A caisson dewatering structure in foundation pit and construction method thereof

Abstract

The present invention relates to a caisson dewatering structure and construction method in a foundation pit applied to the field of groundwater structures, comprising a box body, a plurality of side anchor hooks uniformly distributed at equal intervals fixedly connected to the side walls of the box body, a plurality of bottom anchor hooks uniformly distributed at equal intervals fixedly connected to the bottom side walls of the box body, cross-shaped reinforcing ribs fixedly connected to the inner walls around the box body, and a deformation early warning device arranged in the middle of the box body. The structure quickly discharges water in the foundation pit by sinking the welded box body into the foundation pit and then pouring concrete, thus eliminating the need for drilling dewatering wells, burying water pumps, and manually supervising dewatering, thereby effectively improving construction efficiency, and installing a deformation early warning device inside the box body for internal support, thereby effectively preventing the box body from deforming under concrete pressure, and further utilizing a metal detector to sense metal sheets to monitor the deformation of the box body, thereby providing an early warning of the deformation of the box body and effectively preventing the box body from being excessively deformed and affecting the construction progress.

Description

Technical Field

[0001] The present invention relates to a caisson dewatering structure in a foundation pit and a construction method, and in particular to a caisson dewatering structure in a foundation pit and a construction method applied to the field of groundwater structures. Background Art

[0002] Caisson dewatering is an engineering structure used for underwater construction, mainly used for cofferdam and foundation construction. Caisson dewatering is a technology that drains water from the caisson to lower the water level inside the caisson so that dry construction can be carried out. Traditional dewatering methods are not effective enough and the dewatering duration is long.

[0003] In order to solve the problem of long rainfall duration, a caisson in the market adopts a concrete box design and has a certain market share.

[0004] The specification of Chinese patent CN220888695U discloses a concrete caisson for dewatering in a foundation pit, which includes a concrete box body with an opening at the top; a plurality of support rods are arranged above the concrete box body, and the two ends of the support rods are embedded and fixed on the opposite side walls of the concrete box body; at least two water outlets are evenly arranged at the bottom of the concrete box body; and a plurality of hooks are evenly pre-embedded and fixed at the bottom of the concrete box body. The advantages of this scheme are: the scheme has a simple structure and is easy to implement, which ensures the depth of the foundation pit and meets the construction requirements; simplifies the construction process, speeds up the construction progress, and reduces the cost of dewatering in construction; can be promoted on a large scale, and can achieve good social and economic benefits. However, the concrete caisson needs to be poured in advance, and the size cannot be controlled. The size of the foundation pit needs to be calculated in advance. Once the size of the foundation pit changes, the entire concrete caisson cannot be used, which is difficult to control for construction sites with complex construction environments, so it is not very suitable. Summary of the invention

[0005] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is to speed up the drainage speed and reduce the construction time.

[0006] In order to solve the above problems, the present invention provides a caisson dewatering structure in a foundation pit and a construction method, comprising a box body, a plurality of evenly spaced side anchor hooks are fixedly connected to the side wall of the box body, and a plurality of evenly spaced bottom anchor hooks are fixedly connected to the bottom side wall of the box body, cross-shaped reinforcing ribs are fixedly connected to the inner walls around the box body, a deformation early warning device is arranged in the middle of the box body, and four cross-shaped inner support rods are fixedly connected to the side wall of the deformation early warning device, and an inner support adjusting head is threadedly connected to one end of each inner support rod away from the deformation early warning device, and the inner support adjusting head and the cross intersection of the cross-shaped reinforcing ribs are butted against each other;

[0007] The construction method of the caisson dewatering structure comprises the following steps:

[0008] S1, weld the box with 3-5mm thick steel plate. The size of the box is the outer size of the concrete structure plus 60mm. After welding, check the weld to ensure that there is no water seepage. Then weld cross-shaped reinforcement ribs on the inner walls around the box. The four cross-shaped reinforcement ribs are kept flush. Then weld the upper side anchor hook and the bottom anchor hook on the outer walls and bottom of the box respectively.

