D-shaped fastener for butt joint of longitudinal joint of shield segment and processing method thereof

Abstract

The application relates to the technical field of shield segments, and particularly discloses a D-shaped fastener for butt joint of longitudinal joints of shield segments and a processing method thereof. The D-shaped fastener has a first shaped edge, an anchoring connecting edge, a second shaped edge and a butt joint stop edge which enclose a butt joint cavity, the first shaped edge and the butt joint stop edge are not circumferentially closed and reserve a web through seam which communicates with the butt joint cavity, the anchoring connecting edge, the second shaped edge and the butt joint stop edge are integrally formed and are in a C-shaped structure which is bent on the end face, the first shaped edge is formed by a steel plate and is in an I-shaped structure which is flat on the end face, the anchoring connecting edge is connected with the first shaped edge into an integral whole through a welding matching structure, the anchoring connecting edge, the second shaped edge and the butt joint stop edge which are in a C-shaped structure and are integrally bent cooperate with the first shaped edge to enclose the butt joint cavity which is in a rectangular shape on the end face. The application can guarantee good structural strength and stress performance, is beneficial to reducing the processing technical difficulty, guaranteeing the processing precision and controlling the processing cost.

Description

Technical Field

[0001] This invention relates to the field of tunnel segment technology, specifically a D-type fastener for longitudinal joint connection of tunnel segments, and a processing method for the D-type fastener. Background Technology

[0002] Shield tunnel segments are the permanent lining structures in shield tunnel construction. They are assembled from multiple arc-shaped components into a ring, forming an inner barrier within the tunnel. They bear the responsibility of resisting soil pressure, groundwater pressure, and special loads, and directly affect the tunnel's waterproofness, durability, and structural safety.

[0003] In the assembly structure of tunnel boring machine (TBM) segments, the joint between adjacent circumferential TBM segments is called the longitudinal joint. It is typically connected using bolts, but bolted connections have certain technical drawbacks—such as excessive structural deformation leading to compromised structural safety, or significant weakening of the segment's load-bearing cross-section, resulting in reduced load-bearing capacity. Based on this, the industry has researched D-type fasteners as a longitudinal joint connection structure for TBM segments, for example, the technology published in Chinese patent literature entitled "A Multi-Point Connection Structure for Longitudinal Joints of TBM Segments without Handholes," publication number CN 114810135 A, publication date July 29, 2022. Specifically, the D-type fasteners form an open-circumferential interlocking cavity with a reserved web seam. When adjacent shield tunnel segments are joined, webs with end faces approximately resembling C-shapes are inserted between adjacent D-type fasteners forming the joint, and the corresponding filling structure weds the C-shaped webs tightly within the interlocking cavity of the adjacent D-type fasteners, thereby achieving the connection of adjacent shield tunnel segments.

[0004] The aforementioned D-type fastener consists of a body with a rectangular end face but an unclosed internal interlocking cavity, and several anchor rods extending outward from one outer surface. Currently, there are two methods for molding the body of the D-type fastener: Firstly, it adopts a hot rolling process for integral forming. This method can obtain D-type fasteners with high structural strength and excellent stress performance through the integral forming of high-strength structural steel. However, due to the semi-closed snap-fit ​​cavity of the D-type fastener body and the high technical requirements for the structural dimensions of the D-type fastener, the hot rolling forming process is limited by the complex structure of the D-type fastener body and cannot be formed to the design size in one go. This results in high processing difficulty and complexity, and it is difficult to guarantee the accuracy of the snap-fit ​​cavity size and wall thickness tolerance. This is especially prominent in structures with different wall thicknesses in the design. Secondly, the D-type fastener is formed by welding an all-steel plate. This method involves cutting multiple steel plates independently and assembling them into an integral structure by welding. While this method is beneficial for the processing and ensures processing accuracy, the structural strength and load-bearing capacity of the D-type fastener are significantly insufficient due to residual welding stress and thermal deformation. Moreover, the multiple welds result in a large amount of welding work, low processing efficiency, and poor economic efficiency, making it unsuitable for mass production.

