Assembled diaphragm wall based on occlusal mode, double-c type joint and construction method

Abstract

The application discloses a fabricated ground wall based on a clamping mode, a double-C type joint and a construction method, and is applied to the technical field of super-deep underground continuous walls, the double-C type joint comprises two C type opening structures, the C type opening structure is provided with a gap opening, and the cross section formed in a C type; the two C type opening structures are respectively arranged at the butt joint ends of adjacent fabricated segment walls, and the two C type opening structures are embedded and connected through the gap openings; the fabricated ground wall is formed by layer-by-layer butt joint of the fabricated segment walls, and the butt joint ends of the fabricated segment walls are embedded into the C type opening structures; the construction method mainly relates to butt joint and sinking of the fabricated segment walls and grouting technology; the construction method realizes rapid butt joint of the internal structure of the fabricated ground wall and rapid installation of the fabricated ground wall, improves the butt joint and installation precision of the fabricated segment walls, improves the overall construction quality of the fabricated ground wall, and meanwhile, a triple water stop structure is formed at the joint of the fabricated ground wall, so that a stronger water stop and anti-seepage effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of ultra-deep underground diaphragm wall technology, and particularly to prefabricated diaphragm walls based on interlocking mechanisms, double C-type joints, and construction methods. Background Technology

[0002] Diaphragm walls are foundation engineering projects where a trenching machine excavates a long, narrow trench along the perimeter of a deep excavation project, using slurry wall support. After cleaning the trench, a reinforcing cage is placed inside, and underwater concrete is poured using a tremie pipe method to form a unit segment. This process is repeated segment by segment to build a continuous reinforced concrete wall underground, serving as a water-cutting, seepage-proof, load-bearing, and retaining structure. Traditional construction methods suffer from long construction periods, significant environmental impact, and quality control issues due to trench depth limitations, making traditional diaphragm walls unsuitable for ultra-deep environments. Prefabricated diaphragm walls have emerged as a solution. These walls are constructed by installing prefabricated wall components underground. This method ensures the quality of the wall components while shortening the construction period and reducing environmental impact.

[0003] While existing prefabricated diaphragm walls can be used in environments with a certain depth, the currently developed prefabricated diaphragm walls are suitable for shallow burial depths, generally only a dozen meters, at most twenty meters. For ultra-deep diaphragm walls exceeding 30 meters, existing prefabricated diaphragm walls encounter various problems during construction, resulting in substandard construction quality and failure to meet actual requirements. The main reasons are:

[0004] 1. Inability to meet construction precision requirements. Prefabricated diaphragm walls consist of multiple prefabricated wall components. These components need to be precisely aligned and installed underground. However, in ultra-deep environments, due to the great depth, the requirements for assembly precision are even higher. The verticality of the wall is difficult to control, and any deviation may lead to instability or even damage to the wall. Moreover, in actual construction, in order to reduce the impact on the original geological environment, the trench for diaphragm walls is only slightly wider than the wall thickness of prefabricated diaphragm walls. The width of the trench itself has a significant impact on construction. Since the prefabricated structure is sunk below ground for alignment and installation, complex equipment and techniques are required to ensure precise alignment and installation of the wall. This not only requires a high level of alignment technology but also consumes a lot of time and effort. Furthermore, adjusting the wall within the relatively narrow trench is more difficult, and deviations are very easy to occur during construction. Therefore, the requirements for alignment precision are extremely high.

[0005] 2. Failure to meet the requirements for water-stopping and seepage prevention. In ultra-deep environments, groundwater pressure increases significantly, negatively impacting the seepage prevention performance of prefabricated diaphragm walls. On one hand, high pressure can cause cracks in the wall or damage to the seepage prevention material at the joints, thus affecting its seepage prevention performance. On the other hand, high pressure may also cause deformation of the wall, affecting its overall seepage prevention performance. Due to the need to cope with high pressure and complex geological conditions, the weak point in water-stopping and seepage prevention when using prefabricated structures lies at the joints. However, the joints of existing prefabricated structures are difficult to control, the quality of the seepage prevention material filling at the joints is difficult to guarantee, and the construction difficulty at the joints is significantly increased. Summary of the Invention

[0006] The purpose of this invention is to overcome the aforementioned shortcomings of the prior art and provide a prefabricated diaphragm wall based on an interlocking method, a double C-type joint, and a construction method. This double C-type joint and prefabricated diaphragm wall can be applied in ultra-deep underground environments of 30-50m. During the installation of the prefabricated diaphragm wall, prefabricated segmental walls are directly sunk and connected, enabling rapid construction. The connection and insertion are quick, achieving rapid connection of the internal structure of the prefabricated diaphragm wall and rapid installation, thus improving the connection and installation accuracy of the prefabricated segmental walls. Simultaneously, the quality of the connection structure is easy to control, reducing the likelihood of connection failures and poor connection results, thereby improving the overall construction quality of the prefabricated diaphragm wall.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0008] A double C-type joint comprises two identical C-type opening structures. The C-type opening structures are made of steel and are formed by a gap opening that runs through both ends of the pipe sidewall. The cross-section of the C-type opening structure is C-shaped, and the direction of the gap opening is consistent with the extension direction of the C-type opening structure. The two C-type opening structures are respectively located at the joint ends of adjacent prefabricated segmental walls, and the two C-type opening structures are interlocked and connected through the gap opening.

[0009] Compared to surface construction and shallow diaphragm wall construction, ultra-deep underground environments place higher demands on the installation precision of diaphragm walls. While surface construction and shallow diaphragm wall construction allow for positioning through measurement, the ultra-deep underground environment and narrow slots limit conventional measurement capabilities. Consequently, the position of prefabricated diaphragm walls cannot be determined with high precision, and the verticality of the walls is difficult to control. Any deviation during wall assembly can lead to instability or even damage to the walls. Achieving precise positioning and assembly requires complex equipment and technology, demanding not only advanced alignment techniques but also significant time and effort. By employing double C-type joints, prefabricated segmental walls can be applied in ultra-deep underground environments of 30-50m. Due to the interlocking and mutual positioning of the two C-shaped opening structures, the radial portion of the C-shaped opening structure is embedded within the adjacent C-shaped opening structure, preventing them from detaching. Because the pipe is C-shaped, the interlocking C-shaped opening structures cannot move horizontally, remaining confined to a very small gap. This improves the docking and installation accuracy of prefabricated segmental walls without the need for tools or equipment for positioning. The verticality of the diaphragm wall is also easier to control. After docking construction, the two prefabricated segmental walls are accurately positioned and connected, achieving precise positioning and installation of prefabricated segmental walls in ultra-deep environments. During installation, prefabricated segmental walls are directly sunk and docked. The C-shaped opening structure of the later-sunk segmental wall connects with the C-shaped opening structure of the earlier-sunk segmental wall. The C-shaped opening structures are interlocked. During interlocking, a section of the radially upward C-shaped opening structure enters the interior of the adjacent C-shaped opening structure through a gap opening. Simultaneously, a radially adjacent section of the adjacent C-shaped opening structure also enters the interior of the C-shaped opening structure through a gap opening. This interlocking is achieved. Due to the vertical misalignment between adjacent prefabricated segmental walls before being installed, the two C-shaped opening structures are perfectly interlocked. The later-installed prefabricated segmental wall is then vertically hoisted, and the earlier-installed C-shaped opening structure forms a vertical channel, guiding the later-installed C-shaped opening structure. This allows for rapid hoisting of the prefabricated segmental wall. This enables quick alignment and insertion during docking, achieving rapid docking of the internal structure of the prefabricated diaphragm wall and rapid installation of the prefabricated diaphragm wall. At the same time, the quality of this docking structure is easier to control, reducing the likelihood of docking failure or poor docking results, thus improving the overall construction quality of the prefabricated diaphragm wall.

[0010] In a preferred embodiment of the present invention, the mutual embedding depth range of the two C-shaped opening structures is [D / 3, 2D / 3], where D is the outer diameter of the C-shaped opening structure. By setting the embedding depth, the connection tightness and connection strength of the double C-shaped joint can be enhanced. After filling with concrete or mortar, the mutual force-bearing area of ​​the two C-shaped opening structures is larger, enabling them to bear greater load-bearing capacity and preventing deformation or cracking between adjacent prefabricated segmental walls.

