Pre-tensioning method prestress tensioning device suitable for shield tunnel

Abstract

The invention belongs to the technical field of shield tunnel engineering, and particularly relates to a pre-tensioning method prestress tensioning device suitable for a shield tunnel. Comprising a pre-tensioning supporting frame, a pre-stress screw and two fixed end mechanisms, the two ends of the pre-stress screw penetrate through the two fixed end mechanisms correspondingly, the sides, away from each other, of the two fixed end mechanisms on the pre-stress screw are each provided with a second nut, and the pre-tensioning supporting frame is arranged on the peripheries of the two fixed end mechanisms; the two ends of the prestress screw penetrate through two opposite side plates of the pre-tensioning supporting frame correspondingly and are in threaded connection with first nuts correspondingly, and the first nuts are used for applying prestress to the prestress screw. By arranging the pre-tensioning supporting frame and the first nut, corresponding prestress can be applied to the prestress screw rod in advance before construction, so that the step of applying the prestress on site is omitted, the requirement for the space size is low, and the construction efficiency can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of shield tunnel engineering, and in particular relates to a prestressing device suitable for a shield tunnel. Background Art

[0002] In shield tunnel construction, prestressed reinforcement devices are important tools for improving the rigidity of segments and resisting deformation. The main reinforcement forms currently used include reaction frames and prestressed brackets. These devices enhance the structural performance of segments by applying prestress, but they generally have problems such as large size and weight, and limited construction space, which affects the convenience and efficiency of construction.

[0003] The invention patent with announcement number CN117449608B discloses an automatic leveling carbon fiber plate prestressing tensioning device for curved surface structures. Although it can effectively occupy a smaller space in the curved surface structure and take into account the longitudinal and circumferential stiffness of the pipe segment, the device needs to rely on on-site measurements to determine the specific value when applying prestress, resulting in the inability to conveniently preset the prestress before construction, reducing construction efficiency.

[0004] Therefore, it is urgent to design a prestressing device suitable for shield tunnels that can not only improve the longitudinal and circumferential stiffness of the segments, but also set the prestress size in advance, thereby achieving efficient tensioning and reinforcement operations when the on-site space is limited. Summary of the invention

[0005] In view of the above problems in the prior art, the present invention provides a prestressing device suitable for a shield tunnel, and specifically discloses the following technical solutions:

[0006] A prestressed tensioning device suitable for a shield tunnel comprises a prestressed support frame, a prestressed screw and two fixed end mechanisms, the two ends of the prestressed screw respectively pass through the two fixed end mechanisms, a second nut is threadedly installed on the side of the prestressed screw located away from each other, the two fixed end mechanisms are both used to be fixed to the shield tunnel segment, the prestressed support frame is arranged on the periphery of the two fixed end mechanisms, the two ends of the prestressed screw respectively pass through two opposite side plates of the prestressed support frame and are respectively threadedly connected with a first nut, the first nut is used to apply prestress to the prestressed screw.

[0007] Furthermore, the pre-stressed support frame includes two prestressed anchor plates arranged in parallel, and a structural connecting plate is connected between both ends of the two prestressed anchor plates to form a rectangular structure. Both ends of the prestressed screw rod respectively penetrate the two prestressed anchor plates and are threadedly connected with a first nut.

[0008] Furthermore, both ends of the prestressed anchor plate are provided with concave mortise grooves, and both ends of the structural connecting plate are provided with convex tenons matching with the concave mortise grooves. The prestressed anchor plate and the structural connecting plate are connected by mortise and tenon and fixed by a first bolt.

[0009] Furthermore, the two fixed end mechanisms each include a fixed base and a clamping plate, the two fixed bases each include a bottom plate, the top ends of the two bottom plates are located on both sides of the prestressed screw and are fixedly connected with side plates parallel to the prestressed screw, the two clamping plates are respectively mortise and tenon connected with the ends of the side plates on the two fixed bases away from each other, the two ends of the prestressed screw respectively pass through the two clamping plates and are threadedly connected with a second nut, the bottoms of the ends of the two bottom plates away from each other are fixedly connected with ear plates, the two ear plates are inclined downwardly arranged along the side away from each other, and round holes are opened on the two ear plates for being sleeved on the connecting bolts of the shield tunnel segments.

[0010] Furthermore, a spring is connected between the ends of the two base plates that are close to each other. The number of the springs is two and they are symmetrically arranged on both sides directly below the prestressed screw.

