A prestress tension device fixed to a shield segment embedded sliding groove

Abstract

The utility model discloses a kind of prestress tensioning devices fixed in shield segment embedded slide groove, including tensioning node and steel strand;The tensioning node is located in the slide groove of shield segment, and slides along the slide groove;The steel strand is wound between multiple tensioning nodes, and one end is fixed on the foremost tensioning node, and the other end is connected with traction equipment;The tensioning node includes limiting unit and the tensioning unit on the limiting unit, the tensioning unit rotates on limiting unit, and tensioning unit is equipped with tensioning rod, and the both ends of tensioning rod are equipped with pulley, and the steel strand is wound between multiple tensioning nodes by pulley. By sliding adjustment position of tensioning node in slide groove, then by traction equipment traction steel strand, make it provide tensioning force to tensioning node, realize the tensioning of multiple shield segment, and, when traction equipment reaches preset tensioning force, steel strand can also be twisted by rotating tensioning rod, realize further tensioning.

Description

Technical Field

[0001] The embodiments of this utility model belong to the field of shield tunneling technology, and more specifically, relate to a prestressed tensioning device fixed to the pre-embedded sliding groove of the shield tunnel segment. Background Technology

[0002] As the core component of tunnel support, the assembly quality of tunnel segments directly determines the stability and durability of the tunnel structure. During shield tunneling, after assembly, the segments are prone to problems such as increased gaps between segments, misalignment, and even edge breakage due to the axial thrust of the shield machine during advancement, the radial stress generated by the segment's own weight, and uneven local stress caused by the "head-knocking" phenomenon during the tunnel receiving stage. Without pre-tensioning, the sealing performance at the segment joints will decrease significantly, potentially leading to groundwater leakage. Simultaneously, the overall load-bearing capacity of the segments will weaken, making them susceptible to structural cracking over long-term use, threatening the safe operation of the tunnel. Therefore, it is essential to eliminate assembly gaps in advance using pre-tensioning devices to ensure that the segments form a tightly fitted, integral load-bearing structure.

[0003] Currently, the industry has developed multiple technical approaches for pre-tensioning tunnel segments, with the mainstream methods including mechanical tensioning and combined tensioning. Mechanical tensioning solutions often employ a combination structure of "double-ended studs + wedge clamps + hydraulic jacks." Double-ended studs are inserted into pre-drilled holes in the segments, and axial pressure is applied to the segments using the jacks' pushing and supporting feet. The self-locking effect of the clamps secures the studs, achieving pre-tensioning between segments. Combined tensioning solutions add correction components, such as adjustable jacking blocks next to the tensioning mechanism, to simultaneously correct radial misalignment of the segments during pre-tensioning. Some solutions also introduce connectors to link symmetrically distributed tensioning mechanisms in series, improving the uniformity of overall stress on the segments.

[0004] Although existing technologies can meet basic pre-tensioning requirements, significant shortcomings remain. Firstly, most devices are structurally complex, requiring multiple independent components such as jacks, support legs, and clamps. Installation necessitates repeated adjustments to align these components with the pre-drilled holes in the tunnel segments, making the process cumbersome and time-consuming, especially in the confined space of the tunnel boring machine's tail section, where component transportation and positioning are extremely difficult. Secondly, the controllability of the tensioning effect is insufficient. Traditional mechanical tensioning relies on manual judgment of jack pressure, making it difficult to precisely control the pre-tensioning force of each segment. This can easily lead to localized over-tightening causing segment cracking or localized under-tightening leaving gaps. Furthermore, some devices are large and heavy, increasing equipment procurement and maintenance costs and potentially causing spatial interference with other components of the tunnel boring machine, impacting construction efficiency. Utility Model Content

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this utility model provides a prestressing tensioning device fixed to the pre-embedded groove of a tunnel segment. The tensioning node slides and adjusts its position within the groove, and then a traction device pulls the steel strands to provide tension to the tensioning node, thus tensioning multiple tunnel segments. Furthermore, after the traction device reaches the preset tension, the steel strands can be twisted by rotating the tensioning rod to achieve further tension. This device simplifies the prestressing tensioning operation of tunnel segments while ensuring sufficient tension force and achieving better tensioning results.

[0006] To achieve the above objectives, according to a first aspect of the present utility model, a prestressed tensioning device fixed to the pre-embedded sliding groove of a shield tunnel segment is provided, including a tensioning node and steel strands. The tensioning node is located in the sliding groove of the shield segment and slides along the sliding groove; the steel strand is wound between multiple tensioning nodes, with one end fixed to the foremost tensioning node and the other end connected to the traction equipment. The tensioning node includes a limiting unit and a tensioning unit disposed on the limiting unit. The tensioning unit rotates on the limiting unit and is provided with a tensioning rod. Both ends of the tensioning rod are provided with pulleys. The steel strand passes through the pulleys and travels between multiple tensioning nodes.

