Steel sump for basement and installation construction method thereof

Abstract

The application discloses a steel water collecting well for a basement and a mounting construction method thereof, and relates to the technical field of prefabricated water collecting wells for basements. The steel water collecting well comprises: an annular well shaft body which is formed by welding a rolled steel plate; a circular steel bottom plate which is welded to the bottom of the annular well shaft body; an annular outer stiffening rib which is fixed to the outer sidewall of the annular well shaft body; two expansion rubber waterstop strips which are pasted to the outer sidewall of the upper end of the annular well shaft body through structural adhesive; and an anti-corrosion composite layer which covers the inner and outer surfaces of the annular well shaft body and the surface of the circular steel bottom plate. A water collecting well pit is formed by artificial hole digging, a circular artificial hole digging retaining wall is arranged, and low-density extruded plates are laid at the bottom of the pit. The steel water collecting well is hoisted and positioned. Graded sand and gravel is used to fill the gaps between the retaining walls. A reinforced ring beam is arranged at the opening of the reinforced concrete raft slab, and the steel water collecting well is fixedly connected with the reinforced concrete raft slab. The application has the advantages of small pit excavation depth, small earthwork volume, fast construction speed, good airtightness, excellent durability and the like.

Description

Technical Field

[0001] This invention relates to the field of prefabricated water collection wells for basements, and more specifically, to a steel water collection well for basements and its installation method. Background Technology

[0002] As a key structure in the basement drainage system, the sump pit is mainly used to collect seepage or accumulated water in the elevator pit and basement, and then drain the water through drainage equipment installed in the pit. Traditional sump pits for basements are generally made of reinforced concrete, which has problems such as large excavation depth, large amount of earthwork excavation, high construction difficulty, long construction period, quality being greatly affected by human and environmental factors, and high cost.

[0003] With the development of modular and prefabricated technologies, prefabricated sump pits are increasingly being used in municipal engineering. These pits utilize standardized factory-produced components, which are then assembled on-site, offering advantages such as rapid construction, controllable quality, good overall structural integrity, and significantly improved corrosion resistance through coating or plating of the steel. Currently, the technology in this field focuses primarily on optimizing the structural form of pits in municipal engineering, the sealing design of connection nodes, and improvements in anti-corrosion processes. However, in the practical application of basement sump pit construction projects involving complex rock and soil geology, hydrogeology, and high durability requirements, there is still a lack of prefabricated sump pits that are easy to construct, have a fast construction period, are economical, and durable, along with their installation methods.

[0004] Therefore, this invention proposes a steel sump for basements and its installation method. Summary of the Invention

[0005] The purpose of this invention is to provide a steel sump for basements and its installation method, which solves the problems often encountered in the construction of traditional reinforced concrete sumps, such as large pit area and depth, large amount of earthwork excavation, high difficulty in dewatering, and high project cost.

[0006] To achieve the above-mentioned technical objectives, this invention discloses a steel water collection well and its installation and construction method.

[0007] This invention provides a steel sump for basements, comprising: An annular wellbore body, the annular wellbore body being prefabricated in a factory by welding rolled steel plates; A circular steel base plate, which is fixedly connected to the bottom of the annular well shaft by welding at the factory; At least one annular external stiffening rib, which is fixedly connected to the upper outer wall of the annular well body by welding at the factory; Two expansion rubber waterstop strips are attached to the upper outer wall of the annular well body with structural adhesive. And an anti-corrosion composite layer, which is applied to the inner and outer surfaces of the annular well shaft and the surface of the circular steel base plate during factory fabrication; The anti-corrosion composite layer includes an anti-rust paint layer coated on the inner and outer surfaces of the annular well shaft and the circular steel base plate, and a fiberglass layer wrapped around the outer wall of the annular well shaft and the outer side of the circular steel base plate.

[0008] Furthermore, the anti-rust paint layer comprises three layers of oil-based anti-rust primer and two layers of alkyd magnetic topcoat, which are sequentially applied to the inner and outer surfaces of the annular well shaft and the circular steel base plate. The total thickness of the anti-rust paint layer is not less than 0.18 mm, and the thickness of the fiberglass layer is 2 mm.