[0011] In a preferred embodiment of the present invention, the wall thickness of the aforementioned C-shaped opening structure is in the range of [10mm, 20mm], the width of the gap opening is [t+15mm, t+25mm], where t is the wall thickness of the C-shaped opening structure, and the outer diameter D of the C-shaped opening structure is ≥140mm. By limiting the dimensional parameters of the C-shaped opening structure, within this parameter range, the C-shaped opening structure has a smaller gap opening. On the one hand, this can limit the positional relationship between the two C-shaped opening structures to a certain extent, improving the docking accuracy. On the other hand, the double C-shaped opening structure has smaller seepage channels on both sides. Combined with the arc-shaped cross-section of the C-shaped opening structure, this extends the seepage path, thereby improving the water-stopping and seepage-proof effect. Simultaneously, the steel pipe with these parameters has strong structural strength and can withstand greater tensile and shear forces. With the outer diameter limited, the C-shaped opening structure has a certain internal space, which facilitates hole cleaning, grouting, and grout return.

[0012] In a preferred embodiment of the present invention, the inner wall of the two C-shaped opening structures interlocked together is further provided with a connecting hole for grouting, so that the grouting of the three chambers can be balanced through the connecting hole; since the double C-shaped joint has three chambers, the three chambers can be connected through the connecting hole, so that the grout can fill the three chambers evenly during grouting, thereby improving the compactness of the filling.

[0013] In a preferred embodiment of the present invention, the inner wall of the above-mentioned C-shaped opening structure is provided with a plurality of protruding structures; by setting the protruding structures, the roughness of the pipe wall is increased, thereby enhancing the bonding effect between the C-shaped opening structure and concrete or mortar, so that the concrete can be better fixed to the double C-shaped joint and the grouting effect is improved.

[0014] The prefabricated diaphragm wall based on the interlocking method adopts the above-mentioned double C-type joint. The prefabricated diaphragm wall includes several prefabricated segment walls connected together. Adjacent prefabricated segment walls are connected by double C-type joints. The mating ends of the prefabricated segment walls are embedded with C-type opening structures arranged along the height direction. After the double C-type joints are connected, the two C-type opening structures form three chambers. The three chambers are used for pouring high-strength concrete or high-strength mortar.

[0015] Because the prefabricated segmental walls that make up the prefabricated diaphragm wall use double C-type joints at the joint ends, during the overall construction of the prefabricated diaphragm wall, the C-shaped opening structure can quickly guide and insert the prefabricated segmental walls when they are joined, which facilitates the joint and improves the joint accuracy and quality. This makes the internal connection of the entire prefabricated diaphragm wall tight. After filling with concrete or mortar, a water-stopping structure is formed at the double C-type joint. Since water cannot seep through the C-shaped opening structure, it can only seep through the gap opening. However, the connection structure of the double C-type joint and the small gap opening itself limit the seepage width while increasing the seepage path. This significantly increases the difficulty of seepage, making the double C-type joint have a strong water-stopping and seepage prevention effect. At the same time, the double C-type joint and the concrete jointly participate in the stress, which improves the overall structural strength of the prefabricated diaphragm wall.

[0016] In a preferred embodiment of the present invention, the above-mentioned prefabricated diaphragm wall based on the interlocking method further includes a multi-layer water-stop structure, which includes a water-stop strip structure, and the water-stop strip structure includes:

[0017] Waterstop plate, which is a plate-shaped structure. One end of the waterstop plate is fixed to the side of the joint end of the prefabricated segmental wall by anchors. The other end of the waterstop plate is a cantilever end, which extends to the side of the joint end of the adjacent prefabricated segmental wall and has a gap with the side.

[0018] The first water-swellable component is located on one side of the gap at the cantilever end of the waterstop plate.

[0019] The first protrusion is used to fit the side of the mating end of the adjacent prefabricated segmental wall. The first protrusion is located on the gap side of the cantilever end of the waterstop plate.

[0020] The second water-swellable component is used to fit the first water-swellable component. The second water-swellable component is located on the side of the mating end of the adjacent prefabricated segment wall, and the positions of the second water-swellable component and the first water-swellable component are opposite.

[0021] The second protrusion is used to fit the gap side of the waterstop plate. The second protrusion is located on the side of the joint end of the adjacent prefabricated segment wall. The second protrusion and the first protrusion are respectively located on both sides of the joint position of the first water-swellable part and the second water-swellable part.

[0022] The waterstop plate is fixed to the joint end of the prefabricated segmental wall by anchors. During the jointing process, the waterstop plate blocks most of the seepage channels between adjacent prefabricated segmental walls, allowing seepage to pass through the gaps. The first and second water-swellable components expand upon contact with water and press against each other, blocking the seepage gaps and forming a waterstop structure, thus providing strong water-stopping and seepage prevention capabilities. The first and second protrusions protect the first and second water-swellable components. Due to the water absorption and expansion effect, the waterstop structure can be smoothly lowered as the prefabricated segmental wall is lowered. At the same time, the waterstop plate also provides initial support on both sides of the prefabricated diaphragm wall, playing a certain positioning role and ensuring verticality.

[0023] In a preferred embodiment of the present invention, the aforementioned multiple water-stopping structure further includes an interlocking pipe water-stopping structure and a water-stop plate water-stopping structure. The interlocking pipe water-stopping structure is formed by a double C-shaped joint and the filling grout, which is high-strength mortar or high-strength concrete. The water-stop plate water-stopping structure includes two water-stop plates, which are respectively vertically arranged at the joint ends of adjacent prefabricated segmental walls. The positions of the two water-stop plates are staggered and can fit together when adjacent prefabricated segmental walls are joined. Through the interlocking pipe water-stopping structure and the water-stop plate water-stopping structure, a triple water-stopping structure is formed at the joint of the prefabricated diaphragm wall. The triple water-stopping structure not only provides three layers of water seepage prevention, but also adopts three different structural forms. Since the seepage path is not in the same direction, it is more difficult for seepage to pass through the triple water-stopping structure, thus achieving a stronger water-stopping and seepage-proof effect.

[0024] The construction method for prefabricated diaphragm walls uses the aforementioned double C-type joints, and the construction method includes butt joint construction:

[0025] Docking steps: When sinking adjacent prefabricated segmental walls, the top of the C-shaped opening structure of the first prefabricated segmental wall is offset from the bottom of the C-shaped opening structure of the next adjacent prefabricated segmental wall, so that the two C-shaped opening structures fit together through the gap opening. Then, sink the adjacent prefabricated segmental walls vertically, keeping the two C-shaped opening structures always fitted together, until the positions of the two adjacent prefabricated segmental walls are aligned.

[0026] Cleaning steps: Remove internal impurities from the two C-shaped opening structures by air lift and / or water injection.

[0027] Grouting step: High-strength mortar or high-strength concrete is injected into the two C-shaped opening structures to form a double C-shaped joint and a concrete connection structure, thus completing the connection of adjacent prefabricated segmental walls.

[0028] The assembly of prefabricated segmental walls was completed through a series of steps including docking, cleaning, and grouting. During construction, the C-shaped opening structures were interlocked to facilitate the placement and docking of the prefabricated segmental walls, ensuring they remained vertical and accurately aligned. The docking process involved simply interlocking the tops of the C-shaped opening structures of the later-placed segmental walls with those of the earlier-placed ones, allowing for vertical placement. The C-shaped opening structures within the trench provided guidance, facilitating rapid docking and improving the installation accuracy of the prefabricated segmental walls. This also enabled rapid docking of the internal structures of the prefabricated diaphragm walls and their rapid installation, effectively shortening installation time and increasing the assembly efficiency. The cleaning step removed impurities to facilitate smooth grouting and ensure grouting quality. The grouting step integrated the double C-shaped joints with concrete or mortar, forming a water-stopping interlocking pipe structure and a strong connection structure suitable for ultra-deep underground environments.

[0029] In a preferred embodiment of the present invention, the above construction method further includes:

[0030] Before sinking the prefabricated segmental wall, the following steps are taken: excavating a trench and laying a layer of crushed stone at the bottom of the trench;

[0031] Prefabricated segmental walls are placed at the position of the first wall in the trench, and multiple layers of prefabricated segmental walls are placed above and below each wall position; then, vertical prestressing construction is carried out on the upper and lower layers of prefabricated segmental walls.