[0007] Furthermore, the chute has a T-shaped cross-section and is installed along the inner wall of the tunnel segment; The sliding unit includes a slider, the cross-section of which is the same as that of the groove, and the slider is disposed in the groove and slides along it. The slider is provided with a top plate, and threaded through holes are opened on both sides of the top plate. A matching push bolt is provided in the threaded through hole.

[0008] Furthermore, the top plate is also provided with a connecting seat, and the limiting unit is fixedly connected to the connecting seat; The limiting unit includes a fixed column, which is a cylinder fixed to the connecting seat. A pair of embedded grooves are opened in the middle of the cylindrical surface, and the two embedded grooves are arranged symmetrically around the central axis of the fixed column.

[0009] Furthermore, each recessed slot is provided with a pawl, the rear end of which is rotatably connected to the recessed slot via a pivot, and gradually thins towards the front end to become a pointed tip; A limiting spring is provided between the pawl and the inner groove to provide an outward pushing force to the pawl.

[0010] Furthermore, the tensioning unit includes a sleeve that is fitted onto a fixed post. The sleeve is divided into an upper reset cavity and a lower limiting cavity by a support plate. The limiting cavity contains a ratchet and a release wheel. The release wheel is located at the bottom end of the ratchet, and the two have the same diameter.

[0011] Furthermore, the ratchet is provided with ratchet teeth in an inward circumferential direction, and the arrangement direction of the ratchet teeth is the same as the extension direction of the pawl, thus cooperating with the pawl.

[0012] Furthermore, the sleeve is fitted onto the fixed post through a limiting cavity, and the support plate at the top of the limiting cavity contacts the top of the fixed post to achieve vertical support for the sleeve. The support plate has a through hole in its center.

[0013] Furthermore, a threaded hole is provided at the central axis position of the top of the fixed column, and a cap is provided in the threaded hole. The bottom end of the cap is a screw structure, and the top end is a thin plate structure. The screw of the cover passes downward through the central through hole of the support plate and is detachably connected to the fixed post by the thread. A return spring is also provided between the top thin plate structure of the cover and the support plate. The return spring is compressed.

[0014] Furthermore, the tensioning rod is located at the bottom end of the outer cylindrical surface of the sleeve, with two parallel pulley mounting seats at one end and only one pulley mounting seat at the other end, each pulley mounting seat being equipped with a pulley; The steel strand is wound from one end of the double pulley of the tension rod at the last tensioning node to one end of the single pulley, and then wound towards one end of the double pulley of the front tensioning node until it reaches the frontmost tensioning node and is fixed to one end of the single pulley of its tensioning rod.

[0015] Furthermore, a handwheel is provided at the top of the outer cylindrical surface of the sleeve, through which the sleeve is rotated.

[0016] In summary, compared with the prior art, the above-described technical solution conceived by this utility model can achieve the following beneficial effects: 1. The prestressed tensioning device of this utility model adjusts the position of the tensioning node by sliding it within a chute, and then pulls the steel strands through a traction device to provide tension to the tensioning node, thereby tensioning multiple shield tunnel segments. Furthermore, after the traction device reaches the preset tension, the steel strands can be twisted by rotating the tensioning rod to achieve further tension. This simplifies the prestressed tensioning operation of shield tunnel segments while ensuring sufficient tension force and achieving better tensioning results.

[0017] 2. The prestressed tensioning device of this utility model provides support between the top plate and the shield segment by rotating the jacking bolt after the slider slides to the preset position, thereby increasing the friction between the slider and the chute and fixing the position of the slider in the chute.

[0018] 3. The prestressed tensioning device of this utility model, under the limiting action of ratchet and pawl, the tensioning unit can only rotate in the forward direction, while providing a reverse limiting action, thereby limiting the tensioning rod. When the force of the steel strand acts on the tensioning rod, it can ensure that the tensioning rod does not rotate in the reverse direction and cause unloading. Furthermore, after the subsequent traction equipment stops traction, it avoids excessive stress between the two shield segments and prevents back thrust, thus keeping them in a taut state.

