Construction method for riser structure of sea area drainage tunnel pipe planting method and riser structure

Abstract

The present invention relates to the technical field of submarine drainage tunnel construction, and particularly relates to a construction method and a riser structure for a pipe-planting method riser structure of a sea area drainage tunnel. The construction method includes construction of a drainage hole, construction of pipe-planting of a drainage riser. The drainage riser includes a water-blocking casing, a concrete riser and a concrete pedestal. A grout-stop plate is provided between the concrete pedestal and the concrete riser. The drainage riser is sunk to the designed position and elevation in the steel casing, and then underwater concrete is poured into the area below the concrete pedestal and the gap between the drainage riser and the steel casing by the conduit method, and the steel casing is gradually withdrawn; construction of the connection between the drainage riser and the main tunnel, including shield construction of the main tunnel, grouting and water stoppage at the connection between the riser and the main tunnel, excavation of the riser pedestal, connection of the primary support steel ring and the main tunnel segment, and cast-in-place lining connecting the lower end of the riser and the secondary lining of the main tunnel; covering the drainage head building; most of the work of this method is carried out at sea, greatly reducing the construction time in the shield main tunnel and having high construction safety.

Description

Technical Field

[0001] The present invention relates to the technical field of submarine drainage tunnel construction, and particularly relates to a construction method and a riser structure for a pipe-planting method riser structure in a sea area drainage tunnel. Background Art

[0002] At present, nuclear power plants at home and abroad often adopt coastal or nearshore sites, and seawater needs to be introduced into the condenser to "cool down" the nuclear power plant. With the improvement of the country's requirements for marine protection in recent years, most of the nuclear power plants built in China have abandoned the conventional open-channel intake and drainage methods and adopted the form of tunnels extending into deep water areas for intake and drainage, that is, by constructing tunnels under the seabed to introduce deep-sea seawater into the intake pump house or discharging sewage into the sea through tunnels.

[0003] After the tunnel is excavated from the land area to the deep sea, the prior art generally adopts the vertical jacking process inside the constructed tunnel to form the intake and drainage ports. The vertical jacking process is to reserve a jacking hole on the upper part of the constructed tunnel, and use a jack to jack out the prefabricated riser pipe sections from the jacking hole one by one into the main tunnel. After the top cover plate of the riser reaches the designated height, the cover plate is removed underwater by divers, and then the intake / drainage head is installed to form the intake / drainage port construction process.

[0004] This construction method has the following disadvantages: many construction procedures, complex water-stop measures, and high construction risks; long construction period, and the drainage head cannot be constructed until the main tunnel is completed, occupying the key line construction period; high requirements for the stratum, and when encountering hard rock formations, insufficient jacking force may occur, or excessive jacking force may cause damage to the main tunnel segments.

[0005] Therefore, based on the existing pipe-planting construction method for drainage tunnels, it is necessary to provide a construction method that can effectively reduce the construction risks in the tunnel and shorten the construction period of the drainage project. Summary of the Invention

[0006] The purpose of the present invention is to address the deficiencies of the prior art and provide a construction method and a riser structure for a pipe-planting method riser structure in a sea area drainage tunnel, which are convenient and safe in construction, simple in structure, conducive to shortening the overall construction period of the drainage project, more safe and reliable in structure during the project service period, and particularly suitable for pipe-planting construction of drainage tunnels in hard soil, rock and other hard strata.

