A spiral flow well construction system based on steel casing support and a construction method thereof

Abstract

The application discloses a kind of based on steel casing support's vortex well construction system and construction method, system, including: by upper foundation pit, lower foundation pit and bottom foundation pit constitute foundation pit unit, upper straight cylinder section outer cylinder construction unit, middle straight cylinder section outer cylinder construction unit, cone section construction unit, inner cylinder construction unit, roof construction unit, precipitation well construction unit, top water interception slope;The horizontal height of the top water interception slope is higher than ground level;The steel casing support structure of the application can be prefabricated in advance, directly installed during foundation pit construction, saving the forming time and maintenance time of traditional reinforced concrete support structure, while not affecting the construction of surrounding buildings, shortening the overall project duration;In addition, the steel casing is independently produced and formed on the ground, and the foundation pit is supported by sinking through well formation, with high performance certainty, is not affected by geological conditions, and the construction safety is significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of vortex well construction technology, and more specifically, relates to a vortex well construction system and construction method based on steel casing support. Background Technology

[0002] A vortex well is a type of sedimentation tank widely used in steelmaking and rolling industries for recovering iron oxide from the surface of steel billets. Currently, conventional construction methods for vortex wells mainly include large-scale excavation, forward construction, caisson construction, reverse construction with cast-in-place pile support, and continuous wall support. While these methods can achieve complete construction of a vortex well, the following technical problems still exist:

[0003] (1) Traditional large-scale excavation construction has high requirements for the construction site and is usually only suitable for construction areas with good geological conditions;

[0004] (2) Caisson construction also has high site requirements, and the surrounding foundations cannot be constructed at the same time as the caisson construction.

[0005] (3) The reverse construction method of cast-in-place pile support has poor water-stopping effect between piles, so only the reverse construction method can be used. Water-stopping and sealing between piles are required at the same time as earthwork excavation. Deep well dewatering is required at the same time as earthwork excavation. If the surrounding foundation and vortex well are constructed at the same time, there is also a risk of displacement. The cost of continuous wall support construction method is too high.

[0006] Based on the above discussion, there is an urgent need to improve the construction process, study new methods for vortex well support and construction, reduce safety risks during construction, and improve construction efficiency. Summary of the Invention

[0007] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a vortex well construction system and method based on steel casing support. The steel casing support structure can be prefabricated and directly installed during foundation pit construction, saving the molding and curing time of traditional reinforced concrete support structures. Simultaneously, it does not affect the construction of surrounding buildings, shortening the overall project duration. Furthermore, by independently fabricating and molding the steel casing on the ground and sinking it through a well-forming process to support the foundation pit, its performance is highly deterministic, unaffected by geological conditions, and construction safety is significantly improved.

[0008] To achieve the above objectives, according to a first aspect of the present invention, a construction system includes:

[0009] The foundation pit unit consists of an upper foundation pit, a lower foundation pit, and a bottom foundation pit; an upper straight-cylinder outer cylinder construction unit, a middle straight-cylinder outer cylinder construction unit, and a conical section construction unit are respectively arranged in the upper foundation pit, lower foundation pit, and bottom foundation pit; an inner cylinder construction unit is arranged longitudinally at the center of the foundation pit unit; a top slab construction unit is arranged between the outer cylinder construction unit and the inner cylinder construction unit; a dewatering well construction unit is set around the foundation pit unit; and a top intercepting slope is set at the intersection of the first slope and the ground; the horizontal height of the top intercepting slope is higher than the ground level.

[0010] The middle straight section outer cylinder construction unit includes a steel casing outer formwork assembly that settles inside the lower foundation pit, an inner formwork that is parallel to the inner side of the steel casing outer formwork assembly and is relatively fixed to it by a formwork tie assembly, a cylinder wall reinforcement assembly that is set between the steel casing outer formwork assembly and the inner formwork, and a concrete layer poured between the steel casing outer formwork assembly and the inner formwork.

[0011] The cylinder wall reinforcement assembly includes inner and outer layers of reinforcement arranged in parallel to each other.

[0012] Preferably, the outer template assembly of the steel casing includes:

[0013] Steel casing, steel casing docking unit for coaxial vertical splicing of steel casing segments, structural reinforcement component fixed on the inner wall of the steel casing, flexible foot added to the lower end face of the bottom steel casing segment to assist in penetration into the soil and sinking, steel casing anti-sinking component set on the upper end face of the top steel casing segment, and leveling ruler engraved on the outer surface of the steel casing for assisting in leveling during the sinking stage.

[0014] The steel casing docking unit includes a bevel located on the top and bottom faces of the steel casing, and guide plates located on both sides of the top of the steel casing. The top of the guide plates is higher than the upper end of the bevel, and the two guide plates together form a top latch that engages with the bevel.

[0015] Preferably, the structural reinforcement component includes:

[0016] An annular reinforcing beam and a vertical stiffening plate are fixedly installed on the inner wall of the steel casing, and the annular reinforcing beam and the vertical stiffening plate are kept perpendicular to each other.

[0017] Preferably, the structural reinforcement component includes:

[0018] The annular reinforcing beam is fixed to the inside of the annular reinforcing beam by the first fixed crossbeam.

[0019] Preferably, the steel casing anti-sinking assembly includes:

[0020] The supporting lug plate is fixed to the operating platform, and a second fixed crossbeam is added to the outer side of the upper end of the top steel casing section; the lower surface of the second fixed crossbeam abuts against the upper surface of the supporting lug plate.

[0021] Preferably, the template pull assembly includes:

[0022] A pre-set sleeve fixed to the inner wall of the steel casing in a two-dimensional equidistant array along the horizontal and vertical directions, a tie rod threaded to the pre-set sleeve, a butterfly buckle installed on the tie rod to prevent the template from disengaging, and a fastening nut installed behind the butterfly buckle.

