Underwater construction method for deep overhaul well in coastal water-rich area

Abstract

The invention discloses an underwater construction method for a deep inspection well in a coastal water-rich area, and belongs to the technical field of inspection wells. The underwater construction method for the deep inspection well in the coastal water-rich area comprises the steps that S1, seepage-proofing supporting is conducted, a foundation pit working face is excavated, and a bottom plate of the inspection well is poured; s2, the box-type structure of the overhaul well is divided into a first prefabricated section and a plurality of second prefabricated sections, and segmented prefabrication is conducted; s3, the first prefabricated section is hoisted and lowered to the bottom plate, the second prefabricated sections are hoisted and lowered in sequence, and the second prefabricated sections are stacked on the first prefabricated section in sequence; s4, a heightening pouring section is poured on the second prefabricated section located at the top end; s5, post-cast strips are constructed on the inner walls of the first prefabricated section and the second prefabricated sections; and S6, foundation pit backfilling operation on the exterior of the box type structure is implemented. According to the invention, the high cost caused by complex anti-seepage measures is effectively reduced, so that the investment of an engineering site in the aspect of anti-seepage is greatly reduced, the construction efficiency is improved, and precious human resources are saved.

Description

Technical Field

[0001] The invention relates to the technical field of inspection wells, and in particular to an underwater construction method for deep inspection wells in coastal water-rich areas. Background Art

[0002] When carrying out the construction of water supply and drainage inspection wells in water-rich areas, it is necessary to build a special retaining structure, which must not only have sufficient strength and stability to withstand the lateral pressure and other construction loads from the soil around the foundation pit, but also must have good anti-seepage performance to prevent groundwater from seeping into the foundation pit, ensuring that the inspection well can be cast on site in a dry construction environment to meet the dry construction requirements.

[0003] In the prior art, due to the complex hydrogeological conditions in coastal water-rich areas, once the anti-seepage design of the retaining structure fails to fully consider the actual hydrogeological conditions and causes water seepage problems, water will enter the formwork during the concrete pouring process, thereby changing the water-cement ratio of the concrete, making it difficult for the strength of the concrete to meet the design requirements and the construction quality to be guaranteed. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an underwater construction method for deep inspection wells in coastal water-rich areas, which can reduce wet operations on site, thereby reducing the investment in anti-seepage projects and improving construction efficiency and quality.

[0005] The underwater construction method of a deep inspection well in a coastal water-rich area according to an embodiment of the present invention comprises: S1: performing anti-seepage support operations according to the geological conditions and hydrological conditions on site, excavating the foundation pit working surface according to the established excavation plan and construction standards, and pouring concrete on the bottom plate of the inspection well to achieve leveling of the bottom plate elevation;

[0006] S2: obtaining the depth information of the foundation pit and the height information of the groundwater level in the foundation pit, dividing the box-type structure of the inspection well into a first prefabricated section and a plurality of second prefabricated sections according to the depth information of the foundation pit and the height information of the groundwater level, and prefabricating the first prefabricated section and the plurality of second prefabricated sections at the prefabrication site;

[0007] S3: hoisting and lowering the first prefabricated section to the bottom plate by hoisting equipment, and sequentially hoisting and lowering the plurality of second prefabricated sections by hoisting equipment, so that the plurality of second prefabricated sections are sequentially stacked on the first prefabricated section until the stacking height of the plurality of second prefabricated sections exceeds the groundwater level;

[0008] S4: Casting the connecting height casting section on the second precast section at the top until the top surface of the connecting height casting section reaches the design elevation;

[0009] S5: constructing post-cast strips on the inner walls of the first prefabricated section and the plurality of second prefabricated sections, so that the first prefabricated section and the plurality of second prefabricated sections are connected to form a complete box-type structure;

[0010] S6: Carry out foundation pit backfilling operations outside the box-type structure.