[0007] A construction method for a pipe-planting method riser structure in a sea area drainage tunnel provided by the present invention includes the following steps:

[0008] Drainage port hole-forming construction, including bed leveling, steel casing pile sinking and impact drilling for hole formation;

[0009] Construction of inserting the drainage riser pipe. The drainage riser pipe is a prefabricated drainage riser pipe, which includes a water retaining casing at the upper section, a concrete riser pipe in the middle section, and a concrete foundation at the lower section. The concrete foundation is a concrete pipe, and a slurry stopping plate is provided between the concrete foundation and the concrete riser pipe. The slurry stopping plate is provided with a concrete pouring hole. The construction of inserting the drainage riser pipe includes sinking the prefabricated drainage riser pipe to the designed position and elevation inside the steel casing, and then using the conduit method to pour underwater concrete into the area below the concrete foundation and the gap between the drainage riser pipe and the steel casing through the concrete pouring hole until the specified height, and gradually pulling out the steel casing during the pouring process of the underwater concrete;

[0010] Construction of connecting the drainage riser pipe with the main tunnel, including shield construction of the main tunnel, grouting and water stopping at the connection between the riser pipe and the main tunnel, excavation of the riser pipe foundation, connection of the primary support steel ring with the main tunnel segments, and cast-in-place lining connecting the lower end of the riser pipe with the secondary lining of the main tunnel;

[0011] Covering the drainage head building, including removing the water retaining steel cylinder, installing the head building, and forming a drainage channel.

[0012] Preferably, during the construction of inserting the drainage riser pipe, filter sandbags are also thrown on the slurry stopping plate and removed during the stage of grouting and water stopping at the connection between the riser pipe and the main tunnel.

[0013] Preferably, the shield construction of the main tunnel includes:

[0014] Using the shield method to construct the main tunnel. Before the shield machine reaches the drainage riser pipe, after adjusting the attitude of the shield machine to control the horizontal and vertical position accuracy of the main tunnel segments at this position to meet the design requirements, the shield machine normally advances to break through the concrete foundation.

[0015] Preferably, the grouting and water stopping at the connection between the riser pipe and the main tunnel includes:

[0016] After the shield tunnel passes through the position of the drainage riser pipe, use the offshore operation platform to pump out the seawater inside the drainage riser pipe, clean the filter sandbags inside the riser pipe, drill holes in the drainage riser pipe towards the connection between the drainage riser pipe and the main tunnel, and then inject slurry;

[0017] It also includes grouting and water stopping the rock and soil body near the interface between the drainage riser pipe and the main tunnel through the reserved drill holes on the main tunnel segments inside the main tunnel, and ensuring the water blocking effect at this position through the inspection holes on the main tunnel segments.

[0018] Preferably, the excavation of the riser pipe foundation includes:

[0019] After completing the grouting water-stop measures and confirming that there will be no obvious water seepage, the underwater concrete inside the concrete base of the drainage riser is excavated from top to bottom. The concrete of the concrete base is gradually chiseled from the center outwards, and the primary support steel ring is used as the primary support. During the excavation process, ensure the dewatering in the hole, and the excavation depth reaches the main tunnel segment.

[0020] More preferably, the connection between the primary support steel ring and the main tunnel segment includes:

[0021] After the concrete in the drainage riser is cleared of holes, the main tunnel segment is cut in the main tunnel, and the primary support steel ring is welded to the main tunnel segment by means of steel plate lapping to form a closed water stop.

[0022] More preferably, the connection between the cast-in-place lining connecting the lower end of the riser and the secondary lining of the main tunnel includes:

[0023] After the welding between the primary support steel ring and the main tunnel segment is completed and no leakage is detected, the lower end of the drainage riser and the secondary lining of the main tunnel are simultaneously cast with concrete to make the drainage riser and the main tunnel form an integral whole.

[0024] More preferably, the removal of the water-blocking steel cylinder includes:

[0025] After the construction of the connection between the drainage riser and the main tunnel, after the main tunnel is filled with water, the upper section of the water-blocking cylinder of the drainage riser is removed underwater and replaced with a blanking plate at the top of the riser. The blanking plate is bolted to the concrete riser, and a sealing rubber pad is provided at the connection.

