A red sandstone foundation pit drainage structure and construction method thereof

Abstract

The present invention discloses a red sandstone foundation pit drainage structure and a construction method thereof, which relates to the technical field of foundation pit drainage, and includes a buoyancy component, a water pump, an electromagnetic three-way valve and two groups of sediment filter components. The electromagnetic three-way valve is used to control the two groups of sediment filter components to work alternately. The sediment filter components in the working state filter sediment, and the sediment filter components in the idle state collect and precipitate the trapped sediment. The present invention realizes the alternating operation of the two groups of sediment filter components through the electromagnetic three-way valve, which not only ensures the continuity of drainage, but also effectively utilizes the idle time of the sediment filter components to collect sediment, avoiding the efficiency reduction caused by frequent cleaning of the traditional single filtering system, and the cleaned sediment is collected separately, and will not enter the original water body to increase the sediment concentration and affect the subsequent drainage.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit drainage, and in particular to a red sandstone foundation pit drainage structure and a construction method thereof. Background Art

[0002] In order to ensure the normal progress of foundation pit construction and avoid landslides or even collapse around the foundation pit, it is necessary to drain the foundation pit during foundation pit construction. The general foundation pit drainage device lacks related filtering components when in use. In the process of drainage by open ditch plus collection well, since the open ditch contains more sediment, it will flow into the collection well under the influence of water flow. At the same time, the sediment at the bottom of the collection well will be mixed with the water under the disturbance of water flow, so that when the pump is draining, the sediment will flow into the pump, causing the pump to be blocked or even damaged.

[0003] The patent with authorization announcement number CN211257032U discloses a foundation pit drainage mechanism, which blocks the silt inside the foundation pit through a filter plate. However, the filter plate will inevitably be clogged with silt during long-term use. When cleaning the filter plate, construction workers need to enter the foundation pit to pull out the filter plate for cleaning, which makes cleaning inconvenient.

[0004] Another example is a Chinese patent with the authorization announcement number CN215948239U, which discloses a deep foundation pit drainage structure, which includes a water filter cartridge and a water pump. The water filter cartridge is embedded in a sump dug at the bottom of the foundation pit, the water pump is arranged on the ground, and the water pump is connected to the water filter cartridge. The two ports of the water filter cartridge are arranged in a closed shape, and the lower end side wall of the water filter cartridge is provided with multiple rows of water filter holes, and the water filter cartridge is rotatably connected with a cleaning component for cleaning the water filter holes. By arranging a cleaning component on the deep foundation pit drainage structure, the water filter holes arranged on the water filter cartridge are rotated and cleaned, so that the cleaning work of the water filter holes can be completed without disassembling the water filter cartridge, which realizes the convenient cleaning of the water filter holes and ensures the normal drainage work.

[0005] In the case of red sandstone foundation pit construction, the deep foundation pit drainage structure in the existing technology still faces many challenges. Red sandstone is easy to pulverize, resulting in a large amount of sediment in the foundation pit water. In order to achieve effective filtration of fine sand, the aperture of the water filter holes on the filter cartridge is required to be small enough, which is not only difficult to process, but also the accumulation of fine sand will increase the probability of clogging of the water filter holes. Although the cleaning component can remove the sediment blocked in the filter holes, the removed sediment is still mixed in the water body, resulting in a gradual increase in the sediment concentration in the water body, which cannot meet the needs of actual construction use. Summary of the invention

[0006] The purpose of the present invention is to solve the problem in the prior art that it is difficult to effectively filter the red sandstone foundation pit water when draining the red sandstone foundation pit water with a large sand content, and to propose a red sandstone foundation pit drainage structure and a construction method thereof.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A red sandstone foundation pit drainage structure, comprising:

[0009] A buoyancy component is placed in the water collection well and floats on the water surface in the water collection well under the action of buoyancy;

[0010] A water pump, installed on the buoyancy assembly, having a water suction port and a water discharge port, wherein the water discharge port is connected to a drainage pipe extending to a drainage ditch outside the foundation pit;

[0011] Two sets of sediment filtering components are used to filter the sediment mixed with the water entering the water pump;

[0012] The electromagnetic three-way valve has two input ends and one output end, the output end is sealed and connected to the water suction port of the water pump, and the two input ends are respectively connected to different sediment filtering components;

[0013] The electromagnetic three-way valve is used to control the two groups of sediment filter components to work alternately. The sediment filter components in the working state filter sediment, and the sediment filter components in the idle state precipitate and collect the trapped sediment.