[0011] The underwater construction method for deep inspection wells in coastal water-rich areas according to an embodiment of the present invention has at least the following beneficial effects: according to the foundation pit depth and groundwater level information, the box-type structure of the inspection well is prefabricated in sections at the prefabrication site, and the prefabricated sections are assembled in order by using lifting equipment, and finally the casting sections are connected to form a complete inspection well structure, thereby effectively reducing on-site wet operations, and reducing the interference of groundwater seepage on construction, avoiding quality risks caused by groundwater leakage, and at the same time, the segmented prefabrication operation is carried out in a controlled environment, which can greatly shorten the construction period of concrete pouring and steel bar binding, and there is no need to adopt complex anti-seepage measures, thereby avoiding the high cost of anti-seepage, while ensuring construction efficiency and quality, and achieving maximum economic benefits.

[0012] According to some embodiments of the present invention, in S1, the anti-seepage support operation adopts slope excavation to excavate the foundation pit.

[0013] According to some embodiments of the present invention, in S1, the bottom plate is cast by underwater concrete.

[0014] According to some embodiments of the present invention, in S2, the designed high water level of the groundwater level is obtained, the designed low water level of the groundwater level is obtained, the average water level is calculated based on the designed high water level and the designed low water level, and the average water level is used as the groundwater level height.

[0015] According to some embodiments of the present invention, in S2, the segmented prefabrication includes: opening a post-cast strip groove at a preset downward end of the second prefabricated segment; pre-embedding a portion of the first waterstop at a preset upward end of the first prefabricated segment, and making the first waterstop correspond to the position of the post-cast strip groove.

[0016] According to some embodiments of the present invention, a portion of the second waterstop is embedded in a preset upward end of the second prefabricated section, and the second waterstop is made to correspond to the position of the post-casting strip groove.

[0017] According to some embodiments of the present invention, the post-casting groove is provided on the inner wall of the second prefabricated section.

[0018] According to some embodiments of the present invention, the first waterstop and the second waterstop are both rubber waterstops.

[0019] According to some embodiments of the present invention, in S5, constructing the post-cast strip includes: pumping water from the inside of the first precast section and the second precast section; tying steel bars at predetermined positions according to the structural design requirements of the post-cast strip; installing the post-cast strip formwork according to the width and shape of the post-cast strip; pouring concrete into the post-cast strip groove, and burying the exposed first waterstop and second waterstop in the concrete, and performing curing after vibrating and compacting; when the concrete strength in the post-cast strip groove reaches the demolition strength required by the design, removing the formwork.

[0020] According to some embodiments of the present invention, in S5, after the first prefabricated section and a plurality of second prefabricated sections are connected to form a complete box-type structure, the first prefabricated section is connected to a connecting pipeline.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0023] Figure 1 It is a schematic flow chart of an underwater construction method of a deep inspection well in a coastal water-rich area according to an embodiment of the present invention;

[0024] Figure 2 is a plan view of a maintenance well according to an embodiment of the present invention;

[0025] Figure 3 is a cross-sectional view of a maintenance well according to an embodiment of the present invention;

[0026] Figure 4 yes Figure 3 A magnified schematic diagram of center A.

[0027] Reference numerals:

[0028] Bottom plate 100;

[0029] Inspection well 200, first precast section 210, second precast section 220, connecting high casting section 230, post-casting strip 240, post-casting strip groove 241, first water stop strip 250;

[0030] Connect pipeline 10. DETAILED DESCRIPTION

[0031] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0032] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0033] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0034] refer to Figures 1 to 4 The underwater construction method of a deep inspection well in a coastal water-rich area according to an embodiment of the present invention is described.

[0035] like Figure 1 As shown, the underwater construction method of a deep inspection well in a coastal water-rich area according to an embodiment of the present invention includes:

[0036] S1: Carry out anti-seepage support operations according to the geological and hydrological conditions on site, excavate the foundation pit working surface according to the established excavation plan and construction standards, and use concrete to pour the bottom plate 100 of the inspection well 200 to achieve leveling of the bottom plate 100 elevation;

[0037] S2: obtaining the depth information of the foundation pit and the height information of the groundwater level in the foundation pit, dividing the box-type structure of the inspection well 200 into a first prefabricated section 210 and a plurality of second prefabricated sections 220 according to the depth information of the foundation pit and the height information of the groundwater level, and prefabricating the first prefabricated section 210 and the plurality of second prefabricated sections 220 at the prefabrication site;

