Construction method of integrated prefabricated pump station

Abstract

The application relates to the field of underground pump station construction and provides a construction method of an integrated prefabricated pump station, which comprises the following steps: prefabricating a well cylinder in a factory, connecting a jacking assembly at the bottom of the cylinder, forming an accommodating space by surrounding the downward extension section of the cylinder wall beyond the cylinder bottom with the cylinder bottom, arranging the jacking assembly in the space, arranging a concrete pouring hole and a vibrating and venting hole close to the cylinder bottom on the extension section; hoisting the well cylinder to the preliminary support of a foundation pit; controlling the extension and retraction of the jacking assembly outside the foundation pit, adjusting the posture and lifting of the well cylinder to align the water inlet flange with the water inlet pipeline; after butt joint, pouring concrete into the accommodating space through the pouring hole to fill and bury the jacking assembly, and vibrating through the vibrating and venting hole; after pouring, the layered backfilling can be carried out without waiting for the hardening of the concrete. The application realizes the accurate butt joint of the flange in the limited space, reduces the safety risk, shortens the construction period and enhances the structural stability.

Description

Technical Field

[0001] This application relates to the field of integrated prefabricated pumping station technology, and in particular to a construction method for an integrated prefabricated pumping station. Background Technology

[0002] Underground pumping stations are engineering facilities that bury pump units, pipeline systems, and control equipment entirely underground. They are primarily used to solve urban drainage, water supply boosting, and flood control problems, and are often referred to as the "underground heart" of the urban drainage system. Underground pumping stations use pumps to perform work on water, converting electrical energy into potential energy, enabling sewage or rainwater to overcome terrain differences and be lifted from lower to higher elevations or transported to sewage treatment plants and receiving water bodies. Their core function is to ensure continuous flow in the pipeline network when gravity flow fails (such as in low-lying areas or when crossing obstacles), preventing sewage overflow or road flooding. Based on their purpose, they can be classified into drainage pumping stations, water supply pumping stations (also known as intake pumping stations), and rainwater pumping stations.

[0003] Currently, underground pumping stations are mainly divided into two types: traditional concrete structures and buried integrated prefabricated pumping stations. Buried integrated pumping stations use factory-prefabricated fiberglass (GRP) cylinders, which are entirely buried underground, with only inspection holes remaining on the surface. They have advantages such as small footprint (only 1 / 5 to 1 / 3 of traditional pumping stations), short construction period (3-7 days), strong corrosion resistance (lifespan of over 30 years), and fully automated unattended operation. Traditional concrete pumping stations are constructed on-site, with a long construction period and a large footprint.

[0004] Current underground integrated pumping stations require excavation of a foundation pit before construction, followed by the placement of a prefabricated integrated well casing into the pit. Existing integrated pumping station construction technology has significant shortcomings when dealing with confined space conditions. Precise alignment of the well casing's inlet flange with the pre-installed piping relies heavily on manual visual alignment and fine-tuning. For large integrated pumping stations, the severely limited field of vision and cramped personnel access and operating space within confined spaces lead to extremely low efficiency and high error rates in manual alignment, resulting in long installation cycles. Furthermore, the overlapping work of multiple personnel in confined spaces and the resulting communication delays due to obstructed vision greatly increase the risk of accidents such as crushing and falls. In addition, the connection process requires sufficient operating space for construction personnel, necessitating a large foundation pit area, thus reducing the feasibility of integrated pumping stations in confined spaces. Summary of the Invention

[0005] To address the problems of low efficiency, high safety risks, and large pit area caused by manual flange connection in confined spaces in existing technologies, this application proposes an integrated prefabricated pump station construction method. This method utilizes a factory-prefabricated well shaft with jacking components, and remotely controls the jacking and leveling outside the pit to achieve precise flange connection and bottom concrete pouring and fixing, thus realizing safe, efficient, and high-precision pump station installation.

[0006] To achieve the above objectives, this application adopts the following technical solution: A construction method for an integrated prefabricated pumping station includes the following steps: S100, prefabricating a shaft in a factory; a lifting assembly is connected to the bottom of the shaft; the shaft wall has a downward extension section extending beyond the bottom, the downward extension section and the bottom of the shaft enclosing a receiving space, and the lifting assembly is arranged in the receiving space; the downward extension section is provided with a concrete pouring hole and a vibration venting hole, both of which are connected to the receiving space and are located close to the bottom of the shaft; S200, hoisting the shaft into the foundation pit, the shaft being initially supported in the foundation pit by the downward extension section; S300, outside the foundation pit, via wired... Alternatively, the jacking assembly can be wirelessly controlled to extend and retract, adjusting the wellbore's posture and elevation within the pit to align the wellbore's inlet flange with the water inlet pipe outside the pit; S400, after the wellbore's inlet flange is aligned with the water inlet pipe outside the pit, concrete is poured into the space formed by the downward extension of the concrete pouring hole and the bottom of the wellbore, completely filling the space, with the jacking assembly embedded in the concrete; a vibrator is inserted into the space through the vibration venting hole to vibrate the concrete; S500, after pouring concrete into the space, the pit can be backfilled in layers without waiting for the concrete to harden.

[0007] The above solution integrates the lifting components into the containment space at the bottom of the well during factory prefabrication. The lifting components are remotely controlled from outside the pit to adjust the posture of the well. This replaces the manual alignment and fine-tuning required in the confined space, achieving precise flange connection and eliminating the safety hazards of personnel operating in the pit. At the same time, concrete is poured into the containment space through the pouring holes and vibration venting holes located near the bottom of the well to embed the lifting components, transforming them into a permanent support structure. Backfilling can be done without waiting for the concrete to harden, significantly shortening the construction cycle.