[0009] Furthermore, it also includes at least one annular inner stiffening rib, which is fixedly connected to the inner wall of the annular well body.

[0010] Furthermore, it also includes a connecting steel pipe, one end of which is welded to the side wall of the annular shaft body, and the other end of which is used to connect to the elevator pit.

[0011] Furthermore, the fiberglass layer is wrapped around the outer wall of the annular wellbore and the outer side of the circular steel base plate in areas that cannot be inspected or maintained after installation.

[0012] This invention also provides a method for installing a steel sump pit for basements, using the steel sump pit as described above, and includes the following steps: S1: A water collection well foundation pit is formed by manually excavating holes. A circular manually excavated retaining wall is set on the side wall of the water collection well foundation pit, and a layer of low-density extruded polystyrene board is laid at the bottom of the water collection well foundation pit. S2: The steel water collection well is hoisted and positioned within the water collection well pit; S3: The gap between the outer wall of the steel water collection well and the inner wall of the circular artificially excavated retaining wall is filled with graded sand and gravel. S4: A reinforcing ring beam is installed around the opening of the reinforced concrete raft slab, and the steel water collection well is fixedly connected to the reinforced concrete raft slab.

[0013] Furthermore, in step S2, when there is groundwater in the pit of the water collection well, water is poured into the steel water collection well to make the steel water collection well sink to the design elevation.

[0014] Furthermore, in step S4, the steel water collection well is fixedly connected to the reinforced concrete raft slab through its outer annular reinforcing ribs. The annular reinforcing ribs and the two expanding rubber waterstop strips together constitute the seepage prevention structure on the contact surface between the steel water collection well and the reinforced concrete raft slab.

[0015] Furthermore, in step S4, the reinforcing ring beam is provided with reinforcing steel bars, and the reinforcing ring beam is used to anchor the reinforcing steel bars in the reinforced concrete raft slab that are cut off due to the opening.

[0016] Furthermore, it also includes step S5: welding one end of the connecting steel pipe to the annular shaft of the steel water collection well, and connecting the other end of the connecting steel pipe to the elevator pit.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention, through various measures of prefabricated steel water collection wells and their installation and construction methods, greatly reduces the excavation range and depth of the foundation pit, reduces the difficulty of dewatering and drainage and the amount of earthwork, facilitates installation and construction, has a fast construction speed, and the water collection well has good sealing, strong integrity and excellent durability.

[0018] This invention features a simple structure, light weight, structural safety, good economy, high durability, easy installation and construction, and can be mass-produced. It is suitable for situations with short construction cycles and high requirements for the stability of the water collection well, and is particularly suitable for constructing and installing basement water collection wells in engineering geological environments with soft soil, high permeability, or difficulty in dewatering. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the steel water collection well structure of the present invention; Figure 2 This is a diagram illustrating the construction method of the steel water collection well pit bottom and its relationship with the foundation pit wall of the present invention; Figure 3 This is a schematic diagram of the hoisting and positioning of the steel water collection well of the present invention; Figure 4 This is a diagram illustrating the construction method of the reinforcing ring beam around the raft opening at the installation location of the steel water collection well in this invention. Figure 5 This is a schematic diagram showing the relationship after the steel water collection well of the present invention is installed.

[0020] The attached diagram is labeled as follows: 1. Annular shaft body; 2. Annular inner stiffening rib; 3. Annular outer stiffening rib; 4. Circular steel base plate; 5. Reinforced concrete raft slab; 6. Expanded rubber waterstop strip; 7. Circular manually excavated hole wall protection; 8. Wall protection gap; 9. Low-density extruded polystyrene board; 10. Reinforcing ring beam; 11. Elevator pit; 12. Connecting steel pipe; 15. Sump pit. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0022] Please see Figures 1 to 5 .

[0023] I. Factory Prefabrication of Steel Water Collection Wells like Figure 1 As shown in the figure, the main structure of the steel water collection well for basement provided in this embodiment is prefabricated in the factory.