[0019] 4. In this utility model of prestressed tensioning device, when it is necessary to release the tension of the steel strand or reset the position of the tensioning rod, the reverse rotation limit of the sleeve can be released by lifting the sleeve upwards to disengage the pawl from the ratchet and into the release wheel. Furthermore, since the ratchet and the release wheel have the same inner diameter, the outward opening angle of the pawl will not increase. When the manually applied upward pulling force is removed, it moves downwards under its own weight and the elastic force of the return spring, causing the pawl to automatically re-engage with the ratchet, thus simplifying the reset operation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a prestressed tensioning device fixed to the pre-embedded sliding groove of a shield tunnel segment according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a shield segment structure for a prestressed tensioning device fixed to a pre-embedded groove in a shield segment, according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the tensioning node structure of a prestressed tensioning device fixed to the pre-embedded sliding groove of a shield tunnel segment according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the sliding unit and limiting unit of a prestressed tensioning device fixed to the pre-embedded groove of a shield tunnel segment according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the tensioning unit structure of a prestressed tensioning device fixed to the pre-embedded sliding groove of a shield tunnel segment according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the internal structure of the tensioning unit of a prestressed tensioning device fixed to the pre-embedded groove of a tunnel segment according to an embodiment of the present invention; Figure 7 This is a cross-sectional view of a tensioning node structure of a prestressed tensioning device fixed to a pre-embedded groove of a tunnel segment, according to an embodiment of this utility model. Figure 8 This is a schematic diagram showing the arrangement of steel strands in a prestressed tensioning device fixed to a pre-embedded groove in a tunnel segment, according to an embodiment of this utility model.

[0021] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-shield segment, 11-slide groove, 2-tensioning node, 21-sliding unit, 211-slider, 212-top plate, 213-pushing bolt, 214-connecting seat, 22-limiting unit, 221-fixed column, 222-pawl, 23-tensioning unit, 231-sleeve, 232-ratchet, 233-release wheel, 234-support plate, 235-tensioning rod, 236-pulley, 237-handwheel, 24-cap, 25-reset spring, 3-steel strand. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0023] like Figure 1 , 3 As shown, this utility model embodiment provides a prestressed tensioning device fixed to the pre-embedded sliding groove of a shield tunnel segment, including a tensioning node 2 and a steel strand 3. The tensioning node 2 is disposed in the sliding groove 11 of the shield tunnel segment 1 and slides along the sliding groove 11. The steel strand 3 is wound between multiple tensioning nodes 2, with one end fixed to the foremost tensioning node 2 and the other end connected to a traction device. The tensioning node 2 includes a limiting unit 22 and a tensioning unit 23 disposed on the limiting unit 22. The tensioning unit 23 rotates on the limiting unit 22, and a tensioning rod 235 is provided in the tensioning unit 23. Pulleys 236 are provided at both ends of the tensioning rod 235, and the steel strand 3 passes through the pulleys 236 to wound between multiple tensioning nodes 2. The tensioning node 2 is slidably adjusted within the chute 11 to adjust its position. Then, the steel strand 3 is pulled by the traction device to provide tension to the tensioning node 2, thereby tensioning multiple shield tunnel segments 1. Furthermore, after the traction device reaches the preset tension, the steel strand 3 can be twisted by rotating the tensioning rod 235 to achieve further tension. This method simplifies the prestressing tensioning operation of the shield tunnel segments 1 while ensuring sufficient tension force and achieving better tensioning results.

[0024] like Figure 2 , 4 As shown, the chute 11 has a T-shaped cross-section and is arranged along the inner wall of the shield tunnel segment 1. The sliding unit 21 includes a slider 211, the slider 211 having the same cross-section as the chute 11, and is disposed in the chute 11 and slides along it. The slider 211 is provided with a top plate 212, and threaded through holes are opened on both sides of the top plate 212, and a matching push bolt 213 is provided in the threaded through hole.

[0025] Understandably, after the slider 211 slides to the preset position, the jacking bolt 213 is rotated to provide support between the top plate 212 and the shield segment 1, thereby increasing the friction between the slider 211 and the slide groove 11 and fixing the position of the slider 211 in the slide groove 11.

[0026] As a further preferred embodiment, the end of the slide groove 11 is provided with an opening for assembling and disassembling the slider 211. During installation, the slider 211 enters the slide groove 11 through the opening and slides; during disassembly, the slider 211 slides to the opening and is removed from the slide groove 11.

