Hole channel core mold of shield segment and prefabricating mold of hole channel core mold

Abstract

The invention relates to a duct core mold of a shield segment and a prefabricated mold of the duct core mold. The hole channel core mold comprises a core mold support and a platform mold, and the core mold support is detachably connected with the end of the core mold so as to support the core mold to be in a specified form; the platform mold is connected with the core mold support and arranged at the side edge position of a prefabricated mold of the shield segment, and under the condition that the core mold support and the platform mold are fixedly connected through the core mold fixing piece in the mode that a bolt penetrates through the side edge of the prefabricated mold, the core mold and the core mold support enable the shield segment to be prefabricated to form a hole channel with an expansion section. The platform mold enables the shield segment to be prefabricated to form a demolding platform connected with the expansion section. By arranging the hole channel core mold, the core mold can be stably fixed, meanwhile, an expansion section is formed at the end of the core mold, and meanwhile the demolding difficulty is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunnels, and in particular to a channel core mold mold for a shield segment and a prefabricated mold thereof. Background Art

[0002] The purpose of setting up holes in shield segments is to meet various functional requirements inside the tunnel, including ventilation, drainage, cable routing, pipeline installation, etc. For example, a circumferential hole is set in the shield segment, and a prestressed steel bundle is set in the hole, which can enhance the structural strength and stability of the shield segment and improve the overall bearing capacity and crack resistance of the tunnel. Some of the main functions of prestressed steel bundles in shield segments include: First, by applying prestress, the prestressed steel bundle can generate compressive stress inside the shield segment when it is subjected to external loads, thereby improving the overall strength and stiffness of the segment. This prestress can offset part of the tensile stress caused by external loads and reduce the risk of cracking of the segment. Second, enhance crack resistance; the setting of prestressed steel bundles can effectively control the development of cracks in the shield segment, especially when the tunnel is subjected to uneven settlement or lateral pressure, the prestressed steel bundles can limit the width and length of the cracks and improve the crack resistance of the segment. The reasonable arrangement of prestressed steel bundles can ensure the stability of the segment under various loads. Third, improve the bearing capacity; the application of prestressed steel strands can improve the bearing capacity of the shield segment, enabling it to withstand greater external loads, such as soil pressure, water pressure, etc. Fourth, improve structural performance; the setting of prestressed steel strands can also improve the overall structural performance of the shield segment, such as improving its seismic performance and deformation resistance. Fifth, extend the service life; by applying prestressed steel strands, the damage and deterioration of the shield segment during use can be reduced, extending the service life of the tunnel. The anti-corrosion treatment of prestressed steel strands can also improve the durability of the steel strands, further ensuring the long-term stable operation of the tunnel.

[0003] The casting process of shield segments with annular holes is a delicate and technically demanding process, which requires ensuring the precise location, size and shape of the holes while ensuring the quality and structural strength of the segments. The general steps for casting shield segments with annular holes include:

[0004] (1) Install the core mold or mold assembly used to form the annular channel in the steel frame, ensuring that the position and direction of the core mold are correct and firmly fixed.

[0005] (2) Arrange the steel skeleton and core mold together in the mold.

[0006] (3) Install the core mold used to form the annular channel into the mold, ensuring that the position and direction of the core mold are correct and firmly fixed.

[0007] (4) Prepare concrete that meets the requirements and pour it. Pour the mixed concrete evenly into the mold and vibrate the concrete with a vibrator to remove bubbles and ensure that the concrete is dense. During the pouring process, care should be taken to control the pouring speed and thickness of the concrete to avoid poor concrete flow or segregation.

[0008] (5) After the concrete pouring is completed, necessary treatments shall be carried out on the surface of the shield segment, such as leveling and polishing, to ensure that the surface is flat and smooth.

[0009] (6) After the concrete pouring is completed, the shield segments shall be properly maintained, such as steam curing, curing agent curing, covering with moisturizing materials, water spraying curing, pool curing, etc., to ensure the strength and durability of the concrete.

[0010] (7) After the concrete reaches sufficient strength, the mold is removed and the shield segments are inspected, including the location, size, shape, etc. of the holes, to ensure that the segments meet the design requirements and construction standards.

[0011] The core mold of the channel is usually a specially designed mold assembly used to form the shape and size of the channel during the concrete pouring process. The design and material selection of the core mold need to consider factors such as its stability, durability and ease of disassembly during the concrete pouring and curing process. Common types of channel core molds include wooden core molds, plastic core molds, metal core molds, rubber core molds and composite core molds. Corrugated pipe is a special type of core mold, which is usually made of flexible material and has a corrugated surface structure. Corrugated pipe as a core mold is suitable for shield segments that need to form annular channels, especially when the channels need to have a certain degree of flexibility and sealing. The installation and removal of the corrugated pipe is relatively simple and can adapt to the needs of channels of different sizes and shapes. For example, the flexibility of the corrugated pipe enables it to adapt to slight deformations during concrete pouring and reduce damage to the concrete structure. The corrugated structure of the corrugated pipe can increase its contact area with the concrete and improve the sealing and stability of the channel.

[0012] Preferably, if the core mold is placed in the tube body and acts as a support and bracket, then after the mold is removed, the core mold can be pulled out and reused. If the core mold is used directly to replace the tube body, the core mold is pre-buried in the concrete to form a channel, becomes an integral part of the prefabricated component and cannot be reused. In this case, the core mold is usually a hard tube.

[0013] At present, the channel formed by the corrugated pipe as the core mold is prefabricated into an arc shape. The diameter of the channel is the same. When multiple shield segments are spliced ​​to form a pipe ring, multiple channels are spliced ​​to form a circular channel. When prestressing is applied by the steel bundle in the channel, the following problems often occur:

[0014] (1) Uneven prestress transfer: The end diameter of the ordinary channel does not change, which may lead to uneven transfer of the prestressed steel strands in the channel, affecting the effective application of prestress.