[0023] The preset sleeve includes a sleeve body and a threaded hole formed in the sleeve body perpendicular to the inner wall of the steel sleeve, wherein the depth of the threaded hole is greater than five centimeters.

[0024] Preferably, the inner layer of reinforcing bars is disposed between the inner formwork and the annular reinforcing beam;

[0025] The outer layer of reinforcing bars is located between the annular reinforcing beam and the annular strengthening beam.

[0026] According to a second aspect of the present invention, a construction method for a vortex well construction system based on steel casing support includes the following steps:

[0027] S100: Preparatory work before excavation of the vortex well: S110: Prefabrication of steel casing, which is segmented and fabricated according to the total height and structural characteristics of the steel casing, and welded into a whole during the installation of the steel casing; S120: Measurement and layout according to the design drawings and approved construction plan to determine the position of dewatering wells and the excavation boundary line of the foundation pit; S130: Determine the position, quantity and depth of dewatering wells according to the engineering geological survey report, construct dewatering wells according to the measurement and positioning, and carry out dewatering and drainage construction according to the actual groundwater conditions;

[0028] S200: Earthwork excavation and steel casing support construction; S210: Upper layer earthwork excavation and support; S220: Steel casing support structure sinking construction; S230: Bottom cone section earthwork excavation and cushion layer pouring;

[0029] S300: Construction of vortex well structure; S310: Construction of bottom conical section structure; S320: Construction of middle straight section; S330: Construction of upper straight section; S340: Construction of top plate.

[0030] Preferably, step S210 further includes:

[0031] S211: According to the required soil unloading depth and appropriate slope ratio in the construction plan, the upper soil layer is excavated by slope. During excavation, a two-meter operating platform is reserved from the toe of the slope to the outside of the steel casing. When excavating, the soil is excavated in layers from the middle to the surrounding area, with each layer not exceeding 1 meter in depth. The slope is repaired while excavating.

[0032] S212: After the upper layer of earthwork is excavated and transported, steel mesh is added to the slope and shotcrete is sprayed to protect the slope. When installing the steel mesh, threaded steel bars can be nailed vertically into the slope surface for fixation.

[0033] S213: After the upper layer of earthwork is excavated, a guardrail and a water-cutting slope shall be set at the top of the slope. The width of the water-cutting slope shall be 0.5 to 1 meter and the height shall be 0.2 to 0.5 meters. Its slope direction shall be from the top of the slope outward. The water-cutting slope shall be used to block the water on the ground to prevent water from eroding the slope and pouring into the foundation pit.

[0034] S214: After the upper earthwork slope support is completed, two safety passages from the top of the slope to the bottom of the slope should be set up. A 300mm deep circular drainage ditch should be set up at the bottom of the slope and two 0.6m square water collection wells should be set up to facilitate the drainage of water by water pumps. The water collection wells can be set up near the safety passages for easy pumping operations.

[0035] Preferably, step S220 further includes:

[0036] S221: Apply a release agent to the outer wall of the steel casing to facilitate sinking. Mark the four directions on the outside of the steel casing with red paint at 0.5-meter intervals from top to bottom to facilitate observation during the leveling process of the steel casing.

[0037] S222: Continue excavating downwards along the positioning line of the steel casing, extending 0.5 meters outwards and 1.5 meters inwards, to form a 2-meter wide and 1-meter deep annular trench;

[0038] S223: After hoisting the first section of the steel casing to the preset position, backfill and compact the annular groove on the outer side of the steel casing, and harden the operating platform with concrete.

[0039] S224: Use a long-arm excavator to excavate the soil inside the casing, excavating slowly from the center outwards. During the excavation process, the construction machinery must maintain a reasonable and safe distance from the edge of the foundation pit and the steel casing to avoid lateral pressure on the foundation pit and prevent the steel casing from deforming due to soil pressure. Strictly control the depth of the soil excavation inside the casing, with each layer of excavated soil thickness controlled within 50cm, and the excavator arm and bucket must not touch the steel casing.

[0040] S225: When the earthwork is excavated to the bottom of the steel casing, the entire circumference of the soil is excavated symmetrically. When the soil layer cannot withstand the pressure of the steel casing and breaks, the steel casing will be squeezed and sink under its own weight.

[0041] S226: During earthwork excavation near the steel casing, if the steel casing can sink on its own, the sinking amount should be strictly controlled to ensure a smooth sinking. If the steel casing fails to sink on its own, the following measures can be taken: 1. Gradually excavate the soil below the steel casing to reduce sinking resistance; 2. Apply additional loads using machinery to assist the steel casing in sinking; 3. Inject thixotropic mud between the outer wall of the steel casing and the soil and pour in an appropriate amount of water to reduce frictional resistance; 4. To reduce frictional resistance during the sinking process, apply a release agent to the surface of the steel casing.

[0042] S227: When the lower section of the steel casing sinks to a distance of 1.5 meters from the top of the operating platform, stop excavation, hoist the upper section of the steel casing into place, and weld it to the lower section of the steel casing on the operating platform according to the technical requirements. The outer surface of the weld should be ground smooth.

[0043] S228: Correction measures during the sinking of steel casing: Inclination: Strengthen soil removal on the higher side and reduce or eliminate soil removal on the lower side. After the casing is aligned, remove soil evenly in layers. Backfill with sand and gravel on the lower side to slow down the sinking speed. Deeply excavate the soil on the opposite side of the inclination outside the steel casing to reduce the sinking friction on the higher side. Use machinery or counterweights to apply external force to correct the inclination on the higher side. Deviation: Control the steel casing to prevent it from tilting in the direction of deviation. Intentionally tilt the steel casing in the opposite direction of deviation. It can be restored to the correct position through several tilt corrections.