[0032] The adjacent prefabricated segmental walls are placed at the positions of adjacent wall sections in the trench, and the docking construction is carried out. After the installation of the upper and lower multi-layer prefabricated segmental walls is completed, the prestressing construction described above is also carried out.

[0033] Following the above two steps, complete the placement and installation of prefabricated segmental walls at all wall locations to form prefabricated diaphragm walls;

[0034] Grouting is carried out during the docking construction. Grouting is performed on the gaps between adjacent prefabricated segmental walls, the bottom and side walls of the prefabricated diaphragm wall, so that the prefabricated diaphragm wall forms an integral whole with the surrounding soil.

[0035] Based on conventional shallow prefabricated diaphragm wall construction, the load-bearing capacity of the prefabricated diaphragm wall is improved through prestressed construction. By sinking and installing different wall positions in sequence, the initial construction of the prefabricated diaphragm wall is formed. Then, through grouting, including grouting at C-joints, butt joints, bottom of the wall and side walls, the connection of each double C-joint is realized, forming the prefabricated diaphragm wall into an integral structure and also forming a water-stopping structure. At the same time, the prefabricated diaphragm wall is integrated with the surrounding soil, forming a structure with sufficient structural strength, load-bearing capacity and water-stopping and seepage prevention capabilities, thus completing the construction of prefabricated diaphragm walls in ultra-deep underground environments.

[0036] In a preferred embodiment of the present invention, the portion of the vertical joint located inside the double C-shaped joint is defined as the first joint, and the portion of the vertical joint located outside the double C-shaped joint is defined as the second joint. During the grouting process for butt joint construction:

[0037] First, grouting is performed on the first chamber, the middle chamber, and the second chamber of the double C-type joint. The two C-shaped opening structures divide the double C-type joint into the first chamber, the middle chamber, and the second chamber.

[0038] The first joint is then grouted.

[0039] The second joint was then constructed using grouting.

[0040] In a preferred embodiment of the present invention, the first joint is constructed by underwater grouting during the grouting construction of the first joint.

[0041] In a preferred embodiment of the present invention, when grouting the first joint, the bottom of the first joint is first sealed underwater for 1m to 2m, then the water in the first joint is extracted, and then the remaining part of the first joint is grouted.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] 1. The double C-type joint improves the installation accuracy of prefabricated segmental walls. The interlocking and mutual positioning of the two C-shaped opening structures facilitates control of the verticality of the diaphragm wall. After docking, the two prefabricated segmental walls are accurately positioned and connected, achieving precise positioning and installation in ultra-deep environments. During docking, the staggered position of adjacent prefabricated segmental walls before placement creates a vertical channel in the first C-shaped opening structure, guiding the subsequent C-shaped opening pipe. This allows for rapid hoisting of the prefabricated segmental walls, enabling quick alignment and insertion during docking. This facilitates rapid docking of the internal structure of the prefabricated diaphragm wall and its rapid installation. Furthermore, the quality of this docking structure is easier to control, reducing the likelihood of docking failures or poor results, thus improving the overall construction quality of the prefabricated diaphragm wall.

[0044] 2. Prefabricated diaphragm walls are assembled from prefabricated segmental walls using double C-type joints. The use of double C-type joints facilitates connection while improving connection accuracy and quality. The double C-type joints, combined with concrete or mortar, form a snap-fit ​​water-stop structure. This snap-fit ​​water-stop structure, along with the water-stop strip and water-stop plate, creates a triple water-stop structure, giving the prefabricated diaphragm wall a strong water-stopping and seepage-proof effect. Simultaneously, the double C-type joints and concrete work together to bear the load, improving the overall structural strength of the prefabricated diaphragm wall.

[0045] 3. Through construction methods, the connection between prefabricated segmental walls is completed. During construction, the interlocking of the C-shaped opening structures ensures that the prefabricated segmental walls remain vertical and accurately aligned, improving the installation accuracy. Simultaneously, the prefabricated segmental walls can be quickly connected, enabling rapid installation of the prefabricated diaphragm wall. Finally, the double C-shaped joints are integrated with concrete or mortar through grouting, forming a water-stopping structure and a strong connection. Grouting at the bottom and side walls of the prefabricated diaphragm wall achieves bonding with the surrounding soil, forming a structure with sufficient structural strength, bearing capacity, and water-stopping and seepage prevention capabilities. This allows for the construction of prefabricated diaphragm walls in ultra-deep underground environments, expanding the application depth of prefabricated diaphragm walls. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the structure of the double C-type connector of the present invention;

[0047] Figure 2 This is a top view of the double C-type connector of the present invention;

[0048] Figure 3 This is a top view of the prefabricated segmental wall of the present invention;

[0049] Figure 4 This is a schematic diagram of the connection of the prefabricated segmental wall of the present invention;

[0050] Figure 5 This is a schematic diagram of the triple water-stopping structure of the present invention;

[0051] Figure 6 This is a schematic diagram showing the arrangement of the prestressed channel and grouting pipe in the prefabricated segmental wall of the present invention;

[0052] Figure 7 This is a schematic diagram of the grouting pipe arrangement for the prestressed channel of the present invention;

[0053] Figure 8 This is a schematic diagram of the grouting pipe arrangement of the double C-type joint of the present invention;

[0054] Figure 9 This is a schematic diagram of the grouting pipe arrangement for the vertical joint of the present invention;

[0055] Figure 10 This is a schematic diagram showing the installation of grouting pipes at the bottom of the prefabricated diaphragm wall according to the present invention.

[0056] Figure 11 This is a schematic diagram of the grouting pipe arrangement on the side wall of the prefabricated diaphragm wall of the present invention;

[0057] Figure 12 This is a schematic diagram of the trenching and sinking process of the prefabricated diaphragm wall of the present invention;

[0058] Figure 13 This is a flowchart of the construction method for the prefabricated diaphragm wall of the present invention.

[0059] Markings in the diagram: 1-Prefabricated segmental wall, 11-Vertical joint, 12-Tongue, 13-Groove, 14-Horizontal joint, 15-Side joint, 16-First joint, 17-Second joint, 2-Double C-type joint, 21-First C-type opening structure, 22-Second C-type opening structure, 23-First chamber, 24-Intermediate chamber, 25-Second chamber, 26-Connecting hole, 27-Protruding structure, 28-Gap opening, 3-Waterstop strip construction, 31- 32-Waterstop plate component, 33-Anchor, 34-First water-swellable component, 35-First protrusion, 36-Second water-swellable component, 37-Second protrusion, 4-Waterstop plate waterstop structure, 41-First waterstop plate, 42-Second waterstop plate, 5-Interlocking pipe waterstop structure, 51-Grouting body, 6-Prestressed tendon, 71-Air-lift soil discharge pipe, 72-Water jetting pipe, 73-Prestressed channel, 74-Grouting pipe, 75-Grouting outlet, 8-Crushed stone layer. Detailed Implementation

[0060] The present invention will be further described in detail below with reference to experimental examples and specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0061] Example 1

[0062] Please refer to Figure 1 This embodiment provides a double C-type joint, which includes two identical C-type opening structures, referred to as the first C-type opening structure 21 and the second C-type opening structure 22. The first C-type opening structure 21 and the second C-type opening structure 22 are respectively fixed to the mating ends of adjacent prefabricated segmental walls 1. The double C-type joint 2 is connected by the interlocking of the first C-type opening structure 21 and the second C-type opening structure 22. The double C-type joint 2 and the prefabricated segmental wall 1 using this joint can be applied in ultra-deep underground environments of 30-50m. The connection of the structures improves the installation accuracy between the prefabricated segmental walls 1, making it easier to control the verticality of the diaphragm wall. After the connection construction, the two prefabricated segmental walls 1 are accurately positioned and connected, realizing precise positioning and installation between the prefabricated segmental walls 1 in ultra-deep environments. At the same time, the C-shaped opening structure can be quickly aligned and inserted during the connection, realizing the rapid connection of the internal structure of the prefabricated diaphragm wall and the rapid installation of the prefabricated diaphragm wall. In this way, the quality of the connection structure is also easy to control, and it is less likely to have connection failure or poor connection effect, thus improving the overall construction quality of the prefabricated diaphragm wall.