[0024] First, rolled steel plates meeting design requirements are selected. The thickness of the steel plates is determined through structural calculations based on the depth, diameter, and groundwater pressure of the sump well. The steel plates are rolled into cylindrical shapes using a plate rolling machine. The butt welds are performed using submerged arc welding or carbon dioxide gas shielded welding to form the cylindrical annular well body 1. After the welds pass non-destructive testing, the weld joints are ground to make them flush with the base material.

[0025] Next, select steel plates of the same material and cut them into circles to serve as circular steel base plates 4. Align the circular steel base plates 4 with the bottom opening of the annular well body 1 and weld them using full penetration bevel welding to ensure that the weld between the base plate and the well body is tight and leak-free.

[0026] Next, at least one annular external stiffening rib 3 is welded circumferentially to the upper part of the outer wall of the annular well body 1. The annular external stiffening rib 3 is made of steel plate of the same material as the well body, cut into annular strips, and its width and thickness are determined according to the engineering design. Double-sided fillet welds are used during welding, and the weld height is not less than 0.7 times the thickness of the thinner part to ensure that the annular external stiffening rib 3 is firmly connected to the annular well body 1.

[0027] Furthermore, depending on the stress requirements, at least one annular inner stiffening rib 2 can be welded vertically to the inner wall of the annular well body 1. The location and number of the annular inner stiffening ribs 2 are determined according to the height, diameter and stress conditions of the well body, and are used to enhance the lateral pressure resistance of the well body.

[0028] Secondly, an opening is reserved on the side wall of the annular shaft body 1, and the position of the opening corresponds to the plane position of the elevator pit 11.

[0029] Finally, anti-corrosion treatment is carried out. The inner and outer surfaces of the annular well shaft 1 and the circular steel base plate 4 are derusted. After derusting, the surfaces should be free of visible grease, dirt, scale, rust, paint coatings, and other attachments.

[0030] After rust removal, painting should begin within 2 hours: First, apply three coats of oil-based anti-rust primer, with an interval of at least 4 hours between each coat. Each coat should be fully dry before applying the next. The total dry film thickness of the three primer coats should be no less than 0.12mm. Then, apply two coats of milky white alkyd topcoat, with an interval of at least 6 hours between each coat. The total dry film thickness of the two topcoats should be no less than 0.06mm. The total thickness of the anti-rust paint layer should be no less than 0.18mm. For the outer wall of the annular well shaft 1 and the outer side of the circular steel base plate 4, where inspection and maintenance are not possible after installation, a 2mm thick layer of fiberglass should be wrapped around the area after the anti-rust paint layer has fully dried.

[0031] After the prefabricated steel water collection wells pass inspection, they are transported to the construction site for use.

[0032] II. Construction of the installation pit like Figure 2 As shown, at the construction site, the first step is to lay out the lines according to the design drawings to determine the installation location of the steel water collection well.

[0033] The water collection well foundation pit 15 is formed by manual excavation. The specific operation of manual excavation is as follows: a circular hole with a diameter slightly larger than the outer diameter of the steel water collection well is excavated along the center line of the well location. A circular manual excavation retaining wall 7 is constructed after each certain depth of excavation. The function of the circular manual excavation retaining wall 7 is to prevent the hole wall from collapsing, ensure the safety of construction personnel, and provide a stable hole wall for the subsequent installation of the steel water collection well.

[0034] Manual excavation continues until the design elevation is reached. The principle for determining the design elevation is: after the steel sump is installed, its top elevation is the same as or slightly lower than the top surface elevation of the reinforced concrete raft slab 5, which facilitates the installation of the manhole cover and surface drainage.

[0035] After the excavation of the sump pit 15 is completed, the bottom of the pit is leveled, and loose soil and debris are removed. Then, a layer of low-density extruded polystyrene (XPS) board 9 is laid at the bottom of the pit. The XPS board 9 should cover the entire surface of the pit bottom, and the boards should be tightly joined together without gaps. The low-density XPS board 9 has compressive deformation properties. When the bottom of the steel sump pit is subjected to soil pressure, the XPS board will undergo compressive deformation, which will evenly distribute the concentrated pressure to the foundation at the bottom of the pit, thereby reducing the local stress acting on the bottom of the steel sump pit.