[0026] More preferably, the installation of the head building includes:

[0027] Clean the mud surface around the drainage riser, use the seawater operation platform to sink the drainage head concrete caisson, and layer by layer backfill 10 - 100 kg stones, 1 - 500 kg blasted rocks, and 500 - 800 kg bottom protection stones outside the drainage head concrete caisson. The 1 - 500 kg blasted rocks are located outside the 10 - 100 kg stones, and the 500 - 800 kg bottom protection stones are located on the top of the 10 - 100 kg stones and the 1 - 500 kg blasted rocks. The four walls of the drainage head concrete caisson are provided with water inlet holes;

[0028] The formation of the drainage channel includes that after the installation of the head building is completed, the diver enters the concrete caisson underwater and opens the blanking plate at the top of the drainage riser to form the drainage channel.

[0029] The present invention also provides a precast drainage riser structure for the sea area drainage tunnel pipe planting method, which includes a water retaining casing in the upper section, a concrete riser in the middle section, and a concrete base in the lower section. The concrete riser is connected to the water retaining casing through a flange, and a sealing rubber pad is provided at the connection. The concrete base is a concrete pipe equipped with glass fiber bars. A grout stop plate is provided between the concrete base and the concrete riser. The grout stop plate is provided with a concrete pouring hole for the conduit to pass through, and the concrete pouring hole is communicated with the concrete pipe. Anti-filter sandbags are thrown on the grout stop plate, and a limiting block is circumferentially arranged at the top of the water retaining casing.

[0030] The beneficial effects of the present invention are as follows:

[0031] 1. This method adopts a special precast drainage riser structure, which includes a water retaining casing, a concrete riser, and a concrete base. A grout stop plate is provided between the concrete base and the concrete riser, and the grout stop plate is provided with a concrete pouring hole for the conduit to pass through, and the concrete pouring hole is communicated with the concrete pipe. Before the construction of the main submarine drainage tunnel, the drainage head can be constructed preferentially. After the installation of the drainage riser, underwater concrete pouring can be adopted, and then the main tunnel can be directly excavated through the precast concrete riser base equipped with glass fiber bars. The concrete in the steel casing is excavated from top to bottom to connect the drainage riser with the main tunnel, and then the initial support steel ring is connected to the main tunnel segment, and the cast-in-place lining is connected to the lower end of the riser and the secondary lining of the main tunnel, and finally the drainage head building is covered. This method can complete the pre-planting pipe construction before the main tunnel excavation. After the shield tunneling, only the connection construction between the riser and the main tunnel and the construction of the drainage head building need to be completed. The construction of the riser and the main tunnel does not interfere with each other. This method can carry out most of the work at sea, greatly reducing the construction time in the main shield tunnel, with high construction safety. Its structural form is reasonable, the overall stability is good, and the later operation and maintenance are convenient. And compared with the traditional vertical jacking process, there are no problems such as insufficient vertical jacking force in the tunnel and insufficient bearing capacity of the tunnel base.

[0032] 2. The head building adopts a concrete caisson structure, and the underwater part of the water retaining casing at the upper section of the riser is removed and replaced with a blanking plate at the top of the riser. Water inlets are arranged on the four walls of the caisson. After the blanking plate is opened, an inlet channel can be formed with the water inlets. Compared with the traditional integral drainage head structure, its structural stability is high under the action of waves. Description of the Drawings

[0033] Figure 1 It is a schematic flow chart of the method of the present invention;

[0034] Figure 2 It is a schematic overall layout drawing of the construction of the present invention;

[0035] Figure 3 It is a schematic diagram of the drainage hole formation of the present invention;

[0036] Figure 4 Schematic diagram of pipe planting for the drainage riser of the present invention

[0037] Figure 5 Schematic diagram of the connection between the riser and the main tunnel of the present invention;

[0038] Figure 6 Schematic diagram of the drainage head structure of the present invention.