[0009] S2, put the deformation warning device into the box, first align one pair of inner support adjustment heads with the cross intersection of the cross-shaped reinforcement ribs, then rotate the inner support adjustment heads to make them collide with the cross intersection of the cross-shaped reinforcement ribs, and finally rotate the other pair of inner support adjustment heads to make them collide with the cross intersection of the cross-shaped reinforcement ribs, so as to complete the internal support of the box;

[0010] S3, put the installed box on the bracket for standby, start excavating the foundation pit, pour the counterweight concrete after the excavation of the foundation pit is completed, the concrete volume is calculated according to the volume of the box, and the elevation and flatness of the concrete pouring process must be measured to ensure the position and height of the box installation;

[0011] S4, hoist the box into the foundation pit, and anchor the side anchor hooks and bottom anchor hooks into the newly poured concrete. During this process, the engineering and technical personnel are required to observe the box all the time to ensure the accurate position, and take temporary reinforcement measures until the concrete is finally set;

[0012] S5. During the installation of the box, if there is water in the foundation pit, water should be added to the box to ensure that the liquid levels inside and outside are basically level. After the strength of the counterweight concrete is greater than 50%, the water in the box should be pumped out and cleaned, and waterproofing construction should be performed. The subsequent processes should be constructed according to normal construction procedures.

[0013] In the above-mentioned caisson dewatering structure and construction method in the foundation pit, the steel box body is directly sunk into the foundation pit, and then concrete is poured, which effectively shortens the dewatering time.

[0014] As a further improvement of this application, the calculation formula for the pouring volume of concrete is as follows:

[0015] The buoyancy force on the caisson is F=ρ1gV1, and the volume of the counterweight concrete is V2=F / gρ2;

[0016] The meaning of each symbol F: buoyancy of caisson, V2: volume of counterweight concrete, ρ1: density of water, g: acceleration due to gravity, V1: volume of caisson, ρ2: density of concrete.

[0017] As a further improvement of the present application, the inner wall of the deformation warning device is provided with four cavities which are distributed around at equal intervals, and four inner support rods are respectively inserted into the cavities, one end of the inner support rod located inside the cavity is fixedly connected with a slide plate, and the side wall of the slide plate away from the inner support rod is fixedly connected with a pre-tightening ball head, the inner wall of the cavity is fixedly connected with a pre-tightening seat which is in contact with the pre-tightening ball head, a pre-tightening elastic pad is fixedly connected to the middle position of the inner part of the pre-tightening seat, and the side wall of the pre-tightening elastic pad away from the pre-tightening seat is fixedly inlaid with an elastic metal sheet, and the interiors of the pre-tightening seats located on both sides of the pre-tightening elastic pad are fixedly connected with pre-tightening A tightening and strengthening elastic pad is provided, an opening groove is provided on the inner wall of the pre-tightening seat directly opposite to the pre-tightening elastic pad, and a top head is slidably connected to the inner wall of the opening groove, and a top rod is fixedly connected to the side wall of the elastic metal sheet facing the top head, and an annular fixing seat is also fixedly connected to the inner wall of the cavity which abuts against the pre-tightening seat, a sliding cavity is provided on the inner wall of the annular fixing seat, and two symmetrically distributed moving measuring sliding plugs are sealed and slidably connected to the inner wall of the sliding cavity, an elastic band is fixedly connected between the two moving measuring sliding plugs, a liquid-encapsulating membrane which is internally connected to the sliding cavity is fixedly connected to the side wall of the annular fixing seat, and the liquid-encapsulating membrane and the two moving measuring sliding plugs are The space between the two is filled with driving liquid, and the liquid film is in contact with the top head. The preload seat and the preload ball head are used to make the inner support adjusting head rest on the cross-shaped reinforcing ribs, so as to support the inside of the box. Moreover, since the inner support adjusting head and the inner support rod are threadedly connected, it is convenient to adjust the extension distance of the inner support adjusting head to adapt to different box sizes, and it is also convenient to install and remove the inner support adjusting head, eliminating the trouble of cutting. When pouring concrete, the box is subjected to the pressure of the concrete and the pressure is transmitted to the preload seat through the inner support adjusting head and the inner support rod. The seat relies on the rebound force of the preloaded elastic pad and the preloaded reinforcing elastic pad to offset the pressure on the inner support adjusting head, thereby effectively preventing the box body from deforming. After the preloaded seat is subjected to pressure, the preloaded elastic pad begins to bulge outward, and the outward bulge of the preloaded elastic pad causes it to push the top head to move, and the top head then squeezes the liquid film to push the driving liquid into the annular fixed seat. Under the action of the hydraulic pressure, the two moving measuring slides move away from each other, and the elastic band between the two acts as an obstacle. This can provide a part of the obstacle force for the preloaded seat, thereby effectively strengthening the support for the inside of the box body and effectively preventing the box body from deforming.