[0008] In one implementation, step S200 further includes: setting a groove at the bottom of the pit that is compatible with the downward extension section; inserting the downward extension section into the groove and initially supporting it on the bottom of the groove.

[0009] The above solution uses the groove to seal the bottom periphery of the downward extension section, which is equivalent to a cofferdam. This prevents the concrete in the containment space from flowing out of the groove from the bottom of the downward extension section, thus eliminating the need for additional sealing formwork during concrete pouring and simplifying the construction process.

[0010] In one implementation, step S100 further includes: a plurality of anti-buoyancy legs are connected to the bottom of the cylinder bottom, and the anti-buoyancy legs are distributed in the receiving space; step S200 further includes: the well cylinder is supported on the bottom of the groove by the combined action of the downward extension section and the anti-buoyancy legs; step S400 further includes: the anti-buoyancy legs are embedded in the concrete in the receiving space.

[0011] The above solution improves the placement stability of the wellbore in its initial lowering state by using anti-buoyancy outriggers and downward extension sections for joint support. Furthermore, the anti-buoyancy outriggers can be tightly interlocked with the concrete foundation after being embedded in the concrete, which greatly enhances the overall anti-buoyancy capability and structural stability of the pump station.

[0012] As one implementation method, the following steps are also included: S700, before the well shaft is hoisted into place, mark the reference lines such as the location of the well shaft and the orientation of the inlet flange at the bottom of the foundation pit to ensure that only vertical adjustment is needed after the well shaft is in place, without the need for multi-directional displacement; Step S200 also includes: during the hoisting process, ensure that the axis of the inlet of the well shaft and the axis of the inlet pipe are in the same vertical plane.

[0013] The above scheme, by marking the baseline in advance and controlling the hoisting plane, restricts the positioning and adjustment of the well shaft to the vertical dimension, reduces the complexity of multi-directional displacement adjustment, and further improves docking efficiency.

[0014] In one implementation, step S400 further includes: after aligning the inlet flange of the well shaft with the inlet pipe outside the pit, first locking the lifting assembly, and then connecting the inlet flange of the well shaft with the inlet pipe outside the pit.

[0015] The above solution ensures that the wellbore position remains stable during flange connection by locking the lifting components, thus avoiding disturbance to the leveled wellbore posture during the connection operation and guaranteeing docking accuracy.

[0016] As one implementation method, in step S500, yellow sand is used for layered backfilling. The thickness of each backfill layer is determined according to the size of the confined space. The layers are compacted until the compaction degree meets the design requirements. Water can be sprayed appropriately during the compaction process to improve the density of the yellow sand.

[0017] The above scheme uses yellow sand for layered backfilling and is supplemented by watering and compaction. It can adapt to the working conditions of confined space, ensure that the density of the backfill soil meets the design requirements, and ensure the stability of the soil around the pump station.

[0018] In one implementation, step S500 further includes: after backfilling to the bottom elevation of the well outlet, stopping backfilling and connecting the well outlet flange to the outlet pipe; after the connection is accepted, continuing the backfilling operation.

[0019] The above solution integrates the connection of the outlet flange into the backfilling process, utilizing the operating space provided by the backfilling to a specific elevation for connection. This avoids the problem of the bottom flange being difficult to operate after backfilling is completed, and ensures the connection quality.

[0020] As one implementation method, step S500 also includes: after backfilling to the designed ground elevation and passing the acceptance test, completing the installation and commissioning of the water pump in the well, and at the same time laying, wiring and commissioning of the supporting electrical pipelines to complete the overall equipment installation.

[0021] The above plan involves installing internal water pumps and electrical equipment only after backfilling is completed and the external environment is stable. This avoids the equipment being vibrated or damaged during backfilling and concrete pouring, ensuring the reliability of equipment operation. At the same time, it avoids the significant increase in the overall weight of the pump station caused by early equipment installation, thus reducing the requirements for hoisting, the bearing capacity of the cylinder bottom, and the lifting force of the jacking components.

[0022] As one implementation method, the following steps are also included: S800, before the well shaft enters the site, the foundation pit protection, the soil reinforcement around the foundation pit, the foundation pit excavation, and the foundation pit bottom slab pouring are completed in sequence.

[0023] The above-mentioned scheme, by completing the foundation pit enclosure, reinforcement and bottom slab pouring in advance, provides a safe and reliable foundation environment for subsequent well shaft hoisting and leveling, and reduces the risk of foundation pit deformation and water seepage.

[0024] In one implementation method, C30 commercial concrete is used to pour the containment space in step S400, and a vibrator is used for layered vibration at a frequency of 50Hz.

[0025] The above scheme uses C30 commercial concrete and 50Hz frequency layered vibration to ensure that the concrete can fully fill the containment space and expel internal gas, forming a dense and void-free permanent support and anti-buoyancy structure.

[0026] Beneficial effects: 1. Significantly reduce safety risks: The lifting components are prefabricated in the factory and integrated into the bottom of the well. The lifting components can be remotely controlled by wired or wireless means outside the pit to extend and level. This replaces the traditional manual alignment and fine-tuning in confined spaces, physically isolating personnel from the pit and avoiding safety hazards caused by multiple personnel working together.