[0014] Preferably, the buoyancy assembly comprises a mounting frame, and a plurality of buoyancy members are fixedly arranged on the outer periphery of the mounting frame.

[0015] Preferably, the buoyancy member is a foam board or an air bag.

[0016] Preferably, the sediment filter assembly includes a connecting pipe, a filter cartridge, a sand collecting chamber and a water pumping pipe, one end of the connecting pipe is connected to the input end of the electromagnetic three-way valve, and the other end is connected to the top outlet of the filter cartridge, the sand collecting chamber is coaxially installed with the bottom of the filter cartridge and maintained in communication with the filter cartridge, and the water pumping pipe is installed on the bottom side wall of the filter cartridge;

[0017] A rotating plate with an opening at its center is provided in a sealed and rotatable manner in the filter cartridge, and a variable filtering mechanism corresponding to the opening is fixedly provided on the rotating plate.

[0018] Preferably, the variable filtering mechanism comprises a mounting cylinder coaxially arranged with the opening, the side wall of the mounting cylinder has a plurality of mounting openings, a guide shell is rotatably arranged in the mounting opening, a torsion spring is arranged between the rotating shaft of the guide shell and the mounting opening, the upper end of the guide shell is a closed structure and fits with the inner top surface of the mounting opening, and the lower end of the guide shell is an open frame structure and fits with the top surface of the rotating plate;

[0019] The guide shell has an outer arc surface, an inner arc surface and a filtering arc surface. The rotation axis of the guide shell and the installation port is located at the intersection of the outer arc surface and the inner arc surface. A filter cloth is arranged on the filtering arc surface.

[0020] Preferably, the filter cloth is in a relaxed state under normal conditions and can bulge under the impact of water flow.

[0021] Preferably, a limiting block is installed on one side of the installation opening corresponding to the filtering curved surface.

[0022] Preferably, the bottom of the filter cartridge and the top of the sand collecting chamber are both conical, so that the filter cartridge and the sand collecting chamber form an hourglass structure, a narrow passage is formed between the filter cartridge and the sand collecting chamber, and an upwardly protruding arc piece is provided on the top of the sand collecting chamber near the narrow passage.

[0023] Preferably, it also includes a transmission mechanism arranged between the two filter cylinders, the transmission mechanism includes a transmission shaft passing through the two filter cylinders, bevel gear 1 is fixedly installed at both ends of the transmission shaft, bevel gear 2 is installed on the top of the mounting cylinder, and bevel gear 1 is meshed with corresponding bevel gear 2.

[0024] A construction method for a red sandstone foundation pit drainage structure comprises the following steps:

[0025] The drainage structure is placed in a water collection well, and under the buoyancy of the buoyancy component, the entire drainage structure floats on the water surface;

[0026] The outlet of the drainage pipe is pulled to the drainage ditch outside the foundation pit, and the water pump is started to pump water;

[0027] The electromagnetic three-way valve is controlled to switch the connection state of the two input ends and the output end at intervals, so that the water pump pumps water alternately through the two sediment filter components. The sediment filter component in the working state filters the sediment, and the sediment filter component in the idle state precipitates and collects the intercepted sediment.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. The present invention realizes the alternating operation of two groups of sediment filter components through the electromagnetic three-way valve, which not only ensures the continuity of drainage, but also effectively utilizes the idle time of the sediment filter components to collect sediment, avoiding the efficiency reduction caused by frequent cleaning of the traditional single filtering system, and the cleaned sediment is collected separately, and will not enter the raw water body to increase the sediment concentration and affect the subsequent drainage.

[0030] 2. Aiming at the high sediment content in the construction of red sandstone foundation pit, the present invention adopts filter cloth as the filter material. Compared with the design of traditional rigid filter cartridge plus micro water filter hole, it is not only easier to process, but also has significantly improved filtering effect, ensuring the effective interception of tiny sediment particles and preventing fine sand from entering the pump casing of the water pump and causing damage to the water pump.

[0031] 3. The present invention provides a rotatable guide shell, which can automatically deflect outwards with the pumping work to expose the filter cloth for filtration; and when idle, the guide shell is reset to effectively prevent water backflow.