[0015] (2) When adjacent shield segments are misaligned, the end diameter of the common channel does not change, which may make it difficult to achieve accurate docking of the channel during the misaligned connection, affecting the integrity and sealing of the segment, and also causing difficulties in the construction and operation of the prestressed steel strands in the tunnel. At the misaligned connection, since the diameter of the channel does not change, stress concentration may occur, affecting the structural strength and stability of the segment. During the misaligned construction process, it is necessary to ensure the accurate docking and sealing of the channel, otherwise it may cause water seepage or structural damage.

[0016] Therefore, the structure of the channel should be optimized. However, the optimization of the core mold of the channel encountered many problems. If the two ends of the bellows are simply set to a cone or an expanded trumpet shape, it is found that the core mold cannot be stably fixed.

[0017] Specifically, in terms of fixation: (1) The difficulty of fixation increases. The design of the expanded bell mouth increases the difficulty of fixing the bellows in the mold because the bell mouth part may be displaced or deformed during the concrete pouring process. (2) The fixing point is difficult to determine. It is necessary to design additional fixing points or support structures to ensure the stable position of the bellows in the mold, which may increase the complexity and cost of the mold. (3) The fixing material is not easy to determine. The fixing material and method need to be able to withstand the pressure and vibration during the concrete pouring process to avoid displacement or damage of the bellows.

[0018] In terms of pouring: (1) Concrete flow is obstructed. The expanded bell mouth may hinder the uniform flow of concrete, resulting in uneven distribution of concrete around the hole, affecting the quality and shape of the hole. (2) Due to the change in the shape of the bell mouth, bubbles or gaps may be generated during the concrete pouring process, affecting the density and strength of the hole. (3) The difficulty of vibration increases. During the concrete pouring process, the vibrator may find it difficult to effectively reach the bell mouth part, resulting in insufficient concrete density in this area.

[0019] For example, the patent document with publication number CN114483088A discloses a prestressed steel fiber concrete shield tunnel structure, including a shield ring and an annular prestressed structure, each shield ring includes multiple shield segments, multiple shield segments are connected into an annular whole through the annular prestressed structure, annular prestress is applied to each shield segment through the annular prestressed structure, the annular prestressed structure includes an annular corrugated pipe pre-buried in the shield ring, and the shield segment is cast by steel fiber concrete, which is a multi-phase composite material formed by adding short steel fibers distributed randomly into ordinary concrete. The channel in the shield segment in the invention is a typical ordinary channel, and its diameter does not change. Therefore, when the annular prestress is applied, there are problems of uneven prestress transmission and stress concentration when the platform is misaligned.

[0020] Therefore, how to improve the core mold and the channel structure of the channel and overcome the above-mentioned defects at the same time is the technical problem that the present invention hopes to solve.

[0021] In addition, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making the present invention, but due to space limitations, not all details and contents are listed in detail. However, this does not mean that the present invention does not have the characteristics of these prior arts. On the contrary, the present invention already has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art to the background technology. Summary of the invention

[0022] At present, there are many difficulties in optimizing the core mold of the channel. For example, simply designing the two ends of the bellows into a cone or an expanded trumpet shape will find that the core mold is difficult to fix stably.

[0023] Specifically, in terms of fixation: (1) The difficulty of fixation increases. The expanded bell-mouth design increases the difficulty of fixing the bellows in the mold because the bell-mouth part may be displaced or deformed during the concrete pouring process. (2) The fixing point is difficult to determine. Additional fixing points or support structures need to be designed to ensure the stable position of the bellows in the mold, which may increase the complexity and cost of the mold. (3) It is difficult to select fixing materials. The fixing materials and methods need to be able to withstand the pressure and vibration during the concrete pouring process to prevent the bellows from shifting or being damaged.

[0024] In terms of pouring: (1) Concrete flow is obstructed. The expansion of the bell mouth may hinder the uniform flow of concrete, resulting in uneven distribution of concrete around the hole, affecting the quality and shape of the hole. (2) The change in the shape of the bell mouth may cause bubbles or gaps to form during the concrete pouring process, affecting the density and strength of the hole. (3) The difficulty of vibration increases. During the concrete pouring process, the vibrator may find it difficult to effectively reach the bell mouth part, resulting in insufficient concrete density in this area.

[0025] In view of the deficiencies in the prior art, the present invention provides, from a first aspect, a core mold mold for a tunnel of a shield segment, comprising a core mold bracket and a platform mold, wherein the core mold bracket is detachably connected to the end of the core mold, thereby supporting the core mold in a specified shape; the platform mold is connected to the core mold bracket and is arranged on the side of the prefabricated mold of the shield segment, and when the core mold fixing piece fixes the core mold bracket and the platform mold by bolts penetrating the side of the prefabricated mold, the core mold and the core mold bracket enable the shield segment to be prefabricated into a tunnel with an expansion section, and the platform mold enables the shield segment to be prefabricated into a demoulding platform connected to the expansion section.

[0026] The detachable connection installation method allows the channel core mold to be reused. The precise design of the core mold bracket and the platform mold ensures that the core mold is stably supported in the prefabricated mold and its end is not easily displaced during the pouring process. This design helps to reduce the channel diameter and shape deviation, ensuring that the channel can be accurately docked when spliced ​​into a pipe ring.

[0027] According to a preferred embodiment, the core mold bracket includes a core mold supporting bracket and a core mold expansion bracket; the core mold supporting bracket is a straight column, and the end of the core mold is inserted and fixed in a manner matching the diameter size of the core mold; the core mold expansion bracket forms an expansion shape in a manner of gradually expanding the diameter of the axial cross-section, and its end with a smaller diameter is connected to the core mold supporting bracket, so that the end of the channel forms an expansion section with a gradually changing diameter.

[0028] The shape structure of the core mold support bracket shortens the material length of the core mold while maintaining the shape of the core mold end, reduces the resistance of concrete flowing to the two ends during the pouring process, and strengthens the strength of the core mold end to avoid deformation of the core mold end. The structural design of the core mold expansion bracket enables the core mold to evenly disperse the stress when it is subjected to concrete pressure, reduces local stress concentration, and thus avoids distortion or deformation of the core mold.