[0018] As a further improvement of the present application, the preload seat includes a deformable section and a shaping section, and the inner walls of the shaping sections on both sides of the opening groove are provided with grooves connected to the sliding cavity. The deformable section is made of a soft material, and the deformable section is in contact with the inner wall of the cavity. The shaping section is made of a hard material, and the shaping section is fixedly connected to the inner wall of the cavity. The deformable section begins to deform after being pushed by the inner support rod. At this time, the rebound force of the preload elastic pad and the preload reinforcement elastic pad can hinder the deformation of the deformable section. Such rebound force can make the inner support adjustment head tightly against the cross-shaped reinforcement ribs, which can not only realize the installation of the deformation warning device inside the box, but also facilitate the adjustment of the extension and retraction of the inner support adjustment head, so that the deformation warning device can adapt to boxes of different sizes.

[0019] As another improvement of the present application, a strong magnetic pad is fixedly embedded on the inner wall of the deformable section opposite to the deformation warning device, and a flexible magnetic pad that is magnetically attracted to the strong magnetic pad is fixedly embedded on the side wall of the deformable section. The magnetic attraction between the deformable section and the strong magnetic pad provides the deformable section with a part of the force to offset the deformation, indirectly increasing the supporting force of the inner support rod on the box body, which not only allows the inner support adjustment head to tightly abut against the cross-shaped reinforcement ribs to prevent the deformation warning device from falling off, but also effectively prevents the box body from deforming under concrete squeezing.

[0020] As another improved supplement to the present application, one end of the mobile measuring slide plug away from the elastic band passes through the groove, and the inner wall of the mobile measuring slide plug is fixedly inlaid with multiple metal sheets distributed at equal intervals, and the inner wall of the groove is installed with a metal detector matching the metal sheets, the metal detector includes a sensing module, a sensing times calculation module and an alarm module, and an alarm light electrically connected to the alarm module is installed at the upper end of the deformation early warning device. When the box body begins to deform, the pre-tightening seat will be further pushed by the inner support rod, and then the pre-tightening elastic pad will further bulge outward, and the pre-tightening elastic pad will push the ejector rod to further squeeze the liquid film with the ejector head. At this time, more driving liquid is squeezed into the sliding cavity, and the two mobile measuring slide plugs are in Under the action of hydraulic pressure, they move further away from each other, and the mobile measuring slide moves into the groove with multiple metal sheets. The sensing module on the metal detector is used to detect the metal sheets, and the sensing number calculation module is used to measure the number of detected metal sheets. Since the distance between two adjacent metal sheets is fixed, the moving distance of the mobile measuring slide can be calculated according to the number of detected metal sheets, and then the deformation of the box body can be indirectly known. When the moving distance of the mobile measuring slide exceeds the set threshold, the alarm module is triggered to start the alarm light to send out an alarm signal, which can promptly remind the construction personnel to take corresponding measures and effectively prevent the box body from deforming too much and affecting normal use.

[0021] As another improvement supplement to the present application, a waterproof cover is installed on the outside of the alarm light, and a waterproof sealing ring is installed at the position where the inner support rod passes through the deformation warning device. When water is added to the inside of the box to prevent it from deforming, the water pressure causes the water to penetrate into the interior through the gap where the inner support rod passes through the deformation warning device, so a waterproof sealing ring is used for sealing. Similarly, in order to prevent water from penetrating into the inside of the alarm light, a waterproof cover is installed on the outside of the alarm light.

[0022] As another improvement of the present application, the liquid-coated membrane includes a base layer, and the inner wall of the base layer is fixedly inlaid with an elastic layer. The base layer is made of a flexible material, and the elastic layer is made of an elastic material. The base layer plays a sealing role to prevent the driving liquid from leaking out, and the elastic layer plays a role in restoring the deformation of the base layer. After the deformation alarm is removed, the rebound force of the elastic layer restores the base layer to its original state, which is convenient for the next use of the deformation alarm. In summary, by sinking the welded box into the foundation pit and then pouring concrete to quickly drain the water in the foundation pit, it is unnecessary to dig a precipitation well, bury a water pump, and manually supervise precipitation, effectively improving the construction efficiency, and installing a deformation alarm inside the box for internal support, effectively preventing the box from deforming under concrete pressure. In addition, the metal detector uses the induction of the metal sheet to monitor the deformation of the box, which can warn of the deformation of the box and effectively prevent the box from being excessively deformed and affecting the construction progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a top perspective view of a box body according to a first embodiment of the present application;