[0032] 4. The filter cloth in the present invention is set in a relaxed state, which can increase the filtering area for sediment, and by setting a transmission mechanism, the oblique impact of the water flow on the guide shell will drive the rotating plate to rotate, and the idle rotating plate is driven to rotate in the opposite direction through the transmission mechanism, so that the relaxed filter cloth bulges in the opposite direction, so that the sediment accumulated on the original concave surface of the filter cloth is broken as the filter cloth bulges in the opposite direction, and the water flow forms a recoil effect on the filter cloth during the rotation process, thereby flushing and removing the sediment. In addition, the accumulated sediment is automatically flushed and removed to keep the filter cloth unobstructed.

[0033] 5. When the idle rotating plate in the present invention rotates to reversely flush the filter cloth, the water in the filter cartridge also generates a rotating motion, forming a vortex at the bottom of the conical filter cartridge. Under the action of centrifugal force, the sedimentation of the silt is effectively promoted, and the silt is settled into the sand collecting chamber. Due to the existence of the narrow passage, the silt is not easy to enter the filter cartridge again, ensuring that the silt is collected in a concentrated manner instead of being diffused in the original foundation pit water.

[0034] 6. In the deep foundation pit drainage operation, as the water level continues to drop, the amount of water that the submersible pump needs to lift gradually increases, but the lift may not be able to meet the demand due to the reduction in water depth. Centrifugal pumps are prone to insufficient suction after the water level drops. When the water level drops, the water suction port of the centrifugal pump may not be able to reach below the water surface, resulting in an inability to absorb water. In the present invention, due to the action of the buoyancy component, the entire drainage structure can automatically sink as the water level drops, keeping the pump in the best working position at all times. No matter how the water surface changes, the water suction port of the pump can always remain below the water surface, thereby ensuring that the suction head is always met. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The overall structure of a red sandstone foundation pit drainage structure proposed by the present invention is shown in FIG. Figure 1 ;

[0036] Figure 2 The overall structure of a red sandstone foundation pit drainage structure proposed by the present invention is shown in FIG. Figure 2 ;

[0037] Figure 3A partial cross-sectional structural schematic diagram of a red sandstone foundation pit drainage structure proposed by the present invention;

[0038] Figure 4 This is a structural schematic diagram of the connection relationship between a sediment filter assembly and an electromagnetic three-way valve in a red sandstone foundation pit drainage structure proposed by the present invention;

[0039] Figure 5 This is a structural schematic diagram of a variable filtering mechanism in a red sandstone foundation pit drainage structure proposed by the present invention in a closed state;

[0040] Figure 6 This is a structural schematic diagram of a variable filtering mechanism in an open state in a red sandstone foundation pit drainage structure proposed by the present invention;

[0041] Figure 7 This is a schematic diagram of the structure of a diversion shell in a red sandstone foundation pit drainage structure proposed by the present invention;

[0042] Figure 8 This is a cross-sectional structural schematic diagram of a variable filtering mechanism in a red sandstone foundation pit drainage structure proposed by the present invention in a closed state;

[0043] Fig. 9 It is a cross-sectional structural schematic diagram of a variable filtering mechanism in an open state in a red sandstone foundation pit drainage structure proposed by the present invention;

[0044] Fig.10 for Figure 3 Schematic diagram of the enlarged structure of part A.

[0045] In the figure: 1. buoyancy assembly; 11. mounting frame; 12. buoyancy member; 2. water pump; 21. water inlet; 22. drain outlet; 23. drain pipe; 3. electromagnetic three-way valve; 31. input end; 32. output end; 4. sediment filter assembly; 41. connecting pipe; 42. filter cartridge; 43. sand collecting chamber; 431. arc sheet; 44. water pump pipe; 45. rotating plate; 46. mounting cartridge; 461. limit block; 47. guide shell; 471. outer arc surface; 472. inner arc surface; 473. filter arc surface; 474. filter cloth; 5. transmission shaft. DETAILED DESCRIPTION

[0046] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0047] Reference Figure 1-4 A red sandstone foundation pit drainage structure includes a buoyancy component 1, a water pump 2, an electromagnetic three-way valve 3 and two groups of sediment filtering components 4.

[0048] The buoyancy component 1 is placed in a water collection well and floats on the water surface in the water collection well under the action of buoyancy. The buoyancy component 1 includes a mounting frame 11, which is used to fix a water pump 2 and a sediment filter component 4. A plurality of buoyancy members 12 are fixedly arranged on the periphery of the mounting frame 11. The buoyancy members 12 are foam boards or air bags. In this embodiment, foam boards are used as the buoyancy members 12.