[0029] According to a preferred embodiment, the inclined edge of the longitudinal section of the platform mold forms a demolding angle with its axis, and the platform mold is installed in a manner that the demolding angle expands toward the side of the prefabricated mold, and the diameter of the platform mold is larger than the diameter of the core mold expansion bracket. When the prefabrication of the shield segment is completed, the plane of the demolding platform prefabricated by the platform mold is perpendicular to the circumference of the expansion section.

[0030] The platform mold and the core mold expansion bracket are fixed adjacently, so that the radial surface of the core mold expansion bracket will not be fixed by concrete pouring. At the same time, because the platform mold and the side of the precast mold are tightly fixed, the concrete cannot flow between the platform mold and the precast mold, so that the platform mold and the shield segment cannot be relatively fixed. Therefore, this setting ensures the smooth demoulding of the platform mold and the core mold bracket.

[0031] The setting of the draft angle also reduces the friction and resistance during the demoulding process, making demoulding easier and smoother, and improving the demoulding efficiency. The setting of the draft angle also helps to evenly disperse the force applied to the mold during concrete pouring. The larger diameter design allows the concrete pressure to be more evenly distributed on the demoulding platform, reducing local stress concentration, thereby avoiding deformation or damage to the mold.

[0032] According to a preferred embodiment, the extension lines of the side of the core mold expansion bracket intersect to form an expansion angle β, and the value range of the expansion angle β is 20-50° to reduce the resistance of concrete flowing to the side of the prefabricated mold. Reasonable selection of the expansion angle β allows the concrete to flow more smoothly, reduces the resistance of the concrete around the pores, and helps to evenly distribute and fill the concrete.

[0033] According to a preferred embodiment, the demoulding angle α of the platform mold is in the range of 10 to 75°, so that the stress between the demoulding platform and the platform mold is not concentrated. The reasonable setting of the demoulding angle α also helps to improve the demoulding efficiency. During the demoulding process, the appropriate demoulding angle enables the demoulding platform to be separated from the mold more smoothly, reduces the friction and resistance during the demoulding process, improves the speed and efficiency of demoulding, and is not easy to cause damage to the shield segment.

[0034] According to a preferred embodiment, a groove mold and an anchoring mold are provided in the prefabrication mold, the groove mold is provided on both sides of the anchoring mold, the groove mold is provided with a convex arc structure to prefabricate a groove, the anchoring mold is recessed relative to the groove mold and forms a deep groove, so that the deep groove forms an anchoring tooth block of the shield segment after prefabrication. The core mold is fixed in the anchoring mold, so that a cross channel is formed in the anchoring mold, the annular prestress of the segment forms a closed loop, and the prestress tensioning of the pipe ring is realized, which is more conducive to making the stress of the pipe ring formed by splicing the shield segments more uniform.

[0035] The present invention provides a prefabricated mold for a shield segment from a second aspect. A groove mold and an anchoring mold are provided at the bottom of the prefabricated mold. The groove mold is arranged on both sides of the anchoring mold. The groove mold is arranged with a convex arc structure to prefabricate a groove. The anchoring mold is recessed relative to the groove mold and forms a deep groove, so that the deep groove forms an anchoring tooth block of the shield segment after prefabrication; at least one positioning hole is provided at the side position of the prefabricated mold, for the channel core mold mold to pass through the positioning hole and fix one end of the core mold, and the other end of the core mold is fixed to the vertical side wall of the anchoring mold by an anchor; wherein the channel core mold mold includes a core mold bracket and a platform mold, and the core mold bracket is connected to the end of the core mold in a detachable manner to support the core mold in a specified shape; the platform mold is connected to the core mold bracket and is provided at the side position of the prefabricated mold for the shield segment.

[0036] The prefabricated mold of the present invention enables expansion sections at both ends of the channel of the prefabricated shield segment, and the channels in the anchoring tooth block are cross-arranged, so that one end of the prestressed steel bundle in the channel can be tensioned in the anchoring tooth block.

[0037] According to a preferred embodiment, one end of at least two core molds are fixed to two opposite vertical side walls of the anchoring mold by anchors in a staggered manner in the anchoring mold.

[0038] This design ensures the precise position and stability of the core mold during the prefabrication process. This design helps to improve the prefabrication accuracy of the shield segment channel, and also makes the annular prestress of the segment form a closed loop, realizing the prestressing of the pipe ring.

[0039] According to a preferred embodiment, the core mold fixing member fixes the core mold bracket and the platform mold in a manner that bolts penetrate the positioning holes on the side of the prefabricated mold, the core mold and the core mold bracket enable the shield segment to be prefabricated into a channel with an expansion section, and the platform mold enables the shield segment to be prefabricated into a demoulding platform connected to the expansion section. This design enables the core mold and the core mold bracket to be installed quickly and stably, thereby improving production efficiency.

[0040] According to a preferred embodiment, the core mold bracket includes a core mold supporting bracket and a core mold expansion bracket; the core mold supporting bracket is a straight column, and the end of the core mold is inserted and fixed in a manner matching the diameter size of the core mold; the core mold expansion bracket forms an expansion shape in a manner of gradually expanding the diameter of the axial cross-section, and its end with a smaller diameter is connected to the core mold supporting bracket, so that the end of the channel forms an expansion section with a gradually changing diameter.

