A multi-connected cylinder shaft pump station structure resistant to high external pressure and its construction method

Abstract

The present invention discloses a multi-connected cylinder shaft-type pumping station structure resistant to high external pressure and a construction method thereof. The pumping station structure includes a plurality of cylindrical concrete structures connected side by side. A retaining structure is arranged on the outer side of each cylindrical concrete structure. The plurality of cylindrical concrete structures are integrally embedded in a foundation pit below the ground surface. A water pump unit is arranged inside each cylindrical concrete structure. A plant is arranged at the top of the plurality of cylindrical concrete structures, and a hoisting device is arranged inside the plant. The present invention avoids the problems of large open excavation and backfilling of urban deep foundation pits and much occupation of urban surface resources; it can meet the requirements of a large difference between the installation elevation of the unit and the ground elevation, and avoid the problems of great difficulty in excavation and support of the underground pumping station cavern group and poor surrounding rock stability under adverse geological conditions; it makes full use of the advantage of the good stress condition of the circular pumping station structure under the action of high external water pressure and high external soil pressure.

Description

Technical Field

[0001] The present invention relates to the technical fields of intake pump stations and deep foundation pit construction in urban water conservancy projects, and particularly relates to a multi-connected cylinder shaft-type pump station structure with high external pressure resistance and a construction method therefor. Background Art

[0002] Currently, in the layout types of intake pump stations in water conservancy projects, there are usually ground type, semi-buried type, underground type and other types. The "Code for Design of Pump Stations" GB 50265-2010 stipulates that when the variation range of the water source level is more than 10m, other types of pump stations such as shaft-type pump stations, cable car-type pump stations, floating ship-type pump stations, and submerged pump stations can be adopted. In the actual application process, it is necessary to select a suitable pump station layout type according to different topographical and geological conditions, water levels, external forces, etc.

[0003] When constructing an intake pump station in the urban central area, when the surface land resources are tense, the ground elevation is relatively high, and the installation elevation of the pump station unit is relatively low, if a ground-type pump station is adopted, it is difficult to meet the installation requirements of the unit in terms of elevation, and it occupies a large amount of surface land resources; the underground pump station has high requirements for the geological conditions of the site area. On the shallowly buried strongly weathered, fractured, and soft rock masses underground in the city, the excavation and support of the underground pump station chamber group are extremely difficult, and the problem of the stability of the chamber surrounding rock is prominent; the foundation pit of the semi-buried pump station has a large open-cut slope range, occupies a large amount of surface area, has high land acquisition investment, and high environmental protection pressure, and is not suitable for being arranged in urban dense areas and areas with tense surface land resources.

[0004] In addition, when the installation elevation of the unit is relatively low and the pump station burial depth is large, the peripheral structure of the pump station will face the risks of high groundwater pressure and high external soil pressure. To resist high external pressure, the pump station is preferably arranged in a cylindrical shape. The circular side wall can make full use of the compressive strength of concrete, has a small structural thickness, and low civil engineering cost. However, when the scale of the pump station unit is large and the number of units is large, a single cylindrical pump station cannot arrange all the unit equipment, and after the diameter of the cylinder exceeds a certain degree, the reinforced concrete circular arch effect and stability of the super-large cylinder are poor. Summary of the Invention

[0005] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide a multi-connected cylinder shaft-type pump station structure with high external pressure resistance and a construction method therefor, which has strong applicability, relatively small floor area, and low project investment. The present invention adopts a columnar layout of multiple shaft-type cylindrical pump houses, a connecting tunnel is arranged at the lower part of the pump house as an internal connecting tunnel between each pump house, a corridor-type factory building is arranged at the upper part of the pump house, and a common bridge crane is used, so as to form a multi-connected cylinder shaft-type pump station structure type, so as to solve the disadvantages of inconvenient operation and management and increased investment in lifting equipment caused by the mutual independence of multiple shaft-type cylindrical pump houses, no connecting tunnel between the lower operation layer and the unit pump layer, and inability to share the upper bridge crane.

[0006] To solve the above technical problems, the present invention is achieved by the following technical solutions:

[0007] On the one hand, the present invention provides a multi-connected cylinder shaft-type pumping station structure resistant to high external pressure. The pumping station structure includes a plurality of cylindrical concrete structures connected side by side. A retaining structure is arranged outside each cylindrical concrete structure. The plurality of cylindrical concrete structures are integrally embedded in a foundation pit below the ground surface. A pump unit is arranged inside each cylindrical concrete structure. A plant building is arranged on the top of the plurality of cylindrical concrete structures, and a hoisting device is arranged inside the plant building.

[0008] Preferably, the retaining structure includes a cylindrical jet grouting pile and a cylindrical diaphragm wall. The outer wall of the cylindrical diaphragm wall is attached to the inner wall of the cylindrical jet grouting pile, and the inner wall of the cylindrical diaphragm wall is attached to the outer wall of the cylindrical concrete structure.