[0024] Figure 2 This is a bottom-up stereoscopic view of a box body according to a first embodiment of the present application;

[0025] Figure 3 This is a three-dimensional diagram of a deformation warning device according to a first embodiment of the present application;

[0026] Figure 4 A top view of a deformation warning device according to a first embodiment of the present application;

[0027] Figure 5 This is a top view of the deformation warning device of the first embodiment of the present application when the alarm is triggered;

[0028] Figure 6 for Figure 4 The enlarged view of point A in the middle;

[0029] Figure 7 for Figure 4 The enlarged view of point B in the middle;

[0030] Figure 8 for Figure 5 Enlarged view of point C in the middle;

[0031] Fig. 9 This is a cross-sectional view of the mobile measuring slide before movement according to the second embodiment of the present application;

[0032] Fig.10 This is a cross-sectional view of the preloaded elastic pad of the second embodiment of the present application before being squeezed;

[0033] Fig.11 This is a cross-sectional view of the liquid-encapsulated membrane of the second embodiment of the present application.

[0034] Explanation of numbers in the figure: 1 box body, 101 side anchor hook, 102 bottom anchor hook, 2 cross-shaped reinforcement ribs, 3 deformation warning device, 301 cavity, 4 inner support rod, 5 inner support adjustment head, 6 slide plate, 7 pre-tightening ball head, 8 pre-tightening seat, 801 deformable section, 802 shaping section, 803 groove, 9 pre-tightening elastic pad, 901 elastic metal sheet, 10 pre-tightening reinforced elastic pad, 11 open groove, 12 top head, 13 push rod, 14 annular fixed seat, 1401 sliding cavity, 15 mobile measuring sliding plug, 16 elastic belt, 17 liquid film, 1701 base layer, 1702 elastic layer, 18 driving liquid, 19 metal detector, 20 metal sheet, 21 strong magnetic pad, 22 warning light. DETAILED DESCRIPTION

[0035] Two implementation modes of the present application are described in detail below with reference to the accompanying drawings.

[0036] The first implementation method:

[0037] Figure 1 , 2 and Figure 3 As shown, it includes a box body 1, the side wall of the box body 1 is fixedly connected with a plurality of side anchor hooks 101 evenly distributed at equal intervals, and the bottom side wall of the box body 1 is fixedly connected with a plurality of bottom anchor hooks 102 evenly distributed at equal intervals, and the inner walls around the box body 1 are fixedly connected with cross-shaped reinforcing ribs 2, a deformation early warning device 3 is arranged in the middle of the box body 1, and the side wall of the deformation early warning device 3 is fixedly connected with four cross-shaped inner support rods 4, and the end of each inner support rod 4 away from the deformation early warning device 3 is threadedly connected with an inner support adjusting head 5, and the inner support adjusting head 5 is against the cross intersection of the cross-shaped reinforcing ribs 2;

[0038] Figure 1 , 2 and Figure 3 It is shown that the construction method of the caisson dewatering structure includes the following steps:

[0039] S1, weld the box 1 with a 3-5mm thick steel plate. The size of the box 1 is the outer size of the concrete structure plus 60mm. After welding, check the weld to ensure that there is no water seepage. Then weld the cross-shaped reinforcement ribs 2 on the inner walls around the box 1. The four cross-shaped reinforcement ribs 2 are kept flush. Then, weld the upper side anchor hook 101 and the bottom anchor hook 102 (both are made of steel bars) on the outer walls and bottom of the box 1 respectively.