[0063] In this embodiment, the C-shaped opening structure uses a round steel pipe with a gap opening 28, made of high-strength steel. In other embodiments, the C-shaped opening structure can also use steel alloys, such as titanium steel alloys or nickel steel alloys. By using steel pipes, the double C-shaped joint 2 has strong rigidity, avoiding deformation. The C-shaped opening structure is formed by opening a gap opening 28 through both ends of the round steel pipe wall. Both the first C-shaped opening structure 21 and the second C-shaped opening structure 22 have gap openings 28. The gap opening 28 forms a straight slit in the entire C-shaped opening structure. The setting direction of the gap opening 28 is consistent with the extension direction of the C-shaped opening structure, that is, the extension direction of the gap opening 28 on the pipe wall is parallel to the axial direction of the C-shaped opening structure. The width of the gap opening 28 is [t+15mm, t+25mm], where t is the wall thickness of the C-shaped opening structure. For example, the width of the gap opening 28 can be 25mm, 30mm, or 35mm, or a width between these values. The width of the gap opening 28 cannot be too large, otherwise it will seriously weaken the double C-shaped joint 2. The tensile strength of the inner arc-shaped pipe wall section, the wall thickness range of the C-type opening structure is [10mm, 20mm]. For example, the thickness of the round steel pipe can be 10mm, 12mm, 16mm, or 20mm, or a thickness between these values ​​can be used. The outer diameter D of the C-type opening structure is ≥140mm. If the outer diameter is 140mm, it can also be 160mm, 180mm, 200mm, or other outer diameters greater than 140mm. Under the above parameter constraints, the C-type opening structure has a smaller gap opening 28, which on the one hand allows for… The positional relationship between the two C-shaped opening structures is limited to a certain extent, which improves the docking accuracy. On the other hand, the double C-shaped opening structure has smaller seepage channels on both sides. In addition, the arc-shaped cross-section of the C-shaped opening structure extends the seepage path to improve the water-stopping and seepage prevention effect. At the same time, the steel pipe with these parameters has strong structural strength. The double C-shaped joint 2 mainly bears the tensile force. Thus, the structure under the above parameters can withstand greater tensile and shear forces. Under the limitation of the outer diameter, the C-shaped opening structure has a certain internal space, which facilitates hole cleaning, grouting and grout return.

[0064] In this embodiment, the first C-shaped opening structure 21 and the second C-shaped opening structure 22 are respectively provided at the joint ends of adjacent prefabricated segmental walls 1. The two adjacent prefabricated segmental walls 1 are connected at the joint ends through the first C-shaped opening structure 21 and the second C-shaped opening structure 22. When the two C-shaped opening structures are connected, they are embedded into each other through the gap opening 28. The premise of this embedding method is that the wall thickness of the C-shaped opening structure is less than the width of the gap opening 28. The embedding depth range of the two C-shaped opening structures is [D / 3, 2D / 3], where D is the outer diameter of the C-shaped opening structure. The embedding depth can be D / 3, D / 2 or 2D / 3, or other depth values. In this embodiment, the embedding depth is D / 2. By setting the embedding depth, the connection tightness and connection strength of the double C-shaped joint 2 can be enhanced. After filling with concrete or mortar, the force-bearing area between the two C-shaped opening structures is larger, so that they can bear greater load-bearing capacity and prevent deformation or cracking between adjacent prefabricated segmental walls 1.

[0065] The specific process of connecting the two C-shaped opening structures in this embodiment is as follows: During installation, prefabricated segmental walls are directly lowered and connected. The C-shaped opening structure of the later-lowered segmental wall is fitted into the C-shaped opening structure of the earlier-lowered segmental wall. During fitting, as shown in the figure, a portion of the radially upward C-shaped opening structure enters the interior of the adjacent C-shaped opening structure through the gap opening 28. At the same time, a radially downward portion of the adjacent C-shaped opening structure also enters the interior of the C-shaped opening structure through the gap opening 28. This achieves the fitting. The thickness of the C-shaped opening structure is less than the width of the gap opening 28, which facilitates the embedding of the C-shaped opening structure into the adjacent C-shaped opening structure. However, the width of the gap opening 28 will not be too large. Due to the mutual fitting between the two C-shaped opening structures, they mutually limit each other's positioning. In this arrangement, the two C-shaped opening structures cannot be separated. Since the pipe is C-shaped, the interlocking C-shaped opening structures cannot move in any horizontal direction and are limited to a very small gap opening 28. Thus, without the need for tools or equipment for detection and positioning, and because there is a vertical misalignment between the adjacent prefabricated segmental walls 1 before they are placed, the two C-shaped opening structures are interlocked. After the later-placed prefabricated segmental wall 1 is vertically hoisted, the first-placed C-shaped opening structure forms a vertical channel, which guides the later-placed C-shaped opening structure. This allows for the rapid hoisting of the prefabricated segmental wall 1, thereby enabling the C-shaped opening structure to be quickly inserted into the first-placed C-shaped opening structure as the prefabricated segmental wall 1 is lowered.

[0066] Please refer to Figure 2In this embodiment, the double C-type connector 2 has three chambers, including a first chamber 23, an intermediate chamber 24, and a second chamber 25. The internal pipe wall formed by the interlocking of the two C-type opening structures is also provided with a connecting hole 26 for grouting. The grouting of the three chambers is balanced through the connecting hole 26. The connecting hole 26 is located within 2m of the bottom end of the C-type opening structure. The connecting hole 26 can be made in various shapes, such as square, round, or prismatic. In this embodiment, the connecting hole 26 is a square hole with a width of 40mm and a height of 80mm. The size is required to be less than or equal to half the outer diameter of the steel pipe. A larger size will affect the performance of the C-type opening structure, while a smaller size will affect the cleaning efficiency and the grouting fluidity at the bottom of the C-type opening structure. Only four connecting holes 26 are provided. Too many holes will affect the structural performance of the C-type opening structure. The size of the connecting hole 26 needs to ensure that impurities can be easily removed during cleaning and that cement mortar (high-strength concrete or high-strength mortar) can easily flow and achieve compaction at the bottom of the prefabricated diaphragm wall during filling. The hole cannot be too large, as this would weaken the load-bearing capacity of the steel pipe structure. The high-strength concrete used here refers to concrete with a strength grade of C60 or higher, while high-strength mortar is a special material in this field and is frequently used in civil engineering projects. Regarding the arrangement of the three chambers, due to the tensile force between the C-shaped opening structures, the grouting in the middle chamber 24 and the two arc-shaped pipe sections in the double C-shaped joint 2 experience the most significant stress. Therefore, in principle, the larger the space of the middle chamber 24, the better, so that the double C-shaped joint 2 can provide a higher load-bearing capacity. However, in reality, the spaces of the first chamber 23 and the second chamber 25 cannot be too small, as this would affect hole cleaning and grout flow. Therefore, the spaces of the three chambers should be as close as possible to avoid any chamber being too small, in order to facilitate grouting and grout return. When the above-mentioned embedding depth is 1 / 2D, the sizes of the three chambers are exactly the same, which is the preferred value. Through the setting of the connecting hole 26, the three chambers can be connected, so that the grout can evenly fill the three chambers during grouting, improving the compactness of the filling.

[0067] In the above scheme, the high-strength mortar should have a strength grade at least one level higher than the concrete of the precast diaphragm wall. For example, if the concrete strength grade of the precast wall is C50, the high-strength mortar should be at least C55. The concrete strength grade of prestressed concrete structures should be at least C40, with C50, C55, and C60 being the most commonly used in engineering.

[0068] In this embodiment, the inner wall of the C-shaped opening structure is rough, and the inner wall of the C-shaped opening structure is provided with a protruding structure 27. The protruding structure 27 can be raised texture, which can be dot-shaped, strip-shaped, arc-shaped or other shapes, as long as the protruding structure 27 is raised relative to the inner wall. In this embodiment, the protruding structure 27 is a raised spindle shape, and the protruding structure 27 is arranged obliquely. The protruding structure 27 is distributed all over the inner wall of the C-shaped opening structure. The protruding structure 27 is formed by pressing on the inner wall of the C-shaped opening structure during production. By setting the protruding structure 27, the roughness of the pipe wall is increased, thereby enhancing the bonding between the C-shaped opening structure and concrete or mortar, so that the concrete can be better fixed to the double C-shaped joint 2, and the grouting effect is improved.