[0011] Furthermore, a U-shaped shear bearing member is fixedly installed on one side of the top of the two base plates that are close to each other by a second bolt, and the bottom end of the second bolt passes through the U-shaped shear bearing member and the base plate from top to bottom and is threadedly connected to the shield tunnel segment. The U-shaped shear bearing member is buckled on the prestressed screw to enhance the shear resistance of the prestressed screw.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] In the present invention, by providing a pre-stressing support frame and a first nut, it is possible to apply corresponding prestress to the prestressed screw before construction, thereby omitting the step of applying prestress on site. Therefore, the requirement for space size is relatively low and the construction efficiency can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0015] Figure 2 It is a schematic diagram of the structure of the prestressed anchor plate in the present invention;

[0016] Figure 3 A top view of the prestressed anchor plate of the present invention;

[0017] Figure 4 It is a left view of the prestressed anchor plate in the present invention;

[0018] Figure 5It is a front view of the prestressed anchor plate of the present invention;

[0019] Figure 6 It is a structural schematic diagram of the structural connecting plate in the present invention;

[0020] Figure 7 It is a front view of the structural connecting plate of the present invention;

[0021] Figure 8 It is a left side view of the structural connecting plate of the present invention;

[0022] Fig. 9 A top view of the structural connecting plate of the present invention;

[0023] Fig.10 It is a structural schematic diagram of the card board in the present invention;

[0024] Fig.11 It is a front view of the card board in the present invention;

[0025] Fig.12 It is a left side view of the card board in the present invention;

[0026] Fig.13 A top view of the cardboard in the present invention;

[0027] Fig.14 It is a structural schematic diagram of the fixed base in the present invention;

[0028] Fig.15 It is a front view of the fixed base in the present invention;

[0029] Fig.16 A top view of the fixed base in the present invention;

[0030] Fig.17 It is a left side view of the fixed base in the present invention;

[0031] Fig.18 It is a structural schematic diagram of a U-shaped shear bearing member in the present invention;

[0032] Fig.19 It is a schematic diagram of prestressing tensioning of the prestressed screw in the present invention;

[0033] Fig. 20 It is a schematic diagram of the structure of two fixed end mechanisms in the present invention;

[0034] Fig.21 It is a schematic diagram of the installation process of the present invention;

[0035] Fig. 22 It is a schematic diagram of the installation completion of the present invention.

[0036] Among them: 1-prestressed anchor plate; 2-first bolt; 3-structural connecting plate; 4-prestressed screw; 5-first nut; 6-second nut; 7-clamp plate; 8-fixed base; 9-second bolt; 10-U-shaped shear bearing member; 11-ear plate; 12-spring. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Reference Figure 1-22 A prestressing tensioning device suitable for a shield tunnel by the prestressing method comprises a prestressing support frame, a prestressing screw 4 and two fixed end mechanisms, the two ends of the prestressing screw 4 respectively pass through the two fixed end mechanisms, a second nut 6 is threadedly installed on the side of the prestressing screw 4 that is located away from each other. The two fixed end mechanisms are both used to be fixed to the shield tunnel segment. The prestressing support frame is arranged on the periphery of the two fixed end mechanisms. The two ends of the prestressing screw 4 respectively pass through two opposite side plates of the prestressing support frame and are respectively threadedly connected with a first nut 5. The first nut 5 is used to apply prestress to the prestressing screw 4.

[0039] In this embodiment, in order to adapt to the high humidity and strong corrosive environment in the shield tunnel, the prestressed screw 4 can be made of corrosion-resistant materials such as a double carbon screw or a core screw to improve its durability and corrosion resistance.

[0040] In this embodiment, the pre-stressed support frame includes two parallel prestressed anchor plates 1, and a structural connecting plate 3 is connected between the two ends of the two prestressed anchor plates 1 to form a rectangular structure. The two ends of the prestressed screw 4 respectively pass through the two prestressed anchor plates 1 and are threadedly connected with a first nut 5. By tightening the first nuts 5 at both ends, the corresponding prestress can be applied to the prestressed screw 4. The prestressed anchor plate 1 and the prestressed screw 4 can slide relative to each other, thereby facilitating the application of prestress to the prestressed screw 4.

[0041] In this embodiment, both ends of the prestressed anchor plate 1 are provided with concave mortise grooves, and both ends of the structural connecting plate 3 are provided with convex tenons matching the concave mortise grooves. The prestressed anchor plate 1 and the structural connecting plate 3 are connected by mortise and tenon and fixed by the first bolt 2, thereby ensuring the strength and stability of the prestressing support frame, and further ensuring that the prestressed screw 4 can be stably applied with prestress.

[0042] In this embodiment, the two fixed end mechanisms each include a fixed base 8 and a clamping plate 7. The two fixed bases 8 each include a bottom plate. The top ends of the two bottom plates are located on both sides of the prestressed screw 4 and are fixedly connected with side plates parallel to the prestressed screw 4. The two clamping plates 7 are respectively mortise and tenon connected to the ends of the side plates on the two fixed bases 8 that are away from each other. The two ends of the prestressed screw 4 pass through the two clamping plates 7 respectively and are threadedly connected with a second nut 6. The bottoms of the ends of the two bottom plates that are away from each other are fixedly connected with ear plates 11. The two ear plates 11 are arranged obliquely downward along the side away from each other. Circular holes are opened on the two ear plates 11 for being mounted on the connecting bolts of the shield tunnel segments, thereby providing reliable support points.

[0043] In this embodiment, the clamping plate 7 is provided with a through hole for the prestressed screw 4 to pass through, the diameter of the through hole is larger than the nominal diameter of the prestressed screw 4, a leveling washer is provided between the second nut 6 and the clamping plate 7, the leveling washer is provided on the prestressed screw 4, the side of the leveling washer close to the clamping plate 7 is provided with a spherical surface, and a groove matching the spherical surface of the leveling washer is provided on the periphery of the through hole on the clamping plate 7. The leveling washer can form a ball joint structure at the groove, and can rotate within a certain range to avoid the influence of eccentricity on the prestress.

