A sinking well structure of a preset sinking channel and a construction method

Abstract

The application relates to the technical field of caisson construction, and particularly discloses a caisson structure with a preset sinking channel and a construction method, which comprises a caisson entity structure and a sinking channel. The caisson entity structure is arranged above the sinking channel and comprises multiple longitudinal and transverse intersecting well walls, which separate the caisson into multiple well bin areas. The well wall is a double-wall type concrete wall body, and an upper and lower through middle hollow body is formed by an outer well wall, an inner well wall and a longitudinal and transverse intersection point. The sinking channel is formed by multiple groups of channel piles. The channel piles comprise wall-under channel piles, wall-out channel piles and wall-inter channel piles. The wall-inter channel piles correspond to the positions of the middle hollow body. The wall-under channel piles are arranged below the wall-under cutting feet. The wall-out channel piles are arranged outside the outer well wall and the inner well wall. The caisson can be constructed in different soil layers, can be balancedly and accompaniedly sunk during the construction process, and can be constructed through deep clay layers. The provided deep foundation reinforcement and bottom sealing scheme can realize dry excavation of the well bin earthwork.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of caisson construction, and discloses a caisson structure with preset sinking channels and a construction method. BACKGROUND

[0002] The caisson technology has a long application history and a wide application range, and has formed a mature method in the foundation of a bridge and an anchorage foundation engineering, and is also used in a foundation of a building engineering or an excavation protection engineering.

[0003] The current caisson construction technology is to take out soil in a well hole, sink by relying on self weight, and assist sinking by using air curtain and water jet to ensure smooth sinking. The caisson construction procedure includes: site leveling, first section caisson manufacturing, form removal and timber extraction, soil excavation and sinking, caisson height connection, foundation inspection and other treatments, bottom sealing, well hole filling and capping.

[0004] During the sinking process of the caisson, the following situations may occur: sinking difficulty, sudden sinking or too fast sinking, sand overturning, tilting, deviation and the like. The causes of the situations include: uneven distribution of strata, unbalanced soil taking mode and range and the like.

[0005] During the caisson construction process, there are problems that it is difficult to pass through a deep clay layer and the self weight of the caisson cannot overcome the resistance of the well wall; and the sinking process under the condition of reduced water and drainage is easy to cause surrounding strata subsidence, which is not conducive to surrounding buildings.

[0006] Especially when the caisson is large in scale, the bearing capacity of the upper soft foundation is low, and before the first section caisson is manufactured, the foundation in the range of the longitudinal wall and the transverse wall of the caisson needs to be temporarily reinforced. The sand pile reinforcement to form a composite foundation is a commonly used method. The bearing capacity of the reinforced foundation is improved, which can ensure the stability of the caisson on the foundation where the first section is manufactured. However, the improvement of the bearing capacity of the foundation makes the sinking difficult. SUMMARY

[0007] To solve the above problems, the present application provides the following technical scheme: a caisson structure with preset sinking channels, comprising a caisson entity structure and a sinking channel, wherein the caisson entity structure is arranged above the sinking channel, and the caisson entity structure comprises a plurality of longitudinal and transverse intersecting well walls, which separate the caisson into a plurality of well bay areas, and the longitudinal and transverse intersection points are solid concrete wall bodies; the well wall is a double-wall concrete wall body, which forms an intermediate hollow body penetrating up and down, and the intermediate hollow body is formed by an outer well wall, an inner well wall and the longitudinal and transverse intersection points; the outer well wall and the inner well wall are each provided with a wall lower blade foot; the sinking channel is composed of a plurality of groups of channel piles, the channel piles include wall lower channel piles, wall outer channel piles and wall interchannel piles, the wall interchannel piles correspond to the positions of the intermediate hollow bodies, the wall lower channel piles are arranged below the wall lower blade feet, and the wall outer channel piles are arranged on the outer sides of the outer well wall and the inner well wall respectively.