[0009] Preferably, connection tunnels are arranged between the operating layers and between the volute layers in two adjacent cylindrical concrete structures. The connection tunnels penetrate through the cylindrical concrete structures and the retaining structure.

[0010] Preferably, the plant building is a rectangular plant building, and its length direction is the same as the arrangement direction of the plurality of cylindrical concrete structures.

[0011] Preferably, the hoisting device is fixed in the middle of the plant building.

[0012] Preferably, the hoisting device adopts a bridge crane.

[0013] Preferably, the diameter of a single cylindrical concrete structure is set to be 15 - 40 m.

[0014] On the other hand, the present invention provides a construction method for a multi-connected cylinder shaft-type pumping station structure resistant to high external pressure, including:

[0015] Determine the size and depth of the multi-connected cylinder shaft according to the number of pumping station units, equipment dimensions, elevation of mechanical and electrical installation, and requirements of the operation and maintenance passage size;

[0016] Determine the bottom elevation of the diaphragm wall and the jet grouting pile according to the geological conditions and the requirements of the rock formation boundary. Among them, the bottom elevation of the diaphragm wall should be 1.5 - 2 m lower than the bottom elevation of the shaft and be located in the weakly weathered or slightly weathered rock formation, and the bottom elevation of the jet grouting pile is the lower limit of the completely weathered layer;

[0017] Construct according to the sequence of jet grouting pile → diaphragm wall → vertical shaft body concrete structure → connection tunnel between shafts → shaft bottom slab → upper plant building → concrete structures of the volute layer and operating layer in the shaft → installation of pump units.

[0018] Compared with the prior art, the anti-high external pressure multi-connected cylinder shaft-type pumping station structure and construction method mentioned in the present invention mainly have the following advantages:

[0019] (1) Adopt the combined excavation and support method of jet grouting piles and diaphragm walls to avoid the problems of large occupation of urban surface resources by the slope excavation of deep foundation pits and large investment in excavation and backfilling projects.

[0020] (2) Meet the requirements of a large difference between the installation elevation of the unit and the ground elevation.

[0021] (3) Avoid the problems of great difficulty in excavation and support of the underground pumping station cavern group under poor geological conditions and poor surrounding rock stability.

[0022] (4) Make full use of the advantage of good stress conditions of the circular pumping station structure under the action of high external water pressure and high external soil pressure.

[0023] (5) Solve the restrictive factors that when the unit scale is large and the number of units is large, all units cannot be arranged in a single cylindrical pumping station.

[0024] (6) Solve the problems that multiple independent single cylindrical pumping stations cannot be connected internally, cannot share the upper plant and hoisting equipment, and are inconvenient for operation, maintenance and management.

[0025] (7) The pumping station structure has strong applicability, is safe and reliable in construction and operation, and has good technical economy. Description of the Drawings

[0026] Figure 1 It is a schematic plan view of the deep foundation pit enclosure structure of the anti-high external pressure multi-connected cylinder shaft-type pumping station;

[0027] Figure 2 It is a schematic plan view of the anti-high external pressure multi-connected cylinder shaft-type pumping station;

[0028] Figure 3 It is a schematic cross-sectional view of the anti-high external pressure multi-connected cylinder shaft-type pumping station;

[0029] Figure 4 It is a schematic longitudinal-sectional view of the anti-high external pressure multi-connected cylinder shaft-type pumping station.

[0030] In the figure: 1. Jet grouting pile, 2. Diaphragm wall, 3. Cylindrical concrete structure, 4. Water pump unit, 5. Single cylinder diameter, 6. Plant, 7. Connecting tunnel, 8. Hoisting equipment, 9. Operating layer, 10. Groundwater level line, 11. Earth and rock mass, 12. Ground surface, 13. Volute layer. Detailed Embodiments

[0031] To enable those skilled in the art to better understand the technical solution of the present invention, the preferred implementation of the present invention will be described below in conjunction with specific embodiments. However, it should be understood that the drawings are only for illustrative purposes and cannot be construed as a limitation on this patent; to better illustrate this embodiment, some components in the drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationships described in the drawings are only for illustrative purposes and cannot be construed as a limitation on this patent.

[0032] Glossary in the specification:

[0033] Vertical shaft pump station: It can meet the requirements of large changes in the lift of the pump station and large amplitude of the water intake level, and reduce the occupation of surface resources.

[0034] Deep foundation pit: It refers to a project with a excavation depth exceeding 5 meters (including 5 meters), or a depth not exceeding 5 meters, but with particularly complex geological conditions, surrounding environment and underground pipelines.

[0035] High external pressure: When the soil layer is rich in groundwater and the buried depth of the pump station is relatively large, the peripheral structure of the pump station will bear horizontal loads such as high external water pressure and high external soil pressure.