[0049] The water pump 2 is installed on the buoyancy component 1. The water pump 2 is a centrifugal pump with a water suction port 21 and a water discharge port 22. The water discharge port 22 is connected to a drainage pipe 23 extending to a drainage ditch outside the foundation pit. Two sets of sediment filtering components 4 are used to filter the sediment mixed with water entering the water pump 2. Suction is provided by the water pump 2. Water is pumped after the sediment is filtered by the sediment filtering component 4. The filtered water can reduce the damage to the water pump 2. Under the action of the buoyancy component 1, the drainage structure floats above the water surface, but there is still a certain draft depth. The installation position of the water pump 2 is higher than the top surface of the installation frame 11. It is necessary to ensure that the liquid level does not submerge electrical equipment such as the water pump 2 and the electromagnetic three-way valve 3.

[0050] Foundation pit drainage usually uses one of submersible pumps and centrifugal pumps. First, submersible pumps often face the challenge of insufficient head in application, especially in deep foundation pit drainage operations. As the water level continues to drop, the amount of water that the submersible pump needs to lift gradually increases, but the head may not be able to meet the demand due to the reduction in water depth, which will lead to a decrease in drainage efficiency and even poor drainage. On the other hand, centrifugal pumps are prone to insufficient suction after the water level drops. When the water level drops, the water intake of the centrifugal pump may not be able to reach below the water surface, resulting in an inability to absorb water. Traditional practices usually require manual movement of the centrifugal pump to ensure that its water intake is always below the water surface. This practice is not only time-consuming and labor-intensive, but may also affect the continuity and stability of the drainage operation. In the drainage structure of the present invention, the buoyancy component 1 can ensure that the entire drainage structure moves automatically with the water surface. No matter how the water surface changes, the water intake of the water pump 2 can always remain below the water surface, thereby ensuring that the suction head is always satisfied.

[0051] Reference Figure 4 The electromagnetic three-way valve 3 has two input ends 31 and one output end 32. The output end 32 is sealed and connected to the water suction port 21 of the water pump 2. The two input ends 31 are respectively connected to different sediment filter components 4. The electromagnetic three-way valve 3 can control the opening and closing states of the two input ends 31 to realize single-channel liquid flow. Therefore, by controlling the electromagnetic three-way valve 3, the working states of the two groups of sediment filter components 4 can be controlled. Only the sediment filter component 4 connected to the input end 31 in the open state will have water flow through.

[0052] The two groups of sediment filter components 4 are controlled to work alternately by the electromagnetic three-way valve 3. The sediment filter components 4 in working state filter sediment, and the sediment filter components 4 in idle state collect and precipitate the trapped sediment, which not only ensures the continuity of drainage, but also effectively utilizes the idle time of the sediment filter components 4 to collect and precipitate sediment, avoiding the efficiency loss of the traditional single filtering system due to frequent cleaning. At the same time, this alternating working mode helps to balance the equipment load, extend the service life of the equipment, and reduce energy consumption.

[0053] Reference Figure 4-9 The sediment filtering assembly 4 includes a connecting pipe 41, a filter cartridge 42, a sand collecting chamber 43 and a pumping pipe 44. One end of the connecting pipe 41 is connected to the input end 31 of the electromagnetic three-way valve 3, and the other end is connected to the top outlet of the filter cartridge 42. The sand collecting chamber 43 is coaxially installed at the bottom of the filter cartridge 42 and keeps in communication with the filter cartridge 42. The pumping pipe 44 is installed on the bottom side wall of the filter cartridge 42. Due to the gravity of the entire drainage structure, part of the buoyancy assembly 1 sinks below the water surface, including the pumping pipe 44. When the sediment filtering assembly 4 is working, the suction force generated by the pumping pump 2 sucks water upward through the pumping pipe 44, and the water flows through the filter cartridge 42 for filtration, and then enters the electromagnetic three-way valve 3 through the connecting pipe 41 and is input into the pumping pump 2, and finally is discharged from the drainage pipe 23 into the drainage ditch outside the foundation pit.

[0054] Among them, the end of the suction pipe 44 has a filter cartridge with water filtering holes. The aperture of the water filtering holes on the filter cartridge can be opened larger to block larger impurities such as dead leaves and plastic bags in the foundation pit water. Therefore, the processing difficulty of the filter cartridge is also relatively small. Impurities such as dead leaves will adhere to the surface of the filter cartridge under the suction force of the water pump 2. Since the two groups of sediment filtering components 4 work alternately, when the sediment filtering components 4 are idle, the suction pipe 44 will also lose suction, and the dead leaves, plastic bags, etc. attached to the surface of the filter cartridge will naturally fall off.