[0005] Therefore, it is necessary to design D-type fasteners in a way that effectively balances load-bearing performance, ease of processing, and economic efficiency. Summary of the Invention

[0006] The technical objective of this invention is to address the specific characteristics of the aforementioned D-type fastener for longitudinal joint connection of tunnel segments and the shortcomings of existing technologies, by providing a D-type fastener for longitudinal joint connection of tunnel segments that is beneficial for ensuring structural strength and load-bearing performance, as well as for processing operations, ensuring processing accuracy, and controlling processing costs, and a processing method for the D-type fastener.

[0007] The technical objective of this invention is achieved through the following technical solution: a D-type fastener for connecting longitudinal joints of tunnel segments, wherein the D-type fastener has a first shaping side, an anchoring connection side, a second shaping side, and a fastening stop side that form a fastening cavity, wherein the first shaping side and the fastening stop side are not closed in the circumferential direction and a web plate through-slot that connects to the fastening cavity is reserved. The anchoring connection edge, the second shaping edge, and the snap-fit ​​stop edge are integrally formed steel plates with a C-shaped structure bent on the end face, and the width of the anchoring connection edge is greater than the width of the snap-fit ​​stop edge. The first shaping edge is a steel plate formed into an I-shaped structure with a straight end face; The anchoring connection edge is connected to the first shaping edge in a welded fit structure to form an integral whole. The anchoring connection edge, the second shaping edge, and the snap-fit ​​stop edge, which are bent in a C-shape, together with the first shaping edge, form a snap-fit ​​cavity with a rectangular end face.

[0008] Furthermore, on the side opposite to the snap-fit ​​stop edge, there are several rearward-extending anchor rods arranged, which are spaced along the length of the anchoring connection edge.

[0009] A method for processing D-type fasteners for longitudinal joint connection of tunnel segments as described above, the method comprising the following technological processes: S1. According to the design technical requirements of D-type fasteners, high-strength structural steel is cut and prepared to obtain mutually independent C-shaped and I-shaped components; S2. According to the designed D-type fastener structure, arrange the C-shaped and I-shaped components on the shaping fixture in relative positions, so that the set weld position is in the welding operation space, and clamp and position them. During the clamping and positioning process, a shaping jig is arranged at the web seam to maintain the positioning of the mating distance between the first shaping edge and the fastening stop edge. S3. Weld the set weld seam using the set welding process, and obtain a weld seam reinforcement height higher than the base material, so that the C-shaped component and the I-shaped component clamped together are welded into an integral structure to obtain a D-type fastener blank; S4. After the D-type fastener has cooled down, remove it from the shaping fixture and grind the weld to make it flush with the base material. S5. Straighten the D-type fastener of S4 on a straightening machine according to the straightness requirements of the design; S6. Clamp the D-type fastener of S5 onto the shaping fixture, so that the outer surface of the anchoring connection edge is in a welding operation space, and clamp and position it. S7. Weld several anchor rods to the anchor connection edge using the set welding process; S8. After the D-type fastener from S7 has cooled down, remove it from the shaping fixture and straighten it on the straightening machine according to the straightness requirements of the design. S9. Perform flaw detection on the D-type fastener of S8; Products that pass the flaw detection undergo surface anti-corrosion treatment to obtain the finished product.

[0010] Furthermore, in S1, in accordance with the design technical requirements of the D-type fastener, the anchoring connection edge, the second shaping edge, and the fastening stop edge are obtained by hot-rolled C-shaped structural steel. According to the designed snap-fit ​​cavity size, and the designed thickness of the anchoring connection edge, the second shaping edge and the snap-fit ​​stop edge, the obtained C-shaped part is precision machined by cold drawing or mechanical cutting using a cold drawing die.