[0036] III. Hoisting and Positioning of the Steel Water Collection Well like Figure 3 As shown, after the steel water collection well is transported to the site, it is hoisted into place using a tower crane or truck crane commonly used on construction sites.

[0037] Before hoisting, two expansion rubber waterstop strips 6 are adhered to the outer wall of the upper end of the annular well body 1 of the steel sump using structural adhesive. The structural adhesive is an epoxy resin-based building structural adhesive, mixed according to the ratio specified in the product instructions, and evenly applied to the adhesion area on the outer wall of the upper end of the annular well body 1. Then, the expansion rubber waterstop strips 6 are tightly adhered circumferentially, and gently tapped with a rubber hammer to ensure a tight fit with the well body. The two expansion rubber waterstop strips 6 are spaced apart vertically.

[0038] During hoisting, use appropriate slings and hooks to lift the steel sump smoothly and lower it slowly into the sump pit 15. During lowering, keep the sump vertical and avoid colliding with the circular manually excavated wall 7. When the bottom of the steel sump is close to the bottom of the pit, pause lowering and adjust the sump position so that its center is aligned with the center of the sump pit 15.

[0039] For cases where groundwater exists within the sump pit 15, this embodiment employs the "water-filled caisson" method. The specific operation is as follows: When the steel sump is lowered above the groundwater level, clean water is poured into it. The well's own weight overcomes the buoyancy of the groundwater, causing the well to slowly sink. As the water level rises, the well gradually sinks until it reaches the designed elevation. During the sinking process, the well must be kept vertical to avoid tilting. After the well is in place, the accumulated water is pumped out and the bottom of the well is cleaned.

[0040] A steel pipe matching the pre-drilled hole diameter is selected as the connecting steel pipe 12. One end of the connecting steel pipe 12 is aligned with the pre-drilled hole on the side wall of the annular shaft body 1 and fixedly connected using intersecting welding. During intersecting welding, a bevel bevel matching the curved surface of the shaft body is first opened at the end of the steel pipe, and then all-position welding is performed to ensure a full weld without leakage. Any areas of anti-corrosion coating damaged during on-site welding are repaired. The other end of the connecting steel pipe 12 is left to be connected to the elevator pit 11 on-site.

[0041] IV. Filling the gaps in the protective wall like Figure 2 As shown, after the steel water collection well is in place, a circumferential wall gap 8 is formed between its outer wall and the inner wall of the circular artificially excavated retaining wall 7, and graded sand and gravel is used to fill the wall gap 8.

[0042] Graded aggregate is made by mixing natural sand and crushed stone according to a certain gradation. Before filling, the moisture content of the graded aggregate is adjusted to be near the optimum moisture content.

[0043] During filling, a layered filling and compaction method should be adopted. After each layer is filled, an immersion vibrator or a wall-mounted vibrator should be used for compaction, with no less than 3 compaction passes, until the surface no longer settles. During the filling process, it should be carried out evenly and symmetrically to avoid lateral compression of the well body that could lead to displacement.

[0044] After being filled to the design elevation, the gap 8 of the retaining wall is filled with dense graded sand and gravel. This backfill layer not only serves to fix the position of the steel water collection well, but also makes the lateral earth pressure on the well body uniform and symmetrical.

[0045] V. Treatment of openings in reinforced concrete raft foundations and fixing of sump wells like Figure 4 and Figure 5 As shown, during the construction of the reinforced concrete raft slab 5 in the basement, an opening is reserved at the installation location of the steel sump. The diameter of the opening is slightly larger than the outer diameter of the steel sump to facilitate the passage of the sump.

[0046] A reinforcing ring beam 10 is installed around the opening. The reinforcing ring beam 10 is a reinforced concrete structure surrounding the opening, and its cross-sectional dimensions and reinforcement are determined according to the engineering design. The specific construction method is as follows: During the reinforcement binding process of the reinforced concrete raft slab 5, circumferential reinforcing bars and radial stirrups are arranged around the opening to form a closed ring skeleton. The specifications and quantity of the circumferential reinforcing bars match the cut reinforcing bars of the reinforced concrete raft slab 5, and the radial stirrups are set at certain intervals. The concrete of the reinforcing ring beam 10 is poured together with the concrete of the reinforced concrete raft slab 5.

