Sandy river-facing sewage pump pit structure and construction method

Abstract

The invention belongs to the technical field of sewage pump pits, and particularly relates to a sand river-facing sewage pump pit structure which mainly comprises a pump pit structure and a supporting structure. The pump pit structure comprises a water inlet pipe, a water outlet pipe, a concrete sealing bottom, a pump pit body and a sewage pump assembly. The supporting structure comprises a plurality of cement mixing piles and a plurality of cast-in-place piles. The plurality of cement mixing piles are arranged in a multi-layer annular array, and the cement mixing piles are tightly engaged with one another; the multiple cast-in-place piles are arranged in a circular ring shape and are inserted into the multiple cement mixing piles in a penetrating mode. Wherein the concrete seal bottom is located at the bottom, the pump pit body is located on the concrete seal, the water inlet pipe and the water outlet pipe penetrate through the cement mixing pile to communicate with the pump pit body, and the sewage pump assembly is installed at the bottom and communicates with the water outlet pipe. According to the sand river-facing sewage pump pit structure, the durability and the stability of the pump pit supporting structure are improved through the supporting structure formed by mutual meshing of the multiple cement mixing piles and the cast-in-place piles, the waterproof effect is improved, and the water blocking difficulty is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage pump pits, and in particular relates to a sandbar riverside sewage pump pit structure and a construction method. Background Art

[0002] Foundation pit construction is an important part of construction project construction, including foundation pit support, base reinforcement, precipitation, earth excavation, etc. It has the characteristics of large scale, short distance, large depth and compact area, which can effectively improve the stability and safety of construction projects.

[0003] In a pump pit project in a certain city, it is necessary to construct the pump pit in the geological and hydrological environment of the sandbar near the river. The soil layer below the ground is mixed fill, sand and gravel mixed soil layer, silt layer, gravel layer, and round gravel layer, and the groundwater level is about 0.5m below the ground. Because it is built close to the structure and the Han River, affected by the construction environment, there will be problems such as difficulty in precipitation, difficulty in water blocking, difficulty in concealed connection of pipe network, and poor structural durability and stability during construction. Summary of the invention

[0004] The present application provides a sandbar riverside sewage pump pit structure and construction method, aiming to solve at least one of the above-mentioned technical problems.

[0005] On the one hand, the present application provides a sandbar riverside sewage pump pit structure, comprising:

[0006] A pump pit structure, the pump pit structure comprising an inlet pipe, an outlet pipe, a concrete bottom seal, a pump pit body and a sewage pump assembly;

[0007] A support structure, wherein the support structure comprises a plurality of cement mixing piles and a plurality of cast-in-place piles; the plurality of cement mixing piles are arranged in a multi-layered annular array, and the cement mixing piles are closely engaged with each other; the plurality of cast-in-place piles are arranged in a circular ring shape, and the cast-in-place piles are interspersed among the plurality of cement mixing piles;

[0008] Among them, the concrete bottom seal is located at the bottom of the center of the annular array, the pump pit main body is located above the concrete bottom seal, the water inlet pipe and the water outlet pipe pass through the cement mixing pile and are connected to the pump pit main body, and the sewage pump assembly is installed at the bottom of the pump pit main body and is connected to the water outlet pipe.

[0009] The above-mentioned Shazhou Linjiang sewage pump pit structure has improved the durability and stability of the pump pit support structure through the support structure composed of a number of cement mixing piles and cast-in-place piles that interlock with each other. In addition, a number of cement mixing piles interlock with each other to form a good water-stop curtain effect, which improves the waterproof effect and reduces the difficulty of water blocking.

[0010] In the technical solution of one embodiment, a tension anchor rod is arranged between the pump pit body and the supporting structure.

[0011] In the technical solution of one embodiment, a tension anchor rod is arranged between the pump pit body and the concrete bottom seal.

[0012] In the technical solution of one embodiment, the inner wall of the pump pit body is configured with a GRP glass fiber reinforced plastic cylinder.

[0013] In the technical solution of one embodiment, a pipe joint is pre-buried in the pump pit body, the pipe joint has flanges at both ends and a water stop ring in the middle, and the pipe joint is connected to the water inlet pipe toward the outside.

[0014] In the technical solution of one embodiment, a pipe joint is pre-buried in the pump pit body, the pipe joint has flanges at both ends and a water stop ring in the middle, and the pipe joint is connected to the water outlet pipe toward the outer end.