[0038] S3: using a lifting device to lift and lower the first prefabricated section 210 onto the bottom plate 100, and using a lifting device to lift and lower the plurality of second prefabricated sections 220 in sequence, so that the plurality of second prefabricated sections 220 are stacked in sequence on the first prefabricated section 210, until the stacking height of the plurality of second prefabricated sections 220 exceeds the groundwater level;

[0039] S4: Casting the connecting height casting section 230 on the second prefabricated section 220 at the top until the top surface of the connecting height casting section 230 reaches the designed elevation;

[0040] S5: constructing a post-casting strip 240 on the inner walls of the first prefabricated section 210 and the plurality of second prefabricated sections 220, so that the first prefabricated section 210 and the plurality of second prefabricated sections 220 are connected to form a complete box-type structure;

[0041] S6: Carry out foundation pit backfilling operations outside the box-type structure.

[0042] Therefore, according to the foundation pit depth and groundwater level information, the box-type structure of the inspection well 200 is prefabricated in sections at the prefabrication site, and the various prefabricated sections are assembled in order by using lifting equipment, and finally the high casting section 230 is cast to form a complete inspection well 200 structure. This effectively reduces the time required for on-site wet operations and avoids high costs due to complex anti-seepage measures, thereby greatly reducing the investment in anti-seepage at the project site. On the other hand, since the segmented prefabrication operation is carried out in a controlled environment, the construction period of concrete pouring and steel bar binding can be greatly shortened, which not only improves construction efficiency, but also saves valuable human resources, bringing great convenience to the smooth progress and cost control of the entire project.

[0043] It should be noted that the specific parts of the inspection well 200 structure connected to the elevated casting section 230 provide greater flexibility to meet different design requirements and construction needs. For example, the top of the inspection well 200 is difficult to be completely covered by prefabricated sections due to its complex shape or functional requirements. Therefore, cast-in-place can better meet the requirements of these parts and ensure the integrity and functionality of the structure.

[0044] In some specific embodiments of the present invention, in S1, it is necessary to conduct a detailed survey and analysis of the geological and hydrological conditions on site, including but not limited to soil type, groundwater level, soil permeability coefficient, groundwater flow direction, etc. Among them, the anti-seepage support operation can adopt slope excavation of foundation pit, which can rely on the stability of the soil itself and prevent the influence of the lateral pressure of groundwater and soil on the construction to a certain extent. Therefore, it is possible to determine a reasonable slope through soil mechanics calculation and experience according to the stability of the soil on site, the depth of the groundwater level and the surrounding environment.

[0045] It should be noted that for cast-in-place inspection wells, the degree of anti-seepage support mainly depends on the geological conditions, the depth of the inspection well 200 and the surrounding environment. Among them, for geological conditions, if the construction is in a loose soil with strong permeability, it is generally necessary to adopt a continuous support structure, such as an underground continuous wall, a water-stop curtain, etc., to ensure that an effective anti-seepage barrier can be formed to prevent the infiltration of groundwater and soil particles. For clay, although its own permeability is relatively low, in the presence of groundwater flow or high water level, a certain amount of anti-seepage support is still required, such as the use of a combination of pile rows and water-stop curtains. The pile rows provide lateral support, and the water-stop curtains prevent the infiltration of groundwater to ensure that the flow of groundwater is stopped. In addition, when the groundwater level is high, the anti-seepage support must not only consider preventing the infiltration of groundwater, but also consider the impact of water pressure on the support structure. At this time, the support structure needs to have sufficient strength and rigidity to withstand the water pressure.

[0046] In contrast, for prefabricated inspection wells, although their own structures are relatively complete, they also require corresponding anti-seepage support during the installation process. The main purpose at this time is to prevent soil collapse from affecting the installation of prefabricated inspection wells. According to the actual geological conditions, only light temporary support, such as wooden support or simple steel support, is needed to complete the anti-seepage operation. In addition, when the groundwater level is high, in addition to the above-mentioned temporary support measures, a layer of waterproof membrane or waterproof coating, such as polymer waterproof membrane or polymer cement waterproof coating, can be wrapped around the outside of the prefabricated inspection well to enhance its waterproof performance. At the same time, drainage blind ditches or drainage boards are set at the bottom and around the prefabricated inspection well to reduce the pressure of the groundwater level on the prefabricated inspection well and reduce the possibility of leakage.