[0011] Furthermore, in S2 or S6, the shaping fixture has a base plate, a first support frame and a second support frame spaced apart on both sides of the top surface along the width direction of the base plate, a plurality of first tightening bolts spaced apart on the first support frame along the length direction of the base plate, and a plurality of second tightening bolts spaced apart on the second support frame along the length direction of the base plate. When the D-type fastener is clamped, its length is placed on the base plate between the first and second tightening bolts. The C-shaped component of the D-type fastener has its locking stop edge on the top surface of the base plate with its anchoring edge facing upwards and its second shaping edge facing the second tightening bolt. The I-shaped component of the D-type fastener has its first shaping edge facing the first tightening bolt. The first and second shaping edges are tightened by the helical feed of the first and second tightening bolts, thus clamping and positioning the D-type fastener.

[0012] Furthermore, the shaping fixture also has a first push liner; The first push-up liner is arranged on the outer surface of the first shaping edge of the D-type fastener, and the first tightening bolt, which is fed by a spiral, tightens the first shaping edge through the first push-up liner.

[0013] Furthermore, the shaping fixture also has a second push liner; The second push-up liner is arranged on the outer surface of the second shaping edge of the D-type fastener, and the second tightening bolt, which is fed by a spiral, tightens the second shaping edge through the second push-up liner.

[0014] Furthermore, the first support frame of the shaping fixture is composed of multiple sets of individual units arranged at intervals along the length direction of the base plate.

[0015] Furthermore, the second support frame of the shaping fixture is composed of multiple sets of individual units arranged at intervals along the length direction of the base plate.

[0016] Furthermore, the shaping fixture also has a support; The brackets are arranged at the bottom of the base plate, raising and supporting the base plate.

[0017] Furthermore, in S6 or S9, the straightness of the straightening process over the entire length does not exceed 1.0 mm.

[0018] The beneficial technical effects of the present invention are as follows: the above-mentioned technical measures are aimed at the special characteristics of the D-type fastener for connecting the longitudinal joint of the shield tunnel segments. Each side of the body of the D-type fastener is cut into C-shaped and I-shaped structures independently. One side of the C-shaped structure is used as the anchoring connection side and welded to the I-shaped structure to form an integral structure. The other side of the C-shaped structure (the side relative to the anchoring connection side) is used as the fastening stop side and is matched with the I-shaped structure in the circumferential direction to form the web plate through joint. In this way, the combination of the C-shaped and I-shaped structures forms the body of the D-type fastener, creating a fastening cavity that allows the web plate to be fitted. At the same time, the opposite sides of the integrally formed C-shaped structure serve as anchoring and fastening stops for the longitudinal joints of the tunnel segments. This D-type fastener ensures good structural strength and load-bearing performance. Furthermore, the independent cutting of the C-shaped and I-shaped structures provides sufficient processing space and facilitates processing, reducing processing difficulty and ensuring reliable processing accuracy. The single weld between the C-shaped and I-shaped structures of the entire D-type fastener body significantly reduces the amount of welding required for the combined structure D-type fastener, improving processing efficiency, controlling processing costs, and facilitating mass production.

[0019] The above processing method is specifically designed based on the structural characteristics of the D-type fastener. It is easy to operate and can produce D-type fasteners with the above-mentioned technical advantages. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a D-type fastener of the present invention.

[0021] Figure 2 for Figure 1 A partial structural diagram of the D-type fastener (with anchor rods removed).

[0022] Figure 3 for Figure 2 The exploded diagram.

[0023] Figure 4 This is a schematic diagram of the assembly and positioning process of the D-type fastener (with the anchor rod removed) in the processing method of the present invention.

[0024] Figure 5 for Figure 4 Side view.

[0025] Figure 6 for Figure 4 A schematic diagram of a shaping fixture.