[0041] The combined design of the core mold support bracket and the core mold expansion bracket ensures the precise expansion shape of the channel and improves the structural integrity and functionality of the channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural schematic diagram of the core mold of the duct provided by the present invention;

[0043] Figure 2 It is an angle schematic diagram of the core mold support provided by the present invention;

[0044] Figure 3 It is a structural schematic diagram of the platform mold provided by the present invention;

[0045] Figure 4 It is an angle schematic diagram of the core mold expansion stent provided by the present invention;

[0046] Figure 5 It is an enlarged structural schematic diagram of the core mold support provided by the present invention;

[0047] Figure 6It is a structural schematic diagram of a non-porous fixed mold provided by the present invention;

[0048] Figure 7 It is a schematic diagram of the structure of the shield segments provided by the present invention in a spliced ​​state;

[0049] Figure 8 It is a structural schematic diagram of a duct prefabricated by a core mold support provided by the present invention in a spliced ​​state;

[0050] Fig. 9 It is a structural schematic diagram of the standard segment at the anchor end provided by the present invention;

[0051] Fig.10 It is a structural schematic diagram of the prefabricated mold provided by the present invention;

[0052] Fig.11 is an enlarged schematic diagram of the chamfer of the prefabricated mold provided by the present invention;

[0053] Fig.12 It is a side structural schematic diagram of the arrangement of the inner channel of the standard pipe segment at the anchor end provided by the present invention;

[0054] Fig.13 It is a planar structural schematic diagram of the hole arrangement method of the standard pipe segment at the anchor end provided by the present invention.

[0055] Reference numerals list

[0056] 110: shield segment; 111: standard segment at anchor end; 112: standard segment at non-anchor end; 113: adjacent segment; 114: capping segment; 120: channel; 121: expansion section; 123: demoulding platform; 130: anchor; 140: anchor assembly; 141: groove; 142: anchor tooth block; 143: anchor concrete; 300: prestressed steel strand; 400: prefabricated mold; 410 : Groove mold; 411: Anchoring mold; 420: Core mold; 421: Straight line segment; 422: Arc segment; 423: First chamfer; 424: Second chamfer; 430: Positioning hole; 440: Core mold bracket; 450: Core mold supporting bracket; 460: Core mold expansion bracket; 470: Core mold fixing piece; 480: Platform mold; 481: Bolt; 482: Connecting hole; 490: Fixed mold without channel. DETAILED DESCRIPTION

[0057] The following is a detailed description with reference to the accompanying drawings.

[0058] Currently, the channel 120 formed by the corrugated pipe as the core mold 420 is prefabricated into an arc state. The diameter of the channel 120 is the same. When multiple shield segments 110 are spliced ​​to form a pipe ring, multiple channels 120 are spliced ​​to form a circular channel 120. When prestress is applied by the prestressed steel strand 300 in the channel 120, the following problems often occur:

[0059] (1) Uneven prestress transfer: The end diameter of the common channel 120 does not change, which may cause uneven transfer of the prestressed steel strand 300 in the channel 120, affecting the effective application of prestress.

[0060] (2) When adjacent shield segments 110 are misaligned, the end diameter of the common channel 120 does not change, which may make it difficult to achieve accurate docking of the channel 120 during the misaligned connection, thereby affecting the integrity and sealing of the segment, and also causing difficulties in the construction operation of the prestressed steel bundle 300 in the tunnel. At the misaligned connection, since the diameter of the channel 120 does not change, stress concentration may occur, affecting the structural strength and stability of the segment. During the misaligned construction process, it is necessary to ensure the accurate docking and sealing of the channel 120, otherwise it may cause water seepage or structural damage.

[0061] Therefore, the structure of the duct 120 should be optimized. However, there are many problems in optimizing the core mold 420 of the duct 120. If the two ends of the bellows are simply set to be conical or expanded trumpet-shaped, it is found that the core mold 420 cannot be stably fixed.

[0062] Specifically, in terms of fixation: (1) The difficulty of fixation increases. The design of the expanded bell mouth increases the difficulty of fixing the bellows in the mold because the bell mouth part may be displaced or deformed during the concrete pouring process. (2) The fixing point is difficult to determine. It is necessary to design additional fixing points or support structures to ensure the stable position of the bellows in the mold, which may increase the complexity and cost of the mold. (3) The fixing material is not easy to determine. The fixing material and method need to be able to withstand the pressure and vibration during the concrete pouring process to avoid displacement or damage of the bellows.

[0063] In terms of pouring: (1) Concrete flow is obstructed. The expanded bell mouth may hinder the uniform flow of concrete, resulting in uneven distribution of concrete around the hole 120, affecting the quality and shape of the hole 120. (2) Due to the change in the shape of the bell mouth, bubbles or gaps may be generated during the concrete pouring process, affecting the density and strength of the hole 120. (3) The difficulty of vibration increases. During the concrete pouring process, the vibrator may have difficulty effectively reaching the bell mouth, resulting in insufficient concrete density in this area.

[0064] In view of the shortcomings of the prior art, the present invention provides a tunnel core mold mold for a shield segment and a prefabricated mold thereof. The present invention can also provide a prefabrication method for a shield segment.

[0065] Example 1

[0066] like Figure 1 As shown, the present invention provides a channel core mold mold for a shield segment, including a core mold support 440 and a platform mold 480. The core mold support 440 is connected to the end of the core mold 420 in a detachable manner, so as to support the core mold 420 in a specified shape. The platform mold 480 is connected to the core mold support 440 and is arranged on the side of the prefabricated mold 400 of the shield segment 110. The core mold fixing member 470 is fixedly connected to the core mold support 440 and the platform mold 480 by means of bolts 481 penetrating the side of the prefabricated mold 400. In this case, the core mold 420 and the core mold support 440 act together on the shield segment 110 to prefabricate a channel 120 with an expansion section 121. At the same time, the platform mold 480 prefabricates the shield segment 110 to form a demoulding platform 123 connected to the expansion section 121. Through the detachable connection installation method, the channel core mold mold can be reused. The core mold support 440 and the platform mold 480 are precisely designed to ensure that the core mold 420 is stably supported in the prefabricated mold 400, and its end is not easily displaced during the pouring process. This design helps to reduce the diameter and shape deviation of the channel 120, ensuring that the channel 120 can be accurately docked when spliced ​​into a pipe ring.

[0067] like Figure 2 As shown, the core mold support 440 includes a core mold support support 450 and a core mold expansion support 460. The core mold support support 450 is a linear column, and is inserted into and fixed to the end of the core mold 420 in a manner that matches the diameter size of the core mold 420. The core mold expansion support 460 forms an expansion shape in a manner that the diameter of the axial section gradually expands, and its end with a smaller diameter is connected to the core mold support support 450, so that the end of the channel 120 forms an expansion section 121 with a gradually changing diameter.