[0069] Example 2

[0070] Please refer to Figure 3 This embodiment provides a prefabricated diaphragm wall based on an interlocking method, employing the aforementioned double C-type joint 2. The prefabricated diaphragm wall comprises several interconnected prefabricated segmental walls 1, with several layers. Each layer is formed by connecting several prefabricated segmental walls 1. Adjacent prefabricated segmental walls 1 are connected through the double C-type joint 2 at the connecting ends. After connection, there is a vertical joint 11 between adjacent prefabricated segmental walls 1. High-strength concrete or high-strength mortar is poured into the double C-type joint 2, forming a C-shaped opening structure at the connecting end to bond with the concrete or mortar. The connection structure is combined; after filling with concrete or mortar, a water-stopping structure 5 is formed at the double C-type joint 2. Since water cannot seep through the C-type opening structure, it can only seep through the gap opening 28. However, the connection structure of the double C-type joint 2 and the small gap opening 28 limit the seepage width while increasing the seepage path, which significantly increases the difficulty of seepage. This makes the double C-type joint 2 have a strong water-stopping and seepage prevention effect. At the same time, the double C-type joint 2 and the concrete jointly participate in the stress, which improves the overall structural strength of the prefabricated diaphragm wall.

[0071] Please refer to Figure 4In this embodiment, the prefabricated diaphragm wall uses the double C-type joint 2 from Embodiment 1 at the horizontal joint of the wall. The double C-type joint 2 forms an integral load-bearing structure with the grouting body 51, which is high-strength concrete or high-strength mortar. If high-strength mortar is used, an early-strength agent is added to ensure that the strength of the vertical joint 11 is increased in a short time, avoiding the impact of other construction disturbances on the quality of the vertical joint 11. This load-bearing structure is constrained by the grouting body 51 and mainly bears tensile force, needing to overcome the bending and tensile strength of the C-shaped opening structure. The double C-type joint 2 is integrated with the prefabricated segmental wall 1. The prefabricated segmental wall 1 used here can be of various types, including hollow wall and solid wall. The joint ends of the prefabricated segmental wall 1 can adopt different joint structure forms, and conventional joint structure forms can be used. This results in the structure of prefabricated segmental wall 1. Since this structure can be prefabricated in the factory, it has a high degree of standardization and assembly. Compared with the on-site construction of cast-in-place diaphragm walls, it can greatly reduce the on-site construction time, which is conducive to the rapid assembly of ultra-deep underground diaphragm walls and is easy to promote and apply.

[0072] In this embodiment, the joint end of the prefabricated segmental wall 1 is a socket joint structure. The socket joint includes a tenon 12 and a groove 13 structure. The tenon 12 and the groove 13 serve as the joint ends of the prefabricated segmental wall 1. The protruding part of the tenon 12 and the recessed part of the groove 13 are both arranged along the height direction of the prefabricated segmental wall 1. The joint end of the prefabricated segmental wall 1 is embedded with a C-shaped opening structure arranged along the height direction. Specifically, a C-shaped opening structure is pre-embedded at the joint ends on both sides of the protruding part of the tenon 12. The gap opening 28 of the C-shaped opening structure is exposed. A C-shaped opening structure is also pre-embedded at the joint ends on both sides of the recessed part of the groove 13. The gap opening 28 of the C-shaped opening structure is also exposed. In this way, each joint end of the prefabricated segmental wall 1 is provided with two C-shaped opening structures. After the adjacent C-shaped opening structures are connected to form a double C-shaped joint 2, the two C-shaped opening structures form three chambers. The three chambers are used for pouring high-strength concrete or high-strength mortar. Because the prefabricated segmental wall 1 that makes up the prefabricated diaphragm wall adopts double C-type joints 2 at the docking end, during the overall construction of the prefabricated diaphragm wall, the C-type opening structure of the prefabricated segmental wall 1 can quickly guide and insert when docking, which facilitates docking, improves docking accuracy and docking quality, and makes the internal connection of the entire prefabricated diaphragm wall tight.

[0073] Please refer to Figure 5In this embodiment, the prefabricated diaphragm wall also includes a multi-layer water-stop structure, which includes a water-stop strip water-stop structure 3, an interlocking pipe water-stop structure 5, and a water-stop plate water-stop structure 4. The water-stop strip water-stop structure 3 is provided on both sides of the prefabricated segmental wall 1 and includes: a water-stop plate 31, a first water-swellable member 34, a second water-swellable member 36, a first protrusion 35, and a second protrusion 37. The water-stop plate 31 is a plate-shaped structure, made of rubber or steel plate. One end of the water-stop plate 31 is fixed to the side of the joint end of the prefabricated segmental wall 1 by an anchor 33. The other end of the water-stop plate 31 is a cantilever end, which extends to the side of the joint end of the adjacent prefabricated segmental wall 1 and has a gap with the side. Specifically, one end of the waterstop plate 31 is connected to a pad 32, which maintains the gap between the waterstop plate 31 and the side wall of the prefabricated segmental wall 1. The pad 32 and the waterstop plate 31 can be made into an integral structure. The inner end of the anchor 33 is pre-embedded in the prefabricated segmental wall 1, and this end is set as a T-shaped structure to enhance the anchoring force. The outer end of the anchor 33 is embedded in the pad 32 and the waterstop plate 31, thus forming a connection between the waterstop plate 31 and the prefabricated segmental wall 1. The above-mentioned gap setting avoids serious collision and squeezing between the waterstop plate 31 and the adjacent prefabricated segmental wall 1 during the installation of the prefabricated segmental wall 1, ensuring that the waterstop structure 3 can be smoothly lowered into the ground. The cantilever end of the waterstop plate 31 is also connected to a first water-swellable member 34 and a first protrusion 35. The first water-swellable member 34 is fixed on one side of the gap at the cantilever end of the waterstop plate 31. The first protrusion 35 is used to fit the side of the butt joint of the adjacent prefabricated segmental wall 1. It is located on one side of the gap at the cantilever end of the waterstop plate and is fixed by welding or by a structure integrally formed with the waterstop plate 31.

[0074] On the side of adjacent prefabricated segmental wall 1, a structure is provided to form a water-blocking barrier with the aforementioned water-stop plate 31, including a second water-swellable member 36, which is used to fit the first water-swellable member 34. The second water-swellable member 36 is provided on the side of the mating end of the adjacent prefabricated segmental wall 1, and similarly, it is provided on both sides of the prefabricated segmental wall 1. The second water-swellable member 36 and the first water-swellable member 34 are positioned opposite each other to ensure that the sides of the first water-swellable member 34 and the second water-swellable member 36 are in complete contact to increase the barrier width; in the second water-swellable member 36, the second water-swellable member 36 is provided on the side of the mating end of the adjacent prefabricated segmental wall 1, and the second water-swellable member 36 is provided on both sides of the prefabricated segmental wall 1. A second protrusion 37 is also provided next to the water-swellable component 36, which is used to fit the gap side of the waterstop plate. The second protrusion 37 is provided on the side of the joint end of the adjacent prefabricated segment wall 1, and is also provided on both sides. The setting method is anchoring. The first protrusion 35 and the second protrusion 37 are made of steel strips or rubber strips. The first protrusion 35 and the second protrusion 37 are respectively located on both sides of the joint position of the first water-swellable component 34 and the second water-swellable component 36, which can protect the first water-swellable component 34 and the second water-swellable component 36.

[0075] The water-stop structure 3 uses anchors 33 to fix the water-stop plate 31 to the joint end of the prefabricated segmental wall 1. During the jointing, the water-stop plate 31 blocks most of the seepage channels between adjacent prefabricated segmental walls 1, and seepage can only pass through the gaps. Then, the first water-swellable component 34 and the second water-swellable component 36 can expand and squeeze each other after water is injected, blocking the gaps and forming a water-stop structure, thus providing strong water-stopping and seepage prevention capabilities. The first water-swellable component 34 and the second water-swellable component 36 are both made of expanding rubber. Due to the water absorption and expansion effect, the first water-swellable component 34 and the second water-swellable component 36 can expand and block the gaps after the prefabricated segmental wall 1 is lowered, and can be lowered smoothly with the prefabricated segmental wall 1 before it is lowered. At the same time, the water-stop plate 31 can also provide preliminary support on both sides of the prefabricated diaphragm wall, playing a certain positioning role and ensuring verticality. Another function of the waterstop structure 3 is to prevent mud and sand from flowing into the vertical joint 11 from the outside, and to ensure that the grout in the vertical joint 11 does not easily flow around to the outside, thus improving the grouting quality.