[0026] The symbols in the diagram have the following meanings: 1—D-type fastener; 11—first shaping edge; 12—anchoring connection edge; 13—second shaping edge; 14—fastening stop edge; 15—fastening cavity; 16—web plate through-hole; 17—anchor rod; 2—shaping jig; 3—shaping clamp; 31—support; 32—base plate; 33—first support frame; 34—second support frame; 35—first tightening bolt; 36—second tightening bolt; 37—first pushing liner; 38—second pushing liner. Detailed Implementation

[0027] This invention relates to the field of tunnel boring machine (TBM) segment technology, specifically a D-type fastener for longitudinal joint connection of TBM segments, and a processing method for the D-type fastener. The main technical solution of this invention will be specifically described below with reference to several embodiments. Embodiment 1 is illustrated in conjunction with the accompanying drawings—that is… Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 The technical solution of the present invention is clearly and in detail explained; although other embodiments are not shown in separate drawings, their main structure can still be referred to the drawings of Embodiment 1.

[0028] It should be noted that the accompanying drawings of this invention are schematic, and unnecessary details have been simplified to clarify the technical objectives of this invention, so as to avoid obscuring the technical solutions contributed by this invention to the prior art. Furthermore, the terms "approximately" or "basically" used below to refer to quantities or fit relationships mean that reasonable assembly and processing errors are allowed in the industry, and do not literally describe absolute quantities or fit relationships.

[0029] Example 1 See Figure 1 , Figure 2 and Figure 3 As shown, the present invention is a D-type fastener 1 for connecting longitudinal joints of tunnel segments, which has a first shaping edge 11, an anchoring connection edge 12, a second shaping edge 13 and a fastening stop edge 14 that form a fastening cavity 15.

[0030] Among them, the anchoring connection edge 12, the second shaping edge 13, and the snap-fit ​​stop edge 14 are integrally formed steel plate structures, namely hot-rolled C-shaped steel structures, which are bent at the end face and have an approximate C-shaped structure (basically a right-angle bend). Moreover, in order to accommodate the forming of the web through-slit 16, the width of the anchoring connection edge 12 is greater than the width of the snap-fit ​​stop edge 14.

[0031] The first shaping edge 11 is an I-shaped end face formed from hot-rolled steel sheet, and is basically the same length as the second shaping edge 13 in the C-shaped structure.

[0032] The anchoring connection edge 12 in the aforementioned C-shaped structure is connected to the first shaping edge 11 on one side of the width direction by a welded fit structure to form an integral whole, thereby obtaining a snap-fit ​​cavity 15 with a rectangular end face. Moreover, the snap-fit ​​stop edge 14 in the C-shaped structure is spaced and matched with the first shaping edge 11 on the other side of the width direction to form a web through-slit 16 that connects to the snap-fit ​​cavity 15. In other words, the aforementioned C-shaped integrally bent anchoring connection edge 12, second shaping edge 13, and snap-fit ​​stop edge 14, together with the I-shaped first shaping edge 11, form a snap-fit ​​cavity 15 with a rectangular end face. With the snap-fit ​​cavity 15 as the center, the aforementioned anchoring connection edge 12 and snap-fit ​​stop edge 14 are opposite each other and arranged at intervals. The aforementioned first shaping edge 11 and second shaping edge 13 are opposite each other and arranged at intervals between the anchoring connection edge 12 and snap-fit ​​stop edge 14. At the same time, the first shaping edge 11 and snap-fit ​​stop edge 14 are not closed in the circumferential direction and have a reserved web plate through-slit 16 for communicating with the snap-fit ​​cavity 15.

[0033] When the D-type fastener body described above is used in a tunnel segment, it is anchored at one circumferential end of the segment, with the fastening stop edge 14 serving as the mating interface. The anchoring connection edge 12 is embedded inside the tunnel segment to form the anchor. Therefore, on the side of the anchoring connection edge 12 opposite to the fastening stop edge 14, several rearwardly extending anchor rods 17 are arranged, with these anchor rods 17 spaced approximately evenly along the length of the anchoring connection edge 12.