[0027] 2. Improved installation efficiency and precision: Integrated prefabrication reduces on-site construction procedures, and remote leveling achieves millimeter-level precision in flange connection, eliminating the need for repeated manual adjustments; at the same time, the space can be backfilled in layers after the concrete is poured without waiting for hardening, which greatly shortens the construction cycle.

[0028] 3. Enhance the equipment's anti-buoyancy and stability: The anti-buoyancy support legs at the bottom of the cylinder are embedded in the concrete of the containment space, forming a tight interlock with the concrete. Furthermore, the jacking components are permanently embedded and transformed into a permanent support structure, effectively improving the pump station's anti-buoyancy and overall stability of the foundation structure, and adapting to the hydrogeological conditions of underground confined spaces.

[0029] 4. Strong adaptability and scalability in construction: The downward extension section and the bottom of the cylinder form an enclosing space as an internal template for concrete pouring. Combined with the cofferdam sealing effect of the groove, there is no need for complicated on-site sealing templates and tooling equipment. The operation is standardized and can be adapted to the installation of large integrated pump stations of different sizes in various narrow and restricted underground spaces. Attached Figure Description

[0030] The preferred embodiments will be explained below in a clear and easy-to-understand manner, with reference to the accompanying drawings, to further illustrate the above-mentioned characteristics, technical features, advantages, and implementation methods of an integrated prefabricated pumping station construction method: Figure 1 This is a flowchart illustrating the construction method of this application; Figure 2 This is a schematic diagram of the external structure of a well casing according to an embodiment of this application; Figure 3 yes Figure 2 Another perspective of the embodiment (bottom exposed); Figure 4 yes Figure 2 Longitudinal sectional view of the embodiment; Figure 5 yes Figure 4 An enlarged view of part A in the embodiment.

[0031] Explanation of icon numbers: Well shaft 1, bottom of shaft 11, downward extension section 12, concrete pouring hole 121, vibration venting hole 122, anti-buoyancy support leg 2, enlarged structure 21, guide sleeve 3, slide 31, jack 4, lug 41, buffer pad 5. Detailed Implementation

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.

[0033] To keep the drawings concise, each drawing only schematically shows the parts relevant to this application, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of the components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0034] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0035] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0036] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0037] Example 1: like Figures 1-5 As shown in the figure, this embodiment provides a construction method for an integrated prefabricated pumping station, which mainly includes the following steps: Step S100: Prefabricate the shaft 1 in the factory; a lifting assembly is connected to the bottom 11 of the shaft 1; the wall of the prefabricated shaft 1 has a downward extension section 12 that extends beyond the bottom 11, the downward extension section 12 and the bottom 11 enclose a receiving space, and the lifting assembly is arranged in the receiving space; the downward extension section 12 is provided with a concrete pouring hole 121 and a vibration venting hole 122, both of which are connected to the receiving space, and both of which are located close to the bottom 11.

[0038] Specifically, during the factory prefabrication stage, the lifting assembly is pre-installed on the bottom of the shaft 11, forming an integral structure with the shaft 1. This factory prefabrication and integration method avoids the difficulties of assembling components in narrow pits and eliminates the risks of construction personnel entering the bottom of the pit to operate. As a preferred embodiment, the lifting assembly includes several jacks 4, and several guide sleeves 3 are provided at the bottom of the shaft 11. The guide sleeves 3 correspond one-to-one with the jacks 4, and the jacks 4 are slidably installed in the guide sleeves 3. The guide sleeves 3 guide the jacks 4, ensuring that the jacks 4 are always constrained in the axial direction of the guide sleeves 3 during the extension and retraction process. This ensures that the lifting force is transmitted vertically and stably to the shaft 11, preventing the jacks 4 from tilting or tipping over due to uneven force distribution.

[0039] Furthermore, the guide sleeve 3 is provided with a groove 31, which extends along the length of the guide sleeve 3; the housing of the jack 4 is provided with a lug 41, which is placed in the groove 31. When the jack 4 slides relative to the guide sleeve 3, the lug 41 moves along the groove 31, serving to guide and prevent the jack 4 from rotating circumferentially; when the lug 41 abuts against the bottom end of the groove 31, the jack 4 can no longer slide downward relative to the guide sleeve 3, thereby achieving reliable anti-detachment protection and ensuring the safety of hoisting and lifting operations.

[0040] Furthermore, a buffer pad 5 is provided at one end of the guide sleeve 3 near the bottom 11 of the cylinder. When the jack 4 lifts the bottom 11, the buffer pad 5 is placed between the jack 4 and the bottom 11. The buffer pad 5 undergoes elastic deformation under pressure, which can effectively fill the microscopic gap between the top surface of the jack 4 and the bottom 11, dispersing the concentrated stress into a planar distribution, thereby absorbing and buffering the lifting impact force and preventing local crushing and cracking of the bottom 11. The buffer pad 5 can be a material with elastic modulus and compressive strength, such as a rubber pad, polyurethane elastomer, or silicone pad.

[0041] The downward extension section 12 is equivalent to an annular skirt structure extending downward from the edge of the bottom cylinder 11. Together with the bottom cylinder 11, it forms a relatively closed chamber at the bottom of the shaft 1. The lifting assembly is installed in this chamber before leaving the factory, resulting in a more compact structure. During the lowering process, it is protected by the containment space, preventing collision with the sidewall of the pit. The concrete pouring hole 121 and the vibration venting hole 122 are located in the sidewall area of ​​the downward extension section 12 near the bottom cylinder 11, rather than near the bottom edge, providing a reasonable passage for subsequent bottom-up pouring and vibration venting.