[0044] S229: Use a long-arm excavator to excavate the soil inside the casing and continue to sink the steel casing to the preset position. Then, weld an I-beam horizontally at every 90 degrees on the upper end of the steel casing. Weld a steel plate under the I-beam horizontally to support it on the circular operating platform to prevent accidental sinking during subsequent construction of the vortex pool.

[0045] S2210: Install a steel ladder with a protective cage inside the steel casing to facilitate personnel going up and down.

[0046] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0047] 1. The present invention provides a vortex well construction system based on steel casing support, wherein the steel casing is independently manufactured on the ground and sinks to support the foundation pit through well construction. Its performance is highly deterministic, is not affected by geological conditions, and significantly improves construction safety.

[0048] 2. The present invention provides a vortex well construction system based on steel casing support. The steel casing support structure can be prefabricated in advance and directly installed during the foundation pit construction, saving the molding and curing time of traditional reinforced concrete support structures. At the same time, it does not affect the construction of surrounding buildings and shortens the overall project period.

[0049] 3. The present invention provides a vortex well construction system based on steel casing support, which can use the steel casing as the outer formwork of the vortex well wall concrete to facilitate the reinforcement of the inner formwork, while omitting the side wall waterproofing and rebar installation work, thus reducing and simplifying the workflow.

[0050] 4. The vortex well construction system based on steel casing support of the present invention increases the activity space inside the foundation pit support structure, and allows the use of long-arm excavators to excavate around the top of the slope, realizing unmanned construction of the support structure inside the foundation pit and reducing safety risks.

[0051] 5. In the vortex well construction system based on steel casing support of the present invention, the support structure only needs to reach the top of the conical section, which reduces the depth into the conical section and below the bottom plate compared with the traditional method, thereby reducing the workload and lowering the construction cost;

[0052] 6. The present invention provides a vortex well construction system based on steel casing support, which can treat local hard foreign objects affecting sinking inside the casing. Compared with the vortex well structure caisson construction method, it has a high tolerance for soil conditions and can be applied to vortex well construction in complex soil conditions, as well as in situations where there are old underground buildings. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the overall main view section structure of a vortex well construction system based on steel casing support according to an embodiment of the present invention;

[0054] Figure 2 This is a top view schematic diagram of the overall structure of a vortex well construction system based on steel casing support according to an embodiment of the present invention;

[0055] Figure 3 This is a partially enlarged view (A) of a vortex well construction system based on steel casing support according to an embodiment of the present invention;

[0056] Figure 4 This is a partial enlarged view (B) of a vortex well construction system based on steel casing support according to an embodiment of the present invention;

[0057] Figure 5 This is a partially enlarged view (C) of a vortex well construction system based on steel casing support according to an embodiment of the present invention;

[0058] Figure 6 This is a schematic diagram of the main structure of a vortex well construction system based on steel casing support according to an embodiment of the present invention;

[0059] Figure 7 This is a cross-sectional internal structural diagram of a vortex well construction system based on steel casing support according to an embodiment of the present invention;

[0060] Figure 8This is a top view of the outer formwork assembly of a vortex well construction system based on steel casing support, according to an embodiment of the present invention.

[0061] Figure 9 This is a partially enlarged view (D) of a vortex well construction system based on steel casing support according to an embodiment of the present invention;

[0062] Figure 10 This is a schematic diagram of a pre-set sleeve positioning structure for a vortex well construction system based on steel casing support, according to an embodiment of the present invention.

[0063] Figure 11 This is a first-state diagram of the sinking construction of a vortex well construction system based on steel casing support, according to an embodiment of the present invention.

[0064] Figure 12 This is a second-state diagram of the sinking construction of a vortex well construction system based on steel casing support, according to an embodiment of the present invention.

[0065] Figure 13 This is a third-state diagram of the sinking construction of a vortex well construction system based on steel casing support, according to an embodiment of the present invention.

[0066] Figure 14 This is a schematic diagram of the middle straight section outer cylinder construction unit structure of a vortex well construction system based on steel casing support according to an embodiment of the present invention;

[0067] Figure 15 This is a partially enlarged view (E) of a vortex well construction system based on steel casing support according to an embodiment of the present invention;

[0068] Figure 16 This is a cross-sectional view of the connection structure between steel casings in a vortex well construction system based on steel casing support, according to an embodiment of the present invention.

[0069] Figure 17 This is a flowchart illustrating the overall construction method of a vortex well construction system based on steel casing support, according to an embodiment of the present invention.

[0070] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-Pit unit, 110-Upper pit, 111-Ground surface, 112-First slope, 113-Operating platform, 120-Lower pit, 130-Bottom pit, 131-Second slope, 132-Bottom of well, 2-Upper straight section outer cylinder construction unit, 3-Middle straight section outer cylinder construction unit, 310-Steel casing outer formwork assembly, 311-Steel casing, 312-Structural reinforcement assembly, 3121-Annular reinforcing beam, 3122-Vertical stiffening plate, 3123-First fixed crossbeam, 3124-Annular reinforcing beam, 313-Firm foot, 314-Steel casing protection 3141-Supporting Ear Plate, 3142-Second Fixed Crossbeam, 315-Leveling Ruler, 320-Formwork Tie-off Assembly, 321-Preset Sleeve, 3311-Threaded Hole, 3312-Sleeve Body, 322-Tie-off Rod, 323-Butterfly Buckle, 234-Fastening Nut, 330-Inner Formwork, 340-Cylinder Wall Reinforcement Assembly, 341-Inner Reinforcement, 342-Outer Reinforcement, 4-Cone Section Construction Unit, 401-Bottom Side Wall, 402-Well Bottom, 5-Inner Cylinder Construction Unit, 501-Inner Cylinder, 502-Intermediate Connection, 503-Inclined Connection Section, 6-Top Plate Construction Unit, 7-Dewatering Well Construction Unit, 8-Top Cutoff Slope. Detailed Implementation