[0015] In the technical solution of one embodiment, when installing the GRP glass fiber reinforced plastic cylinder, a plugging plate is arranged on the inner end of the pipe joint, and the plugging plate is detachably connected to the pipe joint.

[0016] In a technical solution of an embodiment, after the GRP cylinder is installed, a grille assembly is disposed toward the inner end of the pipe joint.

[0017] In the technical solution of one embodiment, the pump pit structure also includes a deodorization system, which is installed outside the pump pit body and extends into the pump pit body through a pipeline to remove odor in the pump pit body.

[0018] In a technical solution of an embodiment, the support structure further includes a ring beam, and the ring beam is arranged around the top of the cast-in-place pile.

[0019] In the technical solution of one embodiment, the support structure further includes a plurality of inner supports, each of which is in a circular ring shape and fixedly supports the cement mixing piles in the inner ring.

[0020] On the other hand, the present application provides a construction method for a sewage pump pit structure near the river in Shazhou, including: cement mixing pile construction, cast-in-place pile construction, earth excavation construction, water inlet and outlet pipe construction, bottom sealing concrete construction, pump pit main body construction, and equipment installation construction; wherein,

[0021] In the cast-in-place pile construction: several cast-in-place pile pits are drilled, a water filter pipe is installed at the bottom of 1-3 of the cast-in-place pile pits, and a downpipe is placed inside the water filter pipe to form a downpipe system; cast-in-place piles are cast in the remaining cast-in-place pile pits;

[0022] In the subsequent construction, the dewatering operation is carried out by connecting a water pump to the dewatering pipe. After the dewatering operation is completed, the dewatering system is withdrawn to complete the construction of the bored piles in the bored pile pit.

[0023] In a technical solution of an embodiment, a construction method of a sandbar riverside sewage pump pit structure comprises:

[0024] S100, cement mixing pile construction: the cement mixing piles are constructed from the inside to the outside, and positions for the cast-in-place pile construction are reserved;

[0025] S200, bored pile construction: bored pile pits are drilled at the reserved bored pile construction locations, water filter pipes are installed at the bottoms of 1-3 of the bored pile pits, and downpipes are placed inside the water filter pipes to form a downpipe system; bored piles are cast in the remaining bored pile pits;

[0026] S300, construction of ring beam: after the cast-in-place piles are finally set, a part of the cast-in-place pile heads and cement mixing pile heads is chiseled off, and the steel cage of the ring beam is placed, and it is tied and connected with the steel bars of the cast-in-place piles and cement mixing piles, and concrete is poured;

[0027] S400, earthwork excavation construction: excavate the earthwork within the supporting structure and construct the water outlet and water inlet pipes at the same time;

[0028] S500, side anchor bolt construction: side anchor bolt construction is carried out along with earth excavation;

[0029] S600, bottom seal concrete construction: After excavation to the base, clean the surface, lay thick pebbles and gravel, tamp them to make them dense and flat, pour the bottom seal concrete, and level the surface;

[0030] S700, bottom anchor bolt construction: before the bottom concrete sets, after the concrete slump drops a certain distance, the anchor bolt is inserted immediately;

[0031] S800, pump pit main construction:

[0032] S810, after the concrete strength of the bottom seal reaches more than 75%, tie the steel bars of the lower part, and install the pipe joints and plugging plates;

[0033] S820, hoist the lower half of the GRP cylinder;

[0034] S830, after hoisting the GRP cylinder, pour the concrete of the lower part of the pump pit;

[0035] S840, tie the upper part of the steel bars, hoist the upper GRP cylinder, and pour concrete;

[0036] S850, remove the downcomer pipe and complete the construction of the cast-in-place piles in the cast-in-place pile pit;

[0037] S860, pouring concrete for the remaining part of the pump pit;

[0038] S900, Equipment installation and construction: After the main construction of the pump pit is completed, the grille assembly and sewage pump assembly will be installed and debugged.

[0039] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings in this application are used to illustrate preferred embodiments, so as to facilitate a person skilled in the art to clearly understand various other advantages and benefits, and should not be considered as limiting this application. In addition, the same reference numerals are used to represent the same components in all the drawings.

[0041] Figure 1 It is a schematic elevational cross-sectional view of a Shazhou riverside sewage pump pit structure in one embodiment of the present application.

[0042] Figure 2 It is a schematic cross-sectional view of a support structure in one embodiment of the present application.

[0043] Figure 3 for Figure 2 Schematic diagram of the middle AA direction.

[0044] Figure 4 for Figure 2 Schematic diagram of the middle BB direction.

[0045] Figure 5 for Figure 2 Schematic diagram of CC direction.