[0042] Step S200: The well shaft 1 is hoisted into the foundation pit, and the well shaft 1 is initially supported in the foundation pit by the downward extension section 12.

[0043] Specifically, the hoisting equipment directly lowers the entire shaft 1, equipped with the lifting assembly, into the foundation pit. At this point, the bottom end of the downward extension section 12 directly contacts the bottom of the pit, acting as a support foot and evenly transferring the weight of the entire shaft 1 to the foundation. This provides a stable and reliable initial load-bearing base for the subsequent extension and leveling of the lifting assembly. Compared to existing technologies that directly place the flat-bottomed shaft on the bottom of the pit, the downward extension section 12 provides ample space for the extension and retraction of the lifting assembly.

[0044] Step S300: Control the extension and retraction of the jacking component outside the foundation pit via wired or wireless means. Adjust the posture and lifting of the well barrel 1 in the foundation pit by extending and retracting the jacking component, so that the water inlet flange of the well barrel 1 is aligned with the water inlet pipe outside the foundation pit.

[0045] Specifically, the wired method involves connecting the lifting components to a ground control console via control cables. Construction personnel on the ground can send electrical signals to each lifting component by operating buttons on the control console, driving its independent or collective extension / retraction. The wireless method involves transmitting wireless control signals via a ground-based wireless remote control. A signal receiving module on the lifting component receives these signals and executes the corresponding extension / retraction action. Through this remote control logic, construction personnel can precisely adjust the height and inclination of the well shaft 1 from the ground without entering the pit. In the preferred embodiment where the jacks 4 are used as lifting components, multiple leveling jacks 4 at the bottom are remotely activated via computer to precisely adjust the elevation and inclination of the well shaft 1, enabling vertical elevation adjustment and small-angle inclination correction. Due to the guiding constraint of the guide sleeve 3 and the stress dispersion effect of the buffer gasket 5, each jack 4 can independently and precisely perform the lifting action, with lifting accuracy meeting the millimeter-level requirements for flange docking, until the inlet flange is completely aligned with the reserved pipe flange hole. It should be understood that wired control has the advantages of stable signal transmission and strong anti-interference ability, while wireless control has the advantages of simple wiring and flexible operation. In actual engineering, the most suitable control method can be selected according to the site conditions, or the two methods can be combined as redundant control.

[0046] Step S400: After the water inlet flange of the well shaft 1 is connected to the water inlet pipe outside the pit, concrete is poured into the containment space formed by the downward extension section 12 of the concrete pouring hole 121 and the bottom of the shaft 11. The concrete completely fills the containment space, and the lifting component is embedded in the concrete. The vibrator is inserted into the containment space through the vibration venting hole 122 to vibrate the concrete.

[0047] Specifically, once the well shaft 1 is adjusted to the design requirements, the lifting assembly remains stationary in its current telescopic state. Construction workers simply insert the concrete pump pipe into the concrete pouring hole 121 and directionally inject concrete into the containment space. Since the concrete pouring hole 121 is close to the bottom 11 of the shaft, the concrete gradually fills upwards from below the bottom 11. Simultaneously, workers insert a vibrator through the vibration vent hole 122 into the containment space to vibrate the newly injected concrete in layers, making it more compact, and allowing air in the containment space to escape through the vibration vent hole 122. The containment space formed by the downward extension section 12 confines the concrete pouring area to the critical area at the bottom of the well shaft 1. The downward extension section 12 also acts as a pouring template, achieving directional injection and concentrated containment of the concrete. After completing its leveling mission, the lifting assembly does not need to be disassembled and removed; it is encased in concrete and becomes a permanent support structure at the bottom of the well shaft 1, further enhancing the structural integrity of the pump station foundation and significantly simplifying the construction completion process.

[0048] Step S500: After pouring concrete into the containment space, the foundation pit can be backfilled in layers without waiting for the concrete to harden.

[0049] Specifically, since the concrete within the containment space has been compacted by vibration, and the structure formed by the downward extension section 12 and the bottom of the cylinder 11 has sufficient supporting rigidity, the backfilling operation of the foundation pit can be started immediately after the concrete is poured, without having to wait for the concrete to reach its design strength as in traditional construction. This design significantly shortens the construction cycle and improves construction efficiency within confined spaces.

[0050] Example 2: Based on Example 1, this example further explains the support at the bottom of the wellbore 1. For example... Figures 2-5As shown, step S200 further includes: setting a groove at the bottom of the foundation pit that matches the downward extension section 12; inserting the downward extension section 12 into the groove and initially supporting it on the bottom of the groove. Specifically, after the foundation pit is excavated to the design elevation, an annular groove matching the contour of the downward extension section 12 is pre-formed or excavated on the bottom surface of the foundation pit. When the shaft 1 is hoisted into the foundation pit, the downward extension section 12 is directly inserted into the groove, and the bottom of the groove provides a solid initial support surface for the downward extension section 12. More importantly, the inner wall of the groove and the outer wall of the downward extension section 12 form a fit, and when concrete is poured into the receiving space in the subsequent step S400, the groove acts as a seal on the outer periphery of the bottom end of the downward extension section 12, which is equivalent to a natural cofferdam structure. It should be understood that if the bottom of the shaft 1 is placed directly on the flat bottom surface of the foundation pit, concrete is very likely to flow out in large quantities from the gap between the bottom end of the downward extension section 12 and the bottom surface of the foundation pit, resulting in the need to set up additional sealing formwork. In this embodiment, the cofferdam effect of the groove effectively prevents the concrete in the containment space from flowing out of the groove from the bottom of the downward extension section 12, thus eliminating the need for additional sealing templates during concrete pouring and greatly simplifying the construction process in the confined space.