[0027] The top plate 212 is also provided with a connecting seat 214, and the limiting unit 22 is fixedly connected to the connecting seat 214. The limiting unit 22 includes a fixing post 221, which is a cylinder fixed to the connecting seat 214. A pair of recessed slots are opened in the middle of its cylindrical surface, and the two recessed slots are arranged symmetrically around the central axis of the fixing post 221. Each recessed slot is provided with a pawl 222, the rear end of which is rotatably connected to the recessed slot through a rotating shaft, and gradually thins towards the front end to become a pointed tip. A limiting spring is provided between the pawl 222 and the recessed slot, which provides an outward pushing force to the pawl 222, so that its front end always faces away from the central axis of the fixing post 221.

[0028] like Figure 5-7 As shown, the tensioning unit 23 includes a sleeve 231, which is fitted onto the fixed post 221. The sleeve 231 is divided into an upper reset cavity and a lower limiting cavity by a support plate 234. The limiting cavity contains a ratchet 232 and a release wheel 233, with the release wheel 233 located at the bottom end of the ratchet 232. Both ratchet wheels have the same diameter. The ratchet 232 has circumferentially arranged ratchet teeth, the arrangement of which is the same as the extension direction of the pawl 222, and they cooperate with the pawl 222.

[0029] Understandably, the tensioning unit 23, under the limiting action of the ratchet 232 and the pawl 222, can only rotate in the forward direction, while providing a reverse limiting action, thereby limiting the tensioning rod 235. When the force of the steel strand 3 acts on the tensioning rod 235, it can ensure that the tensioning rod 235 does not rotate in the reverse direction and cause unloading. Furthermore, after the subsequent traction equipment stops traction, it avoids excessive stress between the two shield tunnel segments 1, preventing back thrust and keeping them in a tensioned state.

[0030] The sleeve 231 is fitted onto the fixed post 221 through a limiting cavity. The support plate 234 at the top of the limiting cavity contacts the top of the fixed post 221 to provide vertical support for the sleeve 231. The support plate 234 has a through hole in its center. The fixed post 221 has a threaded hole at its top center axis, and a cover 24 is installed in the threaded hole. The bottom of the cover 24 is a screw structure, and the top is a thin plate structure. The screw of the cover 24 passes downward through the central through hole of the support plate 234 and is detachably connected to the fixed post 221 by threads. A return spring 25 is also provided between the thin plate structure at the top of the cover 24 and the support plate 234. The return spring 25 is compressed and provides thrust between the two, so that the pawl 222 always maintains engagement with the ratchet 232 under normal use.

[0031] The release wheel 233 has a smooth inner wall. When the pawl 222 is in the release wheel 233, it releases the limit unit 22 from the tension unit 23.

[0032] Understandably, when it is necessary to release the tension of the steel strand 3 or to reset the position of the tensioning rod 235, the reverse rotation limit of the sleeve 231 can be released by lifting the sleeve 231 upwards to disengage the pawl 222 from the ratchet 232 and into the release wheel 233. Furthermore, since the ratchet 232 and the release wheel 233 have the same inner diameter, the outward opening angle of the pawl 222 will not increase. When the manually applied upward pulling force is removed, it moves downwards under its own weight and the elastic force of the return spring 25, causing the pawl 222 to automatically re-engage with the ratchet 232, thus simplifying the reset operation.

[0033] like Figure 8 As shown, the tension rod 235 is located at the bottom of the outer cylindrical surface of the sleeve 231. One end of the rod has two parallel pulley mounting seats, while the other end has only one pulley mounting seat. Each pulley mounting seat is equipped with a pulley 236. The steel strand 3 winds from one end of the double pulleys on the tension rod 235 at the last tensioning node 2 to one end of the single pulley, and then winds towards one end of the double pulleys at the front tensioning node 2 until it reaches the frontmost tensioning node 2 and is fixed to one end of the single pulley of its tension rod 235.

[0034] The top of the outer cylindrical surface of the sleeve 231 is also provided with a handwheel 237, which is used to rotate the sleeve 231.

[0035] As a further preferred option, the traction device can be any type of known winch, hydraulic jack, or other similar equipment.

[0036] It is understandable that the tensioning node 2 is temporarily fixed in the chute 11 during construction and is removed after construction is completed, so as not to occupy the shield space and avoid affecting subsequent construction.

[0037] Understandably, shield tunneling can improve the integrity of tunnel segments when traversing dangerous geological conditions, and can serve as a second line of defense to ensure construction safety.