[0055] A rotating plate 45 with an opening in the center is sealed and rotated in the filter cartridge 42. The rotating plate 45 separates the filter cartridge 42. When water is drawn from bottom to top, it passes through the opening in the center of the rotating plate 45. A variable filtering mechanism with a corresponding opening is fixedly provided on the rotating plate 45. The water flowing in passes through the variable filtering mechanism, thereby filtering the sediment.

[0056] Reference Figure 4-9The variable filtering mechanism includes a mounting cylinder 46 coaxially arranged with the opening, and the side wall of the mounting cylinder 46 has a plurality of mounting openings. Muddy water enters the mounting cylinder 46 through the opening and then enters the top of the rotating plate 45 through the mounting opening. A guide shell 47 is rotatably arranged in the mounting opening, wherein a torsion spring is arranged between the rotating shaft of the guide shell 47 and the mounting opening. Under the action of the torsion spring, the guide shell 47 tends to be in a closed state, and the impact of muddy water will cause the guide shell 47 to overcome the elastic force of the torsion spring and deflect outward. After the deflection of the guide shell 47, part of the space will be exposed for water to flow through, and an oblique angle is formed between the inner wall of the guide shell 47 and the side wall of the mounting cylinder 46. Therefore, the impact of the water flow will exert a tangential force on the mounting cylinder 46 to drive the rotating plate 45 to rotate.

[0057] The upper end of the guide shell 47 is a closed structure and fits against the inner top surface of the installation port, and the lower end of the guide shell 47 is an open frame structure and fits against the top surface of the rotating plate 45. Therefore, during the entire process of rotation of the guide shell 47, the upper and lower end surfaces of the guide shell 47 are both in a sealed state. When the guide shell 47 is closed, the lower end surface of the guide shell 47 is exposed in the filter cartridge 42 to facilitate sedimentation.

[0058] Reference Figure 5-7 The guide shell 47 has an outer arc surface 471, an inner arc surface 472 and a filtering arc surface 473. The rotation axis of the guide shell 47 and the installation port is located at the intersection of the outer arc surface 471 and the inner arc surface 472. A filter cloth 474 is arranged at the filtering arc surface 473. Therefore, when the guide shell 47 is deflected, the filtering arc surface 473 is exposed, and the muddy water must be filtered through the filter cloth 474. Among them, the red sandstone foundation pit construction has the characteristic of high sediment content. The filter cloth 474 is used as the filter material. Compared with the traditional rigid filter cartridge plus micro-water filter hole design, it is not only easier to process, but also has significantly improved filtering effect, ensuring the effective interception of tiny sediment particles and preventing fine sand from entering the pump casing of the water pump 2 and damaging the water pump 2.

[0059] It should be noted that the two side walls of the installation port are not flat, but are rounded arc surfaces. The end of the guide shell 47 close to its rotation axis is also chamfered. The rounded corner and the filtering arc surface 473 both take the rotation axis of the guide shell 47 as the center and match the arc surface of the side wall of the installation port. Therefore, when the guide shell 47 rotates, the installation port and the guide shell 47 are always in a fit state.

[0060] The filter cloth 474 is in a relaxed state under normal conditions, but can bulge under the impact of water flow. Under the impact of water flow, the filter cloth 474 bulges outward to form a larger filtering surface, thereby improving the filtering effect.

[0061] A limiting block 461 is installed on one side of the installation port corresponding to the filtering arc surface 473. Under the limiting action of the limiting block 461, the deflection angle of the guide shell 47 is limited, which can prevent the guide shell 47 from deflecting too much and leaving the installation port under the impact of water flow. At the same time, when the guide shell 47 is closed by the torsion spring in the idle state, the outer arc surface 471 and the outer peripheral surface of the installation tube 46 remain concentric.

[0062] Since the guide shell 47 will be closed and blocked by the torsion spring when idle, water cannot pass through the filter cartridge 42. Therefore, when the drainage structure is not in operation, backflow will not occur due to the siphon effect because the position of the drainage structure is lower than the water level of the external drainage ditch.