[0076] In this embodiment, the interlocking pipe water-stopping structure 5 is formed by combining a double C-shaped connector 2 and a filling grout 51. The grout 51 is high-strength mortar or high-strength concrete, which fills the three chambers of the C-shaped opening structure of the double C-shaped connector 2, so that the double C-shaped connector 2 is combined with the concrete or mortar. Since the double C-shaped connector 2 itself has a small gap opening 28 at the interlocking position, the size of the seepage channel is limited, which greatly prevents water from flowing through. Furthermore, the curved arc structure of the double C-shaped connector 2 significantly increases the seepage path and increases the difficulty of seepage. Finally, the high-strength mortar or high-strength concrete further blocks the water penetration, thereby improving the water-stopping and seepage prevention effect.

[0077] The waterstop structure 4 of this embodiment includes two waterstops. The waterstops are made of steel plates or rubber plates, or other seepage-proof materials. The waterstops are square plates. The two waterstops are respectively set vertically at the joint ends of adjacent prefabricated segmental walls 1. Specifically, waterstops are set in the middle of the protruding part of the tenon 12 and the middle of the recessed part of the groove 13 of the prefabricated segmental wall 1 along the height direction. One side of the waterstop is embedded in the tenon 12 and the groove 13 of the prefabricated segmental wall 1. The positions of the two waterstops are exactly staggered, and the two waterstops can fit together when adjacent prefabricated segmental walls 1 are joined. Since the waterstops are partially embedded in the joint ends of the prefabricated segmental walls 1, the exposed length of the waterstops is greater than 1 / 2 of the width of the vertical joint 11. This ensures that when adjacent prefabricated segmental walls 1 are joined, the two waterstops can fit together to form a water-blocking structure.

[0078] In this embodiment, a triple water-stop structure is formed at the vertical joint 11 of the prefabricated diaphragm wall by using the above-mentioned water-stop strip structure 3, interlocking pipe structure 5, and water-stop plate structure 4. The triple water-stop structure not only blocks water seepage three times, but also adopts three different structural forms. Since the seepage path is not in the same direction, it is more difficult for water to seep through the triple water-stop structure, achieving a better water-stopping effect than simple superposition. Thus, this structure achieves a stronger water-stopping and seepage-proof effect.

[0079] Please refer to Figure 6 In order to achieve the prestressing application between the upper and lower prefabricated segment walls 1 and the grouting of the prefabricated diaphragm wall, a prestressing channel 73 and a grouting pipe 74 are also provided in the prefabricated diaphragm wall. Each prefabricated segment wall 1 is provided with a prestressing channel 73 that runs through the top and bottom. The prestressing tendons 6 connect the upper and lower prefabricated segment walls 1 through the prestressing channel 73 and apply prestress at the same time. The construction is carried out using the prestressing tendons 6. Shear keys are set in the horizontal joint 14 between the upper and lower adjacent prefabricated segment walls 1 and epoxy adhesive is applied. After construction, grouting is performed in the prestressing channel 73 to ensure the durability of the prestress.

[0080] Please refer to Figures 7-11 In this embodiment, five types of grouting pipes 74 are provided: grouting pipes 74 for grouting into each prestressed channel 73, grouting pipes 74 for grouting into the double C-type joint 2, grouting pipes 74 for grouting into the vertical joint 11, grouting pipes 74 for grouting into the bottom of the prefabricated diaphragm wall, and grouting pipes 74 for grouting into the side wall of the prefabricated diaphragm wall. Each grouting pipe 74 is pre-embedded in the prefabricated segmental wall 1 during its prefabrication. Each grouting pipe 74 is connected at the upper and lower segments using leak-proof joints. Each grouting pipe 74 has a grouting port at the uppermost layer of the prefabricated segmental wall 1, and a grout outlet 75 is provided at the bottom of the lowermost layer of the prefabricated segmental wall 1 and at the vertical joint 11. At the bottom of the prestressed channel 73 of each prefabricated segmental wall 1, Each side wall is provided with a grout outlet 75. The grout outlet 75 is specifically located at the end face of the bottom joint of the lowest prefabricated segmental wall 1 at the vertical joint 11, at the bottom of the lowest prefabricated segmental wall 1, and on the side wall of each prefabricated segmental wall 1 and at the bottom inner wall of the prestressed channel 73. In the side wall and bottom of the prefabricated segmental wall 1, the grouting pipe 74 is arranged horizontally along the side wall or horizontally along the bottom. The horizontally arranged grouting pipe 74 has multiple grout outlet holes at intervals and grout outlets 75 are opened at corresponding positions on the side wall and bottom of the prefabricated segmental wall 1. In this way, grout can be transported to the double C-type joint 2, the vertical joint 11, the bottom and side wall of the prefabricated diaphragm wall through five different grouting pipes 74.

[0081] Example 3

[0082] Please refer to Figure 12This embodiment provides a construction method for prefabricated diaphragm walls. Using the double C-type joints in Embodiment 1, the prefabricated diaphragm wall in Embodiment 2 is constructed. It is suitable for soft soil, sandy soil, gravel and other strata. It is suitable for retaining wall structures with high requirements for soil retention and water stopping, as well as permanent structures that bear the upper load and water and soil pressure load. Under these strata conditions, the prefabricated segmental wall 1 can be quickly assembled and constructed, which improves the docking accuracy between prefabricated segmental walls 1 and the overall construction efficiency. It promotes the standardization and assembly application of prefabricated diaphragm walls in construction, and has good economic benefits and fast construction speed.

[0083] Please refer to Figure 13 The prefabricated modular segmental wall 1 is adopted. This modular segmental wall 1 has a C-shaped opening structure at the joint end. It is manufactured in the prefabrication factory and then installed on site. The specific construction method includes the following steps:

[0084] S1. Excavation and trenching: Mark out the site and use a trenching machine to excavate trenches with a width d0, a length L equal to 3-5 prefabricated modular wall unit 1 lengths, and a depth slightly greater than the designed depth of the prefabricated diaphragm wall. The trench width d0 should be at least 10cm greater than the thickness of the prefabricated modular wall unit 1. Divide the trench into installation positions for multiple wall sections. After trenching, lay a crushed stone layer 8 at the bottom of the trench. The crushed stone layer 8 uses graded sand and gravel with a maximum particle size not exceeding 1cm. The height of the crushed stone layer 8 should be 5-10cm higher than the designed wall bottom elevation to ensure the stability of the prefabricated diaphragm wall during subsequent construction and effectively transfer the load of the prefabricated diaphragm wall to the surrounding soil.

[0085] S2. The prefabricated segmental wall 1 is hoisted on the ground using lifting equipment. The prefabricated segmental wall 1 is placed at the position of the first wall in the trench. The placed prefabricated segmental wall 1 is not placed at the bottom of the trench. Multiple layers of prefabricated segmental walls 1 are placed above and below each wall position to ensure that the two ends of the prefabricated segmental wall 1 are aligned and each layer of prefabricated segmental wall 1 is placed horizontally, so that the positions of the multiple layers of prefabricated segmental walls 1 above and below each wall position are accurately positioned. At this time, the prefabricated segmental walls 1 above and below are in a suspended state, and the C-shaped opening structures of the upper and lower layers are aligned to form a through groove for guidance.

[0086] S3. Next, prestressed tendons 6 are lowered. In this embodiment, prestressed steel bars are used. The prestressed steel bars are vertically inserted into the prestressed channels 73 of the upper and lower layers, and anchoring devices are lowered to fix the bottom end of the prestressed steel bars to the bottom of the lowest layer of prefabricated segmental wall 1. Alternatively, prestressed steel bars with hooks at the bottom are used, and the bottom end of the prestressed steel bars is fixed to the bottom of the lowest layer of prefabricated segmental wall 1 through the hook structure. Then, the prefabricated segmental walls 1 of the upper and lower layers are lowered as a whole. After being lowered into place, each prefabricated segmental wall 1 can further compact the crushed stone layer 8. Then, prestress is applied to the prestressed steel bars at the top of the uppermost prefabricated segmental wall 1 to realize the vertical prestressed construction of the upper and lower multi-layer prefabricated segmental walls 1. Finally, the prestressed steel bars are anchored to the top of the uppermost prefabricated segmental wall 1.