[0039] In the figure: 101 - Offshore operation platform; 102 - Platform support; 103 - Platform operation crane; 104 - Punching pile positioning guide frame; 201 - Gravel cushion; 202 - Rock block cushion; 203 - 10 - 100 kg rock blocks; 204 - 1 - 500 kg blasted rock; 205 - 500 - 800 kg bottom protection rock blocks; 301 - Steel casing; 302 - Concrete riser; 303 - Grout stop plate; 304 - Concrete foundation; 305 - Water retaining steel cylinder; 306 - Flange; 307 - Underwater concrete; 308 - Limit block; 309 - Conduit; 310 - Filter sandbag; 311 - Grout; 401 - Main tunnel segment; 402 - Secondary lining of the main tunnel; 403 - Primary support steel ring; 404 - Blank plate; 405 - Drainage head concrete caisson Specific embodiments

[0040] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0041] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0042] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application 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, and therefore should not be construed as a limitation to the present application.

[0043] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality of" means two or more unless otherwise specifically defined.

[0044] In the following description, specific details such as specific system architectures, technologies, etc. are set forth for the purpose of illustration and not limitation in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art should understand that this application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of this application with unnecessary details.

[0045] It should be understood that when used in the specification and appended claims of this application, the term "comprises" indicates the presence of the described features, wholes, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0046] It should also be understood that the term "and / or" as used in the specification and appended claims of this application refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0047] As used in the specification and appended claims of this application, the term "if" may be construed, depending on the context, as "when", "once", "in response to determining", or "in response to detecting". Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be construed, depending on the context, as meaning "once determined", "in response to determining", "once [the described condition or event] is detected", or "in response to detecting [the described condition or event]".

[0048] In addition, in the description of the specification and appended claims of this application, the terms "first", "second", "third", etc. are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0049] References to "an embodiment" or "some embodiments" or the like described in the specification of this application mean that specific features, structures, or characteristics described in connection with that embodiment are included in one or more embodiments of this application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "comprising", "including", "having" and their variants mean "including but not limited to", unless otherwise specifically emphasized. "Plurality" means "two or more".

[0050] Embodiment 1

[0051] Figure 1 The flow schematic diagram of a construction method for a riser structure of a sea area drainage tunnel pipe planting method provided by a preferred embodiment of this application is shown. For the drainage project of a nuclear power plant, a tunnel hidden drainage scheme is adopted. The main tunnel is constructed by the shield method, and 8 drainage risers are arranged at the drainage outlet. The main tunnel is 3 m below the moderately weathered rock stratum, and the upper overburden is silty soil for description. For the sake of convenience of description, this embodiment takes the drainage project of this nuclear power plant as an example, and only the parts related to this embodiment are shown below and are described in detail as follows:

[0052] A construction method for a riser structure of a sea area drainage tunnel pipe planting method provided by the present invention includes the following steps:

[0053] Step 1, construction of a hole at the drainage outlet, including the following 3 steps;

[0054] Step 101, bedding leveling;

[0055] As Figure 2 , 3 shown, locate the position of the drainage head. Before the steel casing 301 is sunk, slope-excavate the foundation trench to the rock-soil interface, and backfill after the steel casing pile sinking is completed.

[0056] Step 102, steel casing pile sinking;

[0057] Construct a marine operation platform 101, and use the platform operation crane 103 to lift the steel casing 301 into the punching pile positioning guide frame 104. In this embodiment, the steel casing 301 is made of Q345 steel, with a diameter of 3m and a length of 17m. A crane and a hydraulic vibratory hammer are used to drive the steel casing 301 into the pile. During the pile driving process, the steel casing is positioned and corrected in time through the guiding device to ensure that the vertical deviation of the steel casing is not more than 1 / 200. The top elevation of the steel casing is higher than the designed high water level of the sea area and is fixed in the punching pile positioning guide frame 104. The depth A of the bottom end of the steel casing 301 into the moderately weathered bedrock is 1m. After the steel casing 301 is driven into the pile, a gravel cushion layer 201 and a riprap cushion layer 202 are laid in layers, and the backfill height is 3m.

[0058] Step 103, drill a hole with an impact drill;

[0059] Use the impact drill on the marine operation platform 101 to excavate the moderately weathered rock layer inside the steel casing. The excavation depth exceeds the bottom of the steel casing until the position where the distance B in the main tunnel section is 1m.