[0047] In some specific embodiments of the present invention, in S1 , the bottom plate 100 is cast by underwater concrete.

[0048] In some specific embodiments of the present invention, in S2, the designed high water level of the groundwater level is obtained, the designed low water level of the groundwater level is obtained, the average water level is calculated based on the designed high water level and the designed low water level, and the average water level is used as the groundwater level height.

[0049] In some specific embodiments of the present invention, in S2, the segmented prefabrication includes: opening a post-cast strip groove 241 at a preset downward end of the second prefabricated segment 220; pre-embedding a portion of the first waterstop 250 at a preset upward end of the first prefabricated segment 210, and making the position of the first waterstop 250 correspond to that of the post-cast strip groove 241.

[0050] In some specific embodiments of the present invention, a portion of the second waterstop is pre-buried at the preset upward end of the second prefabricated section 220, and the second waterstop corresponds to the position of the post-casting strip groove 241. It should be noted that when there is only one second prefabricated section 220, the second waterstop does not need to be pre-buried at the upward end of the second prefabricated section 220, and when there are multiple second prefabricated sections 220, the second waterstop needs to be pre-buried at the upward end of the second prefabricated section 220 located at the lower end of two adjacent second prefabricated sections 220.

[0051] Specifically, the post-casting groove 241 is disposed on the inner wall of the second prefabricated section 220 .

[0052] Specifically, the first waterstop 250 and the second waterstop are both rubber waterstops.

[0053] In some specific embodiments of the present invention, in S3, the end surface of the post-cast strip 240 is 150 mm×150 mm.

[0054] In some specific embodiments of the present invention, in S5, constructing the post-cast strip 240 includes: pumping water from the inside of the first precast section 210 and the second precast section 220, and tying steel bars at predetermined positions according to the structural design requirements of the post-cast strip 240; installing the post-cast strip 240 template according to the width and shape of the post-cast strip 240, pouring concrete into the post-cast strip groove 241, and burying the exposed first waterstop 250 and second waterstop in the concrete, vibrating and compacting them, and then curing them, and when the concrete strength in the post-cast strip groove 241 reaches the design demolition strength, the template is removed.

[0055] Specifically, first, the first prefabricated section 210 and the second prefabricated section 220 are pumped out, and the water inside is pumped out using pumping equipment to ensure a dry and safe construction environment. Secondly, according to the structural design requirements of the post-casting strip 240, the steel bars are tied at the predetermined position, and the specifications, spacing and arrangement of the steel bars are determined according to the design requirements to ensure that the steel bars are firmly tied and the bearing capacity of the structure is guaranteed. Then, according to the width and shape of the post-casting strip 240, the post-casting strip 240 template is installed. The installation of the template must ensure sealing and firmness to prevent concrete from leaking during the pouring process. Finally, the concrete is poured into the post-casting strip groove 241, and the exposed first water stop 250 and second water stop are buried in the concrete. The concrete is vibrated with a vibrating rod, and then cured after being vibrated and compacted. The curing time and conditions are determined according to the characteristics of the concrete to ensure the strength development of the concrete. When the concrete strength in the post-casting strip groove 241 reaches the removal strength required by the design, the template is removed.

[0056] In some specific embodiments of the present invention, Figure 2 As shown, in S5 , after the first prefabricated section 210 and a plurality of second prefabricated sections 220 are connected to form a complete box-type structure, the first prefabricated section 210 is connected to the connecting pipeline 10 .

[0057] In some specific embodiments of the present invention, in S6, after the box-type structure is assembled and connected, the foundation pit outside the box-type structure is backfilled. First, it is necessary to select appropriate backfill materials according to the design requirements, and then backfill according to the predetermined layer thickness. During the backfilling process, appropriate compaction equipment is used to compact the backfill material and control the compaction degree to ensure the quality of the backfill and the stability of the foundation pit. It should be noted that the backfilling should be carried out symmetrically to avoid uneven lateral pressure on the box-type structure and affect the overall stability of the structure.