[0046] Figure 6 It is a schematic elevational cross-sectional view of a pump pit structure in one embodiment of the present application.

[0047] Figure 7 This is a partial schematic diagram of a pipe joint in one embodiment of the present application.

[0048] Figure 8 It is a top view schematic diagram of the sandbar riverside sewage pump pit structure in one embodiment of the present application.

[0049] Description of Figure Numbers:

[0050] 100. Pump pit structure; 101. Water inlet pipe; 102. Water outlet pipe; 103. Concrete bottom seal; 104. Pump pit body; 105. Pull anchor rod; 106. GRP fiberglass cylinder; 107. Sewage pump assembly; 108. Grille assembly; 109. Pipe joint; 110. Deodorization system; 111. Blocking plate; 112. Locking bolts and nuts;

[0051] 200. Support structure; 201. Cement mixing piles; 202. Cast-in-place piles; 203. Ring beam; 204. Internal support; 205. Downflow pipe; 206. Cast-in-place pile pit; 207. Water filter pipe. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0055] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0056] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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 a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0057] In a pump pit project, the applicant conducted an investigation and study and found that the construction site was located in a geological and hydrological environment of a sandbar near the river. The soil layers below the ground were miscellaneous fill, sand and gravel mixed soil, silt, gravel, and rounded gravel, and the groundwater level was about 0.5m below the ground. Because it was built close to the structure and the Han River, and was affected by the construction environment, we found the following problems after research: (1) The pump pit is close to the structure, and the foundation pit construction has a greater impact on the foundation, which can easily cause foundation subsidence, leading to hazards such as cracking of the structure; (2) The pump pit is close to the Han River, the groundwater level in the sandbar environment is high, the sand is soft, the river water has a strong infiltration pressure, and precipitation brings high sand and soil settlement. Conventional construction "support + water reduction and water stopping" cannot take into account the site environment, and may cause greater hazards, such as foundation pit seepage, inability to form effective precipitation, foundation subsidence, collapse of holes, deformation, etc.; (3) The conventional pump pit itself has defects in structure, and the pollution hazards caused by structural leakage to the water body and the erosion of the structure itself have not been evaluated. The anti-floating of the buoyancy fluctuation caused by the water level fluctuation in the pump pit has not been considered; (4) The deeper pipes need to be connected secretly, and the ordinary support structure needs to be drilled and sand fixed. It is extremely difficult to seal in the sandy and high water level environment; (5) It is extremely difficult to drill holes for bored piles in sandbar environments. It is extremely difficult to form water stops and ensure concealed connections of pipes with precast piles, steel sheet piles, steel pipe piles, etc., and there is a lack of pile combination options; etc.

[0058] For one of the above technical issues, see Figure 1-8 As shown, an embodiment of the present application provides a sandbar riverside sewage pump pit structure, including a pump pit structure 100 located outside and a support structure 200 located inside. The pump pit structure 100 generally includes an inlet pipe 101, an outlet pipe 102, a concrete bottom seal 103, a pump pit body 104 and a sewage pump assembly 107. The support structure 200 includes a plurality of cement mixing piles 201 and a plurality of cast-in-place piles 202; the plurality of cement mixing piles 201 are arranged in a multi-layer annular array, and the cement mixing piles 201 are tightly engaged with each other; the plurality of cast-in-place piles 202 are arranged in a circular ring, and the cast-in-place piles 202 are interspersed among the plurality of cement mixing piles 201. The concrete bottom seal 103 is located at the bottom of the center of the annular array, the pump pit body 104 is located above the concrete bottom seal 103, the water inlet pipe 101 and the water outlet pipe 102 pass through the cement mixing pile 201 and are connected to the pump pit body 104, and the sewage pump assembly 107 is installed at the bottom of the pump pit body 104 and is connected to the water outlet pipe 102. The above-mentioned Shazhou Linjiang sewage pump pit structure improves the durability and stability of the pump pit support structure through the support structure 200 composed of a plurality of cement mixing piles 201 and cast-in-place piles 202 interlocking with each other, and a plurality of cement mixing piles 201 interlock to form a good water-stopping curtain effect, which improves the waterproof effect and reduces the difficulty of water blocking.

[0059] It should be noted that the cement mixing piles 201 arranged in a multi-layer annular array have at least two layers, preferably in the range of 3-7 layers; preferably 5 layers, and the number of outer layers of the cast-in-place piles 202 is greater than the number of inner layers of the cast-in-place piles 202.