[0060] Step 2, construct the drainage riser pipe embedding, including the following 4 steps;

[0061] Step 201, level the bottom of the hole;

[0062] Lay a layer of coarse sand at the bottom of the drilled hole, and use the impact drill hammer to tamp the bottom of the drilled hole to ensure that the bottom of the hole is flat and reaches the set elevation, at the position where the distance in the main tunnel section is 1m.

[0063] Step 202, prefabricate the drainage riser pipe;

[0064] As Figure 4 shown, the drainage riser pipe is a prefabricated drainage riser pipe, which is prefabricated in the prefabrication factory before construction. The prefabricated drainage riser pipe includes a water retaining casing 305 at the upper section to ensure that seawater does not enter the inside of the riser pipe, creating a dry construction environment inside the riser pipe, a concrete riser pipe 302 in the middle section, and a concrete base 304 at the lower section. The concrete riser pipe 302 in the middle section is bolted to the water retaining casing 305 with a flange 306, and a sealing rubber pad is provided at the connection; a limiting block 308 is circumferentially provided at the top of the water retaining casing 305. The concrete base 304 is a concrete pipe equipped with glass fiber bars. A layer of grout stop board 303 is provided between the concrete base 304 and the concrete riser pipe 302. A concrete pouring hole is provided on the grout stop board 303 for the conduit 309 to pass through, so as to serve as a channel for pouring underwater concrete 307 later. Anti-filter sandbags 310 are thrown on the grout stop board 303 for anti-filtration to prevent the underwater concrete 307 from entering the riser pipe;

[0065] Step 203, install the drainage riser pipe;

[0066] Install the drainage riser. Through the offshore operation platform 101, accurately sink the prefabricated drainage riser together with its concrete pedestal 304 to the designed position and elevation in the steel casing 301 through the limit block 308;

[0067] Step 204, underwater concrete pouring;

[0068] After the installation of the riser is completed, underwater pour the gap between the riser and the steel casing and the area below the pedestal through the conduit 309 by the conduit method to fix the riser. The underwater concrete 307 is poured to 1 m below the flange 306 of the drainage riser. During the pouring process of the underwater concrete 307, the steel casing 301 is gradually pulled out. The underwater concrete 307 needs to have good fluidity to densely fill the gap between the riser and the steel casing. After the steel casing is pulled out, it is necessary to further check that the verticality of the riser meets the design accuracy requirements.

[0069] Step 3, connection construction between the riser and the main tunnel;

[0070] Step 301, shield construction of the main tunnel;

[0071] After the construction of the drainage riser pipe embedding is completed, the main tunnel is constructed by the shield method. Before the shield machine reaches the drainage riser, by adjusting the attitude of the shield machine, after controlling the horizontal and vertical position accuracies of the main tunnel segment 401 (steel segment) at this position to meet the design requirements, the shield machine normally advances to break through the concrete pedestal 304 containing glass fiber bars.

[0072] Step 302, grouting for water stop at the connection between the riser and the main tunnel;

[0073] After the shield tunnel passes through the position of the drainage riser, use the offshore operation platform to pump out the seawater inside the riser, clean the filter sandbags 310 inside the riser, drill holes in the riser towards the connection between the riser and the main tunnel and inject the grout 311 (C-S grout) for water stop. In addition, grouting for water stop can also be carried out on the rock and soil body near the interface between the riser and the tunnel through the reserved drill holes on the main tunnel segment 401 inside the tunnel, and ensure the water blocking effect at this position through the inspection holes on the main tunnel segment 401.

[0074] Step 303, excavation of the riser pedestal;

[0075] As Figure 5 shown, after completing the grouting water stop measures and confirming that there will be no obvious water seepage, excavate the underwater concrete 307 inside the concrete pedestal 304 of the riser from top to bottom in the riser. Gradually chisel the concrete of the concrete pedestal 304 from the center outwards, and use the primary support steel ring 403 as the primary support. Ensure dewatering in the hole during the excavation process, and the excavation depth reaches the main tunnel segment 401.