[0058] like Figure 3 to Figure 4 As shown, the underwater construction method of the deep inspection well in the coastal water-rich area is specifically described below with a specific implementation, wherein: Figure 3H1 is the foundation pit excavation elevation, H2 is the bottom plate top elevation, H3 is the groundwater level elevation, H4 is the top elevation of the connected cast-in-place section, and H5 is the design elevation of the top of the inspection well.

[0059] In the construction of a deep inspection well 200 in a water-rich area in Linhai, a detailed geological and hydrological survey was first conducted on the site. The groundwater level in this area is high, and the soil layer is silty sand with a certain degree of permeability. According to the survey results, the anti-seepage support operation was carried out by slope excavation, and the slope was determined to be 1:1.5. At the same time, a water collection well was set up for drainage. An excavator was used to excavate the foundation pit working surface according to the designed excavation depth and range, and the groundwater level and soil stability were monitored while excavating.

[0060] After the excavation of the foundation pit working surface is completed, underwater concrete is poured as the bottom plate 100 of the inspection well 200. The mix ratio of the underwater concrete is cement: sand: stone: water: admixture = 1:2:3:0.5:0.02, ensuring that the strength of the bottom plate 100 reaches C30 and the anti-seepage grade is P8.

[0061] The high water level of the groundwater is obtained as +2.0m, the low water level is obtained as -1.0m, and the average water level is calculated to be +0.5m. According to the average water level information, the box-type structure of the inspection well 200 is divided into a first prefabricated section 210 and a second prefabricated section 220. During the prefabrication process, a post-casting groove 241 with a size of 150mm×150mm is opened on the inner wall of the second prefabricated section 220 toward the lower end, and a rubber waterstop is embedded in the upper end of the first prefabricated section 210. It should be noted that since only one second prefabricated section 220 is provided in this specific implementation, the rubber waterstop is not embedded in the upper end of the second prefabricated section 220.

[0062] Use a crane to hoist the first prefabricated section 210 onto the base plate 100, and then hoist the second prefabricated section 220 onto the first prefabricated section 210, wherein the size and weight of the first prefabricated section 210 and the second prefabricated section 220 are determined according to design requirements, and the lifting capacity and working radius of the crane meet the hoisting requirements.

[0063] After the lifting is completed, the top of the second prefabricated section 220 exceeds the groundwater level, and the pouring of the elevated pouring section 230 is carried out on the top of the second prefabricated section 220. Specifically, ordinary concrete with a strength grade of C35 is used, and the conventional operations of formwork support, steel bar binding, concrete pouring and maintenance are followed until the design elevation is reached.

[0064] Water is pumped out from the first precast section 210 and the second precast section 220, the steel bars are tied with binding wire, wooden formwork is installed as the formwork for the post-cast strip 240, C40 slightly expansive concrete is poured, the vibration time is 30 seconds, and the concrete is covered with plastic film for curing for 28 days. When the concrete strength reaches the design strength, the formwork is removed.

[0065] Finally, use sand to backfill the foundation pit symmetrically with a layer thickness of 300mm and use a roller to compact it to complete the entire construction process.

[0066] By carrying out anti-seepage support operations according to the on-site geological and hydrological conditions and adopting a reasonable excavation plan, the groundwater leakage problem in the coastal water-rich area is effectively solved, the stability and safety of the foundation pit working surface are guaranteed, and construction accidents and structural damage caused by groundwater problems are avoided. On the other hand, the use of segmented prefabrication facilitates the manufacture, transportation and hoisting of prefabricated sections, improves construction efficiency and construction operability, and at the same time, water stop strips and post-casting strip grooves 241 are set on the prefabricated sections to enhance the waterproofness and integrity of the structure, ensuring the long-term use performance of the inspection well 200, thereby not only ensuring the construction quality and efficiency, but also greatly reducing the overall investment of the project site.