[0034] The aforementioned D-type fastener 1 is formed by welding a bent C-shaped structure and a straight I-shaped structure. The C-shaped structure can be directly hot-rolled, and the open internal space facilitates precision machining. Whether the wall thickness of the anchoring connection edge 12, the second shaping edge 13, and the fastening stop edge 14 is designed to be equal or unequal, it is easy to process, reducing processing difficulty and reliably ensuring processing accuracy. The formation of the I-shaped structure is even easier. Thus, the fastening cavity 15 formed by the C-shaped and I-shaped structures ensures stable formation within the shield tunnel segment, thereby ensuring reliable filling of the web filling structure during the longitudinal joint connection of the shield tunnel segments and guaranteeing connection accuracy.

[0035] Meanwhile, based on the force of the D-type fastener 1 in the longitudinal joint of the shield tunnel segment, the fastening stop 14 of the web plate fastener is integrally formed with the anchoring connection side 12 through the second shaping side 13. There is no weld between the fastening stop 14 and the anchoring connection side 12 that affects the structural strength, which makes its structural strength high and its stress performance good.

[0036] It is evident that although the aforementioned D-type fastener 1 is formed by welding and assembly, eliminating the technical drawbacks of integral forming of four sides, it also retains the technical advantages of integral forming of four sides. At the same time, single-seam welding can significantly reduce the welding amount of the D-type fastener in the assembly structure, which is conducive to improving processing efficiency, controlling processing costs, and also conducive to realizing mass production.

[0037] See Figure 4 , Figure 5 and Figure 6 As shown, based on the above-mentioned D-type fastener 1 structure, the specific processing method includes the following technological processes: S1. According to the design technical requirements of D-type fastener 1, hot-rolled C-shaped steel and steel plate with high strength structure are cut and blanked to obtain independent C-shaped components with bent end faces and straight I-shaped components; Among them, the C-shaped structural steel formed by hot rolling is used to obtain the integrally formed anchoring connection edge 12, second shaping edge 13 and snap-fit ​​stop edge 14. The precision of the hot-rolled C-shaped structure is difficult to meet the design requirements. Therefore, according to the designed snap-fit ​​cavity 15 size and the designed thickness of the anchoring connection edge 12, second shaping edge 13 and snap-fit ​​stop edge 14, the obtained C-shaped component is cold-drawn and precision-machined using a cold-drawing die (or precision-machined by mechanical cutting). To accommodate welding, a welding bevel is machined at the end of the anchoring connection edge 12; Hot-rolled I-shaped structural steel can be directly formed without cold drawing or machining. Of course, this does not exclude finishing processes; the specific process or construction requirements will be determined flexibly. Typically, to ensure the strength grade, the steel used in the high-strength structure is any one of Q355 / Q390 / Q420 / Q460 / Q500 / Q550 / Q620 / Q690; S2. According to the designed D-type fastener 1 structure, arrange the C-shaped and I-shaped components in relative positions as follows: Figure 4 , Figure 5 and Figure 6 On the shaping fixture 3 shown, the position of the set weld between the first shaping edge 11 and the anchoring connection edge 12 is positioned upwards in the welding operation space, and is clamped and positioned by the first tightening bolt 35 and the second tightening bolt 36 on the left and right sides. The specific clamping and positioning process is described in the following description of the structure and application of the shaping fixture. During the clamping and positioning process, since there is a matching gap between the first shaping edge 11 and the fastening stop edge 14, and the force required for clamping and positioning, a shaping jig 2 is arranged at the set web seam 16 position to maintain the matching distance between the first shaping edge 11 and the fastening stop edge 14. The shaping jig 2 fills and fills the matching distance between the first shaping edge 11 and the fastening stop edge 14 to ensure the stability of the clamping force applied by the first tightening bolt 35 and the second tightening bolt 36 from the left and right sides. S3. Weld the weld seam specified in S2 using the set welding process. The weld seam reinforcement is slightly higher than the base material - usually 0.5mm higher than the base material. This allows the C-shaped component and the I-shaped component to be welded together into an integral structure, resulting in a D-type fastener blank. The above welding process is usually carbon dioxide gas shielded welding (or laser hybrid welding / laser filler wire welding, etc.). S4. After the D-type fastener has cooled down, remove it from the shaping fixture and use a grinding tool to grind the weld so that the weld is flush with the base material. S5. Place the D-type fastener from S4 on the straightening machine and straighten it according to the straightness requirements of the design. Typically, the straightness of the entire length after straightening should not exceed 1.0 mm; S6. Clamp the D-type fastener from S5 onto the... Figure 4 , Figure 5 and Figure 6 On the fixture shown, the outer surface of the anchoring connection edge is facing upwards and positioned in a welding operation space, and then clamped and positioned. S7. Weld several anchor rods to the anchor connection edge using the set welding process; The above welding process is usually carbon dioxide gas shielded welding (or stud welding). S8. After the D-type fastener from S7 has cooled down, remove it from the shaping fixture and straighten it on the straightening machine according to the straightness requirements of the design. Typically, the straightness of the entire length after straightening should not exceed 1.0 mm; S9. Perform flaw detection on the D-type fastener of S8; Products that pass the flaw detection undergo surface anti-corrosion treatment, such as zinc diffusion, electroplating, or painting, to obtain the finished product, which is then packaged.