[0040] S2, put the deformation warning device 3 into the box body 1, first align one pair of inner support adjustment heads 5 with the cross intersection of the cross-shaped reinforcement ribs 2, then rotate the inner support adjustment heads 5 to make them abut against the cross intersection of the cross-shaped reinforcement ribs 2, and finally rotate the other pair of inner support adjustment heads 5 to also abut against the cross intersection of the cross-shaped reinforcement ribs 2, so as to complete the internal support of the box body 1;

[0041] S3, the installed box 1 is placed on the bracket for standby use, and the foundation pit is excavated. After the foundation pit is excavated, counterweight concrete is poured. The concrete volume is calculated according to the volume of the box 1. During the concrete pouring process, the elevation and flatness of the concrete pouring must be measured to ensure the installation position and height of the box 1;

[0042] S4, hoisting the box body 1 into the foundation pit, anchoring the side anchor hooks 101 and the bottom anchor hooks 102 into the newly poured concrete. During this process, the engineering and technical personnel need to observe the box body 1 all the time to ensure the accurate position, and take temporary reinforcement measures until the concrete is finally set;

[0043] S5, during the installation of the box 1, if there is water in the foundation pit, water should be added to the box 1 to ensure that the inner and outer liquid levels are basically flush. After the strength of the counterweight concrete is greater than 50%, the water in the box 1 is pumped out and cleaned, and waterproofing construction is performed. The subsequent procedures are carried out according to the normal construction procedures;

[0044] The calculation formula for the concrete pouring earthwork volume is as follows:

[0045] The buoyancy force on the caisson is F=ρ1gV1, and the volume of the counterweight concrete is V2=F / gρ2;

[0046] The meaning of each symbol F: buoyancy of caisson, V2: volume of counterweight concrete, ρ1: density of water, g: acceleration due to gravity, V1: volume of caisson, ρ2: density of concrete.

[0047] The second implementation method:

[0048] Figure 4 , 5 , 6 and Figure 7As shown, the inner wall of the deformation warning device 3 is provided with four cavities 301 distributed around at equal intervals, and four inner support rods 4 are respectively inserted into the cavities 301, and one end of the inner support rod 4 located inside the cavity 301 is fixedly connected to a slide plate 6, and the side wall of the slide plate 6 away from the inner support rod 4 is fixedly connected to a pre-tightening ball head 7, and the inner wall of the cavity 301 is fixedly connected to a pre-tightening seat 8 in contact with the pre-tightening ball head 7, and the pre-tightening seat 8 includes a deformable section 801 and a shaping section 802, and the shaping section 802 is located The inner walls on both sides of the opening groove 11 are provided with grooves 803 connected to the sliding cavity 1401. The deformable section 801 is made of a soft material (preferably a rubber material, and other materials can also be selected according to actual needs), and the deformable section 801 is in contact with the inner wall of the cavity 301. The shaping section 802 is made of a hard material (preferably a high-strength plastic material, and other materials can also be selected according to actual needs), and the shaping section 802 is fixedly connected to the inner wall of the cavity 301. The deformable section 801 is made of a soft material (preferably a rubber material, and other materials can also be selected according to actual needs). 01 begins to deform after being pushed by the inner support rod 4. At this time, the rebound force of the pre-tightening elastic pad 9 and the pre-tightening reinforced elastic pad 10 can hinder the deformation of the deformable section 801. Such rebound force can make the inner support adjusting head 5 tightly against the cross-shaped reinforcing rib 2, which can not only realize the installation of the deformation warning device 3 inside the box body 1, but also facilitate the adjustment of the extension and contraction of the inner support adjusting head 5, so that the deformation warning device 3 can adapt to boxes 1 of different sizes. The deformation warning device 3 is also fixedly inlaid with a strong magnetic pad 21 on the inner wall facing the deformable section 801, and the side wall of the deformable section 801 is fixedly inlaid with a flexible magnetic pad that is magnetically attracted to the strong magnetic pad 21. The magnetic attraction between the deformable section 801 and the strong magnetic pad 21 provides the deformable section 801 with a part of the force to offset the deformation, indirectly increasing the supporting force of the inner support rod 4 on the box body 1, not only can the inner support adjusting head 5 be tightly against the cross-shaped reinforcing rib 2 to prevent the deformation warning device 3 from falling off, but also can effectively prevent the box body 1 from deforming under the extrusion of concrete;