[0068] The design of the core mold support bracket 450 not only maintains the end shape of the core mold 420, shortens the material length, reduces the resistance of concrete flowing to the ends on both sides during the pouring process, but also enhances the end strength and avoids deformation. The structural design of the core mold expansion bracket 460 enables the core mold 420 to evenly disperse the stress when bearing the concrete pressure, reduces local stress concentration, and thus avoids the distortion or deformation of the core mold 420.

[0069] like Figure 3As shown, the inclined edge of the longitudinal section of the platform mold 480 forms a demolding angle with its axis, and the platform mold 480 is installed in a manner that the demolding angle expands toward the side of the prefabricated mold 400, and the diameter of the platform mold 480 is larger than the diameter of the core mold expansion bracket 460. When the shield segment 110 is prefabricated, the plane of the demolding platform 123 prefabricated by the platform mold 480 is perpendicular to the circumference of the expansion section 121.

[0070] The platform mold 480 and the core mold expansion bracket 460 are fixed adjacently, so that the radial surface of the core mold expansion bracket 460 will not be fixed by concrete pouring, and at the same time, because the platform mold 480 is tightly fixed to the side of the precast mold 400, the concrete cannot flow between the platform mold 480 and the precast mold 400, so that the platform mold 480 cannot be relatively fixed to the shield segment 110. Therefore, such a setting ensures the smooth demoulding of the platform mold 480 and the core mold bracket 440.

[0071] The setting of the demoulding angle also reduces the friction and resistance during the demoulding process, making demoulding easier and smoother, improving the demoulding efficiency, and not easily causing damage to the shield segment. The setting of the demoulding angle also helps to evenly disperse the force applied to the mold during the concrete pouring process. The larger diameter design allows the concrete pressure to be more evenly distributed on the demoulding platform 123, reducing local stress concentration, thereby avoiding deformation or damage to the mold.

[0072] like Figure 2 and Figure 4 As shown, the extension lines of the side of the core mold expansion bracket 460 intersect to form an expansion angle β, and the value range of the expansion angle β is 20-50 degrees, so as to reduce the resistance of the concrete flowing to the side of the precast mold 400. Reasonable selection of the expansion angle β allows the concrete to flow more smoothly, reduces the resistance of the concrete around the channel 120, and helps to evenly distribute and fill the concrete.

[0073] Preferably, the angle of the expansion angle β is further preferably 25 to 35°. Further preferably, the angle of the expansion angle β is 30°. Setting the expansion angle β to 30° helps the core mold expansion bracket 460 to be more easily removed from the expansion section 121 of the channel 120. When the length of the expansion section 121 is determined, if the expansion angle β is too large, that is, the expansion angle β of the expansion section 121 is too large, the side wall of the expansion section 121 at the end of the prefabricated pipe segment will lose its guiding function. When misalignment occurs, the prestressed steel strand 300 cannot be smoothly introduced into the channel 120. The thickness of the wall is related to the size of the stress. The thin wall reduces the stress bearing capacity, and the thick wall increases the stress bearing capacity. Not only that, the size of the expansion angle β is also related to the thickness of the wall. The size of the expansion angle β will cause the hole diameter of the expansion section 121 at the end of the prefabricated pipe segment to change accordingly, thereby causing the wall thickness between the side of the prefabricated pipe segment and the hole to change accordingly. If the expansion angle β is too large, the hole diameter of the expansion section 121 at the end of the prefabricated pipe segment will increase accordingly, and the wall will become thinner. Therefore, the size of the expansion angle β cannot be set arbitrarily. If the expansion angle β is too small, when misalignment occurs, the friction between the prestressed steel bundle 300 and the hole wall of the expansion section 121 will increase, and the resistance of the prestressed steel bundle 300 when moving in the expansion section 121 cannot be effectively reduced. Therefore, the present invention sets the expansion angle β to 30°, so that the thickness of the hole wall of the expansion section 121 is sufficient to withstand stress, and the core mold expansion bracket 460 is also easy to escape from the expansion section 121, and the resistance between the prestressed steel bundle 300 and the hole wall at the end of the prefabricated pipe segment is also small.

[0074] like Figure 3 and Figure 5 As shown, the angle range of the demoulding angle α of the platform mold 480 is 10 to 75°, so that the stress between the demoulding platform 123 and the platform mold 480 is not concentrated. Further preferably, the angle range of the demoulding angle α is 15 to 65°. Further preferably, the angle of the demoulding angle α is 20°. The reasonable setting of the demoulding angle α also helps to improve the demoulding efficiency. During the demoulding process, the appropriate demoulding angle α enables the demoulding platform 123 to be more smoothly separated from the mold, reduces the friction and resistance during the demoulding process, improves the speed and efficiency of demoulding, and is not easy to cause damage to the shield segment.

[0075] If the core mold expansion bracket 460 is directly connected to the end of the precast mold 400 only by bolts 481, not only is it easy for concrete to flow into the gap, but without the platform mold 480 to disperse the force, the pressure of the concrete may cause stress concentration at the contact point between the core mold expansion bracket 460 and the precast mold 400, which may cause local deformation or damage to the core mold expansion bracket 460 or the precast mold 400. Concrete may directly impact the end of the precast mold 400, causing the concrete surface to be uneven or form defects. During the pouring process, the direct contact between the concrete and the core mold expansion bracket 460 and the precast mold 400 may generate more vibration and noise.

[0076] The functions of platform mold 480 include two aspects:

[0077] First, the gap between the core mold expansion bracket 460 and the precast mold 400 is filled to prevent concrete from flowing into the gap and forming an obstacle that hinders demoulding on the surface of the core mold expansion bracket 460, so the diameter of the platform mold 480 is larger than the maximum diameter of the core mold expansion bracket 460. The platform mold 480 can improve the sealing performance between the core mold expansion bracket 460 and the end of the precast mold 400, especially when there may be slight unevenness between the core mold expansion bracket 460 and the end of the precast mold 400, the platform mold 480 can fill these unevenness to prevent leakage of air or concrete.