[0063] Reference Figure 3 and 10 The bottom of the filter cartridge 42 and the top of the sand collecting chamber 43 are both conical, so that the filter cartridge 42 and the sand collecting chamber 43 form an hourglass structure, and a narrow channel is formed between the filter cartridge 42 and the sand collecting chamber 43. When the filter cartridge 42 in an idle state is used for sedimentation, the sediment enters the sand collecting chamber 43 through the narrow channel, and an upwardly protruding arc piece 431 is provided on the top of the sand collecting chamber 43 near the narrow channel. The arc piece 431 further avoids the influence of the water flow in the filter cartridge 42 on the sand collecting chamber 43. Therefore, the sediment entering the sand collecting chamber 43 will not be lifted up again during the impact of the water flow. Specifically, a threaded cover is provided at the bottom of the sand collecting chamber 43, and the cover can be opened by rotating to clean the sediment.

[0064] Reference Figure 4-9The red sandstone foundation pit drainage structure also includes a transmission mechanism arranged between the two filter cylinders 42, the transmission mechanism includes a transmission shaft 5 that passes through the two filter cylinders 42, bevel gears 1 are fixedly installed at both ends of the transmission shaft 5, and bevel gears 2 are installed on the top of the installation cylinder 46. Bevel gears 1 are meshed and connected with corresponding bevel gears 2. The guide shells 47 in the two groups of sediment filter assemblies 4 are installed in the same direction. When one of the rotating plates 45 rotates, the other rotating plate 45 is driven to rotate through the transmission mechanism, and the two rotating plates 45 rotate in opposite directions. During normal operation, under the impact of water flow, the rotating plate 45 rotates toward the side where the rotating shaft of the guide shell 47 is located, and the other rotating plate 45 in an idle state rotates toward the direction where the filter cloth 474 is located. The filter cloth 474 that performs normal filtering work 74 is bulged on the outside of the guide shell 47, and the sediment is trapped in the inner concave surface of the filter cloth 474. There is a certain amount of squeezing when the sediment accumulates on the concave surface, and compaction may occur. The time required for direct sedimentation is too long. When the filter cloth 474 in the idle sediment filtering assembly 4 is settling, the guide shell 47 is in a closed state, and the rotation direction is opposite to the rotation direction of the filtering state. Therefore, the filter cloth 474 will bulge on the inside of the guide shell 47, and the reversely bulged filter cloth 474 makes the compacted sediment accumulated on the original concave surface of the filter cloth 474 break as the filter cloth 474 reversely bulges to form a convex surface, and the water flow forms a recoil effect on the filter cloth 474 during the rotation process, thereby achieving the flushing and removal of the sediment, and automatically flushing and removing the accumulated sediment, keeping the filter cloth 474 unobstructed.

[0065] Reference Figure 8-9 When the idle rotating plate 45 rotates to backwash the filter cloth 474, the water in the filter cylinder 42 is also rotated to form a vortex at the bottom of the conical filter cylinder 42. Under the action of centrifugal force, the sedimentation of the silt is effectively promoted, and the silt is settled into the sand collecting chamber 43. Due to the existence of the narrow channel, the silt is not easy to enter the filter cylinder 42 again, ensuring that the silt is collected in a concentrated manner instead of being diffused in the original foundation pit water, thereby avoiding the increase of silt concentration in the foundation pit water body and increasing the difficulty of filtration.

[0066] A construction method for a red sandstone foundation pit drainage structure comprises the following steps:

[0067] The drainage structure is placed in the water collection well. Under the buoyancy of the buoyancy component 1, the entire drainage structure floats on the water surface;

[0068] Draw the outlet of the drainage pipe 23 to the drainage ditch outside the foundation pit, and start the water pump 2 to pump water;

[0069] The electromagnetic three-way valve 3 is controlled to switch the connection state of the two input ends 31 and the output end 32 at intervals, so that the water pump 2 pumps water alternately through the two sediment filter components 4. The sediment filter component 4 in the working state filters the sediment, and the sediment filter component 4 in the idle state precipitates and collects the trapped sediment.