[0036] Jet grouting pile: Also known as jet grouting method, it uses a drill rig to place the jet grouting pipe and nozzle at the designed elevation of the pile bottom. After the pre-prepared slurry is passed through a high-pressure generating device to obtain huge energy, it is ejected at high speed from the nozzle on the side of the grouting pipe, forming a jet flow with highly concentrated energy, which directly destroys the soil body. During the jetting process, the drill rod rotates and is lifted at the same time, so that the slurry and the soil body are fully stirred and mixed, forming a columnar consolidation body with a certain diameter in the soil, thereby strengthening the foundation.

[0037] Diaphragm wall: It is a kind of trenching machine used on the ground in foundation engineering. Along the peripheral axis of the deep excavation project, under the condition of slurry support, a long and narrow deep trench is excavated. After the trench is cleaned, a steel reinforcement cage is lowered into the trench, and then underwater concrete is poured by the conduit method to form a unit trench section. In this way, it is carried out section by section to build a continuous reinforced concrete wall underground as a water cutoff, anti-seepage, load-bearing and water retaining structure.

[0038] In order to solve the problems that when there are many restrictive conditions such as tense urban surface resources, low unit installation elevation, poor geological conditions, large buried depth of the pump station, high external water pressure, high external soil pressure, large unit scale and large number of units, the selection of surface type, underground type, semi-buried type and single-cylinder type pump stations has problems such as the unit installation elevation is difficult to meet the requirements, the excavation and support of the underground pump station chamber group are difficult, the open excavation and backfilling of the foundation pit are large and occupy a large amount of surface resources, and all units cannot be arranged in the single-cylinder type pump station. The present invention provides a high-external-pressure multi-connected cylinder vertical shaft pump station structure, which has strong applicability, relatively small floor area and low project investment.

[0039] Refer to Figures 1 to 4 It can be known that when six pump units 4 need to be arranged in a single row, under the conditions of a large difference in elevation between the installation elevation of the units and the ground surface, a shortage of urban surface resources, unsuitability for slope excavation in the open, and a large number of ground buildings in the surrounding area, it is more appropriate to select the layout type of a shaft-type circular pumping station. The circular pumping station structure has good stress conditions under the action of high external water pressure (groundwater level line 10) and high external soil pressure (soil and rock mass 11). The combined support method of jet grouting piles 1 and diaphragm walls 2 is used to excavate the deep foundation pit of the shaft pumping station. The jet grouting piles 1 and diaphragm walls 2 can play the roles of soil reinforcement, water cutoff, anti-seepage, and load-bearing to ensure the stability of the deep foundation pit shaft wall. The construction of jet grouting piles and diaphragm walls must ensure that the stability of the deep foundation pit shaft wall and surface settlement meet the requirements of the specifications. The excavation depth of the shaft foundation pit must meet the requirements of the installation elevation of the units. The lower cylindrical concrete structure of the shaft pump house and the diaphragm wall are jointly stressed to jointly bear the external groundwater pressure and soil pressure.

[0040] According to the statistics of the data of existing projects, at present, the maximum diameter of a single cylinder in China is about 40m. The reinforced concrete circular arch effect and stability of super-large diameter cylinders are relatively poor. Therefore, the cylindrical concrete structure 3 is used to arrange six pump units 4. The upper plant 6 of the multi-connected cylinder shaft pumping station is built on the ground surface 12. The plant 6 is set as a rectangular plant, which is combined with the lower cylindrical concrete structure 3 to form a multi-connected cylinder shaft pumping station structure with a round bottom and a square top. Lifting equipment 8 such as bridge cranes is arranged in the upper rectangular plant of the multi-connected cylinder shaft pumping station. Each cylindrical pump house can share a bridge crane 8 to meet the lifting of large equipment inside the pumping station and reduce the investment in lifting equipment. Connecting tunnels 7 are arranged on the operating layer 9 and volute layer 13 inside the cylindrical concrete structure 3 to facilitate the passage of operation and maintenance personnel inside each cylindrical pump house.

[0041] Based on the above structural design, the present invention provides a construction method for a multi-connected cylinder shaft pumping station structure with high external pressure resistance, including:

[0042] Determine the size and depth of the multi-connected cylinder shaft according to the number of pump units in the pumping station, equipment size, elevation of mechanical and electrical installation, and size requirements of operation and maintenance channels;

[0043] Determine the bottom elevation of the diaphragm wall and jet grouting piles according to the geological conditions and requirements of the rock formation boundary. Among them, the bottom elevation of the diaphragm wall should be 1.5 - 2m lower than the bottom elevation of the shaft and be located in the weakly weathered or slightly weathered rock formation, and the bottom elevation of the jet grouting pile is the lower limit of full weathering;

[0044] Construct according to the sequence of jet grouting piles → diaphragm wall → shaft wall concrete structure → connecting tunnels between shafts → shaft bottom slab → upper plant → concrete structures of volute layer and operating layer in the shaft → installation of pump units.