[0060] In some embodiments, see Figure 1 and 6 As shown, a tension anchor rod 105 is arranged between the pump pit body 104 and the support structure 200, which effectively enhances the integrity and anti-floating performance of the structure.

[0061] Furthermore, a tension anchor rod 105 can also be arranged between the pump pit body 104 and the concrete bottom seal 103. This can also effectively enhance the integrity and anti-floating performance of the structure. The pump pit body 104, the concrete bottom seal 103, and the support structure 200 (cement mixing pile 201 and cast-in-place pile 202) are pulled together into a whole by the tension anchor rod 105, thereby enhancing the anti-floating performance of the structure and ensuring the stable operation of the structure.

[0062] In some embodiments, see Figure 6 , 7 As shown in Figure 8, the inner wall of the pump pit body 104 is provided with a GRP glass fiber reinforced plastic cylinder 106. The GRP glass fiber reinforced plastic cylinder 106 is used as a template during the construction period and as an anti-corrosion protective layer during the operation period, thereby enhancing the anti-penetration performance and visual quality of the structure, effectively reducing complex processes, reducing costs, improving safety, and preventing sewage from corroding and damaging the pump pit body 104.

[0063] In some embodiments, see Figure 7 As shown, a pipe joint 109 is pre-buried in the pump pit body 104. The pipe joint 109 has flanges at both ends and a water stop ring in the middle. The pipe joint 109 is connected to the water inlet pipe 101 at the outer end. A plugging plate 111 is arranged at the inner end of the pipe joint 109. The plugging plate 111 and the pipe joint 109 are detachably connected (such as connected by locking bolts and nuts 112). The pipe joint 109 can be temporarily matched with the plugging plate 111 during construction to prevent slurry leakage.

[0064] It is understandable that a pipe joint 109 can also be designed at the water outlet pipe 102, and the principle and effect are the same as above and will not be repeated.

[0065] In some embodiments, after the GRP cylinder 106 is installed, a grille assembly 108 is disposed at the inner end of the pipe joint 109 to filter debris and prevent blockage, and a flange connection is also used for drainage.

[0066] In some embodiments, see Figure 6As shown, the pump pit structure 100 further includes a deodorization system 110, which is installed outside the pump pit body 104 and extends into the pump pit body 104 through a pipeline, and is used to remove odor in the pump pit body 104 to protect the environment.

[0067] In some embodiments, see Figure 4 and 5 As shown, the support structure 200 further includes a ring beam 203, which is arranged around the top of the cast-in-place pile 202. The ring beam 203 effectively connects the cement mixing pile 201 and the cast-in-place pile 202 into a whole, thereby effectively improving the overall lateral pressure resistance of the foundation pit support structure.

[0068] Optionally, the width of the ring beam 203 is equal to the diameter of the cast-in-place pile 202, the thickness is 300 mm, and the concrete strength is ≧C25.

[0069] In some embodiments, see Figure 3 and 4 As shown, the support structure 200 also includes a plurality of inner supports 204, which are annular and fixedly supported on the inner ring of cement mixing piles 201. The plurality of inner supports 204 support a circle of cement mixing piles 201 inside the support structure 200, thereby enhancing the overall performance and ensuring the normal progress of subsequent construction.

[0070] Optionally, the inner support 204 may be composed of multiple sections of arc-shaped 12#-18# I-beams, which are fixed on the side wall of the cement mixing pile 201 by rivets, with one section arranged every 3m-4m up and down.

[0071] See also Figure 1-8 As shown, another embodiment of the present application provides a construction method for the sewage pump pit structure of Shazhou Linjiang based on any of the above-mentioned implementations, which mainly includes the following steps: construction of cement mixing piles 201, construction of cast-in-place piles 202, construction of earth excavation, construction of water inlet and outlet pipes, construction of bottom sealing concrete 103, construction of pump pit body 104, and equipment installation. Among them, in the construction of cast-in-place piles 202: drilling and excavation of several cast-in-place pile pits 206, installing filter pipes 207 at the bottom of 1-3 cast-in-place pile pits 206, and placing downflow pipes 205 in the filter pipes 207 to form a downflow system; casting construction of cast-in-place piles 202 is performed on the remaining cast-in-place pile pits 206; in the subsequent construction, a water pump is connected to the downflow pipe 205 to perform downflow operations. After the downflow operations are completed, the downflow system is withdrawn to complete the construction of cast-in-place piles 202 in the cast-in-place pile pits 206. Through the dewatering system temporarily designed in the cast-in-place pile pit 206, it is used as a dewatering well in the early stage to dewater the foundation pit to ensure subsequent construction, and later as cast-in-place piles 202 to ensure the integrity, strength and water-stopping properties of the structure.