[0078] Second, it is conducive to fixing the core mold expansion bracket 460. The shape and size of the core mold expansion bracket 460 will affect the path and speed of concrete flow. Due to the existence of the expansion angle β, the concrete near the core mold expansion bracket 460 flows along the inclined profile, and the direction of the force will change with the change of the expansion profile. When the concrete flows from the surface of the core mold 420 to the surface of the core mold expansion bracket 460, the direction of the force will gradually change from the vertical direction to the horizontal direction, and the stress distribution will be uneven. At this time, if the platform mold 480 is set between the core mold expansion bracket 460 and the end of the precast mold 400, the platform mold 480 can help transfer the weight and pressure of the concrete to the core mold expansion bracket 460 and the precast mold 400 more evenly, reducing local stress concentration. The platform mold 480 can also absorb the impact force during concrete pouring, prevent the concrete from directly impacting the connection between the core mold expansion bracket 460 and the precast mold 400, thereby reducing the risk of damage. The platform mold 480 can also reduce the direct contact between the core mold expansion bracket 460 and the precast mold 400, thereby reducing vibration and noise.

[0079] Third, it is easy to demould. The platform mold 480 provides an additional contact surface, making it easier to separate the prefabricated pipe segment from the prefabricated mold 400. In particular, when the platform mold 480 is tilted on all sides and forms a demoulding angle α in the cross section, the larger surface of the platform mold 480 makes it easier to demould from the end of the prefabricated pipe segment. Since there is only or no obstacle formed by concrete in the gap between the core mold expansion bracket 460 and the platform mold 480, the resistance to demoulding of the core mold expansion bracket 460 is reduced, and the wear of the core mold expansion bracket 460 is also reduced, extending its service life.

[0080] like Fig.10 As shown, a groove mold 410 and an anchoring mold 411 are provided in the prefabricated mold 400. The groove mold 410 is provided on both sides of the anchoring mold 411. The groove mold 410 is provided in a convex arc structure to prefabricate the groove 141. The anchoring mold 411 is recessed relative to the groove mold 410 and forms a deep groove, so that the deep groove forms the anchoring tooth block 142 of the shield segment 110 after prefabrication. The core mold 420 is fixed in the anchoring mold 411, so that a cross channel 120 is formed in the anchoring mold 411, and the annular prestress of the segment forms a closed loop, realizing the prestress tensioning of the pipe ring, which is more conducive to making the stress of the pipe ring formed by splicing the shield segments 110 more uniform.

[0081] like Fig. 9 As shown, the anchor assembly 140 includes a groove 141 and an anchor tooth block 142. A hole 120 is also provided in the anchor tooth block 142. The groove 141 is provided on the side of the anchor tooth block 142, and the extension direction of the groove 141 is perpendicular to the central axis of the prefabricated segment. In the prefabricated anchor assembly 140, the tensioning end of the prestressed steel bundle 300 is sealed by the sealing anchor concrete 143, so that the groove 141, the anchor tooth block 142 and the sealing anchor concrete 143 together form a force-bearing structure. This ensures that the tensioning force of the prestressed steel bundle 300 can be effectively transmitted to the prestressed shield segment 110, thereby improving the overall stability and tensile performance of the structure.

[0082] like Fig.11 As shown, the arc profile of the groove mold 410 includes a straight line segment 421 and an arc segment 422. The straight line segment 421 and the arc segment 422 are naturally transitioned. A second chamfer 424 is provided at the connection between the groove mold 410 and the anchoring mold 411. A first chamfer 423 is provided at the bend between the vertical side wall and the bottom of the anchoring mold 411.

[0083] Preferably, the groove mold 410 and the anchoring mold 411 are formed by welding two steel plates, or by bending a single steel plate. Preferably, the first chamfer 423 is an inner fillet. The first chamfer 423 cannot be less than 10 mm. The second chamfer 424 is an outer fillet. The second chamfer 424 is at least 6 mm. The first chamfer 423 and the second chamfer 424 are arranged in opposite directions.

[0084] like Figure 6 As shown, when the channel 120 is not required in the prefabricated segment, a non-channel fixed mold 490 is provided at the positioning hole 430 of the prefabricated mold 400 to block the positioning hole 430 and prevent the concrete from flowing out of the positioning hole 430 during pouring. The non-channel fixed mold 490 is different from the platform mold 480 in that it is a circular sheet and the cross section thereof when it is arranged longitudinally is not provided with a draft angle α.

[0085] Example 2

[0086] This embodiment is a further improvement on Embodiment 1, and the repeated contents will not be repeated here.

[0087] The present invention provides a prefabricated mold 400 for a shield segment, such as Fig.10 As shown, a groove mold 410 and an anchoring mold 411 are provided at the bottom of the prefabrication mold 400. The groove mold 410 is provided on both sides of the anchoring mold 411. The groove mold 410 is provided in a convex arc structure so as to prefabricate the groove 141. The anchoring mold 411 is recessed relative to the groove mold 410 and forms a deep groove, so that the deep groove forms the anchoring tooth block 142 of the shield segment 110 after prefabrication, and the groove mold 410 forms the groove 141 of the shield segment 110 after prefabrication.

[0088] like Fig.10 As shown, at least one positioning hole 430 is provided on the side of the prefabricated mold 400. Figure 2 and Fig.10 As shown, a bolt 481 passes through the positioning hole 430, and bolts the core mold fixing member 470 to the connecting hole 482 on the core mold expansion bracket 460, thereby fixing one end of the core mold 420 through the channel core mold mold. The other end of the core mold 420 is fixed to the vertical side wall of the anchoring mold 411 by the anchor 130. The channel core mold mold includes a core mold bracket 440 and a platform mold 480. The core mold bracket 440 is connected to the end of the core mold 420 in a detachable manner, so as to support the core mold 420 in a specified shape. The platform mold 480 is connected to the core mold bracket 440 and is set at the side position of the prefabricated mold 400 of the shield segment 110.