[0087] S4. Following steps S2 to S3, adjacent prefabricated segmental walls 1 are placed at adjacent wall positions within the trench, and the docking construction is carried out. When placing adjacent prefabricated segmental walls 1, the top of the C-shaped opening structure of the first placed prefabricated segmental wall 1 is offset from the bottom of the C-shaped opening structure of the next placed adjacent prefabricated segmental wall 1, so that the two C-shaped opening structures are fitted together through the gap opening 28. Then, adjacent prefabricated segmental walls 1 are placed vertically, keeping the two C-shaped opening structures fitted together until the positions of the two adjacent prefabricated segmental walls 1 are aligned. After all the prefabricated segmental walls 1 at this wall position are placed, the placement and docking of adjacent prefabricated segmental walls 1 are completed. After the installation of the upper and lower multi-layer prefabricated segmental walls 1 is completed, the above-mentioned prestressing construction is carried out. Prestressing construction improves the load-bearing capacity of the prefabricated diaphragm wall. At the same time as this step is completed, the first waterstop plate 41 and the second waterstop plate 42 are aligned, and the waterstop plate waterstop structure 4 is formed.

[0088] The above-described sinking and docking process ensures that the prefabricated segmental walls 1 remain vertical and accurately aligned. During docking, the C-shaped opening structure of the later-sinking prefabricated segmental wall 1 can be vertically sinked as long as the top of the C-shaped opening structure of the earlier-sinking prefabricated segmental wall 1 interlocks. The C-shaped opening structure located in the groove provides guidance, enabling rapid docking and improving the installation accuracy of the prefabricated segmental wall 1. At the same time, it enables rapid docking of the internal structure of the prefabricated diaphragm wall and rapid installation of the prefabricated diaphragm wall, effectively shortening the installation time and improving the assembly efficiency of the prefabricated diaphragm wall.

[0089] S5. Following step S4, complete the sinking and installation of the prefabricated segmental wall 1 at all wall locations. A total of 2 to 5 wall installation locations need to be sinked to complete the construction of one trench segment, forming a prefabricated diaphragm wall. In this way, through the sequential sinking and installation of different wall locations, the preliminary construction of the prefabricated diaphragm wall is formed, that is, the installation is in place.

[0090] S6. Fill the side joint 15 between the prefabricated diaphragm wall and the surrounding soil with graded sand and gravel to stabilize the prefabricated diaphragm wall in the trench. This step provides support for the prefabricated diaphragm wall on both sides to ensure its verticality and positioning, thereby ensuring installation accuracy.

[0091] S7. Grouting is performed at the bottom of each prestressed channel 73 through the corresponding grouting pipe 74. The grout enters the bottom end of the lowest prefabricated segmental wall 1 and enters the bottom end of the prestressed channel 73 through the grout outlet 75. Then the grout fills the entire prestressed channel 73 from bottom to top. Grouting is then performed on the prestressed channel 73 of the next layer of prefabricated segmental wall 1 in layers. Finally, grouting is performed on the prestressed channel 73 of the uppermost prefabricated segmental wall 1. Grouting is stopped after the grout emerges and each prestressed channel 73 is sealed by anchor plates.

[0092] S8. Clean the internal impurities of the two C-shaped opening structures by air lifting and / or high-pressure water injection. Use a water jet pipe 72 and an air-lift soil discharge pipe 71 to extend to the bottom of the prefabricated segmental wall 1 to clean the intermediate chamber 24 and vertical joint 11 in the double C-shaped joint 2. Specifically, insert the water jet pipe 72 into the intermediate chamber 24 of the double C-shaped joint 2 and inject clean water under high pressure to rinse the mud and sand in the intermediate chamber 24. At the same time, use the air-lift soil discharge pipe 71 to discharge the mud and sand out of the pipe. Then, insert the water jet pipe 72 into the first chamber 23 and the second chamber 25 of the double C-shaped joint 2 and inject clean water under high pressure to rinse the mud and sand in the first chamber 23 and the second chamber 25. At the same time, use the air-lift soil discharge pipe 71 placed in the intermediate chamber 24 to discharge the mud and sand out of the pipe. The mud and sand in the first chamber 23 and the second chamber 25 flow through the connecting hole 26 provided at the bottom of the C-shaped opening structure. When the water discharged from the air-lift soil discharge pipe 71 is relatively clear, the air-lift soil discharge pipe 71 and the water jet pipe 72 are pulled out. The cleaning process removes impurities, effectively clearing mud, sand, or other impurities from the three chambers, facilitating smooth grouting and ensuring grouting quality. Simultaneously, the first and second expansion components expand upon contact with water, forming the water-stopping structure 3. The air-lift method utilizes pressurized gas injected into the C-shaped opening structure to remove impurities from its interior.

[0093] S9. High-strength concrete or high-strength mortar is injected into the intermediate chamber 24, first chamber 23, and second chamber 25 of the double C-type joint 2 through the corresponding grouting pipe 74. The grout can quickly fill the C-type joint. The strength of the high-strength mortar is not less than 60MPa. When using high-strength mortar, an early-strength agent is added to the mortar to ensure that the strength of the vertical joint 11 is increased in a short time, avoiding the impact of other construction disturbances on the quality of the vertical joint 11. There is a double C-type joint 2 between each adjacent prefabricated segment wall 1. By injecting high-strength mortar or high-strength concrete into the two C-type opening structures, a connection structure between the double C-type joint 2 and the concrete is formed, completing the connection between the adjacent prefabricated segment walls 1. At this time, a water-stop structure is formed at the vertical joint 11 between the adjacent prefabricated segment walls 1, blocking water seepage. The double C-type joint 2 is integrated with the concrete or mortar through the grouting step, forming an interlocking water-stop structure 5 and a strong connection structure, which can be used in ultra-deep underground environments.

[0094] S10. Clean the vertical joint 11, inject clean water into the grouting pipe 74 embedded in the wall on one side of the vertical joint 11, and at the same time insert a water pump into the vertical joint 11 to extract the mud containing impurities. When the extracted water is clear, stop injecting clean water and pull out the water pump.

[0095] S11. Grouting is performed on the vertical joints 11 of the prefabricated segmental wall 1 through the corresponding grouting pipe 74. The grout enters the vertical joint 11 from the joint end of the prefabricated segmental wall 1 at the vertical joint 11. High-strength concrete or high-strength mortar is used for grouting. Thus, the vertical gap is filled from bottom to top. When high-strength concrete or high-strength mortar emerges from the top joint of the prefabricated diaphragm wall, the grouting is stopped, and the grouting construction of the vertical joint 11 is completed. In this way, a closed vertical joint 11 is formed between the prefabricated segmental walls 1.

[0096] S12. Grouting is performed on the bottom of the lowest prefabricated segmental wall 1 through the corresponding grouting pipe 74. The grout is discharged from each grout outlet 75 at the bottom and enters the crushed stone layer 8, compacting and filling the voids in the crushed stone layer 8 at the bottom of the wall, forming a bearing layer with high load-bearing capacity at the wall end, effectively controlling the settlement of the entire prefabricated diaphragm wall.

[0097] S13. Grouting is performed on both sides of the prefabricated segmental wall 1 through the corresponding grouting pipe 74. After the grout is discharged from the side wall of the prefabricated segmental wall 1, it enters the side joint 15 between the prefabricated diaphragm wall and the surrounding soil, so that the prefabricated diaphragm wall and the surrounding soil are connected as a whole, forming a strong connection structure.

[0098] The grouting process described above involves grouting the gaps between adjacent prefabricated segmental walls 1, as well as the bottom and sidewalls of the prefabricated diaphragm wall. Post-grouting is employed to ensure the prefabricated diaphragm wall integrates with the surrounding soil, sharing the load. Grouting at C-joints, butt joints, and the bottom and sidewalls connects each double C-joint 2, forming a unified structure and a water-stopping feature. This also integrates the prefabricated diaphragm wall with the surrounding soil, creating a structure with sufficient structural strength, load-bearing capacity, and water-stopping and seepage-proofing capabilities, thus completing the construction of the prefabricated diaphragm wall in ultra-deep underground environments. This overall construction method overcomes the shortcomings of cast-in-place diaphragm wall construction, such as difficulty in quality control, long construction periods, and significant environmental pollution. It effectively enables rapid and efficient prefabricated application of diaphragm wall foundations. Its application is not limited to general retaining structures and seepage-proof walls; it can also be applied to main load-bearing structures such as high-rise buildings and large bridges, and is suitable for various geological conditions.