[0008] Preferably, the intermediate hollow body is further provided with an inner support, which is a solid concrete structure and is fixedly connected with the inner well wall and the outer well wall.

[0009] Preferably, the inner support is provided with one row in horizontal direction and one row in vertical direction, with a spacing of 2 meters.

[0010] Preferably, the outer well wall and the inner well wall are further provided with a friction-reducing member, which is a convex structure and is arranged horizontally along the outer side of the outer well wall and the inner well wall.

[0011] Preferably, the channel pile is filled with one or a combination of medium sand, fine sand, sandy soil, gravel and pebble.

[0012] The application further discloses a sinking well construction method of a preset sinking channel.

[0013] S1: marking a sinking well construction area and leveling the site;

[0014] S2: determining the sinking channel plane size according to the well wall width and marking the sinking channel range on the ground;

[0015] S3: setting a wall-to-wall channel pile at the center of the intermediate hollow body, setting a wall-under channel pile at the center axis of the wall-under blade foot position, and setting a wall-out channel pile at the outer side of the outer well wall and the inner well wall; the setting method of the channel pile includes the procedures of pipe pulling, reverse insertion, vibration leaving and re-punching, and the foundation bearing capacity of different soil layers is adjusted by controlling the stroke length and time of the pipe pulling, reverse insertion and vibration leaving procedures and the re-punching times.

[0016] S4: excavating the sinking channel range by 2 meters from the ground to form a first-section sinking well steel shell installation working groove;

[0017] S5: after the first-section sinking well steel shell installation is completed, backfilling and compacting the sinking well wall outer side installation working groove;

[0018] S6: pouring the first-section sinking well solid structure concrete;

[0019] S7: gradually reducing the wall-to-wall channel pile and the surrounding soil by using the water power method of the high-pressure water gun combined with the air suction machine in the intermediate hollow body, and gradually sinking the sinking well; when the top surface of the first-section sinking well approaches the ground, stopping the air suction machine;

[0020] S8: performing next-section sinking well height connection operation;

[0021] S9: gradually reducing the wall-to-wall channel pile and the surrounding soil by using the water power method of the high-pressure water gun combined with the air suction machine in the intermediate hollow body, and gradually sinking the sinking well; when the top surface of the current-section sinking well approaches the ground, stopping the air suction machine;

[0022] S10: repeat the process of S8, S9 until the designed sinking depth is reached.

[0023] S11: complete the soil removal work in the well warehouse area, and the construction is completed.

[0024] Further, the first section of the caisson solid structure adopts a steel shell concrete structure, and the other sections adopt a reinforced concrete structure.

[0025] Further, according to different sealing bottom techniques, the step S11 can have two construction modes, which are specifically:

[0026] The first mode is:

[0027] S111: deep foundation reinforcement is performed in the well warehouse area;

[0028] S112: dry excavation operation is performed in the well warehouse area; the excavation is performed to the top surface of the deep foundation reinforcement; and the construction is completed.

[0029] The second mode is:

[0030] S111: underwater concrete pouring is performed in the intermediate hollow body to make the caisson solid structure reach a stable state;

[0031] S112: the water power method of high-pressure water gun combined with air suction machine is adopted to remove soil in the well warehouse area;

[0032] S113: when the soil removal in the well warehouse area reaches the bottom elevation of the caisson, underwater concrete sealing is performed, and the construction is completed.

[0033] Compared with the prior art, the present application has the following beneficial effects:

[0034] 1. The passage pile penetrating the whole depth of the caisson makes the soil layer below the caisson wall consistent and homogenized, so that the sinking amount of the caisson is more uniform and synchronous; the passage pile penetrates the thick clay layer, effectively pre-damages the bearing capacity and cohesion of the clay layer, and promotes the sinking to be more smooth; the water power method of high-pressure water gun combined with air suction machine is adopted to gradually reduce the wall passage pile and the surrounding soil body from the intermediate hollow body, so that the bearing capacity of the composite foundation of the sinking passage can be adjusted and reduced in the construction process, which adapts to the sinking needs of the caisson, and adjusts the foundation bearing capacity along with the process of the caisson sinking and rising. The caisson can be uniformly and accompaniedly sunk in the construction process, and can also be built through the thick clay layer.