[0051] Further, step S100 also includes: a plurality of anti-buoyancy legs 2 are connected to the bottom of the cylinder bottom 11, and the anti-buoyancy legs 2 are distributed in the receiving space; step S200 also includes: the well shaft 1 is supported on the bottom of the groove by the combined action of the downward extension section 12 and the anti-buoyancy legs 2; step S400 also includes: the anti-buoyancy legs 2 are embedded in the concrete in the receiving space. Specifically, the connection between the anti-buoyancy legs 2 and the cylinder bottom 11 can be integrally formed or fixedly connected by fasteners such as flanges and bolts, and they are evenly distributed around the central area of ​​the cylinder bottom 11. During the initial placement, the bottom end of the anti-buoyancy legs 2 and the bottom end of the downward extension section 12 jointly contact the bottom of the groove, forming a multi-point support system. Compared with relying solely on the annular edge support of the downward extension section 12, the anti-buoyancy legs 2 extend the support points from the edge to the central area, effectively dispersing the force on the cylinder bottom 11 and improving the placement stability of the well shaft 1 in the initial lowering state. When the buoyancy of groundwater acts on the well shaft 1, the anti-buoyancy support leg 2 embedded in the concrete can be tightly engaged with the concrete foundation, greatly improving the overall anti-buoyancy capability of the pump station.

[0052] Furthermore, the end of the anti-buoyancy support leg 2 furthest from the bottom 11 is provided with an enlarged structure 21. The enlarged structure 21 is used to increase the connection strength between the anti-buoyancy support leg 2 and the concrete. Specifically, the enlarged structure 21 can be in the form of a conical enlarged head, an inverted T-shaped plate, or a hemispherical protrusion. It should be understood that if the anti-buoyancy support leg 2 only adopts a smooth straight rod structure, after it is embedded in the concrete, it mainly relies on the friction between the concrete and the surface of the rod to provide anti-buoyancy resistance. When the buoyancy of the groundwater is large, the smooth straight rod is very easy to slip relative to the concrete or even be pulled out. In this embodiment, by setting the enlarged structure 21 at the end of the anti-buoyancy support leg 2, the contact area between the anti-buoyancy support leg 2 and the concrete is significantly increased. After the concrete solidifies, the enlarged structure 21 is tightly wrapped by the concrete, and a strong mechanical interlocking force is formed between the two. When the buoyancy force generated by the groundwater acts on the well barrel 1, the enlarged structure 21 can effectively resist the upward pull force and prevent the anti-buoyancy support leg 2 from being pulled out of the concrete, thus achieving reliable mechanical anchoring.

[0053] To further improve docking efficiency, this embodiment also includes the following steps: S700, before hoisting the well shaft 1 into place, mark the location of the well shaft 1 and the orientation of the inlet flange, etc., at the bottom of the foundation pit to ensure that only vertical adjustment is needed after the well shaft 1 is in place, without the need for multi-directional displacement; Step S200 also includes: ensuring that the axis of the inlet of the well shaft 1 and the axis of the inlet pipe are in the same vertical plane during hoisting. Specifically, before the hoisting operation, the construction personnel mark the outer contour line of the well shaft 1 and the projection center line of the inlet flange on the bottom plate of the foundation pit according to the design drawings. During hoisting, through the cooperation of the ground command personnel and the crane operator, the attitude of the well shaft 1 in the air is adjusted so that the orientation of its inlet flange is aligned with the baseline, and the axis of the inlet is in the same vertical plane as the axis of the inlet pipe. This simplifies the complex attitude adjustment that originally needed to be carried out in three-dimensional space to only the adjustment of vertical height and slight tilt. Since the translation and rotation of large components in a confined space are extremely difficult and dangerous, by marking the baseline in advance and controlling the hoisting plane, the horizontal displacement requirement after the well shaft 1 is in place is eliminated from the source, which greatly shortens the time for remote leveling and improves the installation efficiency.

[0054] Example 3: Based on Example 1, this example further explains the leveling and locking process and the concrete pouring and curing process. For example... Figures 1-5As shown, the construction method in this embodiment also includes the following steps: S800, before the well shaft 1 arrives at the site, the following steps are completed in sequence: foundation pit protection, foundation pit surrounding soil reinforcement, foundation pit excavation, and foundation pit bottom slab pouring. Specifically, before the well shaft 1 arrives at the construction site, it must be ensured that the civil engineering preconditions for the foundation pit are fully met. Foundation pit protection and surrounding soil reinforcement provide safe and reliable lateral protection for subsequent hoisting and leveling operations, preventing foundation pit collapse; bottom slab pouring provides a hard landing surface with a certain bearing capacity for the bottom structure of the well shaft 1. If the well shaft 1 is hoisted directly without completing the bottom slab pouring, the original soil or soft foundation at the bottom of the foundation pit is prone to uneven settlement under the self-weight of the well shaft 1 and the concentrated pressure of the jacking components, causing the subsequent leveling operation to fail. By implementing step S800 in advance, the risk of attitude instability caused by insufficient foundation bearing capacity is eliminated from the source.