[0049] Figure 6 , 7 , 8 and Fig.10As shown, a pre-tightening elastic pad 9 is fixedly connected to the middle position of the interior of the pre-tightening seat 8, and the side wall of the pre-tightening elastic pad 9 away from the pre-tightening seat 8 is fixedly inlaid with an elastic metal sheet 901, and the interior of the pre-tightening seat 8 on both sides of the pre-tightening elastic pad 9 is fixedly connected with a pre-tightening reinforcing elastic pad 10, the pre-tightening seat 8 is provided with an open groove 11 on the inner wall facing the pre-tightening elastic pad 9, and the inner wall of the open groove 11 is slidably connected with a head 12, and the head 12 is fixedly connected with a push rod 13 toward the side wall of the elastic metal sheet 901, and the inner wall of the cavity 301 is also fixedly connected with an annular fixed seat 14 that abuts against the pre-tightening seat 8, and the inner wall of the annular fixed seat 14 is provided with a sliding cavity 1401, and the inner wall of the sliding cavity 1401 is sealed and slidably connected with two symmetrically distributed movable measuring slides 15, and an elastic belt 16 is fixedly connected between the two movable measuring slides 15, and the side wall of the annular fixed seat 14 is fixedly connected with an internal The liquid-encapsulating membrane 17 connected to the sliding cavity 1401 comprises a base layer 1701, and an elastic layer 1702 is fixedly inlaid on the inner wall of the base layer 1701. The base layer 1701 is made of a flexible material (rubber material is preferably selected, and other materials can also be selected according to actual needs), and the elastic layer 1702 is made of an elastic material (elastic polyurethane material is preferably selected, and other materials can also be selected according to actual needs). The base layer 1701 plays a sealing role to prevent the driving liquid 18 from leaking out, and the elastic layer 1702 plays a role in restoring the deformation of the base layer 1701. After the deformation alarm 3 is disassembled, the rebound force of the elastic layer 1702 restores the base layer 1701 to its original state, which is convenient for the next use of the deformation alarm 3. The space between the liquid-encapsulating membrane 17 and the two movable measuring slide plugs 15 is filled with the driving liquid 18 at the same time, and the liquid-encapsulating membrane 17 is in contact with the top head 12;

[0050] Fig. 9 , 10As shown, the inner support adjusting head 5 is pressed against the cross-shaped reinforcing rib 2 by the counteraction of the pre-tightening seat 8 and the pre-tightening ball head 7, so as to support the inside of the box body 1. Moreover, since the inner support adjusting head 5 and the inner support rod 4 are threadedly connected, it is convenient to adjust the extension distance of the inner support adjusting head 5 to adapt to different sizes of the box body 1, and it is also convenient to install and remove the inner support adjusting head 5, eliminating the trouble of cutting. When pouring concrete, the box body 1 is subjected to the pressure of the concrete and the pressure is transferred to the pre-tightening seat 8 through the inner support adjusting head 5 and the inner support rod 4. The pre-tightening seat 8 relies on the pre-tightening elastic pad 9 and the pre-tightening reinforcing elastic force The rebound force of the pad 10 offsets the pressure on the inner support adjustment head 5, so as to effectively prevent the box body 1 from deforming. After the pre-tightening seat 8 is under pressure, the pre-tightening elastic pad 9 begins to bulge outward, and the outward bulge of the pre-tightening elastic pad 9 causes it to push the head 12 to move, and the head 12 then squeezes the liquid film 17 to push the driving liquid 18 into the annular fixed seat 14. Under the action of the hydraulic pressure, the two moving measuring slide plugs 15 move away from each other, and the elastic band 16 between the two acts as an obstacle, which can provide a part of the obstacle force for the pre-tightening seat 8, thereby effectively strengthening the support for the inside of the box body 1 and effectively preventing the box body 1 from deforming.

[0051] Fig. 9 , 10It is shown that the end of the movable measuring slide 15 away from the elastic band 16 passes through the groove 803, and the inner wall of the movable measuring slide 15 is fixedly inlaid with a plurality of metal sheets 20 distributed at equal intervals, and the inner wall of the groove 803 is installed with a metal detector 19 matching the metal sheet 20 (the specific model is selected according to actual needs and is not described in detail here), the metal detector 19 includes a sensing module, a sensing times calculation module and an alarm module (the specific connection structure and working principle between the modules are well-known technologies for technicians in the relevant field and are not described in detail here), and the upper end of the deformation warning device 3 is installed with an alarm light 22 electrically connected to the alarm module. When the box body 1 begins to deform, the pre-tightening seat 8 will be further pushed by the inner support rod 4, and then the pre-tightening elastic pad 9 will further bulge outward, and the pre-tightening elastic pad 9 will push the ejector rod 13 to further squeeze the liquid film with the ejector head 12. 17, at this time, more driving fluid 18 is squeezed into the sliding cavity 1401, and the two movable measuring sliding plugs 15 are further separated from each other under the action of hydraulic pressure, and the movable measuring sliding plug 15 moves into the groove 803 with multiple metal sheets 20. The sensing module on the metal detector 19 is used to detect the metal sheets 20, and the sensing times calculation module is used to measure the number of detected metal sheets 20. Since the distance between two adjacent metal sheets 20 is fixed, the moving distance of the movable measuring sliding plug 15 can be calculated according to the number of detected metal sheets 20, and then the deformation of the box body 1 can be indirectly known. When the moving distance of the movable measuring sliding plug 15 exceeds the set threshold, the alarm module is triggered to start the alarm light 22 to send out an alarm signal, which can timely remind the construction personnel to take corresponding measures and effectively prevent the box body 1 from deforming too much and affecting normal use;