[0045] The present invention circumvents the problems of large-scale open excavation and backfilling of deep foundation pits in cities and the large occupation of urban surface resources; it can meet the requirements of a large difference between the installation elevation of the unit and the ground elevation, and avoid the problems of difficult excavation and support of the underground pump station chamber group and poor surrounding rock stability under adverse geological conditions; it makes full use of the advantage of the good stress condition of the circular pump station structure under the action of high external water pressure and high external soil pressure; it solves the restrictive factors that the unit scale is large, the number of units is large, and all units cannot be arranged in a single cylindrical pump station, as well as the poor circular arch effect and stability of the super-large cylindrical reinforced concrete; it solves the problem that multiple single cylindrical pump stations cannot be connected to each other, cannot share the upper plant and lifting equipment, and are inconvenient for operation, maintenance and management; the construction and operation are safe and reliable, and the technical economy is good. When the scale of the pump station is large and the number of units is large, the present invention can also meet the space requirements for unit layout by increasing the number of cylinders, and has strong applicability.

[0046] Based on the description and drawings of the present invention, those skilled in the art can easily manufacture or use a multi-connected cylinder shaft-type pump station structure of the present invention and can produce the positive effects recorded in the present invention.

[0047] Unless otherwise specified, in the present invention, if there are terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the orientation or positional relationship in the present invention are only used for exemplary illustration and cannot be understood as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood by combining the drawings and according to the specific situation.

[0048] Unless otherwise clearly defined and limited, in the present invention, if there are terms such as "set", "connected" and "connected", they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific situation.

[0049] The above are only the preferred implementation schemes of the present invention, but the present invention is not limited to the above specific implementation schemes. Without departing from the principle of the present invention, those of ordinary skill in the art can also make several modifications, supplements or use similar methods for substitution, which should also be regarded as the protection scope of the present invention.

Claims

1. An anti-high external pressure multi-connected cylinder shaft-type pumping station structure, characterized in that, the pumping station structure includes a plurality of cylindrical concrete structures (3) connected side by side. A retaining structure is arranged outside each cylindrical concrete structure (3). The plurality of cylindrical concrete structures (3) are integrally embedded inside a foundation pit below the ground surface (12). A pump unit (4) is arranged inside each cylindrical concrete structure (3). A plant building (6) is arranged on the top of the plurality of cylindrical concrete structures (3). A hoisting device (8) is arranged inside the plant building (6); the retaining structure includes a cylindrical jet grouting pile (1) and a cylindrical diaphragm wall (2). The outer wall of the cylindrical diaphragm wall (2) is attached to the inner wall of the cylindrical jet grouting pile (1). The inner wall of the cylindrical diaphragm wall (2) is attached to the outer wall of the cylindrical concrete structure (3); Connecting tunnels (7) are arranged between the operating floors (9) and between the volute floors (13) in two adjacent cylindrical concrete structures (3). The connecting tunnels (7) penetrate through the cylindrical concrete structures (3) and the retaining structure; The diameter of a single cylindrical concrete structure (3) is set to be 15 - 40m.

2. The anti-high external pressure multi-connected cylinder shaft-type pumping station structure according to claim 1, characterized in that: the plant building (6) is a rectangular plant building (6), and the length direction thereof is the same as the arrangement direction of the plurality of cylindrical concrete structures (3).

3. The anti-high external pressure multi-connected cylinder shaft-type pumping station structure according to claim 1, characterized in that: the hoisting device (8) is fixed in the middle of the plant building (6).

4. The anti-high external pressure multi-connected cylinder shaft-type pumping station structure according to claim 1 or 3, characterized in that: the hoisting device (8) adopts a bridge crane.

5. A construction method of the anti-high external pressure multi-connected cylinder shaft-type pumping station structure according to any one of claims 1 - 4, characterized in that, it includes: determining the size and depth of the multi-connected cylinder shaft according to the requirements of the number of pumping station units, equipment dimensions, elevation of mechanical and electrical installation, and dimensions of the operation and maintenance passage; determining the bottom elevation of the diaphragm wall and the jet grouting pile according to the geological conditions and the requirements of the rock stratum boundary line. Among them, the bottom elevation of the diaphragm wall should be 1.5 - 2m lower than the bottom elevation of the shaft and be located in the weakly weathered or slightly weathered rock stratum. The bottom elevation of the jet grouting pile is the lower limit of the completely weathered layer; constructing according to the sequence of jet grouting pile → diaphragm wall → shaft barrel body concrete structure → connecting tunnel between shafts → shaft bottom slab → upper plant building → volute floor and operating floor concrete structures inside the shaft → installation of pump units.

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