[0072] In some embodiments, see Figure 3 and4 As shown, a construction method of a sandbar riverside sewage pump pit structure may specifically include the following steps:

[0073] S100, construction of cement mixing piles 201: according to the pile position and pile length design of cement mixing piles 201, the construction of cement mixing piles 201 is carried out from the inside to the outside, and a construction position for cast-in-place piles 202 is reserved; if interrupted for some reason, it should be resumed within 3 hours, and the engagement of adjacent piles should be completed before the initial setting of the cement mixing piles.

[0074] S200, construction of bored piles 202: bored pile pits 206 are drilled at the reserved bored pile 202 construction positions, water filter pipes 207 are installed at the bottoms of 1-3 of the bored pile pits 206, and downpipes 205 are placed inside the water filter pipes 207 to form a downpipe system; the remaining bored pile pits 206 are cast with bored piles 202.

[0075] Specifically, after the strength of the cement mixing pile 201 reaches the design requirements and passes the test, the rotary drilling pile construction technology and underwater concrete pouring technology are used for construction. After the mud and sand in the gap of the bored pile 202 reserved by the cement mixing pile 201 are rotary drilled, the mud and sand on the pile wall of the cement mixing pile 201 and the soil at the bottom of the pile are promptly dealt with to ensure the bonding quality between the bored pile 202 and the cement mixing pile 201. The verticality and pile position deviation should be ensured during the construction process to avoid damage to the cement mixing pile 201. If the drill is stuck or it is difficult to rotary drill during the construction process, the deviation should be adjusted in time.

[0076] Optionally, the end of the water filter pipe 207 is welded to the steel cage of the bored pile 202, and a permeable concrete filter pipe can be used, the pipe diameter is the same as the pile diameter of the bored pile 202, and the length is 2.5m-4m.

[0077] For the cast-in-place pile pit 206, which is the location of the temporary drainage well (i.e., drainage system), the mud wall protection process is used to continue drilling 3m-4m downward, and then the filter pipe 207 is welded to the lower end of the steel cage of the cast-in-place pile 202 and lowered into the cast-in-place pile pit 206, and fixed at the specified depth; the filter head and the pump are assembled on the drainage pipe 205 to form a drainage system, and the drainage pipe 205 with the filter head installed is lowered from the middle of the steel cage, so that the filter head is suspended at a position 20cm away from the bottom of the filter pipe 207. After installation and debugging, it is immediately used for drainage. The other cast-in-place pile holes are promptly equipped with steel cages and concrete poured.

[0078] It can be understood that the filter head is installed at the end of the downcomer 205 to form a water extraction pipeline, and filter holes are densely arranged around and at the bottom of the filter head. Optionally, the downcomer 205 is a PE pipe.

[0079] It is understandable that precipitation systems are generally designed in two sets, one as a backup.

[0080] S300, construction of ring beam 203: after the cast-in-place pile 202 is finally set, a part of the pile head of the cast-in-place pile 202 and the pile head of the cement mixing pile 201 is chiseled off, and the steel cage of the ring beam 203 is placed, and it is tied and connected with the steel bars of the cast-in-place pile 202 and the cement mixing pile 201, and concrete is poured.

[0081] S400, earthwork excavation construction: excavate the earthwork inside the support structure 200, and construct the outlet pipe 102 and the inlet pipe 101 at the same time. Specifically, the outlet pipe 102 is constructed first and then the inlet pipe 101 in the order of shallow construction first and deep construction later. Among them, the outlet pipe 102 is shallowly buried (less than 1.5m), so it can be excavated by open excavation method, and the cement mixing pile 201 is drilled by water drilling. If it is deeper, it is appropriate to use the same construction process as the inlet pipe 101. The inlet pipe 101 adopts the dragging pipe process, and the pump pit is designed as a horizontal straight end pressure relief pit. The soil is excavated to the bottom elevation of the inlet pipe 101, and the construction is carried out by drilling against the water and dragging back along the water; after the construction is completed by the dragging pipe process, the mud should be cleaned in time, and the mud, floating sand, residue, pumice, etc. on the side wall of the cement mixing pile 201, the gap in the pipe wall of the cement mixing pile 201, and the directional drilling drill hole are cleaned, and the foamed cement grouting is used to seal. The earthwork is excavated downwards using a long-arm small excavator. The excavated soil should be piled at a place more than 2 times the depth of the foundation pit or transported out as it is excavated. When the excavation reaches the specified elevation, internal support construction should be carried out in time, with an excess depth of 2m.