[0052] Figure 3 It is shown that a waterproof cover is installed on the outside of the alarm light 22, and a waterproof sealing ring is installed at the position where the inner support rod 4 penetrates the deformation warning device 3. When water is added to the inside of the box body 1 to prevent its deformation, the water penetrates into the inside through the gap where the inner support rod 4 penetrates the deformation warning device 3 due to the water pressure, so a waterproof sealing ring is used for sealing. Similarly, in order to prevent water from penetrating into the alarm light 22, a waterproof cover is installed on the outside of the alarm light 22. Combined with current actual needs, the above-mentioned implementation adopted by this application is not limited to this, and various changes made within the knowledge of those skilled in the art without departing from the concept of this application still fall within the protection scope of the present invention.

Claims

1. A caisson dewatering structure in a foundation pit, characterized in that: The invention comprises a box body (1), wherein the side wall of the box body (1) is fixedly connected with a plurality of side anchor hooks (101) evenly distributed at equal intervals, and the bottom side wall of the box body (1) is fixedly connected with a plurality of bottom anchor hooks (102) evenly distributed at equal intervals, and the inner walls of the four sides of the box body (1) are fixedly connected with cross-shaped reinforcing ribs (2), a deformation warning device (3) is arranged in the middle of the box body (1), and the side wall of the deformation warning device (3) is fixedly connected with four inner support rods (4) distributed in a cross shape, and the end of each inner support rod (4) away from the deformation warning device (3) is threadedly connected with an inner support adjustment head (5), and the inner support adjustment head (5) abuts against the cross intersection of the cross-shaped reinforcing ribs (2); The inner wall of the deformation warning device (3) is provided with four cavities (301) which are equally spaced and distributed around each other, and the four inner support rods (4) are respectively inserted into the cavities (301), one end of the inner support rod (4) located inside the cavity (301) is fixedly connected to a slide plate (6), and the side wall of the slide plate (6) away from the inner support rod (4) is fixedly connected to a pre-tightening ball head (7), and the inner wall of the cavity (301) is fixedly connected to a pre-tightening seat (8) which is in contact with the pre-tightening ball head (7). The preload seat (8) comprises a deformable section (801) and a shaping section (802), and the inner walls of the shaping section (802) on both sides of the opening groove (11) are provided with grooves (803) communicating with the sliding cavity (1401), the deformable section (801) is made of a soft material, and the deformable section (801) is in contact with the inner wall of the cavity (301), and the shaping section (802) is made of a hard material, and the shaping section (802) is fixedly connected to the inner wall of the cavity (301); A pre-tightening elastic pad (9) is fixedly connected to the middle position of the interior of the pre-tightening seat (8), and a side wall of the pre-tightening elastic pad (9) away from the pre-tightening seat (8) is fixedly inlaid with an elastic metal sheet (901), and the interior of the pre-tightening seat (8) located on both sides of the pre-tightening elastic pad (9) is fixedly connected with a pre-tightening reinforcement elastic pad (10), the pre-tightening seat (8) is provided with an opening groove (11) directly facing the inner wall of the pre-tightening elastic pad (9), and the inner wall of the opening groove (11) is slidably connected to a head (12), and the head (12) is fixedly connected to a push rod (13) facing the side wall of the elastic metal sheet (901), and the inner wall of the cavity (301) is also fixedly connected to An annular fixed seat (14) is connected to the preload seat (8), the inner wall of the annular fixed seat (14) is provided with a sliding cavity (1401), and the inner wall of the sliding cavity (1401) is sealed and slidably connected to two symmetrically distributed movable measuring sliding plugs (15), an elastic band (16) is fixedly connected between the two movable measuring sliding plugs (15), the side wall of the annular fixed seat (14) is fixedly connected to a liquid-encapsulating membrane (17) which is internally connected to the sliding cavity (1401), and the space between the liquid-encapsulating membrane (17) and the two movable measuring sliding plugs (15) is simultaneously filled with a driving liquid (18), and the liquid-encapsulating membrane (17) is in contact with the head (12).