[0047] The function of strengthening the ring beam 10 is to compensate for the loss of load-bearing capacity of the reinforced concrete raft slab 5 due to the opening, to strengthen the stress concentration area around the opening, and at the same time to provide a solid installation foundation for the steel sump well.

[0048] The steel sump and the reinforced concrete raft slab 5 are fixedly connected by annular external stiffening ribs 3. During the pouring of the reinforced concrete raft slab 5, the annular external stiffening ribs 3 at the upper end of the steel sump are embedded into the concrete, forming an anchor. The annular external stiffening ribs 3 act as mechanical anchors between the steel sump and the concrete, firmly connecting the sump and the reinforced concrete raft slab 5 as a single unit.

[0049] Meanwhile, two expanding rubber waterstop strips 6, attached to the outer wall of the upper end of the annular well body 1, are in close contact with the concrete of the reinforced concrete raft slab 5. After the concrete is poured, the expanding rubber waterstop strips 6 expand upon contact with water, filling the tiny gaps between the well body and the concrete, forming a reliable seepage-proof seal. The annular external stiffening ribs 3 and the two expanding rubber waterstop strips 6 together constitute the seepage-proof structure on the contact surface between the steel sump and the reinforced concrete raft slab 5. The annular external stiffening ribs 3 provide mechanical fixation, while the expanding rubber waterstop strips 6 provide a water-expanding seal; the two work together to ensure that the contact surface is leak-proof.

[0050] VI. Connection of connecting pipes like Figure 4As shown, a connection opening is reserved on the side wall of the annular well body 1 of the steel water collection well, and the connection is made on site to the port of the connecting steel pipe 12.

[0051] The other end of the connecting steel pipe 12 is embedded in the elevator pit during the on-site pouring of the side wall concrete of the elevator pit 11. The horizontal section of the connecting steel pipe 12 should be sloped towards the steel sump well to ensure that the water in the elevator pit 11 can flow into the sump well by gravity.

[0052] VII. Manhole Cover Installation and Post-Installation Maintenance The cover of a sump drain is similar to those of other circular sump drains or inspection wells and can be determined by the engineering design team. The cover is typically made of cast iron or composite materials and is installed flush with the basement floor for easy routine inspection and maintenance.

[0053] Since the outer walls of the steel sump and the outer side of the circular steel base plate cannot be inspected and maintained after installation, this embodiment has reinforced the anti-corrosion treatment of these parts during factory prefabrication, namely, wrapping them with 2mm thick fiberglass. Fiberglass has excellent corrosion resistance and anti-aging properties, and can remain intact for a long time in underground high-humidity and high-corrosion environments, ensuring the service life of the steel sump.

[0054] Compared with traditional reinforced concrete water collection wells, the steel water collection well and its installation method described in this embodiment have the following advantages: Small excavation depth: The depth of traditional reinforced concrete sump pits usually reaches the depth of the well plus the thickness of the bottom slab plus the thickness of the cushion layer. However, the steel sump pit in this embodiment is directly sunk into the sump pit 15, without the need for an additional bottom slab and cushion layer, thus significantly reducing the depth of the pit.

[0055] Less earthwork excavation: Due to the reduced depth of the sump pit and the use of manual excavation, there is no need for large-scale slope excavation, resulting in a significant reduction in earthwork excavation compared to traditional methods.

[0056] Fast construction speed: Steel sump wells are prefabricated in the factory, and only hoisting, filling and fixing are required on site, which shortens the installation time. In contrast, traditional reinforced concrete sump wells require a longer time for on-site formwork, steel bar binding, concrete pouring and curing.

[0057] Good sealing performance: The steel water collection well adopts a fully welded structure, and the well body itself is leak-free; the double anti-seepage structure of the annular external stiffening rib 3 and the expansion rubber waterstop strip 6 ensures that the contact surface between the well body and the reinforced concrete raft slab 5 is leak-free.

[0058] Excellent durability: The inner and outer surfaces of the steel water collection well are coated with anti-rust paint, and the outside is wrapped with fiberglass to form a double layer of anti-corrosion protection, which can adapt to harsh geological environments such as soft soil, high permeability, and high corrosion.