[0076] Step 304, connection between the primary support steel ring and the main tunnel segment;

[0077] After the concrete in the riser is cleared of holes, the main tunnel segment 401 is cut in the main tunnel, and the primary support steel ring 403 is welded to the main tunnel segment 401 by means of steel plate lapping to form a closed water stop.

[0078] Step 305, cast-in-place lining connects the lower end of the riser to the secondary lining of the main tunnel;

[0079] After the welding of the primary support steel ring 403 and the main tunnel segment 401 is completed and no leakage is detected, the lower end of the riser and the secondary lining 402 of the main tunnel are simultaneously cast with concrete to integrate the riser with the shield main tunnel.

[0080] Step 4, cover the drainage head building, including the following 3 sub-steps:

[0081] Step 401, remove the water retaining steel cylinder;

[0082] After the connection construction between the riser and the main tunnel is completed and the main tunnel is filled with water, the upper water retaining protection cylinder 305 of the riser is removed underwater and replaced with a blanking plate 404 at the top of the riser. The blanking plate 404 is bolted to the concrete riser 302, and a sealing rubber pad is provided at the connection to prevent seawater backflow during tunnel maintenance.

[0083] Step 402, install the head building;

[0084] As Figure 6 shown, clean the mud surface around the riser, and use the seawater operation platform to sink the drainage head concrete caisson 405. The outside of the drainage head concrete caisson 405 is filled with 10 - 100 kg riprap 203, 1 - 500 kg blasted rock 204, and 500 - 800 kg bottom protection riprap 205 in layers to provide counterweight to ensure the stability of the drainage outlet concrete caisson 405. Among them, the 1 - 500 kg blasted rock is located outside the 10 - 100 kg riprap, and the 500 - 800 kg bottom protection riprap is located on the top of the 10 - 100 kg riprap and the 1 - 500 kg blasted rock. The four walls of the drainage head concrete caisson are provided with water inlet holes.

[0085] Step 403, form a drainage channel;

[0086] After the drainage head construction is completed, a diver enters the drainage head concrete caisson 405 underwater and opens the blanking plate 404 at the top of the riser to form a drainage channel.

[0087] In one embodiment, the hole depth in step 103 should reach 1 m inside the cross-section of the main tunnel.

[0088] In one embodiment, the top elevation of the concrete pedestal 304 in step 202 should be 1 m above the top of the main tunnel. The concrete pedestal 304 is equipped with glass fiber bars, and the main tunnel shield directly passes through the area of the riser pedestal.

[0089] In one embodiment, for the underwater concrete in step 204, C15 concrete with relatively low strength is preferably used, which is convenient for subsequent shield tunneling and chiseling of the concrete in the hole.

[0090] In one embodiment, for grouting in step 302, C-S slurry can be used for grouting to stop water leakage. Then, the seawater inside the riser pipe is pumped out, and the water seepage situation inside the riser pipe is continuously observed. After checking and confirming no leakage, the connection construction between the riser pipe and the main tunnel can be carried out.

[0091] In one embodiment, water-stop rubber rings shall be provided at the joints of the riser pipe sections.

[0092] In one embodiment, according to the service period of the drainage tunnel, warning lights can be installed on the pillars of the offshore operation platform after the construction of the drainage head is completed, which also serves as a warning pile for the drainage head.