[0044] In this embodiment, a spring 12 is connected between the ends of the two bottom plates that are close to each other. There are two springs 12, which are symmetrically arranged on both sides just below the prestressed screw 4. The spring 12 can connect the two fixed bases 8 into one body, ensure the safety during the installation process, and prevent the fixed base 8 from accidentally falling.

[0045] In this embodiment, the U-shaped shear bearing member 10 is fixedly installed on the side of the top of the two base plates that are close to each other by the second bolt 9. The bottom end of the second bolt 9 passes through the U-shaped shear bearing member 10 and the base plate from top to bottom and is threadedly connected with the shield tunnel segment. The second bolt 9 can lock the U-shaped shear bearing member 10 on the fixed base 8 and fix the fixed base 8 on the shield tunnel segment. The U-shaped shear bearing member 10 is buckled on the prestressed screw 4 to enhance the shear resistance of the prestressed screw 4.

[0046] The installation method of the present invention is:

[0047] First, install the two clamps 7 and the two second nuts 6 on the prestressed screw 4 in the corresponding position sequence, and then install the two prestressed anchor plates 1 and the two first nuts 5 at the two ends of the prestressed screw 4 respectively, and then install the structural connecting plate 3 between the two prestressed anchor plates 1 and fix them. After the fixation is completed, tighten the first nut 5 to apply the corresponding prestress to the prestressed screw 4. After the prestress is applied, the semi-finished structure is transported to the construction site, so that the two clamps 7 are respectively fixedly connected to the two fixed bases 8 that have been fixed to the shield tunnel segments through the ear plates 11. After the fixation is completed, tighten the second nut 6 and then loosen the first nut 5, so that the prestress is transmitted to the fixed base 8 through the clamp 7, and finally the pre-tensioning support frame is removed.

[0048] In the present invention, by providing a pre-stressing support frame and a first nut, it is possible to apply corresponding prestress to the prestressed screw before construction, thereby omitting the step of applying prestress on site. Therefore, the requirement for space size is relatively low and the construction efficiency can be effectively improved.

[0049] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A prestressing device suitable for shield tunnels, characterized in that: It includes a pre-stressed support frame, a prestressed screw and two fixed end mechanisms, the two ends of the prestressed screw respectively pass through the two fixed end mechanisms, a second nut is threadedly installed on the side of the prestressed screw located away from each other, the two fixed end mechanisms are both used to be fixed to the shield tunnel segment, the pre-stressed support frame is arranged on the periphery of the two fixed end mechanisms, the two ends of the prestressed screw respectively pass through two opposite side plates of the pre-stressed support frame and are respectively threadedly connected with a first nut, the first nut is used to apply prestress to the prestressed screw.

2. A prestressing device for shield tunneling according to claim 1, characterized in that: The pre-stressed support frame includes two parallel prestressed anchor plates, and a structural connecting plate is connected between the two ends of the two prestressed anchor plates to form a rectangular structure. The two ends of the prestressed screw rod respectively penetrate the two prestressed anchor plates and are threadedly connected with a first nut.

3. The prestressing device for shield tunneling according to claim 2 is characterized in that: Both ends of the prestressed anchor plate are provided with concave mortise grooves, and both ends of the structural connecting plate are provided with convex tenons matching with the concave mortise grooves. The prestressed anchor plate and the structural connecting plate are connected by mortise and tenon and fixed by a first bolt.

4. The prestressing device for prestressing of a shield tunnel according to claim 1, characterized in that: The two fixed end mechanisms each include a fixed base and a clamping plate, the two fixed bases each include a bottom plate, the top ends of the two bottom plates are located on both sides of the prestressed screw and are fixedly connected with side plates parallel to the prestressed screw, the two clamping plates are respectively mortise and tenon connected with the ends of the side plates on the two fixed bases away from each other, the two ends of the prestressed screw respectively pass through the two clamping plates and are threadedly connected with a second nut, the bottoms of the ends of the two bottom plates away from each other are fixedly connected with ear plates, the two ear plates are inclined downwardly arranged along the side away from each other, and round holes are opened on the two ear plates for being mounted on the connecting bolts of the shield tunnel segments.

5. A prestressing device for prestressing of shield tunnels according to claim 4, characterized in that: A spring is connected between the ends of the two bottom plates that are close to each other. The number of the springs is two and they are symmetrically arranged on both sides directly below the prestressed screw rod.

6. The prestressing device for shield tunneling according to claim 4, characterized in that: A U-shaped shear bearing member is fixedly installed on one side of the top of the two base plates that are close to each other through a second bolt, and the bottom end of the second bolt passes through the U-shaped shear bearing member and the base plate from top to bottom and is threadedly connected to the shield tunnel segment. The U-shaped shear bearing member is buckled on the prestressed screw to enhance the shear resistance of the prestressed screw.

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