[0089] The prefabricated mold 400 of the present invention provides expansion sections 121 at both ends of the channel 120 of the prefabricated shield segment 110, and the channels 120 in the anchoring tooth block 142 are cross-arranged, so that one end of the prestressed steel bundle 300 in the channel 120 can be tensioned in the anchoring tooth block 142.

[0090] like Fig.13 As shown, one end of at least two core molds 420 are fixed to two opposite vertical side walls of the anchor mold 411 by anchors 130 in a staggered manner in the anchor mold 411, forming a cross channel 120 in the anchor tooth block 142. There is also a non-cross channel 120 in the anchor end standard segment 111. The non-cross channel 120 forms a prestressed channel in the circumferential direction of the shield tunnel. In the circumferential direction, the non-cross channel 120 is parallel to the cross channel 120, or close to parallel.

[0091] like Fig.12 and Fig.13 As shown, after the prefabricated segment is finalized, the core mold 420 is not disassembled and forms a part of the channel 120. When the channel core mold mold is disassembled, the ends of the channel 120 on both sides of the anchor tooth block 142 respectively include expansion sections 121. In this part, an anchor 130 is arranged in the anchor tooth block 142. After the prestressed steel bundle 300 is inserted into the channel 120, the anchor 130 is used to tension the prestressed steel bundle 300 to form sufficient prestress. Such a design ensures the precise position and stability of the core mold 420 during the prefabrication process. This design helps to improve the prefabrication accuracy of the channel 120 of the shield segment 110, ensures that the channel core mold mold can accurately penetrate the positioning hole 430 and fix the core mold 420, and also enables the prestressed steel bundle 300 to form a closed loop in the circumferential prestress of the segment, realizes the prestress tensioning of the pipe ring, and thus improves the quality and consistency of the prefabricated segment.

[0092] like Figure 1 As shown, the core mold fixing member 470 fixes the core mold support 440 and the platform mold 480 in a manner that a bolt 481 penetrates the positioning hole 430 on the side of the prefabricated mold 400, and the core mold 420 and the core mold support 440 enable the shield segment 110 to prefabricate the channel 120 with the expansion section 121, and the platform mold 480 enables the shield segment 110 to prefabricate the demoulding platform 123 connected to the expansion section 121. This design allows the core mold 420 and the core mold support 440 to be installed quickly and stably, thereby improving production efficiency.

[0093] like Figure 1As shown, the core mold support 440 includes a core mold support support 450 and a core mold expansion support 460. The core mold support support 450 is a linear column, and is inserted into and fixed to the end of the core mold 420 in a manner that matches the diameter size of the core mold 420. The core mold expansion support 460 forms an expansion shape in a manner that the diameter of the axial section gradually expands, and its end with a smaller diameter is connected to the core mold support support 450, so that the end of the channel 120 forms an expansion section 121 with a gradually changing diameter.

[0094] The combined design of the core mold support bracket 450 and the core mold expansion bracket 460 ensures the precise expansion shape of the channel 120 and improves the structural integrity and functionality of the channel 120.

[0095] Example 3

[0096] This embodiment provides a prefabricated pipe segment made by the molds of Embodiment 1 and Embodiment 2.

[0097] like Figure 7 As shown, the shield segment 110 is composed of an anchor end standard segment 111, a non-anchor end standard segment 112, an adjacent segment 113 and a capping segment 114. The anchor end standard segment 111 is equipped with an anchor assembly 140. The non-anchor end standard segment 112 is located between two anchor end standard segments 111. The anchor end standard segment 111 is connected to the adjacent segment 113, and the adjacent segment 113 is connected to the capping segment 114. A channel 120 is designed inside each shield segment 110. Figure 8 As shown, each shield segment 110 has at least one channel 120, and expansion sections 121 are provided at both ends of the channel 120. Ideally, the number of channels 120 in the shield segment 110 should be two or four. When multiple shield segments 110 are assembled into a pipe ring, the channels 120 inside them are also connected successively to form a continuous circular channel, such as Figure 8 For example, the diameter of the channel 120 in the non-expanded portion is 56 mm inside diameter and 60 mm outside diameter. Figure 7 It can be seen that the prestressed steel strands 300 pass through the circular holes 120 and are tensioned at the anchoring assemblies 140 , thereby applying prestress to each shield segment 110 .

[0098] The anchor end standard segment 111, the non-anchor end standard segment 112, the adjacent segment 113 and the capping segment 114 have their own structural characteristics. For example, the center angles of the anchor end standard segment 111 and the non-anchor end standard segment 112 are set between 67.3 degrees and 67.5 degrees, the center angle of the adjacent segment 113 is also within this range, and the center angle of the capping segment 114 is set between 22.3 degrees and 22.5 degrees. Figure 7As shown, the sum of the central angles of all these segments is not less than 180 degrees. This assembly method makes the center of gravity of the prestressed shield tunnel deviate from its geometric center, forming an eccentricity, thereby reducing the bending moment internal force of the shield segment 110.

[0099] This design allows the center of gravity of the prestressed shield tunnel to deviate from the geometric center, reducing the impact of the internal force of the bending moment on the segment, thereby improving the tunnel's ability to resist bending deformation and extending the tunnel's service life. In addition, by adjusting the eccentricity, the internal force of the bending moment of the shield segment 110 can be effectively reduced, which can greatly reduce the amount of steel reinforcement of the shield segment 110, thereby reducing the project cost. Usually, the weight of each ring is reduced from about 1 t to about 600 kg, and the weight of the shield segment using steel fiber concrete is further reduced to about 300 kg.

[0100] like Figure 7 and 9 As shown, the anchor end standard segment 111 is preset with an anchor assembly 140, and the end faces of its two ends are parallel to the central axis of the pipe ring. The non-anchor end standard segment 112 and the capping segment 114 are not provided with an anchor assembly 140, and their end faces are also parallel to the central axis of the pipe ring, but the two end faces of the capping segment 114 are relatively inclined. The structure of the adjacent segment 113 matches the capping segment 114, and the end face of its first end is parallel to the central axis of the pipe ring, which enables the adjacent segment 113 to be assembled with the anchor end standard segment 111; while the end face of the second end is relatively inclined with the central axis of the pipe ring, and the inclination angle is consistent with the inclination angle of the end of the capping segment 114, which in turn enables the adjacent segment 113 to be assembled with the capping segment 114.