[0055] Furthermore, step S400 also includes: after aligning the inlet flange of the well shaft 1 with the inlet pipe outside the pit, locking the jacking assembly first, and then connecting the inlet flange of the well shaft 1 with the inlet pipe outside the pit. Specifically, after adjusting the well shaft 1 to be fully aligned with the reserved pipe flange hole position through remote control jacks 4, all jacks 4 must first be locked to fix the telescopic rods of the jacks 4 at the current height and prevent any further slight displacement. After confirming that the locking is complete, the construction personnel can then proceed with the insertion and tightening of the flange bolts. It should be understood that flange connections often require millimeter-level precision. If the flange connection operation is performed directly with the jacking assembly not locked, the force applied by the construction personnel during the bolt tightening process can easily disturb the balance of the well shaft 1, causing the aligned hole positions to become misaligned. In addition, the method of locking before connecting allows the lifting assembly to act as a rigid support base during flange connection, ensuring the absolute stability of the wellbore 1's attitude during connection operations and avoiding poor sealing or rework caused by attitude disturbances.

[0056] Furthermore, in step S400, C30 ready-mixed concrete is used to pour the containment space, and a vibrator is used for layered vibration at a frequency of 50Hz. Specifically, the containment space contains lifting components and anti-buoyancy supports, and the space is relatively small with many dead corners, placing extremely high demands on the flowability and compaction of the concrete. C30 ready-mixed concrete is chosen because it has good workability and compressive strength, and can smoothly penetrate the complex structural gaps within the containment space under its own weight and pump pressure. At the same time, layered vibration at a frequency of 50Hz can generate suitable high-frequency micro-vibrations, which can effectively break up internal air bubbles and ensure that the concrete can fully fill the tiny corners between the enlarged structure 21 and the bottom of the cylinder 11. It should be understood that if the vibration frequency is too low, such as below 30Hz, the vibration force will be insufficient to allow the concrete to flow fully. This can easily lead to voids or honeycombs forming at the bottom of the anti-buoyancy support legs or on the four sides of the jacks. This results in a reduced contact area between the anti-buoyancy support legs and the concrete after curing, significantly reducing the anti-buoyancy capacity. Furthermore, local voids can cause stress concentration, creating a potential for foundation settlement. Similarly, if the concrete grade is incorrect or the water-cement ratio is too high, causing segregation, coarse aggregate will accumulate and block the pouring path. Therefore, the combination of C30 concrete and a 50Hz vibration frequency achieves the optimal balance between fluidity and density. It is an irreplaceable parameter choice to ensure that the containment space is filled densely without voids, forming a reliable permanent support and anti-buoyancy structure.

[0057] Example 4: Based on Example 1, this example further explains the timing of backfilling and equipment installation. For example... Figure 1 As shown, in step S500, yellow sand is used for layered backfilling. The thickness of each layer is determined according to the size of the confined space. Each layer is compacted until the compaction meets the design requirements. During the compaction process, water can be sprayed appropriately to improve the density of the yellow sand. Specifically, since integrated pump stations are usually buried underground, the density of the backfill soil around the foundation pit directly affects the stability of the soil around the pump station and the risk of subsequent ground settlement. Yellow sand is chosen as the backfill material because yellow sand particles are uniform, have good permeability, and are easy to spread and compact in confined spaces. During layered backfilling, the thickness of each layer needs to be reasonably determined according to the narrow distance between the foundation pit and the well shaft 1. For example, the thickness of each layer should be controlled between 200mm and 300mm to ensure that the compaction machinery can effectively act on each layer of backfill material. During the compaction process, water is sprayed appropriately. The lubrication effect of water molecules between sand particles makes it easier for the sand particles to slide relative to each other and rearrange to the densest state, thereby significantly improving the overall density and bearing capacity of the backfill. It should be understood that backfill materials are not limited to yellow sand. Under other geological conditions or engineering requirements, materials with good compaction performance, such as graded crushed stone and medium-coarse sand, can also be used, as long as they can meet the compaction requirements in confined spaces.

[0058] Furthermore, step S500 also includes: after backfilling to the bottom elevation of the outlet of well 1, stopping backfilling and connecting the outlet flange of well 1 to the outlet pipe; after the connection is accepted, continuing the backfilling operation. Specifically, the outlet is usually located in the upper middle part of well 1. If the entire foundation pit is backfilled to the design elevation at once before connecting the outlet flange, the outlet will be deeply buried in the backfill material. Construction workers will have no operating space to insert bolts or tighten the flange. Forced excavation will easily disturb the compacted backfill and the connected inlet pipe. Therefore, in this embodiment, the connection of the outlet flange is interspersed in the backfilling process. When backfilling to the bottom elevation of the outlet, the outlet is located above the working surface formed by the backfill material. At this time, construction workers have sufficient operating space and a good field of vision to connect and tighten the flange. After the connection is accepted, backfilling continues upwards. This timing logic cleverly utilizes the elevation platform naturally formed during the backfilling process, avoiding the predicament of the bottom flange being inoperable or requiring destructive rework after full backfilling, thus ensuring connection quality and construction continuity.

[0059] Furthermore, step S500 also includes: after backfilling to the designed ground elevation and passing acceptance, completing the installation and commissioning of the water pump inside well 1, and simultaneously laying, connecting, and commissioning the supporting electrical wiring to complete the overall equipment installation. Installing the internal water pump and electrical systems only after backfilling is complete and the external environment is stable avoids vibration or damage to the equipment during backfilling and concrete pouring, ensuring the reliability of equipment operation. It also avoids a significant increase in the overall weight of the pump station due to early equipment installation, thus reducing the requirements for hoisting, bottom bearing capacity, and jacking force of the jacking components.