[0035] 2、The sinking state of the caisson is changed from the method of relying on the high connection configuration to the method of adjusting the bearing capacity of the composite foundation of the sinking channel to promote the sinking of the caisson; the height of each section of the high connection of the caisson can be reduced, and at the same time, the high connection can be sunk once, so that the sinking state is achieved without the need for multiple high connections, and the reduction of the height of the high connection avoids high-altitude operation, making the construction safer; the stirring of the sand and gravel channel pile under the action of water force can simultaneously destroy the cohesion of the deep clay layer, and the soil removal efficiency in the clay layer is higher, avoiding the occurrence of the sinking state of the caisson; the bearing capacity of the composite foundation of the sinking channel can be adjusted and unloaded artificially, and the first section can be self-sinking, avoiding the use of the method of lowering the drainage to assist sinking, which can avoid the influence on surrounding buildings, pipelines and the like; the setting of the wall outside channel pile and the friction reducing piece can reduce the friction resistance of the outer wall of the longitudinal wall and the transverse wall, making the sinking of the caisson more smooth. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is the overall structure of the application;

[0037] Figure 2 It is the side view of the local structure of the caisson body of the application;

[0038] Figure 3 It is the side view of the caisson body and the channel pile of the application;

[0039] 1. Well wall; 11. Outer well wall; 12. Inner well wall; 2. Intermediate hollow body; 3. Inner support; 4. Longitudinal and transverse intersection; 5. Channel pile; 51. Wall outside channel pile; 52. Wall under channel pile; 53. Wall between channel pile; 6. Friction reducing piece; 7. Wall under blade foot. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0041] The sinking well structure of preset sinking channel comprises a sinking well entity structure and a sinking channel, and the sinking well entity structure is arranged above the sinking channel, characterized in that: the sinking well entity structure comprises a plurality of longitudinal and transverse intersecting well walls 1, which separate the sinking well into a plurality of well bin areas, and the longitudinal and transverse intersection points 4 are solid concrete walls; the well wall 1 is a double-wall concrete wall, and an upper and lower through hollow body 2 is formed by an outer well wall 11, an inner well wall 12 and the longitudinal and transverse intersection points 4, and the outer well wall 11 and the inner well wall 12 are both provided with a wall lower blade foot 7; the sinking channel is composed of a plurality of groups of channel piles 5, the channel piles 5 comprise a wall lower channel pile 52, a wall outer channel pile 51 and a wall interchannel pile 53, the wall interchannel pile 53 corresponds to the position of the hollow body 2, the wall lower channel pile 52 is arranged below the wall lower blade foot 7, and the wall outer channel pile 51 is arranged outside the outer well wall 11 and the inner well wall 12 respectively.

[0042] Specifically, the hollow body is further provided with an inner support 3, and the inner support 3 is a solid concrete structure and is fixedly connected with the outer well wall 11 and the inner well wall 12.

[0043] Specifically, the inner support 3 is arranged at an interval of 2 meters in the horizontal direction and at an interval of 2 meters in the vertical direction.

[0044] Specifically, the outer well wall 11 and the inner well wall 12 are further provided with a friction reducing element 6, the friction reducing element 6 is a convex structure and is arranged horizontally outside the outer well wall 11 and the inner well wall 12.

[0045] Specifically, the channel pile is formed by filling materials such as medium sand, fine sand, sandy soil, gravel and pebbles.