[0071] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0072] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0073] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0074] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0075] like Figures 1-15 As shown in the embodiment of the present invention, a vortex well construction system based on steel casing support includes:

[0076] The foundation pit unit 1 consists of an upper foundation pit 110, a lower foundation pit 120, and a bottom foundation pit 130. Construction units include: an upper straight section outer cylinder construction unit 2, a middle straight section outer cylinder construction unit 3, and a conical section construction unit 4, all arranged in the upper, lower, and bottom foundation pits 110, 120, and 130 respectively; an inner cylinder construction unit 5 longitudinally arranged at the center of the foundation pit unit 1; a top slab construction unit 6 arranged between the outer cylinder construction unit and the inner cylinder construction unit 5; dewatering well construction units 7 located around the foundation pit unit 1; and a top intercepting slope 8 located at the intersection of the first slope 112 and the ground surface 111. The horizontal height of the top intercepting slope 8 is higher than the ground level.

[0077] The middle straight section outer cylinder construction unit 3 includes a steel casing outer formwork assembly 310 that settles inside the lower foundation pit 120, an inner formwork 330 that is parallel to the inner side of the steel casing outer formwork assembly 310 and is relatively fixed to it by a formwork tie assembly 320, a cylinder wall reinforcement assembly 340 that is set between the steel casing outer formwork assembly 310 and the inner formwork 330, and a concrete layer poured between the steel casing outer formwork assembly 310 and the inner formwork 330;

[0078] The cylinder wall reinforcement assembly 340 includes inner reinforcement 341 and outer reinforcement 342 arranged in parallel with each other.

[0079] like Figure 1 , Figures 5-9 , Figure 16 As shown, in this embodiment of the invention, the steel casing outer template assembly 310 includes:

[0080] Steel casing 311, steel casing docking unit 316 for coaxial vertical splicing of steel casing 311 segments, structural reinforcement component 312 fixedly installed on the inner wall of the steel casing 311, flexible foot 313 added to the lower end face of the bottom steel casing 311 segment to assist in penetration into the soil and sinking, steel casing anti-sinking component 314 installed on the upper end face of the top steel casing 311 segment, and leveling ruler 315 engraved on the outer surface of the steel casing 311 for assisting in leveling during the sinking stage;

[0081] The steel casing docking unit 316 includes a bevel on the top and bottom faces of the steel casing 311 and guide plates 3161 on both sides of the top of the steel casing 311. The top of the guide plates 3161 is higher than the upper end of the bevel, and the two guide plates 3161 form a top latch 3163 that engages with the bevel.

[0082] like Figures 7-9 As shown, in this embodiment of the invention, the structural reinforcement component 312 includes:

[0083] The annular reinforcing beam 3121 and the vertical stiffening plate 3122 are fixedly installed on the inner wall of the steel casing 311, and the annular reinforcing beam 3121 and the vertical stiffening plate 3122 are kept perpendicular to each other.

[0084] like Figures 7-9 As shown, in this embodiment of the invention, the structural reinforcement component 312 includes:

[0085] The annular reinforcing beam 3124 is fixed to the inner side of the annular reinforcing beam 3121 by the first fixed crossbeam 3123.

[0086] like Figure 1 , Figure 3 , Figure 6 and Figure 7 As shown, in this embodiment of the invention, the steel casing anti-sinking assembly 314 includes:

[0087] The supporting ear plate 3141 is fixed to the operating platform 113, and the second fixed crossbeam 3142 is added to the outer side of the upper end of the top steel protective cylinder 311 segment; the lower surface of the second fixed crossbeam 3142 abuts against the upper surface of the supporting ear plate 3141.

[0088] like Figure 7 , Figure 14 and Figure 15 As shown, in this embodiment of the invention, the template pull assembly 320 includes:

[0089] A pre-set sleeve 321 is fixed to the inner wall of the steel sleeve 311 in a two-dimensional equidistant array along the horizontal and vertical directions; a tie rod 322 is threadedly connected to the pre-set sleeve 321; a butterfly buckle 323 is installed on the tie rod 322 and used to prevent the template from disengaging; and a fastening nut 234 is installed behind the butterfly buckle 323.

[0090] The preset sleeve 321 includes a sleeve body 3312 and a threaded hole 3311 opened in the sleeve body 3312 perpendicular to the inner wall surface of the steel sleeve 311. The depth of the threaded hole 3311 is greater than 5cm.

[0091] like Figure 1 , Figure 4 , Figure 5 , Figure 14 and 15 As shown, in this embodiment of the invention, the inner reinforcing bar 341 is disposed between the inner formwork 330 and the annular reinforcing beam 3124;

[0092] The outer reinforcing bar 342 is located between the annular reinforcing beam 3121 and the annular strengthening beam 3124.

[0093] like Figure 17 As shown in the embodiment of the present invention, the construction method of the vortex well construction system based on steel casing support includes the following steps: It should be noted that the following parts...

[0094] S100: Preparatory work before excavation of the vortex well: S110: Prefabrication of steel casing, which is segmented and fabricated according to the total height and structural characteristics of the steel casing, and welded into a whole during the installation of the steel casing; S120: Measurement and layout according to the design drawings and approved construction plan to determine the position of dewatering wells and the excavation boundary line of the foundation pit; S130: Determine the position, quantity and depth of dewatering wells according to the engineering geological survey report, construct dewatering wells according to the measurement and positioning, and carry out dewatering and drainage construction according to the actual groundwater conditions;

[0095] S200: Earthwork excavation and steel casing support construction; S210: Upper layer earthwork excavation and support; S220: Steel casing support structure sinking construction; S230: Bottom cone section earthwork excavation and cushion layer pouring;

[0096] S300: Construction of vortex well structure; S310: Construction of bottom conical section structure; S320: Construction of middle straight section; S330: Construction of upper straight section; S340: Construction of top plate.