[0060] Example 5: Based on the above embodiments, this embodiment takes the construction and application of a large-scale venting pump station in a confined underground space as an example to further illustrate the actual operational effect of the technical solution. (Comprehensive Reference) Figures 1 to 5 The well shaft 1 is designed with a diameter of 4.2m and a height of 15m, with an inlet pipe diameter of 1200mm and an outlet pipe diameter of 600mm. The well shaft 1 is made of fiberglass and is a prefabricated, integrated structure. The internal piping and auxiliary components have been pre-assembled in the factory, with only a water pump installation location reserved for on-site construction. For such large and tall prefabricated components, adjusting their orientation and connecting pipes within the confined underground space is extremely difficult. Traditional methods relying on personnel entering the bottom of the pit for manual leveling are not only time-consuming and labor-intensive but also pose significant safety hazards.

[0061] During construction, step S800 is executed first. Before the well shaft 1 arrives on site, the foundation pit retaining structure, the soil reinforcement around the foundation pit, the foundation pit excavation, and the foundation pit bottom slab pouring are completed sequentially. Specifically, for this large pump station, the foundation pit is deep and the surrounding environment is complex. It is essential to ensure that the bottom slab pouring reaches the design strength to provide a solid bearing surface for the subsequent hoisting of heavy components. Then, step S700 is executed. Before the well shaft 1 is hoisted into place, baselines such as the location of the well shaft 1 and the orientation of the inlet flange are marked at the bottom of the foundation pit to ensure that only vertical adjustments are needed after the well shaft 1 is in place, without the need for multi-directional displacement. This pre-positioning is particularly crucial for a behemoth with a diameter of 4.2m, as horizontal translation and rotation adjustments are almost impossible within the confined space.

[0062] Next, step S100 is performed, in which the well shaft 1 is prefabricated in the factory. A lifting assembly is connected to the bottom 11 of the well shaft 1. The wall of the prefabricated well shaft 1 has a downward extension section 12 extending beyond the bottom 11, which, together with the bottom 11, forms a receiving space. The lifting assembly is positioned within this receiving space. The downward extension section 12 is provided with a concrete pouring hole 121 and a vibration venting hole 122, both of which communicate with the receiving space and are located close to the bottom 11. Simultaneously, several anti-buoyancy legs 2 are connected to the bottom of the well shaft 11, distributed within the receiving space. Specifically, six guide sleeves 3 and six anti-buoyancy support legs 2 are evenly and symmetrically arranged at the bottom of the cylinder bottom 11. A jack 4 is slidably installed inside each guide sleeve 3. The guide sleeve 3 is provided with a groove 31, and the shell of the jack 4 is provided with a lug 41 placed in the groove 31. A buffer pad 5 is provided at the end of the guide sleeve 3 near the cylinder bottom 11. The end of the anti-buoyancy support leg 2 away from the cylinder bottom 11 is provided with an enlarged structure 21. The enlarged structure 21 adopts a conical enlarged head shape to prepare for subsequent interlocking with concrete to enhance the anti-buoyancy ability.

[0063] Then, step S200 is executed, in which the well casing 1 is hoisted into the foundation pit. A groove adapted to the downward extension section 12 is set at the bottom of the foundation pit; the downward extension section 12 is inserted into the groove and initially supported on the bottom of the groove. The well casing 1 is supported on the bottom of the groove by the combined action of the downward extension section 12 and the anti-buoyancy support leg 2. During the hoisting process, it is ensured that the axis of the water inlet of the well casing 1 is in the same vertical plane as the axis of the water inlet pipe. Specifically, a large-tonnage hoisting equipment is used to hoist the integrated well casing 1 into the foundation pit as a whole. The inner wall of the groove fits with the outer wall of the downward extension section 12 to form a natural cofferdam closed structure to prevent subsequent concrete leakage.

[0064] Next, step S300 is executed, where the jacking assembly is controlled via wired or wireless means outside the foundation pit to extend and retract. This extension and retraction adjusts the posture and elevation of the well shaft 1 within the pit, aligning the inlet flange of the well shaft 1 with the inlet pipe outside the pit. Specifically, construction personnel remotely adjust the jacking height of six jacks 4 from the ground via computer. Due to the guiding constraint of the guide sleeve 3 and the force-dispersing effect of the buffer pad 5, each jack 4 can independently and precisely perform the jacking action, achieving millimeter-level accuracy. By adjusting the extension and retraction of the jacks 4 in different positions, the levelness deviation of the pump station is controlled within 0.1%, ensuring precise alignment of the inlet flange with the reserved pipe flange. The entire leveling process is performed remotely, eliminating the need for personnel to enter the core area of ​​the confined space, thus mitigating construction safety risks from the outset.

[0065] After alignment, first lock the lifting assembly, and then connect the water inlet flange of well 1 to the water inlet pipe outside the pit. Specifically, after locking the mechanical locking mechanisms of all jacks 4, then insert and tighten the flange bolts to ensure the absolute stability of the posture of well 1 during the connection operation.