[0082] S500, construction of side anchor rods 105: construction of side anchor rods 105 is performed as the earthwork is excavated. As the foundation pit is excavated and the side walls of the cement mixing piles 201 are cleaned, construction of side anchor rods 105 is performed as required. Optionally, the anchor rods 105 can be made of threaded steel bars.

[0083] S600, construction of bottom concrete 103: after the excavation reaches the base, clean the surface slurry soil, lay thick pebbles and gravel, tamp them to make them dense and flat, pour the bottom concrete 103, and level the surface; among them, except for the internal support 204 in the bottom concrete 103, all other internal supports 204 are removed to ensure the stability of the structure during pouring.

[0084] Optionally, the bottom sealing concrete 103 should be made of self-compacting and anti-seepage concrete of ≥P6C25, with additives such as micro-expansion agent and underwater non-dispersant added at ≥0.3%, and a thickness of ≥1.5m.

[0085] S700, construction of bottom anchor rod 105: before the initial setting of the bottom sealing concrete 103, after the concrete slump drops a certain distance, the anchor rod 105 is inserted immediately; cement slurry is added to the disturbance mouth formed by the insertion, and the disturbance surface is pressed and leveled in time.

[0086] S800, the construction of the pump pit body 104 may include the following steps:

[0087] S810, after the strength of the bottom concrete 103 reaches more than 75%, tie the steel bars of the lower half of the pump pit body 104, weld the lower water stop steel plate (not shown in the figure), and install the pipe joint 109 and the sealing plate 111.

[0088] S820. Hoist the lower half of the GRP cylinder 106. During the hoisting process, adjust the direction of the hook of the anchor bolt (not shown in the figure) to avoid conflict with the bottom plate steel bars (not shown in the figure).

[0089] S830, after hoisting the GRP glass fiber reinforced plastic cylinder 106, the concrete of the lower part of the pump pit body 104 is poured; and grouting is performed in other cavities of the molding. Specifically, the lower half of the GRP glass fiber reinforced plastic cylinder 106 can also be divided into two sections, and when hoisting the first section, the temporary blocking plate 111 is used to block the pipe joint 109 to fix the first section of the GRP glass fiber reinforced plastic cylinder 106. When installing the second section, the temporary blocking plate 111 is used to block the pipe joint 109 to fix the first section of the GRP glass fiber reinforced plastic cylinder 106.

[0090] S840, dismantle the inner support 204, tie the steel bars of the upper part of the pump pit body 104, weld the upper water stop steel plate (not shown in the figure), hoist the upper half of the GRP glass fiber reinforced plastic cylinder 106, and pour concrete.

[0091] S850, withdraw the downcomer 205, and complete the construction of the cast-in-place piles 202 in the cast-in-place pile pit 206.

[0092] S860, pour the remaining part of the pump pit body 104 into concrete.

[0093] S900, equipment installation and construction: after the construction of the pump pit main body 104 is completed, installation and commissioning of equipment components such as the grille assembly 108 and the sewage pump assembly 107 are carried out.

[0094] This method has simplified process, strong overall operability, and safe and reliable construction process, and achieves the advantages of riverside water-stop curtain, bored pile drilling, foundation pit dewatering, structural corrosion resistance and leakage resistance, and safety and stability, reducing construction costs and subsequent operation and maintenance costs, and improving construction safety performance and quality.

[0095] In summary, this application has the following beneficial effects:

[0096] (1) Rationally utilize the characteristics of sandy soil in the sandbar, set cement mixing piles around the foundation pit to stabilize the sand and reduce foundation disturbance, and effectively reduce the impact of pump pit excavation and support structure construction on surrounding structures. Cement mixing piles can effectively ensure the quality of the hole formed by the dragging pipe, realize the penetration of the water-stopping support structure, and will not cause serious seepage of quicksand through the pipe wall. Ensure the stability of the foundation of adjacent structures, avoid the disturbance of the surrounding areas caused by the construction of water inlet and outlet pipes, effectively reduce construction costs, and make construction simple and convenient. At the same time, increase the structure's anti-seepage, anti-erosion, and anti-floating properties, and reduce the impact of surrounding structures, sandy soil and the high water level of the Han River on the pump pit construction.