[0097] In this embodiment of the invention, step S110 further includes:

[0098] S111: The fabrication of each steel casing section includes the casing wall, vertical stiffening plates, reinforcing ring beams, and reinforced ring beams and their crossbeams. A 0.3-0.5 meter section without stiffening plates and ring beams is reserved at the bottom of the steel casing wall as a flexible foot for the steel casing to sink.

[0099] S112: The dimensions and positions of the steel casing, reinforcing ring beam, strengthening ring beam, and their supporting crossbeams are determined according to the structural dimensions of the vortex well. The reinforcing ring beam, which is close to the inner side of the steel casing, should be located outside the outer layer of reinforcing bars on the outer wall of the vortex well. The strengthening ring beam, which is inside the reinforcing ring beam, should be located in the middle of the two layers of reinforcing bars on the outer wall of the vortex well, so as not to affect the installation of the reinforcing bars on the outer wall of the vortex well.

[0100] S113: A single-sided bevel should be reserved at the joint of the two steel casing sections during the manufacturing process, with the bevel facing the outside of the steel casing, so that welding can be carried out on the outside after the joint is completed.

[0101] S114: Several pairs (generally no less than 4) of guide plates need to be installed at the upper end of the steel casing to be butt-welded. The thickness and width of these guide plates are the same as the stiffening plates, and their length is 300mm. The lower 200mm of each guide plate is welded to the side of the steel casing, and the upper 100mm section slopes upwards at a 45° angle from the top of the steel casing. Each set of guide plates is in an inverted V-shape (funnel shape) to assist in the butt-welding of the upper and lower sections of the steel casing. After the butt weld of the steel casing is completed, the guide plates on the outer side can be removed and reused, while the guide plates on the inner side can be removed or not.

[0102] In this embodiment of the invention, step S210 further includes:

[0103] S211: According to the required soil unloading depth and appropriate slope ratio in the construction plan, the upper soil layer is excavated by slope. During excavation, a two-meter operating platform is reserved from the toe of the slope to the outside of the steel casing. When excavating, the soil is excavated in layers from the middle to the surrounding area, with each layer not exceeding 1 meter in depth. The slope is repaired while excavating.

[0104] S212: After the upper layer of earthwork is excavated and transported, steel mesh is added to the slope and shotcrete is sprayed to protect the slope. When installing the steel mesh, threaded steel bars can be nailed vertically into the slope surface for fixation.

[0105] S213: After the upper layer of earthwork is excavated, a guardrail and a water-cutting slope shall be set at the top of the slope. The width of the water-cutting slope shall be 0.5 to 1 meter and the height shall be 0.2 to 0.5 meters. Its slope direction shall be from the top of the slope outward. The water-cutting slope shall be used to block the water on the ground to prevent water from eroding the slope and pouring into the foundation pit.

[0106] S214: After the upper earthwork slope support is completed, two safety passages from the top of the slope to the bottom of the slope should be set up. A 300mm deep circular drainage ditch should be set up at the bottom of the slope and two 0.6m square water collection wells should be set up to facilitate the drainage of water by water pumps. The water collection wells can be set up near the safety passages for easy pumping operations.

[0107] In this embodiment of the invention, step S220 further includes:

[0108] S221: Apply a release agent to the outer wall of the steel casing to facilitate sinking. Mark the four directions on the outside of the steel casing with red paint at 0.5-meter intervals from top to bottom to facilitate observation during the leveling process of the steel casing.

[0109] S222: Continue excavating downwards along the positioning line of the steel casing, extending 0.5 meters outwards and 1.5 meters inwards, to form a 2-meter wide and 1-meter deep annular trench;

[0110] S223: After hoisting the first section of the steel casing to the preset position, backfill and compact the annular groove on the outer side of the steel casing, and harden the operating platform with concrete.

[0111] S224: Use a long-arm excavator to excavate the soil inside the casing, excavating slowly from the center outwards. During the excavation process, the construction machinery must maintain a reasonable and safe distance from the edge of the foundation pit and the steel casing to avoid lateral pressure on the foundation pit and prevent the steel casing from deforming due to soil pressure. Strictly control the depth of the soil excavation inside the casing, with each layer of excavated soil thickness controlled within 50cm, and the excavator arm and bucket must not touch the steel casing.

[0112] S225: When the earthwork is excavated to the bottom of the steel casing, the entire circumference of the soil is excavated symmetrically. When the soil layer cannot withstand the pressure of the steel casing and breaks, the steel casing will be squeezed and sink under its own weight.

[0113] S226: During earthwork excavation near the steel casing, if the steel casing can sink on its own, the sinking amount of the steel casing should be strictly controlled to ensure that the steel casing sinks smoothly. If the steel casing cannot sink on its own, the following measures can be taken: 1) Gradually excavate the soil below the steel casing to reduce sinking resistance; 2) Use machinery to apply additional loads to assist the steel casing in sinking; 3) Inject thixotropic mud between the outer wall of the steel casing and the soil and pour an appropriate amount of water to reduce frictional resistance; 4) To reduce frictional resistance during the sinking process of the steel casing, apply a release agent to the surface of the steel casing.

[0114] S227: When the lower section of the steel casing sinks to a distance of 1.5 meters from the top of the operating platform, stop excavation, hoist the upper section of the steel casing into place, and weld it to the lower section of the steel casing on the operating platform according to the technical requirements. The outer surface of the weld should be ground smooth.