[0101] It should be noted that the above-mentioned specific embodiments are exemplary, and those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also belong to the disclosure scope of the present invention and fall within the protection scope of the present invention. Those skilled in the art should understand that the present invention specification and its drawings are illustrative and do not constitute a limitation on the claims. The scope of protection of the present invention is defined by the claims and their equivalents. The present invention specification contains multiple inventive concepts, such as "preferably" and "according to a preferred embodiment", which means that the corresponding paragraph discloses an independent concept, and the applicant reserves the right to file a divisional application based on each inventive concept.

Claims

1. A tunnel core mold for a shield segment, characterized in that: It includes a core mold support (440) and a platform mold (480), The core mold support (440) is detachably connected to the end of the core mold (420), thereby supporting the core mold (420) in a specified shape; The platform mold (480) is connected to the core mold support (440) and is arranged on the side of the prefabricated mold (400) of the shield segment (110). When the core mold fixing member (470) fixes the core mold support (440) and the platform mold (480) in connection with each other by means of bolts (481) penetrating the side of the prefabricated mold (400), the core mold (420) and the core mold support (440) enable the shield segment (110) to be prefabricated into a channel (120) having an expansion section (121), and the platform mold (480) enables the shield segment (110) to be prefabricated into a demoulding platform (123) connected to the expansion section (121).

2. The channel core mold of the shield segment according to claim 1 is characterized in that: The core mold support (440) comprises a core mold supporting support (450) and a core mold expansion support (460); The core mold support bracket (450) is a linear column, and is inserted into and fixed to the end of the core mold (420) in a manner matching the diameter size of the core mold (420); The core mold expansion bracket (460) forms an expansion shape in a manner that the diameter of the axial section gradually expands, and its end with a smaller diameter is connected to the core mold support bracket (450), so that the end of the channel (120) forms an expansion section (121) with a gradually changing diameter.

3. The channel core mold of the shield segment according to claim 1 or 2, characterized in that: The inclined side of the longitudinal section of the platform mold (480) forms a demoulding angle with its axis, The platform mold (480) is installed in a manner such that the demoulding angle expands toward the side of the prefabricated mold (400), and the diameter of the platform mold (480) is greater than the diameter of the core mold expansion bracket (460). When the shield segment (110) is prefabricated, the plane of the demoulding platform (123) prefabricated by the platform mold (480) is perpendicular to the circumference of the expansion section (121).

4. The tunnel core mold for a shield segment according to any one of claims 1 to 3, characterized in that: The extension lines of the side edges of the core mold expansion bracket (460) intersect to form an expansion angle β, The expansion angle β has a value range of 20 to 50 degrees, so as to reduce the resistance of concrete flowing to the side of the prefabricated mold (400).

5. The tunnel core mold for a shield segment according to any one of claims 1 to 4, characterized in that: The demoulding angle of the platform mold (480) ranges from 10 to 75 degrees, so that stress between the demoulding platform (123) and the platform mold (480) is not concentrated.

6. The tunnel core mold for a shield segment according to any one of claims 1 to 5, characterized in that: The prefabricated mold (400) is provided with a groove mold (410) and an anchoring mold (411). The groove mold (410) is arranged on both sides of the anchoring mold (411), and the groove mold (410) is arranged in a convex arc structure to prefabricate the groove (141). The anchoring mold (411) is recessed relative to the groove mold (410) to form a deep groove, so that the deep groove forms an anchoring tooth block (142) of the shield segment (110) after prefabrication.

7. A prefabricated mold for a shield segment, characterized in that: The bottom of the prefabricated mold (400) is provided with a groove mold (410) and an anchoring mold (411). The groove mold (410) is arranged on both sides of the anchoring mold (411), and the groove mold (410) is arranged in a convex arc structure to prefabricate the groove (141). The anchoring mold (411) is recessed relative to the groove mold (410) to form a deep groove, so that the deep groove forms an anchoring tooth block (142) of the shield segment (110) after prefabrication; At least one positioning hole (430) is provided at the side of the prefabricated mold (400), for the channel core mold to pass through the positioning hole (430) and fix one end of the core mold (420). The other end of the core mold (420) is fixed to the vertical side wall of the anchoring mold (411) by an anchor (130); The channel core mold mold includes a core mold support (440) and a platform mold (480), wherein the core mold support (440) is detachably connected to the end of the core mold (420) so as to support the core mold (420) in a specified shape; the platform mold (480) is connected to the core mold support (440) and is arranged on the side of the prefabricated mold (400) of the shield segment (110).

8. The prefabricated mold for shield segment according to claim 7, characterized in that: One end of at least two core molds (420) is fixed in a staggered manner in the anchoring mold (411) by anchors (130) to two opposite vertical side walls of the anchoring mold (411).

9. The prefabricated mold for shield segment according to claim 7 or 8, characterized in that: The core mold fixing member (470) is fixedly connected to the core mold support (440) and the platform mold (480) by means of a bolt (481) penetrating a positioning hole (430) on the side of the prefabricated mold (400). The core mold (420) and the core mold support (440) enable the shield segment (110) to be prefabricated into a channel (120) having an expansion section (121), and the platform mold (480) enables the shield segment (110) to be prefabricated into a demoulding platform (123) connected to the expansion section (121).

10. The prefabricated mold for shield segment according to any one of claims 7 to 9, characterized in that: The core mold support (440) comprises a core mold supporting support (450) and a core mold expansion support (460); The core mold support bracket (450) is a linear column, and is inserted into and fixed to the end of the core mold (420) in a manner matching the diameter size of the core mold (420); The core mold expansion bracket (460) forms an expansion shape in a manner that the diameter of the axial section gradually expands, and its end with a smaller diameter is connected to the core mold support bracket (450), so that the end of the channel (120) forms an expansion section (121) with a gradually changing diameter.

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