[0038] See Figure 4 , Figure 5 and Figure 6As shown, the shaping fixture 3 used in the above processing method includes a bracket 31, a base plate 32, a first support frame 33, a second support frame 34, a first tightening bolt 35, a second tightening bolt 36, a first push liner 37, and a second push liner 38.

[0039] Specifically, the bracket 31 is arranged at the bottom of the base plate 32 to raise and support the base plate 32 and the structures arranged on the base plate 32 for construction operations.

[0040] The base plate 32 has a rectangular profile structure on its top surface that conforms to the outer contour of the D-type fastener. It is supported by the bracket 31 and has a shorter width and a longer length. The top surface of the base plate 32 is flat and serves as a worktable.

[0041] The first support frame 33 has multiple sets of support unit-plate structures, which are arranged at approximately uniform intervals along the length of the base plate 32 on one side of the top surface in the width direction of the base plate 32. The second support frame 34 is arranged approximately symmetrically about the center in the width direction on the top surface of the base plate 32. In this way, the first support frame 33 and the second support frame 34 are arranged at intervals along the width direction of the base plate 32 on both sides of the top surface.

[0042] The first support frame 33 and the second support frame 34 need to bear the corresponding tightening bolts to clamp the D-type fastener. Therefore, in order to ensure the stability of the clamping force, the protrusion height of the first support frame 33 and the second support frame 34 on the top surface of the base plate 32 should at least correspond to the center of the width of the anchoring connection edge of the D-type fastener, but should not exceed or align with the anchoring connection edge of the D-type fastener, otherwise it will affect the construction operation.

[0043] The first tightening bolts 35 are in multiple sets, arranged corresponding to each individual unit of the first support frame 33, and are spirally installed on the corresponding unit. Their axial direction corresponds to the width direction of the base plate 32. All the first tightening bolts 35 are arranged above the base plate 32 with a basically equal height. In this way, multiple first tightening bolts 35 are arranged at intervals along the length direction of the base plate 32 on the first support frame 33.

[0044] The second tightening bolts 36 are in multiple sets, arranged corresponding to each individual unit of the second support frame 34, and are spirally installed on the corresponding unit. Their axial direction corresponds to the width direction of the base plate 32. All the second tightening bolts 36 are arranged above the base plate 32 with a basically equal height. In this way, multiple second tightening bolts 36 are arranged at intervals along the length direction of the base plate 32 on the second support frame 34.

[0045] When the D-type fastener is clamped, its length is placed on the base plate 32 between the first tightening bolt 35 and the second tightening bolt 36 along the length of the base plate 32. The C-shaped component that makes up the D-type fastener has its fastening stop edge located on the top surface of the base plate 32 with its anchoring connection edge facing upward and its second shaping edge facing the second tightening bolt 36. The I-shaped component that makes up the D-type fastener has its first shaping edge facing the first tightening bolt 35. The first shaping edge and the second shaping edge are tightened by the helical feeding of the first tightening bolt 35 and the second tightening bolt 36, thereby clamping and positioning the D-type fastener.