[0115] S228: Correction measures during the sinking of steel casing: 1) Inclination: Strengthen soil removal on the higher side and reduce or eliminate soil removal on the lower side. After the casing is aligned, remove soil evenly in layers. Backfill with sand and gravel on the lower side to slow down the sinking speed. Deeply excavate the soil on the opposite side of the inclination outside the steel casing to reduce the sinking friction on the higher side. Use machinery or counterweights to apply external force to correct the inclination on the higher side. 2) Deviation: Control the steel casing to prevent it from tilting in the direction of deviation. Intentionally tilt the steel casing in the opposite direction of deviation. It can be restored to the correct position through several tilt corrections.

[0116] S229: Use a long-arm excavator to excavate the soil inside the casing and continue to sink the steel casing until it reaches the preset position. Then, weld a 0.8-meter-long I18 steel beam horizontally at every 90° direction on the upper end of the steel casing. Weld a 0.8*0.8-meter steel plate (10-16mm thick) below the I18 steel beam to support it on the circular operating platform to prevent accidental sinking during subsequent construction of the vortex pool.

[0117] S2210: Install a steel ladder with a protective cage inside the steel casing to facilitate personnel going up and down.

[0118] In this embodiment of the invention, step S230 further includes:

[0119] S231: The excavation of the vertebral segment foundation pit adopts a combination of mechanical and manual excavation methods. A long-arm excavator is used to excavate the middle soil, leaving a minimum thickness of 300mm. Then, the remaining soil is excavated manually, and the slope is trimmed, shaped, and compacted according to the design drawings.

[0120] S232: After the foundation pit excavation meets the design requirements and the experience pit is qualified, pour the concrete cushion layer to seal the bottom in a timely manner.

[0121] S233: If a large amount of groundwater is found when the bottom is excavated to the design elevation, the following measures can be taken: 1) Increase the output of the dewatering well outside the pool or add a dewatering well; 2) When constructing the foundation layer, reserve a 0.5*0.5*0.5m water collection pit at the bottom and use a submersible pump to drain the accumulated water.

[0122] In this embodiment of the invention, step S310 further includes:

[0123] S311: After setting the pads on the bottom layer, install the reinforcing bars. At the tapered slope, fix the concrete pads below the lower layer of reinforcing bars. Set up reinforcing bar stirrups and supports on the lower layer of reinforcing bars, and then install the upper layer of reinforcing bars. Install the waterstop steel plate at the construction joint. The waterstop steel plate is located between the two layers of reinforcing bars. The center line of the waterstop steel plate is flush with the top surface of the concrete pouring, and the water-facing side of the waterstop steel plate faces the inside of the cylinder wall.

[0124] S312: Install the reserved steel bars of the bottom support beam of the inner cylinder on the inclined surface of the tapered section, and seal the bottom surface of the inclined beam with a template;

[0125] S313: After fixing the pads on the upper layer of steel bars, install the tapered section inclined side formwork. The formwork is reinforced by tie rods. One end of the tie rod is welded to the bottom layer of steel bars, and the other end is fixed with a butterfly buckle through the tail nut. The butterfly buckle hooks two steel pipes as the main beam and presses down the timber above the formwork as the secondary beam.

[0126] S314: Construct the base plate and the inclined side of the cone section. After the base plate is completed, the pouring speed of the inclined side should be slowed down to ensure that the top surface of the base plate does not slurry up.

[0127] S315: Construction of the inclined beam supporting the bottom of the inner cylinder;

[0128] S316: Construction of the ring beam at the bottom of the inner cylinder.

[0129] In this embodiment of the invention, step S320 further includes:

[0130] S321: Erect the slab support frame for the vortex well according to the construction plan. This frame serves two purposes: it acts as a support frame for the slab formwork and as scaffolding for the construction of the central straight section. The frame is arranged in a ring between the inner and outer cylinders of the vortex well. The uprights of the frame resting on the inclined surface can be fixed by pre-embedded steel bars or by welding pre-embedded steel plates.

[0131] S322: Connect the vertical reinforcing bars with straight threaded sleeves, then tie the horizontal reinforcing bars to the vertical reinforcing bars. After fixing the concrete pads on the outside of the reinforcing bars, install the formwork. The formwork is reinforced by tie rods. The nuts and butterfly buckles at the tail of the tie rods hold the wooden blocks and steel pipes that reinforce the formwork. The other end of the tie rod is screwed into the sleeve that is pre-welded to the inside of the steel sleeve. This sleeve has internal threads and is matched with the tie rod.

[0132] S323: As in S311, after installing a water-stop steel plate at the construction joint of the top well wall of the steel casing, concrete is poured for the outer wall of the vortex well.

[0133] S324: The protective steel cylinder on the inner wall of the inner cylinder is hoisted onto the bottom ring beam of the inner cylinder;

[0134] S325: Connect the vertical steel bars of the inner cylinder of the vortex well with a straight threaded sleeve, then tie the horizontal steel bars to the vertical steel bars, fix the concrete pads on the outside of the steel bars, and then install the formwork. The formwork is reinforced by tie rods. The nuts and butterfly buckles at the tail of the tie rods hold the wooden blocks and steel pipes that reinforce the formwork. The other end of the tie rod is screwed into the sleeve that is pre-welded to the inside of the protective steel cylinder. This sleeve has internal threads and is matched with the tie rod.

[0135] S326: Concrete pouring for the inner wall of the vortex well.

[0136] In this embodiment of the invention, step S330 further includes:

[0137] S331 erected double-row scaffolding along the outer wall of the outer cylinder on the operating platform, while the scaffolding inside the vortex well was simultaneously erected and raised to serve as scaffolding for the construction of the upper straight cylinder section structure.

