat operations S3-S5 until the sinking of the caisson is blocked; S7, pumping out clean water in the empty chamber (32) on the well wall to form a workable space; S8, removing the plug of the air hole (111) on the outer well wall (11) as needed, connecting a high-pressure air pipe, and spraying high-pressure air outward through the air hole (111) to form a local air curtain, so that the caisson continues to sink and maintains the balance of the caisson; S9. Repeat operations S6-S8 until the caisson is completely sunk.

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