[0059] In summary, the steel sump for basement and its installation method provided in this embodiment have the advantages of structural safety, reasonable construction, convenient construction, and excellent technical and economic performance. They are particularly suitable for constructing and installing basement sumps in engineering geological environments with soft soil, high permeability, or high difficulty in dewatering.

[0060] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A steel sump for basement water collection, characterized in that, include: An annular wellbore (1) is formed in a factory by welding rolled steel plates; A circular steel base plate (4) is fixedly connected to the bottom of the annular well body (1) by welding; At least one annular external stiffening rib (3) is fixedly connected to the upper outer wall of the annular well body (1); Two expansion rubber waterstop strips (6) are attached to the upper outer wall of the annular well body (1) by structural adhesive. And an anti-corrosion composite layer, which covers the inner and outer surfaces of the annular well body (1) and the surface of the circular steel base plate (4); The anti-corrosion composite layer includes an anti-rust paint layer coated on the inner and outer surfaces of the annular well body (1) and the circular steel base plate (4), and a fiberglass layer wrapped around the outer wall of the annular well body (1) and the outer side of the circular steel base plate (4).

2. The steel sump for basement water collection as described in claim 1, characterized in that, The anti-rust paint layer includes three layers of oil-based anti-rust primer and two layers of alkyd magnetic topcoat applied sequentially to the inner and outer surfaces of the annular well body (1) and the circular steel base plate (4). The total thickness of the anti-rust paint layer is not less than 0.18 mm, and the thickness of the fiberglass layer is 2 mm.

3. The steel sump for basement water collection as described in claim 1, characterized in that, It also includes at least one annular inner stiffening rib (2), which is fixedly connected to the inner wall of the annular well body (1).

4. The steel sump for basement water collection as described in claim 1, characterized in that, It also includes a connecting steel pipe (12), one end of which is welded to the side wall of the annular shaft body (1), and the other end of which is used to connect to the elevator pit (11).

5. A method for installing a steel sump pit in a basement, characterized in that, The steel water collection well as described in any one of claims 1 to 4 includes the following steps: S1: A water collection well foundation pit (15) is formed by manual excavation construction method. A circular manual excavation retaining wall (7) is set on the side wall of the water collection well foundation pit (15), and a layer of low-density extruded polystyrene board (9) is laid at the bottom of the water collection well foundation pit (15). S2: The steel water collection well is hoisted and positioned inside the water collection well pit (15); S3: Use graded sand and gravel to fill the gap (8) between the outer wall of the steel water collection well and the inner wall of the circular artificial hole protective wall (7); S4: A reinforcing ring beam (10) is set around the opening of the reinforced concrete raft slab (5), and the steel water collection well is fixedly connected to the reinforced concrete raft slab (5).

6. The installation and construction method according to claim 5, characterized in that, In step S2, when there is groundwater in the water collection well pit (15), water is poured into the steel water collection well so that the steel water collection well sinks to the design elevation.

7. The installation and construction method according to claim 5, characterized in that, In step S4, the steel water collection well is fixedly connected to the reinforced concrete raft slab (5) through the annular external stiffening rib (3) on its outer side. The annular external stiffening rib (3) and the two expansion rubber waterstop strips (6) together constitute the seepage prevention structure on the contact surface between the steel water collection well and the reinforced concrete raft slab (5).

8. The installation and construction method according to claim 5, characterized in that, In step S4, the reinforcing ring beam (10) is provided with reinforcing steel bars, and the reinforcing ring beam (10) is used to anchor the reinforcing steel bars cut off due to the opening in the reinforced concrete raft slab (5).

9. The installation and construction method according to claim 5, characterized in that, It also includes step S5: welding one end of the connecting steel pipe (12) to the annular well body (1) of the steel water collection well, and connecting the other end of the connecting steel pipe (12) to the elevator pit (11).

10. The steel sump for basement water collection well according to claim 1, characterized in that, The fiberglass layer is wrapped around the outer wall of the annular well body (1) and the outer side of the circular steel base plate (4) in areas that cannot be inspected or maintained after installation.

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