[0138] S332 connects the vertical steel bars with straight threaded sleeves, then ties the horizontal steel bars to the vertical steel bars, fixes the concrete pads on the outside of the steel bars, and then installs the formwork. The formwork is reinforced by tie rods, which pass through the cylinder wall and the inner and outer layers of the formwork. The formwork is reinforced by tie rods and nuts at both ends.

[0139] S333 outer cylinder upper straight section concrete pouring;

[0140] The protective steel cylinder for the inner wall of the S334 cyclone well is prefabricated and installed in sections as in steps S112 and S113. The construction of the upper straight section of the inner cylinder is the same as in S325.

[0141] In this embodiment of the invention, step S340 further includes:

[0142] S341: The scaffolding outside the upper straight section of the vortex well is removed, and the earthwork is backfilled and compacted to below the top plate of the vortex well.

[0143] S342: After the top plate formwork support frame between the inner and outer cylinders of the vortex well is erected to the predetermined height, the bottom formwork of the top plate of the vortex well is installed. Then the top plate reinforcement is installed. The concrete pad is fixed below the bottom layer of reinforcement to ensure the thickness of the reinforcement protective layer. The reinforcement stirrups are installed between the double layers of reinforcement in the top plate to ensure the spacing of the reinforcement. After the pre-embedded pipelines and iron parts are installed, the top plate concrete is poured.

[0144] S343: Remove the side formwork of the top slab and backfill and compact the earthwork to the design elevation.

[0145] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A vortex well construction system based on steel casing support, characterized in that, include: The foundation pit unit (1) consists of an upper foundation pit (110), a lower foundation pit (120) and a bottom foundation pit (130), and an upper straight section outer cylinder construction unit (2), a middle straight section outer cylinder construction unit (3) and a conical section construction unit (4) respectively arranged in the upper foundation pit (110), the lower foundation pit (120) and the bottom foundation pit (130), an inner cylinder construction unit (5) arranged longitudinally at the center of the foundation pit unit (1), a top plate construction unit (6) arranged between the outer cylinder construction unit and the inner cylinder construction unit (5), a dewatering well construction unit (7) opened around the foundation pit unit (1), and a top water-cutting slope (8) set at the intersection of the first slope (112) and the ground (111); the horizontal height of the top water-cutting slope (8) is higher than the ground plane; The middle straight section outer cylinder construction unit (3) includes a steel casing outer formwork assembly (310) that settles inside the lower foundation pit (120), an inner formwork (330) that is parallel to the inner side of the steel casing outer formwork assembly (310) and is relatively fixed to it by the formwork tie assembly (320), a cylinder wall reinforcement assembly (340) that is set between the steel casing outer formwork assembly (310) and the inner formwork (330), and a concrete layer poured between the steel casing outer formwork assembly (310) and the inner formwork (330); The cylinder wall reinforcement assembly (340) includes an inner layer of reinforcement (341) and an outer layer of reinforcement (342) arranged in parallel with each other. The outer formwork assembly (310) of the steel casing includes: a steel casing (311), a steel casing docking unit (316) for coaxial vertical splicing of steel casing (311) segments, a structural reinforcement component (312) fixedly installed on the inner wall of the steel casing (311), a flexible foot (313) added to the lower end face of the bottom steel casing (311) segment to assist in penetration into the soil and sinking, a steel casing anti-sinking component (314) installed on the upper end face of the top steel casing (311) segment, and a leveling ruler (315) engraved on the outer surface of the steel casing (311) for assisting in leveling during the sinking stage. The steel casing docking unit (316) includes a bevel on the top and bottom faces of the steel casing (311) and guide plates (3161) on both sides of the top of the steel casing (311); the top height of the guide plates (3161) is higher than the upper end of the bevel, and the two guide plates (3161) form a top latch (3163) that engages with the bevel. The template pull assembly (320) includes: a pre-set sleeve (321) fixed in a two-dimensional equidistant array along the horizontal and vertical directions on the inner wall of the steel casing (311); a pull rod (322) threadedly connected to the pre-set sleeve (321); a butterfly buckle (323) installed on the pull rod (322) and used to prevent the template from disengaging; and a fastening nut (234) installed behind the butterfly buckle (323); the pre-set sleeve (321) includes a sleeve body (3312) and a threaded hole (3311) opened in the sleeve body (3312) perpendicular to the inner wall surface of the steel casing (311), the threaded hole (3311) having a depth greater than five centimeters.

2. The vortex well construction system based on steel casing support according to claim 1, characterized in that, The structural reinforcement component (312) includes: The annular reinforcing beam (3121) and the vertical stiffening plate (3122) are fixedly installed on the inner wall of the steel casing (311), and the annular reinforcing beam (3121) and the vertical stiffening plate (3122) are kept perpendicular to each other.

3. The vortex well construction system based on steel casing support according to claim 2, characterized in that, The structural reinforcement component (312) includes: The annular reinforcing beam (3124) is fixed inside the annular reinforcing beam (3121) by the first fixed crossbeam (3123).

4. The vortex well construction system based on steel casing support according to claim 3, characterized in that, The steel casing anti-sinking assembly (314) includes: The supporting ear plate (3141) is fixed to the operating platform (113), and the second fixed crossbeam (3142) is added to the outer side of the upper end of the top steel casing (311) section; the lower surface of the second fixed crossbeam (3142) abuts against the upper surface of the supporting ear plate (3141).

5. A vortex well construction system based on steel casing support according to claim 4, characterized in that, The inner layer of reinforcing bars (341) is placed between the inner formwork (330) and the annular reinforcing beam (3124); The outer reinforcing bar (342) is located between the annular reinforcing beam (3121) and the annular strengthening beam (3124).