[0097] (2) By designing multiple circles of cement mixing piles that interlock with each other (inner circle, middle circle (cast-in-place pile circle), and outer circle), a multi-layer water-stopping effect is formed to effectively isolate groundwater. The cement mixing piles form a stable wall structure around the cast-in-place piles, which can effectively prevent the impact of hole collapse on surrounding structures during the cast-in-place pile drilling process. The cast-in-place piles in the middle of the cement mixing piles effectively form a keel that resists pressure measurement, effectively improving the support structure's ability to resist lateral pressure. By reinforcing the gaps with cement slurry when pouring cast-in-place piles, the water-stopping effect is effectively guaranteed.

[0098] (3) The number of layers in the outer ring of the cement mixing pile is greater than that in the inner ring (relative to the inside and outside of the cast-in-place pile), forming a seepage pressure drop difference. The cast-in-place pile pit is used to reduce the water pressure inside the pump pit, effectively avoiding the hazards of hole collapse and settlement, ensuring dry bottom construction at the bottom of the pit and avoiding spring gushing.

[0099] (4) By setting a ring beam on the top of the bored pile, the cement mixing piles and bored piles around the pump pit are effectively connected into a whole, which effectively improves the overall lateral pressure resistance of the foundation pit support structure and effectively avoids the damage of the bored pile pit used as a dewatering well.

[0100] (5) By using the GRP fiberglass cylinder as the inner formwork, the complex process is effectively reduced, the cost is reduced, the safety is improved, the visual quality and anti-penetration performance of the main structure of the pump pit are effectively guaranteed, and the erosion and damage of the pump barrel by sewage and the erosion of the concrete pump suction by the submersible sewage system are effectively avoided. In this structure, the GRP fiberglass cylinder is used on the inner side of the main structure of the pump pit, which is used as a formwork during the construction period and as an anti-erosion protective layer during the operation period to enhance the anti-penetration performance of the structure.

[0101] (6) By setting anchor rods at multiple locations, the integrity and anti-floating performance of the structure are effectively enhanced. The anchor rods are used to tie the pump pit body to the concrete bottom and the cement mixing piles and cast-in-place piles on the sides to form a whole, thereby enhancing the anti-floating performance of the structure and ensuring the stable operation of the structure.

[0102] (7) Through the support structure, the pump pit body and the GRP glass fiber reinforced plastic cylinder, a water stop is formed from the outside to the inside, and a three-layer anti-leakage structure is formed from the inside to the outside, which effectively ensures the tightness of the sewage pipe network and the water environment protection effect.

[0103] (8) By placing the dewatering pipe in the hole of the cast-in-place pile used as a dewatering well in the early stage, a dewatering system is formed to facilitate dewatering operations during construction. The cast-in-place piles ensure the stability of the dewatering support structure.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A sandbar riverside sewage pump pit structure, characterized in that: include: A pump pit structure (100), the pump pit structure (100) comprising a water inlet pipe (101), a water outlet pipe (102), a concrete bottom seal (103), a pump pit body (104) and a sewage pump assembly (107); A support structure (200), the support structure (200) comprising a plurality of cement mixing piles (201) and a plurality of cast-in-place piles (202); the plurality of cement mixing piles (201) are arranged in a multi-layered annular array, and the cement mixing piles (201) are closely engaged with each other; the plurality of cast-in-place piles (202) are arranged in a circular ring shape, and the cast-in-place piles (202) are interspersed among the plurality of cement mixing piles (201); The concrete bottom seal (103) is located at the bottom of the center of the annular array, the pump pit body (104) is located above the concrete bottom seal (103), the water inlet pipe (101) and the water outlet pipe (102) pass through the cement mixing pile (201) and are connected to the pump pit body (104), and the sewage pump assembly (107) is installed at the bottom of the pump pit body (104) and is connected to the water outlet pipe (102).

2. The sandbar riverside sewage pump pit structure according to claim 1 is characterized in that: An anchor rod (105) is arranged between the pump pit body (104) and the support structure (200). and / or An anchor rod (105) is arranged between the pump pit body (104) and the concrete bottom seal (103).

3. The sandbar riverside sewage pump pit structure according to claim 1 is characterized in that: The inner wall of the pump pit body (104) is provided with a GRP glass fiber reinforced plastic cylinder (106).

4. The sandbar riverside sewage pump pit structure according to claim 3 is characterized in that: A pipe joint (109) is pre-buried in the pump pit body (104), the pipe joint (109) has flanges at both ends and a water stop ring in the middle, and the pipe joint (109) is connected to the water inlet pipe (101) at the outer end; and / or A pipe joint (109) is pre-buried in the pump pit body (104), the pipe joint (109) having flanges at both ends and a water stop ring in the middle, and the pipe joint (109) is connected to the water outlet pipe (102) at the outer end.