[0099] During the grouting process described above, the portion of the vertical joint 11 located inside the double C-shaped joint 2 is defined as the first joint 16, and the portion of the vertical joint 11 located outside the double C-shaped joint 2 is defined as the second joint 17. In the grouting process during the butt joint construction:

[0100] First, grouting is performed on the first chamber 23, the intermediate chamber 24, and the second chamber 25 of the double C-type joint 2, wherein the two C-shaped opening structures divide the double C-type joint 2 into the first chamber 23, the intermediate chamber 24, and the second chamber 25; then, grouting is performed on the first joint 16; and then grouting is performed on the second joint 17.

[0101] During the grouting construction of the first joint 16, the first joint 16 was constructed by underwater grouting.

[0102] Alternatively, during the grouting construction of the first joint 16, first seal the bottom of the first joint 16 underwater for 1m to 2m, then extract the water from the first joint 16, and then grout the remaining part of the first joint 16.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A prefabricated diaphragm wall based on an interlocking mechanism, characterized in that: The system comprises several prefabricated segmental walls (1) connected together. Adjacent prefabricated segmental walls (1) are connected by double C-type joints (2). Each double C-type joint (2) includes two C-type opening structures with identical structures. The C-type opening structures are made of steel and are formed by opening a gap opening (28) through both ends on the side wall of the pipe fitting. The cross-section of the C-type opening structure is C-shaped. The setting direction of the gap opening (28) is consistent with the extension direction of the C-type opening structure. The two C-type opening structures are respectively set at the joint ends of adjacent prefabricated segmental walls (1), and the two C-type opening structures are interlocked and connected through the gap opening (28). The joint end of the prefabricated segmental wall (1) is embedded with the C-shaped opening structure arranged along the height direction. After the double C-shaped joint (2) is connected, the two C-shaped opening structures form three chambers. The inner wall of the two C-shaped opening structures that fit together is also provided with a connecting hole (26) for grouting, through which the grouting of the three chambers is balanced; It also includes a grouting pipe (74) for grouting into the double C-type joint (2), the grouting pipe (74) being embedded in the prefabricated segmental wall (1); The double C-type joint (2) and the filled grout (51) combine to form a bite-tube water-stop structure (5), which, together with the water-stop strip water-stop structure (3) on the side of the assembled segmental wall (1) and the water-stop plate water-stop structure (4) at the joint end, forms a multi-layer water-stop structure. The waterstop structure (3) includes: Waterstop plate (31), the waterstop plate (31) is a plate structure, one end of the waterstop plate (31) is fixed to the side of the joint end of the prefabricated segmental wall (1) by anchor (33), the other end of the waterstop plate (31) is a cantilever end, the cantilever end extends to the side of the joint end of the adjacent prefabricated segmental wall (1) and has a gap with the side; The first water-swellable component (34) is disposed on one side of the gap at the cantilever end of the waterstop plate (31); The first protrusion (35) is used to fit the side of the mating end of the adjacent prefabricated segmental wall (1), and the first protrusion (35) is provided on the gap side of the cantilever end of the waterstop plate. The second water-swellable component (36) is used to fit the first water-swellable component (34). The second water-swellable component (36) is provided on the side of the mating end of the adjacent prefabricated segmental wall (1), and the second water-swellable component (36) is opposite to the first water-swellable component (34). The second protrusion (37) is used to fit one side of the gap of the waterstop plate. The second protrusion (37) is provided on the side of the joint end of the adjacent prefabricated segmental wall (1). The second protrusion (37) and the first protrusion (35) are respectively located on both sides of the fitting position of the first water-swellable part (34) and the second water-swellable part (36).

2. The prefabricated diaphragm wall based on interlocking method according to claim 1, characterized in that, The mutual embedding depth range of the two C-shaped opening structures is [D / 3, 2D / 3], where D is the outer diameter of the C-shaped opening structure.

3. The prefabricated diaphragm wall based on the interlocking method according to claim 1, characterized in that, The wall thickness of the C-shaped opening structure is in the range of [10mm, 20mm], the width of the gap opening (28) is [t+15mm, t+25mm], t is the wall thickness of the C-shaped opening structure, and the outer diameter D of the C-shaped opening structure is ≥140mm.

4. The prefabricated diaphragm wall based on interlocking method according to claim 1, characterized in that, The inner wall of the C-shaped opening structure is provided with several protruding structures (27).

5. The prefabricated diaphragm wall based on the interlocking method according to claim 1, characterized in that, The three chambers are used for pouring high-strength concrete or high-strength mortar.

6. The prefabricated diaphragm wall based on interlocking method according to claim 1, characterized in that, The grouting body (51) is high-strength mortar or high-strength concrete. The waterstop structure (4) includes two waterstops. The two waterstops are respectively set vertically at the joint ends of the adjacent prefabricated segmental walls (1). The positions of the two waterstops are staggered and can fit together when the adjacent prefabricated segmental walls (1) are joined.

7. A construction method for prefabricated diaphragm walls, characterized in that, The prefabricated diaphragm wall based on the interlocking method described in any one of claims 1-6 is constructed using a method including butt joint construction: Docking steps: When the adjacent prefabricated segmental walls (1) are laid down, the top of the C-shaped opening structure of the prefabricated segmental wall (1) laid down first is offset from the bottom of the C-shaped opening structure of the adjacent prefabricated segmental wall (1) laid down later, so that the two C-shaped opening structures are fitted together through the gap opening (28). Then the adjacent prefabricated segmental walls (1) are laid down in the vertical direction, keeping the two C-shaped opening structures fitted together until the positions of the two adjacent prefabricated segmental walls (1) are aligned. Cleaning steps: Remove internal impurities from the two C-shaped opening structures that are joined together by air lift and / or water injection. Grouting steps: By injecting high-strength mortar or high-strength concrete into the two C-shaped opening structures that are connected, the connection structure of the double C-shaped joint (2) and the concrete is formed, and the connection of the adjacent prefabricated segmental wall (1) is completed.

8. The construction method for prefabricated diaphragm walls according to claim 7, characterized in that, Construction methods also include: Before sinking the prefabricated segmental wall (1), the following steps are performed: excavating a trench and laying a layer of crushed stone at the bottom of the trench; The prefabricated segmental wall (1) is placed at the position of the first wall in the trench, and multiple layers of prefabricated segmental walls (1) are placed above and below each wall position; then the prefabricated segmental walls (1) are constructed vertically. The adjacent prefabricated segmental wall (1) is placed at the position of the adjacent wall in the trench, and the docking construction is carried out. After the installation of the upper and lower multi-layer prefabricated segmental wall (1) is completed, the above-mentioned prestressing construction is carried out in the same way. Following the above two steps, the prefabricated segmental wall (1) at all wall locations is laid down and installed to form a prefabricated diaphragm wall; Grouting is carried out for docking construction. Grouting is performed on the gaps between adjacent prefabricated segmental walls (1), the bottom and side walls of the prefabricated diaphragm wall, so that the prefabricated diaphragm wall and the surrounding soil form an integral whole.

9. The construction method of the prefabricated diaphragm wall according to claim 8, characterized in that, The portion of the vertical joint (11) located inside the double C-shaped joint (2) is defined as the first joint (16), and the portion of the vertical joint (11) located outside the double C-shaped joint (2) is defined as the second joint (17). During the grouting process for the butt joint construction: First, grouting is carried out on the first chamber (23), the intermediate chamber (24), and the second chamber (25) of the double C-type joint (2). The two C-type opening structures divide the double C-type joint (2) into the first chamber (23), the intermediate chamber (24), and the second chamber (25). The first joint (16) is then grouted, in which, First joint of underwater grouting construction (16). or, First, seal the bottom of the first joint (16) underwater for 1m~2m, then extract the water from the first joint (16), and then pour the remaining part of the first joint (16) into the water. The second joint (17) was then grouted.

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