6. A construction method applied to the vortex well construction system based on steel casing support as described in claim 5, characterized in that, Includes the following steps: S100: Preparatory work before excavation of the vortex well: S110: Prefabrication of steel casing, which is segmented and fabricated according to the total height and structural characteristics of the steel casing, and welded into a whole during the installation of the steel casing; S120: Measurement and layout according to the design drawings and approved construction plan to determine the position of dewatering wells and the excavation boundary line of the foundation pit; S130: Determine the position, quantity and depth of dewatering wells according to the engineering geological survey report, construct dewatering wells according to the measurement and positioning, and carry out dewatering and drainage construction according to the actual groundwater conditions; S200: Earthwork excavation and steel casing support construction; S210: Upper layer earthwork excavation and support; S220: Steel casing support structure sinking construction; S230: Bottom cone section earthwork excavation and cushion layer pouring; S300: Construction of vortex well structure; S310: Construction of bottom conical section structure; S320: Construction of middle straight section; S330: Construction of upper straight section; S340: Construction of top plate.

7. The construction method of a vortex well construction system based on steel casing support according to claim 6, characterized in that, Step S210 further includes: S211: According to the required soil unloading depth and appropriate slope ratio in the construction plan, the upper soil layer is excavated by slope. During excavation, a two-meter operating platform is reserved from the toe of the slope to the outside of the steel casing. When excavating, the soil is excavated in layers from the middle to the surrounding area, with each layer not exceeding 1 meter in depth. The slope is repaired while excavating. S212: After the upper layer of earthwork is excavated and transported, steel mesh is added to the slope and shotcrete is sprayed for slope protection. When installing the steel mesh, threaded steel bars are nailed vertically into the slope surface for fixation. S213: After the upper layer of earthwork is excavated, a guardrail and a water-cutting slope shall be set at the top of the slope. The width of the water-cutting slope shall be 0.5 to 1 meter and the height shall be 0.2 to 0.5 meters. Its slope direction shall be from the top of the slope outward. The water-cutting slope shall be used to block the water on the ground to prevent water from eroding the slope and pouring into the foundation pit. S214: After the upper earthwork slope support is completed, two safety passages from the top of the slope to the bottom of the slope should be set up. A 300mm deep circular drainage ditch should be set up at the bottom of the slope and two water collection wells should be set up to facilitate the drainage of water by water pumps. The water collection wells should be set up near the safety passages for easy pumping operations.

8. The construction method of a vortex well construction system based on steel casing support according to claim 7, characterized in that, Step S220 further includes: S221: Apply a release agent to the outer wall of the steel casing to facilitate sinking. Mark the four directions on the outside of the steel casing with red paint at 0.5-meter intervals from top to bottom to facilitate observation during the leveling process of the steel casing. S222: Continue excavating downwards along the positioning line of the steel casing, extending 0.5 meters outwards and 1.5 meters inwards, to form a 2-meter wide and 1-meter deep annular trench; S223: After hoisting the first section of the steel casing to the preset position, backfill and compact the annular groove on the outer side of the steel casing, and harden the operating platform with concrete. S224: Use a long-arm excavator to excavate the soil inside the casing, excavating slowly from the center outwards. During the excavation process, the construction machinery must maintain a reasonable and safe distance from the edge of the foundation pit and the steel casing to avoid lateral pressure on the foundation pit and prevent the steel casing from deforming due to soil pressure. Strictly control the depth of the soil excavation inside the casing, with each layer of excavated soil controlled within 50 cm, and the excavator arm and bucket must not touch the steel casing. S225: When the earthwork is excavated to the bottom of the steel casing, the entire circumference of the soil is excavated symmetrically. When the soil layer cannot withstand the pressure of the steel casing and breaks, the steel casing will be squeezed and sink under its own weight. S226: During the earthwork excavation process near the steel casing, if the steel casing can sink on its own, the sinking amount of the steel casing should be controlled to ensure that the steel casing sinks smoothly. If the steel casing cannot sink on its own, the following measures should be taken:

1. Gradually excavate the soil under the steel casing to reduce the sinking resistance; 2. Apply additional loads using machinery to assist the steel casing in sinking; 3. Inject thixotropic mud between the outer wall of the steel casing and the soil and pour in an appropriate amount of water to reduce frictional resistance; 4. To reduce frictional resistance during the sinking process of the steel casing, apply a release agent to the surface of the steel casing. S227: When the lower section of the steel casing sinks to a distance of 1.5 meters from the top of the operating platform, stop excavation, hoist the upper section of the steel casing into place, and weld it to the lower section of the steel casing on the operating platform according to the technical requirements. The outer surface of the weld should be ground smooth. S228: Correction measures during the sinking of steel casing: Inclination: Strengthen soil removal on the higher side and reduce or eliminate soil removal on the lower side. After the casing is aligned, remove soil evenly in layers. Backfill with sand and gravel on the lower side to slow down the sinking speed. Deeply excavate the soil on the opposite side of the inclination outside the steel casing to reduce the sinking friction on the higher side. Use machinery or counterweights to apply external force to correct the inclination on the higher side. Deviation: Control the steel casing to prevent it from tilting in the direction of deviation. Intentionally tilt the steel casing in the opposite direction of deviation. It can be restored to the correct position through several tilt corrections. S229: Use a long-arm excavator to excavate the soil inside the casing and continue to sink the steel casing to the preset position. Then, weld an I-beam horizontally at every 90 degrees on the upper end of the steel casing. Weld a steel plate under the I-beam horizontally to support it on the circular operating platform to prevent accidental sinking during subsequent construction of the vortex pool. S2210: Install a steel ladder with a protective cage inside the steel casing to facilitate personnel going up and down.

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