[0046] In the above clamping and positioning, in order to prevent the first tightening bolt 35 from damaging the first shaping edge of the D-type fastener, the first pushing liner 37 is arranged on the outer surface of the first shaping edge of the D-type fastener, and it cooperates with the first shaping edge in a surface contact relationship. The first tightening bolt 35, which is spirally fed, tightens the first shaping edge through the first pushing liner 37.

[0047] In the above clamping and positioning, in order to prevent the second tightening bolt 36 from damaging the second shaping edge of the D-type fastener, the second push liner 38 is arranged on the outer surface of the second shaping edge of the D-type fastener, and it cooperates with the second shaping edge in a surface contact relationship. The spirally fed second tightening bolt 36 tightens the second shaping edge through the second push liner 38.

[0048] Example 2 The rest of the content of this embodiment is the same as that of embodiment 1, except that: The first support frame of the shaping fixture is a single plate structure.

[0049] Example 3 The rest of the content of this embodiment is the same as that of embodiment 1, except that: The second support frame of the shaping fixture is a single plate structure.

[0050] Example 4 The rest of the content of this embodiment is the same as that of embodiment 1, except that: The shaping fixture removes the first push liner, and the tightening end face of the first tightening bolt is a large and flat planar structure, for example, formed in a T-shape.

[0051] Example 5 The rest of the content of this embodiment is the same as that of embodiment 1, except that: The shaping fixture removes the second push liner, and the tightening end face of the second tightening bolt is a large and flat planar structure, for example, formed in a T-shape.

[0052] The above embodiments are only used to illustrate the present invention and are not intended to limit it.

[0053] Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions of the above embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the present invention.

Claims

1. A D-type fastener for connecting longitudinal joints of tunnel segments, wherein the D-type fastener (1) has a first shaping edge (11), an anchoring connection edge (12), a second shaping edge (13), and a fastening stop edge (14) forming a fastening cavity (15), wherein the first shaping edge (11) and the fastening stop edge (14) are not closed in the circumferential direction and a web through-slot (16) is reserved to connect the fastening cavity (15). Its features are: The anchoring connection edge (12), the second shaping edge (13) and the snap-fit ​​stop edge (14) are integrally formed steel plates with a C-shaped structure bent on the end face, and the width of the anchoring connection edge (12) is greater than the width of the snap-fit ​​stop edge (14). The first shaping edge (11) is a steel plate formed into an I-shaped structure with a straight end face; The anchoring connection edge (12) is connected to the first shaping edge (11) in a welded fit structure to form an integral whole. The anchoring connection edge (12), the second shaping edge (13), and the snap-fit ​​stop edge (14) are bent in a C-shape and together with the first shaping edge (11) to form a snap-fit ​​cavity (15) with a rectangular end face.

2. The D-type fastener for longitudinal joint connection of shield tunnel segments according to claim 1, characterized in that: The anchoring connection edge (12) is opposite to the snap-fit ​​stop edge (14) and has a number of rearward extending anchor rods (17) arranged on one side. These anchor rods (17) are arranged at intervals along the length direction of the anchoring connection edge (12).

3. A method for processing a D-type fastener for longitudinal joint connection of shield tunnel segments as described in claim 1 or 2, characterized in that, The processing method includes the following technological steps: S1. According to the design technical requirements of D-type fasteners, high-strength structural steel is cut and prepared to obtain independent C-shaped and I-shaped components; S2. According to the designed D-type fastener structure, arrange the C-shaped and I-shaped components on the shaping fixture in relative positions, so that the set weld position is in the welding operation space, and clamp and position them. During the clamping and positioning process, a shaping jig is arranged at the web seam to maintain the positioning of the mating distance between the first shaping edge and the fastening stop edge. S3. Weld the set weld seam using the set welding process, and obtain a weld seam reinforcement height higher than the base material, so that the C-shaped component and the I-shaped component clamped together are welded into an integral structure to obtain a D-type fastener blank; S4. After the D-type fastener has cooled down, remove it from the shaping fixture and grind the weld to make it flush with the base material. S5. Straighten the D-type fastener of S4 on a straightening machine according to the straightness requirements of the design; S6. Clamp the D-type fastener of S5 onto the shaping fixture, so that the outer surface of the anchoring connection edge is in a welding operation space, and clamp and position it. S7. Weld several anchor rods to the anchor connection edge using the set welding process; S8. After the D-type fastener from S7 has cooled down, remove it from the shaping fixture and straighten it on the straightening machine according to the straightness requirements of the design. S9. Perform flaw detection on the D-type fastener of S8; Products that pass the flaw detection undergo surface anti-corrosion treatment to obtain the finished product.