[0038] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A prestressed tensioning device fixed to the pre-embedded sliding groove of a tunnel segment, characterized in that, Includes tensioning nodes (2) and steel strands (3); The tensioning node (2) is located in the groove (11) of the shield segment (1) and slides along the groove (11); the steel strand (3) is wound between multiple tensioning nodes (2), with one end fixed to the foremost tensioning node (2) and the other end connected to the traction equipment. The tensioning node (2) includes a sliding unit (21), a limiting unit (22), and a tensioning unit (23) provided on the limiting unit (22). The tensioning unit (23) rotates on the limiting unit (22), and a tensioning rod (235) is provided in the tensioning unit (23). Pulleys (236) are provided at both ends of the tensioning rod (235). The steel strand (3) passes through the pulleys (236) and travels between multiple tensioning nodes (2).

2. The prestressed tensioning device fixed to the pre-embedded sliding groove of the shield tunnel segment according to claim 1, characterized in that, The chute (11) has a T-shaped cross section and is set along the inner wall of the shield tunnel segment (1); The sliding unit (21) includes a slider (211), the cross section of which is the same as that of the groove (11), and the slider (211) is disposed in the groove (11) and slides along it; The slider (211) is provided with a top plate (212), and threaded through holes are opened on both sides of the top plate (212), and a matching push bolt (213) is provided in the threaded through hole.

3. The prestressing tensioning device fixed to the pre-embedded sliding groove of the shield tunnel segment according to claim 2, characterized in that, The top plate (212) is also provided with a connecting seat (214), and the limiting unit (22) is fixedly connected to the connecting seat (214); The limiting unit (22) includes a fixed column (221), which is a cylinder and fixed on the connecting seat (214). A pair of embedded grooves are opened in the middle of its cylindrical surface, and the two embedded grooves are arranged symmetrically around the central axis of the fixed column (221).

4. The prestressed tensioning device fixed to the pre-embedded sliding groove of the shield tunnel segment according to claim 3, characterized in that, Each inner slot is provided with a pawl (222), the rear end of which is rotatably connected to the inner slot via a rotating shaft, and gradually thins towards the front end to become a pointed tip; A limiting spring is provided between the pawl (222) and the inner groove to provide an outward thrust to the pawl (222).

5. A prestressed tensioning device fixed to the pre-embedded sliding groove of a shield tunnel segment according to claim 4, characterized in that, The tensioning unit (23) includes a sleeve (231), which is fitted onto the fixed post (221). The sleeve (231) is divided into an upper reset cavity and a lower limiting cavity by a support plate (234). The limiting cavity includes a ratchet (232) and a release wheel (233). The release wheel (233) is located at the bottom end of the ratchet (232), and the two have the same diameter.

6. A prestressed tensioning device fixed to the pre-embedded sliding groove of a shield tunnel segment according to claim 5, characterized in that, The ratchet (232) is provided with ratchet teeth in the inward circumferential direction. The arrangement direction of the ratchet teeth is the same as the extension direction of the pawl (222) and cooperates with the pawl (222).

7. A prestressed tensioning device fixed to the pre-embedded sliding groove of a shield tunnel segment according to claim 6, characterized in that, The sleeve (231) is fitted onto the fixed post (221) through the limiting cavity. The support plate (234) at the top of the limiting cavity contacts the top of the fixed post (221) to achieve vertical support for the sleeve (231). The support plate (234) has a through hole in the center.

8. A prestressed tensioning device fixed to the pre-embedded sliding groove of a shield tunnel segment according to claim 7, characterized in that, The top center axis of the fixed column (221) is provided with a threaded hole, and a cover (24) is provided in the threaded hole. The bottom end of the cover (24) is a screw structure and the top end is a thin plate structure. The screw of the cover (24) passes downward through the central through hole of the support plate (234) and is detachably connected to the fixed column (221) by the thread. A return spring (25) is also provided between the top thin plate structure of the cover (24) and the support plate (234). The return spring (25) is compressed.

9. A prestressed tensioning device fixed to the pre-embedded sliding groove of a shield tunnel segment according to claim 8, characterized in that, The tension rod (235) is located at the bottom of the outer cylindrical surface of the sleeve (231). One end of the rod has two parallel pulley mounting seats, and the other end has only one pulley mounting seat. Each pulley mounting seat is equipped with a pulley (236). The steel strand (3) is wound from one end of the double pulley of the tension rod (235) on the last tension node (2) to one end of the single pulley, and then wound towards one end of the double pulley of the front tension node (2) until the frontmost tension node (2) is fixed to one end of the single pulley of its tension rod (235).

10. A prestressed tensioning device fixed to the pre-embedded sliding groove of a shield tunnel segment according to claim 9, characterized in that, The top of the outer cylindrical surface of the sleeve (231) is also provided with a handwheel (237), through which the sleeve (231) is rotated.

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