[0066] Subsequently, step S400 is executed. After the inlet flange of the well casing 1 is connected to the inlet pipe outside the pit, concrete is poured into the containment space formed by the downward extension section 12 through the concrete pouring hole 121 and the bottom of the casing 11. The concrete completely fills the containment space, and the lifting component is embedded in the concrete. The vibrator is inserted into the containment space through the vibration vent hole 122 to vibrate the concrete. The anti-buoyancy support leg 2 is embedded in the concrete in the containment space. C30 commercial concrete is used to pour the containment space, and the vibrator is used for layered vibration at a frequency of 50Hz. Specifically, the construction personnel only need to insert the concrete pump pipe into the concrete pouring hole 121 near the bottom of the casing 11 and directionally inject C30 commercial concrete into the containment space. The concrete gradually fills upward from below the bottom of the casing 11, while the vibrator is inserted into the containment space through the vibration vent hole 122 for layered vibration at a frequency of 50Hz to ensure that the concrete is fully and densely filled without voids. Jack 4 remains in its current leveled state and is not removed, forming a permanent support structure as it is permanently embedded in the concrete; the tapered enlarged head at the end of the anti-buoyancy leg 2 engages tightly with the concrete, significantly improving the pump station's anti-buoyancy capability and structural stability.

[0067] Finally, in step S500, after pouring concrete in the containment space, the foundation pit can be backfilled in layers without waiting for the concrete to harden. Yellow sand is used for layered backfilling, with the thickness of each layer determined by the size of the confined space. Each layer is compacted until the compaction meets the design requirements. Water can be sprinkled appropriately during compaction to increase the density of the yellow sand. After backfilling to the bottom elevation of the outlet of well 1, backfilling is stopped, and the outlet flange of well 1 is connected to the outlet pipe. After the connection is accepted, backfilling continues. After backfilling to the design ground elevation and acceptance, the water pump inside well 1 is installed and commissioned. Simultaneously, the supporting electrical wiring is laid, connected, and commissioned, completing the overall equipment installation. Specifically, layered yellow sand backfilling ensures the stability of the surrounding soil, and the interspersed outlet flange connection utilizes the operating space provided by the backfill elevation, avoiding the predicament of being unable to operate after full backfilling.

[0068] This embodiment fully demonstrates that the construction method of the integrated prefabricated pump station, through the complete process of factory prefabrication and integration, remote precise leveling outside the foundation pit, groove cofferdam to prevent grout leakage, mechanical interlocking of anti-buoyancy legs, concrete pouring with specific parameters, and permanent burial, not only significantly reduces the safety risks of working in confined spaces, but also perfectly adapts to the construction needs of narrow underground spaces with its millimeter-level leveling accuracy and compact bottom structure design, and has extremely high commercial value and scalability.

[0069] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An integrated prefabricated pumping station that can be used in confined spaces, characterized in that, The system includes a foundation pit and a precast well shaft, with a lifting assembly connected to the bottom of the precast well shaft. During construction, the lifting assembly and the precast well shaft are lowered into the foundation pit as a whole. The lifting assembly is configured to be controlled by wired or wireless means to extend and retract, adjusting the posture and lifting / lowering of the precast well shaft. After leveling, the lifting assembly is embedded in concrete. After construction is completed, both the lifting assembly and the precast well shaft are embedded in the foundation pit.

2. The integrated prefabricated pumping station according to claim 1, characterized in that, The precast well casing has a downward extension section extending beyond the bottom of the casing. The downward extension section and the bottom of the casing enclose a receiving space, and the lifting assembly is arranged in the receiving space. Before the leveling process is carried out, the precast well casing is supported in the foundation pit by the downward extension section.

3. The integrated prefabricated pumping station according to claim 2, characterized in that, The downward extension section is provided with a concrete pouring hole and a vibration venting hole. Both the concrete pouring hole and the vibration venting hole are connected to the receiving space and are located close to the bottom of the cylinder. After leveling, concrete is poured in the receiving space, and the lifting component is embedded in the concrete.

4. The integrated prefabricated pumping station according to claim 3, characterized in that, The bottom of the wellbore is connected to several anti-buoyancy legs, which are arranged in the accommodating space; before the leveling process, the anti-buoyancy legs are used to support the prefabricated wellbore. After leveling, the anti-buoyancy support leg is embedded in the concrete of the receiving space.

5. The integrated prefabricated pumping station according to claim 4, characterized in that, The anti-buoyancy support leg has an enlarged structure at one end away from the bottom of the cylinder, which is used to increase the connection strength between the anti-buoyancy support leg and the concrete.

6. The integrated prefabricated pumping station according to claim 3, characterized in that, The lifting assembly includes several jacks; the bottom of the cylinder is provided with several guide sleeves, each guide sleeve corresponding to one of the jacks, and the jacks are slidably installed inside the guide sleeves.

7. The integrated prefabricated pumping station according to claim 6, characterized in that, The guide sleeve is provided with a sliding groove that extends along the length of the guide sleeve; the housing of the jack is provided with a lug that is placed in the sliding groove; when the jack slides relative to the guide sleeve, the lug moves along the sliding groove; when the lug abuts against the bottom end of the sliding groove, the jack can no longer slide downward relative to the guide sleeve.

8. The integrated prefabricated pumping station according to claim 6, characterized in that, A buffer pad is provided at one end of the guide sleeve near the bottom of the cylinder. When the jack lifts the bottom of the cylinder, the buffer pad is placed between the jack and the bottom of the cylinder.

9. The integrated prefabricated pumping station according to claim 8, characterized in that, The buffer pad is a rubber pad.

10. The integrated prefabricated pumping station according to any one of claims 1-9, characterized in that, The prefabricated well casing is made of fiberglass or polyethylene resin.

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