5. The sandbar riverside sewage pump pit structure according to claim 4 is characterized in that: When the GRP glass fiber reinforced plastic cylinder (106) is installed, a blocking plate (111) is arranged at the inner end of the pipe joint (109), and the blocking plate (111) is detachably connected to the pipe joint (109).

6. The sandbar riverside sewage pump pit structure according to claim 4 is characterized in that: After the GRP cylinder (106) is installed, a grille assembly (108) is disposed toward the inner end of the pipe joint (109).

7. The sandbar riverside sewage pump pit structure according to claim 1 is characterized in that: The support structure (200) further comprises a ring beam (203), wherein the ring beam (203) is arranged around the top of the cast-in-place pile (202).

8. The sandbar riverside sewage pump pit structure according to claim 1 is characterized in that: The support structure (200) further comprises a plurality of inner supports (204), wherein the inner supports (204) are in the shape of a circular ring and are fixedly supported on the cement mixing piles (201) in the inner ring.

9. A construction method for a sewage pump pit structure near a sandbar, characterized in that: include: Construction of cement mixing piles (201), construction of cast-in-place piles (202), earth excavation, construction of water inlet and outlet pipes, construction of bottom sealing concrete (103), construction of pump pit body (104), and equipment installation; among which, During the construction of the cast-in-place piles (202), several cast-in-place pile pits (206) are drilled, a water filter pipe (207) is installed at the bottom of 1-3 of the cast-in-place pile pits (206), and a water drop pipe (205) is placed inside the water filter pipe (207) to form a water drop system; and cast cast-in-place piles (202) are performed on the remaining cast-in-place pile pits (206); In the subsequent construction, the dewatering pipe (205) is connected to an external water pump to carry out dewatering operations. After the dewatering operations are completed, the dewatering system is withdrawn to complete the construction of the cast-in-place piles (202) in the cast-in-place pile pit (206).

10. The construction method of the sandbar riverside sewage pump pit structure according to claim 9 is characterized in that: include: S100, construction of cement mixing piles (201): construction of the cement mixing piles (201) is performed sequentially from the inside to the outside, and a construction position for the cast-in-place piles (202) is reserved; S200, construction of cast-in-place piles (202): drilling cast-in-place pile pits (206) at reserved cast-in-place pile (202) construction locations, installing water filter pipes (207) at the bottoms of 1-3 cast-in-place pile pits (206), placing downflow pipes (205) in the water filter pipes (207) to form a downflow system; and casting cast-in-place piles (202) for the remaining cast-in-place pile pits (206); S300, construction of the ring beam (203): after the cast-in-place pile (202) is finally set, a portion of the pile head of the cast-in-place pile (202) and the pile head of the cement mixing pile (201) is chiseled off, and a steel cage of the ring beam (203) is placed, and the steel cage is tied and connected with the steel bars of the cast-in-place pile (202) and the cement mixing pile (201), and concrete is poured; S400, earth excavation construction: excavating the earth inside the supporting structure (200), and constructing the water outlet pipe (102) and the water inlet pipe (101) at the same time; S500, side anchor bolt (105) construction: side anchor bolt (105) construction is performed along with earth excavation construction; S600, bottom seal concrete (103) construction: after the earthwork is excavated to the base, the surface layer is cleaned, thick pebbles and gravels are laid, and compacted and leveled, and the bottom seal concrete (103) is poured to level the surface; S700, construction of bottom anchor rod (105): before the bottom sealing concrete (103) is initially set, after the concrete slump drops a certain distance, the anchor rod (105) is inserted immediately; S800, Pump pit main body (104) construction: S810, after the strength of the bottom concrete (103) reaches more than 75%, tie the steel bars of the lower part, install the pipe joint (109) and the plugging plate (111); S820, hoist the lower half of the GRP cylinder (106); S830, after the GRP glass fiber reinforced plastic cylinder (106) is hoisted, the concrete pouring of the lower part of the pump pit body (104) is carried out; S840, tie the steel bars of the upper part, hoist the upper GRP cylinder (106), and pour concrete; S850, withdrawing the downcomer (205) and completing the construction of the cast-in-place piles (202) in the cast-in-place pile pit (206); S860, pouring the remaining concrete of the pump pit body (104); S900, equipment installation and construction: after the construction of the pump pit body (104) is completed, the grille assembly (108) and the sewage pump assembly (107) are installed and debugged.

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