[0046] The application further discloses a sinking well construction method of preset sinking channel, and the specific steps are as follows:

[0047] S1: marking a sinking well construction area and leveling the site;

[0048] S2: determining the sinking channel plane size according to the width of the well wall 1, and marking the sinking channel range on the ground;

[0049] S3: punching the wall interchannel pile 53 at the center of the hollow body 2, punching the wall lower channel pile 52 at the central axis of the wall lower blade foot 7, and punching the wall outer channel pile 51 outside the edge line of the outer well wall 11 and the inner well wall 12; the punching method of the channel pile comprises the procedures of pipe pulling, reverse insertion, vibration leaving and re-punching, and the foundation bearing capacity of different soil layers is adjusted by controlling the stroke length and time of the pipe pulling, reverse insertion and vibration leaving procedures and the re-punching times.

[0050] S4: excavating the sinking channel range downward by two meters from the ground to form a first section sinking well steel shell installation working face groove;

[0051] S5: After the first section caisson steel shell installation is completed, backfill and compact the caisson wall outside installation working surface groove;

[0052] S6: Pouring the first section caisson solid structure concrete;

[0053] S7: In the middle hollow body 2, using high pressure water gun combined with air suction machine water power method gradually reduces the wall passage pile 53 and the peripheral soil, the caisson gradually sinks, when the first section caisson top surface approaches the ground, stop the air suction machine work;

[0054] S8: Perform the next section caisson connection work;

[0055] S9: In the middle hollow body 2, using high pressure water gun combined with air suction machine water power method gradually reduces the wall passage pile 53 and the peripheral soil, the caisson gradually sinks, when the first section caisson top surface approaches the ground, stop the air suction machine work;

[0056] S10: Repeat S8, S9 process until the design sinking depth is reached;

[0057] S11: Complete the subsequent well warehouse area soil removal work, construction is completed.

[0058] Specifically, the first section of the caisson solid structure adopts a steel shell concrete structure, and other sections adopt a reinforced concrete structure.

[0059] Specifically, the step S11 is specifically:

[0060] S111: Perform underwater concrete pouring in the middle hollow body 2 to make the caisson solid structure reach a stable state;

[0061] S112: Perform well warehouse area soil removal by using high pressure water gun combined with air suction machine water power method;

[0062] S113: When the well warehouse area soil removal reaches the caisson bottom elevation, perform underwater bottom sealing of concrete, and the construction is completed.

[0063] The basic principle of the application is that the caisson wall is provided as a through structure, the inner and outer walls are provided with wall under blades, and the sinking passage is formed through the auxiliary action of the passage pile, so that the wall can sink while retaining the original soil in the well warehouse area, and finally the soil in the well warehouse is removed after the caisson wall reaches the design depth and is stable.

[0064] The core technical solution for achieving the purpose of the application is the design of the passage pile, which reserves a sinking passage for the caisson, adjusts the bearing capacity of each soil layer, directly avoids the risk of sudden sinking that may occur during the sinking process of the previous caisson construction, and also ensures the balance of the caisson.

[0065] The soil taking work after the caisson sinking to the design depth is flexible, which can be dry work soil taking after deep foundation reinforcement, or hydraulic method soil taking work after the caisson wall is stable, and the optimal solution can be provided for the construction personnel when different working conditions are encountered.

[0066] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and specific embodiments of this application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