[0067] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. An underwater construction method for deep inspection wells in coastal water-rich areas, characterized in that: include: S1: performing anti-seepage support operations according to the geological and hydrological conditions on site, excavating the foundation pit working surface according to the established excavation plan and construction standards, and pouring concrete on the bottom plate (100) of the inspection well (200) to achieve leveling of the bottom plate (100); S2: obtaining depth information of a foundation pit and height information of a groundwater level in the foundation pit, dividing the box-type structure of the inspection well (200) into a first prefabricated section (210) and a plurality of second prefabricated sections (220) according to the depth information of the foundation pit and the height information of the groundwater level, and prefabricating the first prefabricated section (210) and the plurality of second prefabricated sections (220) at a prefabrication site; S3: using a lifting device to lift and lower the first prefabricated section (210) onto the bottom plate (100), and using a lifting device to sequentially lift and lower a plurality of the second prefabricated sections (220), so that the plurality of the second prefabricated sections (220) are sequentially stacked on the first prefabricated section (210), until the stacking height of the plurality of the second prefabricated sections (220) exceeds the groundwater level; S4: Casting a connecting height casting section (230) on the second prefabricated section (220) located at the top, until the top surface of the connecting height casting section (230) reaches the designed elevation; S5: constructing a post-casting strip (240) on the inner walls of the first prefabricated section (210) and the plurality of the second prefabricated sections (220), so that the first prefabricated section (210) and the plurality of the second prefabricated sections (220) are connected to form a complete box-type structure; S6: Carry out foundation pit backfilling operation on the outside of the box-type structure.

2. The underwater construction method for deep inspection wells in coastal water-rich areas according to claim 1 is characterized in that: In S1, the anti-seepage support operation adopts slope excavation to excavate the foundation pit.

3. The underwater construction method for deep inspection wells in coastal water-rich areas according to claim 1 is characterized in that: In S1, the bottom plate (100) is cast using underwater concrete.

4. The underwater construction method for deep inspection wells in coastal water-rich areas according to claim 1 is characterized in that: In S2, the designed high water level of the groundwater level is obtained, the designed low water level of the groundwater level is obtained, the average water level is calculated based on the designed high water level and the designed low water level, and the average water level is used as the height of the groundwater level.

5. The underwater construction method for deep inspection wells in coastal water-rich areas according to claim 1 is characterized in that: In S2, the segmented prefabrication includes: A post-casting groove (241) is provided at a preset downward end of the second prefabricated section (220); A portion of the first water stop strip (250) is pre-buried at a preset upward end of the first prefabricated section (210), and the first water stop strip (250) is positioned to correspond to the position of the post-casting strip groove (241).

6. The underwater construction method for deep inspection wells in coastal water-rich areas according to claim 5 is characterized in that: A portion of the second water stop is embedded in a preset upward end of the second prefabricated section (220), and the second water stop is positioned to correspond to the position of the post-casting strip groove (241).

7. The underwater construction method for deep inspection wells in coastal water-rich areas according to claim 5 is characterized in that: The post-casting groove (241) is arranged on the inner wall of the second prefabricated section (220).

8. The underwater construction method for deep inspection wells in coastal water-rich areas according to claim 5 is characterized in that: The first waterstop (250) and the second waterstop are both rubber waterstops.

9. The underwater construction method for deep inspection wells in coastal water-rich areas according to claim 1 is characterized in that: In S5, the construction of the post-cast strip (240) includes: Pumping water from inside the first prefabricated section (210) and the second prefabricated section (220); According to the structural design requirements of the post-cast strip (240), steel bars are tied at a predetermined position; According to the width and shape of the post-casting strip (240), a template for the post-casting strip (240) is installed; Concrete is poured into the post-casting groove (241), and the first water stop strip (250) and the second water stop strip exposed are buried in the concrete, and then vibrated and compacted to perform curing; When the concrete strength in the post-cast strip groove (241) reaches the removal strength required by the design, the formwork is removed.

10. The underwater construction method for deep inspection wells in coastal water-rich areas according to claim 1, characterized in that: In S5, after the first prefabricated section (210) and a plurality of the second prefabricated sections (220) are connected to form a complete box-type structure, the first prefabricated section (210) is connected to a connecting pipeline (10).

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