[0093] Embodiment 2

[0094] The present invention also provides a precast drainage riser pipe structure for the pipe-laying method of a sea area drainage tunnel, including a water-blocking casing 305 in the upper section to ensure that seawater does not enter the interior of the riser pipe and create a dry construction environment inside the riser pipe, a concrete riser pipe 302 in the middle section, and a concrete base 304 in the lower section. The concrete riser pipe 302 in the middle section is bolted to the water-blocking casing 305 by a flange 306, and a sealing rubber pad is provided at the connection. A limiting block 308 is circumferentially provided at the top of the water-blocking casing 305. The concrete base 304 is a concrete pipe equipped with glass fiber bars. A layer of grout-stop plate 303 is provided between the concrete base 304 and the concrete riser pipe 302. A concrete pouring hole is provided on the grout-stop plate 303 for the conduit 309 to pass through, thereby serving as a channel for pouring underwater concrete 307 in the later stage. Anti-filter sandbags 310 are thrown on the grout-stop plate 303 for anti-filtration to prevent the underwater concrete 307 from entering the riser pipe.

[0095] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the protection scope of the present disclosure. The appended method claims present the elements of various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0096] In the foregoing detailed description, various features are combined in a single embodiment to simplify the present disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than those expressly recited in each claim. On the contrary, as reflected in the appended claims, the invention lies in less than all of the features of the single disclosed embodiment. Accordingly, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing alone as a separate preferred embodiment of the invention.

[0097] The above-described disclosed embodiments have been described so as to enable any person skilled in the art to make or use the present invention. For those skilled in the art, various modifications to these embodiments will be readily apparent, and the general principles defined herein may be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0098] The foregoing description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but those of ordinary skill in the art should recognize that each embodiment can be further combined and arranged. Accordingly, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, this term is inclusive in a manner similar to the term "including", as that term is interpreted when used as a transitional word in a claim. In addition, any use of the term "or" in the claims or specification is intended to mean "non-exclusive or".

[0099] The above-described embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included within the protection scope of the present application.

Claims

1. A construction method for the riser structure of the pipe-laying method in a sea area drainage tunnel, characterized in that, It includes the following steps: Hole construction of the drainage outlet, including bed leveling, driving of the steel casing (301), and hole drilling with a percussion drill; Pipe installation construction of the drainage riser. The drainage riser is a prefabricated drainage riser, which includes a water retaining casing (305) in the upper section, a concrete riser (302) in the middle section, and a concrete base (304) in the lower section. The concrete base (304) is a concrete pipe. A grout stop plate (303) is provided between the concrete base (304) and the concrete riser (302). The grout stop plate (303) is provided with a concrete pouring hole. The pipe installation construction of the drainage riser includes lowering the prefabricated drainage riser into the designed position and elevation in the steel casing (301), and then using the conduit method to pour underwater concrete (307) into the area below the concrete base (304) and the gap between the drainage riser and the steel casing (301) through the concrete pouring hole to a specified height, and gradually pulling out the steel casing (301) during the pouring process of the underwater concrete (307); Connection construction between the drainage riser and the main tunnel, including shield construction of the main tunnel, grouting and water stopping at the connection between the riser and the main tunnel, excavation of the riser base, connection between the primary support steel ring (403) and the main tunnel segment (401), and cast-in-place lining connecting the lower end of the riser and the secondary lining (402) of the main tunnel; Covering the drainage head building, including removing the water retaining casing (305), installing the head building, and forming a drainage channel; During the pipe installation construction of the drainage riser, filter sandbags (310) are also thrown on the grout stop plate (303), and the filter sandbags (310) are cleared during the grouting and water stopping stage at the connection between the riser and the main tunnel; The connection between the primary support steel ring (403) and the main tunnel segment (401) includes: After the concrete in the drainage riser is cleared of holes, the main tunnel segment (401) is cut in the main tunnel, and the primary support steel ring (403) is welded to the main tunnel segment (401) by means of steel plate lapping to form a closed water stop; The removal of the water retaining casing (305) includes: After the connection construction between the drainage riser and the main tunnel, after the main tunnel is filled with water, the upper water retaining casing (305) of the drainage riser is removed underwater and replaced with a blanking plate (404) at the top of the riser. The blanking plate (404) is bolted to the concrete riser (302), and a sealing rubber pad is provided at the connection; 2. The construction method of the riser structure of the sea area drainage tunnel pipe-laying method according to claim 1, characterized in that, The shield construction of the main tunnel includes: The main tunnel is constructed by the shield method. Before the shield machine reaches the drainage riser, by adjusting the attitude of the shield machine, after controlling the horizontal and vertical position accuracies of the main tunnel segment (401) at this position to meet the design requirements, the shield machine normally advances to break through the concrete base (304).