Claims

1. A caisson structure with a pre-set sinking channel, comprising a caisson body structure and a sinking channel, wherein the caisson body structure is positioned above the sinking channel, characterized in that: The caisson structure includes multiple crisscrossing caisson walls (1), dividing the caisson into multiple caisson compartments. The intersections (4) are solid concrete walls. The caisson walls (1) are double-walled concrete walls, consisting of an outer caisson wall (11), an inner caisson wall (12), and the intersections (4) forming a hollow intermediate body (2) that runs vertically through the caisson. Both the outer caisson wall (11) and the inner caisson wall (12) are equipped with undercut edges (7). The sinking channel is composed of multiple sets of channel piles (5), including under-wall channel piles (52), outer-wall channel piles (51), and inter-wall channel piles (53). The inter-wall channel piles (53) correspond to the position of the hollow intermediate body (2). The wall-mounted channel pile (52) is located below the wall-mounted cutting edge (7), and the wall-mounted channel pile (51) is located on the outer side of the outer well wall (11) and the inner well wall (12). The outer side of the outer well wall (11) and the inner well wall (12) is also provided with a friction-reducing component (6). The friction-reducing component (6) is a convex structure and is arranged horizontally along the outer side of the outer well wall (11) and the inner well wall (12). The channel pile (5) is filled with one or a combination of medium sand, fine sand, sandy soil, crushed stone, and pebble materials. The hollow body (2) in the middle is also provided with an inner support (3). The inner support (3) is a solid concrete structure and is fixedly connected to the outer well wall (11) and the inner well wall (12).

2. The caisson structure with a pre-set sinking channel according to claim 1, characterized in that: The inner support (3) is installed at 2-meter intervals in the horizontal direction and at 2-meter intervals in the vertical direction.

3. A method for constructing a caisson with a pre-set sinking channel, comprising a caisson structure with a pre-set sinking channel as described in any one of claims 1-2, wherein the specific steps of the caisson construction method are as follows: S1: Mark out the construction area for the caisson and level the site; S2: Determine the planar dimensions of the sinking channel based on the width of the well wall (1), and mark the range of the sinking channel on the ground; S3: Drive the wall passage pile (53) at the center of the hollow body (2); drive the wall passage pile (52) at the center axis of the cutting edge (7) of the wall; drive the wall passage pile (51) outside the outer wall wall (11) and inner wall wall (12); the driving method of the passage pile includes the procedures of pipe pulling, reverse insertion, vibration retention and re-driving. By controlling the stroke length and time of the pipe pulling, reverse insertion and vibration retention procedures and the number of re-driving times, the bearing capacity of the foundation of different soil layers can be adjusted. S4: Excavate the sinking channel area two meters down from the ground to form the trench for the installation of the first section of the caisson steel shell. S5: After the first section of the caisson steel shell is installed, backfill and compact the trench on the outside of the caisson wall for the installation working face. S6: Pour concrete for the first section of the caisson's solid structure; S7: In the hollow body (2), the hydraulic method of high pressure water gun and air suction machine is used to gradually lower the wall channel pile (53) and the surrounding soil. The caisson gradually sinks. When the top surface of the first section of the caisson is close to the ground, the air suction machine is stopped. S8: Proceed to the next section of the caisson extension operation; S9: In the hollow body (2), the hydraulic method of high pressure water gun and air suction machine is used to gradually lower the wall channel pile (53) and the surrounding soil. The caisson gradually sinks. When the top surface of the caisson in this section is close to the ground, the air suction machine is stopped. S10: Repeat steps S8 and S9 until the designed sinking depth is reached; S11: Complete the subsequent soil removal work in the well site area; construction is now complete.

4. The method for constructing a caisson with a pre-set sinking channel according to claim 3, characterized in that: The first section of the caisson's physical structure is made of steel-concrete composite, while the other sections are made of reinforced concrete.

5. The method for constructing a caisson with a pre-set sinking channel according to claim 3, characterized in that: Step S11 specifically involves: S111: Deep foundation reinforcement to be carried out in the well site area; S112: Dry excavation of earthwork is carried out in the well area; excavation is carried out to the top surface of the deep foundation reinforcement; construction is completed.

6. The method for constructing a caisson with a pre-set sinking channel according to claim 3, characterized in that: Step S11 specifically involves: S111: Underwater concrete pouring is carried out in the intermediate hollow body (2) to make the caisson structure reach a stable state; S112: Soil removal from the well site area is carried out using a hydraulic method combining a high-pressure water gun and an air suction sludge machine; S113: When the soil excavation in the well area reaches the bottom elevation of the caisson, underwater concrete sealing is carried out, and the construction is completed.

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