4. The processing method of the D-type fastener for longitudinal joint connection of shield tunnel segments according to claim 3, characterized in that, In S1, according to the design technical requirements of D-type fasteners, hot-rolled C-shaped structural steel is used to obtain an integrally formed anchoring connection edge, second shaping edge and fastening stop edge; According to the designed snap-fit ​​cavity size, and the designed thickness of the anchoring connection edge, the second shaping edge and the snap-fit ​​stop edge, the obtained C-shaped part is precision machined by cold drawing or mechanical cutting using a cold drawing die.

5. The processing method of the D-type fastener for longitudinal joint connection of shield tunnel segments according to claim 3, characterized in that, In S2 or S6, the shaping fixture (3) has a base plate (32), a first support frame (33) and a second support frame (34) spaced along the width direction of the base plate (32) on both sides of the top surface, a plurality of first tightening bolts (35) spaced along the length direction of the base plate (32) on the first support frame (33), and a plurality of second tightening bolts (36) spaced along the length direction of the base plate (32) on the second support frame (34). When the D-type fastener is clamped, the length direction of the D-type fastener is placed on the base plate (32) between the first tightening bolt (35) and the second tightening bolt (36) along the length of the base plate (32). The fastening stop edge of the C-shaped component that makes up the D-type fastener is located on the top surface of the base plate (32), the anchoring connection edge is facing upward, and the second shaping edge is facing the second tightening bolt (36). The I-shaped component that makes up the D-type fastener serves as the first shaping edge facing the first tightening bolt (35). The first shaping edge and the second shaping edge are tightened by the respective spiral feed of the first tightening bolt (35) and the second tightening bolt (36), thereby achieving clamping and positioning of the D-type fastener.

6. The processing method of the D-type fastener for longitudinal joint connection of shield tunnel segments according to claim 5, characterized in that, The shaping fixture (3) also has a first push liner (37); The first push-up liner (37) is arranged on the outer surface of the first shaping edge of the D-type fastener, and the first tightening bolt (35) fed by the spiral feed tightens the first shaping edge through the first push-up liner (37).

7. The processing method of the D-type fastener for longitudinal joint connection of shield tunnel segments according to claim 5, characterized in that, The shaping fixture (3) also has a second push liner (38); The second push liner (38) is arranged on the outer surface of the second shaping edge of the D-type fastener, and the second tightening bolt (36) fed by the spiral feed tightens the second shaping edge through the second push liner (38).

8. The processing method of the D-type fastener for longitudinal joint connection of shield tunnel segments according to claim 5, characterized in that, The first support frame (33) of the shaping fixture (3) is composed of multiple sets of individual units arranged at intervals along the length direction of the base plate (32); And / or, the second support frame (34) of the shaping fixture (3) is composed of multiple sets of individual units arranged at intervals along the length direction of the base plate (32).

9. The processing method of the D-type fastener for longitudinal joint connection of shield tunnel segments according to claim 5, 6, 7 or 8, characterized in that, The shaping fixture (3) also has a support (31); The bracket (31) is arranged at the bottom of the base plate (32) to raise and support the base plate (32).

10. The processing method of the D-type fastener for longitudinal joint connection of shield tunnel segments according to claim 3, characterized in that, In S6 or S9, the straightness of the straightening process over the entire length shall not exceed 1.0 mm.

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