2. The caisson dewatering structure in a foundation pit according to claim 1, characterized in that: A strong magnetic pad (21) is also fixedly embedded on the inner wall of the deformation warning device (3) facing the deformable section (801), and a flexible magnetic pad that is magnetically attracted to the strong magnetic pad (21) is fixedly embedded on the side wall of the deformable section (801).

3. The caisson dewatering structure in a foundation pit according to claim 1, characterized in that: One end of the movable measuring slide plug (15) away from the elastic band (16) penetrates into the groove (803), and the inner wall of the movable measuring slide plug (15) is fixedly inlaid with a plurality of metal sheets (20) distributed at equal intervals, and the inner wall of the groove (803) is installed with a metal detector (19) matching the metal sheets (20), the metal detector (19) comprising a sensing module, a sensing times calculation module and an alarm module, and an alarm light (22) electrically connected to the alarm module is installed at the upper end of the deformation warning device (3).

4. The caisson dewatering structure in a foundation pit according to claim 3, characterized in that: A waterproof cover is installed on the outside of the warning light (22), and a waterproof sealing ring is installed at the position where the inner support rod (4) passes through the deformation warning device (3).

5. The caisson dewatering structure in a foundation pit according to claim 1, characterized in that: The liquid-encapsulating membrane (17) comprises a base layer (1701), and an elastic layer (1702) is fixedly embedded on the inner wall of the base layer (1701); the base layer (1701) is made of a flexible material, and the elastic layer (1702) is made of an elastic material.

6. A caisson dewatering construction method in a foundation pit, characterized in that: A construction method for a caisson dewatering structure in a foundation pit according to any one of claims 1 to 5: S1, welding the box body (1) with a 3-5 mm thick steel plate, the size of the box body (1) being the outer size of the concrete structure plus 60 mm, and after welding, checking the weld to ensure that it is watertight, then welding cross-shaped reinforcement ribs (2) on the inner walls around the box body (1), the four cross-shaped reinforcement ribs (2) being kept flush, and then welding the upper side anchor hooks (101) and the bottom anchor hooks (102) on the outer walls around the box body (1) and the bottom respectively; S2, placing the deformation warning device (3) into the box body (1), first aligning one pair of inner support adjustment heads (5) with the cross intersection of the cross-shaped reinforcement ribs (2), then rotating the inner support adjustment heads (5) so that they abut against the cross intersection of the cross-shaped reinforcement ribs (2), and finally rotating the other pair of inner support adjustment heads (5) so that they abut against the cross intersection of the cross-shaped reinforcement ribs (2), thereby completing the internal support of the box body (1); S3, placing the installed box (1) on the bracket for standby use, starting to excavate the foundation pit, pouring counterweight concrete after the excavation of the foundation pit is completed, the concrete volume is calculated according to the volume of the box (1), and the elevation and flatness of the concrete pouring process must be measured to ensure the installation position and height of the box (1); S4, hoisting the box body (1) into the foundation pit, allowing the side anchor hooks (101) and the bottom anchor hooks (102) to anchor into the newly poured concrete. During this process, the engineering and technical personnel are required to observe the box body (1) all the time to ensure the accurate position, and take temporary reinforcement measures until the concrete is finally set; S5, during the installation of the box body (1), if there is water in the foundation pit, water should be added to the box body (1) to ensure that the liquid levels inside and outside are basically flush. After the strength of the counterweight concrete is greater than 50%, the water in the box body (1) is pumped out and cleaned, and waterproofing construction is performed. The subsequent procedures are carried out according to the normal construction procedures; The calculation formula for the concrete pouring earthwork volume is as follows: The buoyancy force on the caisson is F=ρ1gV1, and the volume of the counterweight concrete is V2=F / gρ2; The meaning of each symbol F: buoyancy of caisson, V2: volume of counterweight concrete, ρ1: density of water, g: acceleration due to gravity, V1: volume of caisson, ρ2: density of concrete.

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