3. The construction method of the riser structure of the sea area drainage tunnel pipe-laying method according to claim 1, characterized in that, The grouting and water stopping at the connection between the riser and the main tunnel includes: After the shield tunnel passes through the position of the drainage riser, the seawater inside the drainage riser is pumped out by using an offshore operation platform, the filter sandbags (310) inside the riser are cleared, and slurry (311) is injected after drilling holes at the connection between the drainage riser and the main tunnel in the drainage riser; It also includes grouting and water stopping for the rock and soil mass near the interface between the drainage riser and the main tunnel through the pre - reserved boreholes on the main tunnel segment (401) inside the main tunnel, and ensuring the water - blocking effect at this position through the inspection holes on the main tunnel segment (401).

4. The construction method of the riser structure of the sea area drainage tunnel pipe-laying method according to claim 1, characterized in that, The excavation of the riser base includes: After completing the grouting and water - stopping measures and confirming that there will be no obvious water seepage, excavate the underwater concrete (307) inside the concrete base (304) from top to bottom in the drainage riser, gradually chisel the concrete of the concrete base (304) from the center outwards, and use the primary support steel ring (403) as the primary support. Ensure the dewatering in the hole during the excavation process, and the excavation depth reaches the main tunnel segment (401).

5. The construction method of the riser structure of the sea area drainage tunnel pipe planting method according to claim 1, characterized in that, The cast - in - place lining connecting the lower end of the riser and the secondary lining (402) of the main tunnel includes: After completing the welding of the primary support steel ring (403) and the main tunnel segment (401) and checking for no leakage, cast the concrete for the lower end of the drainage riser and the secondary lining (402) of the main tunnel simultaneously, so that the drainage riser and the main tunnel form an integral whole.

6. The construction method of the riser structure of the sea area drainage tunnel pipe-laying method according to claim 1, characterized in that, The installation of the head building includes: Clean the mud surface around the drainage riser, use the seawater operation platform to sink the drainage head concrete caisson (405), and layer - by - layer backfill 10 - 100 kg boulders (203), 1 - 500 kg blasted rocks (204), and 500 - 800 kg bottom - protection boulders (205) outside the drainage head concrete caisson (405). The 1 - 500 kg blasted rocks (204) are located outside the 10 - 100 kg boulders (203), and the 500 - 800 kg bottom - protection boulders (205) are located on the top of the 10 - 100 kg boulders (203) and the 1 - 500 kg blasted rocks (204). Water inlet holes are provided on the four walls of the drainage head concrete caisson (405). The formation of the drainage channel includes, after the installation of the head building is completed, the diver enters the drainage head concrete caisson (405) underwater, opens the blanking plate (404) at the top of the drainage riser, and forms the drainage channel.

7. A prefabricated drainage riser structure of the sea area drainage tunnel pipe planting method constructed by the construction method of the riser structure of the sea area drainage tunnel pipe planting method described in any one of claims 1 to 6, characterized in that: It includes the upper - section water - retaining casing (305), the middle - section concrete riser (302), and the lower - section concrete base (304). The concrete riser (302) is connected to the water - retaining casing (305) through a flange, and a sealing rubber pad is provided at the connection. The concrete base (304) is a concrete pipe equipped with glass - fiber bars. A grout - stopping plate (303) is provided between the concrete base (304) and the concrete riser (302). Concrete pouring holes for the ducts to pass through are provided on the grout - stopping plate (303), and the concrete pouring holes are communicated with the concrete pipe. Anti - filtering sandbags (310) are thrown on the grout - stopping plate (303), and a limiting block is circumferentially provided at the top of the water - retaining casing (305).

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