Claims

1. A red sandstone foundation pit drainage structure, characterized in that: include: A buoyancy assembly (1) is placed in the water collection well and floats on the water surface in the water collection well under the action of buoyancy; A water pump (2) is installed on the buoyancy assembly (1), and has a water suction port (21) and a water discharge port (22), wherein the water discharge port (22) is connected to a drainage pipe (23) extending to a drainage ditch outside the foundation pit; Two sets of sediment filtering components (4) for filtering sediment mixed with water entering the water pump (2); The electromagnetic three-way valve (3) has two input ends (31) and an output end (32), wherein the output end (32) is sealedly connected to the water suction port (21) of the water pump (2), and the two input ends (31) are respectively connected to different sediment filtering components (4); The two groups of sediment filter components (4) are controlled to work alternately by the electromagnetic three-way valve (3), the sediment filter components (4) in the working state filter sediment, and the sediment filter components (4) in the idle state precipitate and collect the retained sediment; The sediment filtering assembly (4) comprises a connecting pipe (41), a filter cartridge (42), a sand collecting chamber (43) and a water pumping pipe (44); one end of the connecting pipe (41) is connected to the input end (31) of the electromagnetic three-way valve (3), and the other end is connected to the top outlet of the filter cartridge (42); the sand collecting chamber (43) is coaxially mounted on the bottom of the filter cartridge (42) and is in communication with the filter cartridge (42); and the water pumping pipe (44) is mounted on the bottom side wall of the filter cartridge (42); A rotating plate (45) having an opening at its center is provided in a sealed and rotatable manner in the filter cartridge (42), and a variable filtering mechanism corresponding to the opening is fixedly provided on the rotating plate (45); The variable filtering mechanism comprises a mounting cylinder (46) coaxially arranged with the opening, the side wall of the mounting cylinder (46) having a plurality of mounting openings, a guide shell (47) rotatably arranged in the mounting opening, a torsion spring being arranged between the rotating shaft of the guide shell (47) and the mounting opening, the upper end of the guide shell (47) being a closed structure and being in contact with the inner top surface of the mounting opening, and the lower end of the guide shell (47) being an open frame structure and being in contact with the top surface of the rotating plate (45); The guide shell (47) has an outer arc surface (471), an inner arc surface (472) and a filtering arc surface (473); the rotation axis of the guide shell (47) and the mounting opening is located at the intersection of the outer arc surface (471) and the inner arc surface (472); and a filter cloth (474) is provided at the filtering arc surface (473); It also includes a transmission mechanism disposed between the two filter cylinders (42), the transmission mechanism including a transmission shaft (5) penetrating the two filter cylinders (42), bevel gears 1 being fixedly mounted at both ends of the transmission shaft (5), bevel gear 2 being mounted on the top of the mounting cylinder (46), and bevel gear 1 being meshingly connected with corresponding bevel gear 2.

2. A red sandstone foundation pit drainage structure according to claim 1, characterized in that: The buoyancy assembly (1) comprises a mounting frame (11), and a plurality of buoyancy members (12) are fixedly arranged on the outer periphery of the mounting frame (11).

3. A red sandstone foundation pit drainage structure according to claim 2, characterized in that: The buoyancy member (12) is a foam board or an air bag.

4. The red sandstone foundation pit drainage structure according to claim 1, characterized in that: The filter cloth (474) is in a relaxed state under normal conditions, and can bulge under the impact of water flow.

5. The red sandstone foundation pit drainage structure according to claim 1, characterized in that: A limiting block (461) is installed on one side of the installation opening corresponding to the filtering curved surface (473).

6. The red sandstone foundation pit drainage structure according to claim 1, characterized in that: The bottom of the filter cartridge (42) and the top of the sand collecting chamber (43) are both conical, so that the filter cartridge (42) and the sand collecting chamber (43) form an hourglass-shaped structure, a narrow passage is formed between the filter cartridge (42) and the sand collecting chamber (43), and an upwardly protruding arc sheet (431) is provided at the top of the sand collecting chamber (43) near the narrow passage.

7. A construction method for a red sandstone foundation pit drainage structure, characterized in that: The drainage structure according to any one of claims 1 to 6 comprises the following steps: The drainage structure is placed in a water collection well, and under the buoyancy of the buoyancy component (1), the entire drainage structure floats on the water surface; The outlet of the drainage pipe (23) is pulled to the drainage ditch outside the foundation pit, and the water pump (2) is started to pump water; The electromagnetic three-way valve (3) is controlled to switch the connection state of the two input ends (31) and the output end (32) at intervals, so that the water pump (2) pumps water alternately through the two sediment filter assemblies (4), the sediment filter assemblies (4) in the working state filter sediment, and the sediment filter assemblies (4) in the idle state precipitate and collect the retained sediment.

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