A self-locking prestressed anchor system and construction method

Abstract

The present invention relates to a self-locking prestressed anchoring system, one end of which is a pre-expanded self-locking anchoring structure, including an embedded part and a cable assembly, the embedded part including an embedded pipe (10) buried together in a pre-embedded channel and axially penetrated, a lower anchor pad (8) and a protective cover (3), a circumferentially arranged multi-petal slider (4) is arranged in the protective cover (3), the multi-petal slider (4) can be radially contracted under the extrusion of an elastic body, and a temporary expansion positioning piece (14) is further arranged in the inner ring of the multi-petal slider (4), so that the inner ring of the multi-petal slider (4) forms a reserved hole for the cable assembly to penetrate from the pre-embedded channel into the deep part of the protective cover (3); the expansion positioning piece (14) can be pushed down by the inserted cable assembly to release the temporary expansion effect on the multi-petal slider (4), so that the multi-petal slider (4) forms an embracing locking on the cable assembly. The present application adopts an expansion positioning piece to make the self-locking component have a pre-expansion function, and the cable threading construction is labor-saving and time-saving.

Description

Technical Field

[0001] The invention relates to a prestressed anchoring structure, a corresponding prestressed anchoring system and an installation construction method of the anchoring system. Background Art

[0002] In engineering construction technology, prefabrication technology has been gradually promoted and applied. For example, the box beams, piers and other components of bridges are first made in sections. The anchor embedded parts of the prestressed anchor system are first buried in the segmented structure at the prefabrication site, and then transported to the project site for assembly section by section. After assembly, prestressed cable components are installed between the segments. By tensioning the cables, the cables are connected to the anchor embedded parts to form an overall structure to jointly bear the load. In some engineering occasions, such as prefabricated bridge piers, since the anchor embedded parts at one end of the anchor system are buried to form a "blind hole" structure, after the anchor cable is inserted, a self-locking anchor structure is required to connect the cable and the anchor embedded parts.

[0003] The Chinese patent application document with application number 201210030063.2 discloses a "self-locking prestressed anchor structure and vertical prestressed anchor system and construction method". The scheme adopts components including multi-petal sliders and elastic bodies, which have the function of being able to expand and gather. When the cable is inserted, under the action of the guide head at the end of the extruded cable body, the multi-petal slider is expanded, the extruded cable body guide sleeve and the anchor sleeve enter the anchor embedded part, and the multi-petal slider is gathered under the action of the elastic body, so that the anchor sleeve of the extruded cable body is pressed on the gathered slider to achieve the purpose of self-locking. Although this scheme realizes the function of self-locking, when the constraint force of the elastic body is large, it is necessary to apply a large thrust to the cable. However, the cable is a flexible component. When the cable length is long and the cable specification is small, due to the small stiffness of the cable body, there will be insufficient thrust, and the slider will be difficult to expand and the risk of not being able to expand. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and to provide a self-locking anchoring structure with a pre-expansion function for post-wire construction scenarios, which can effectively lock the cable bundle (cable assembly) that penetrates the anchoring structure, and this locking effect can be achieved after the cable bundle penetrates the anchoring structure without the need for external force for locking.

[0005] The present application further relates to a prestressed anchoring system with the self-locking anchoring structure and a construction method thereof. The prestressed anchoring system has a simple structure, making the cable threading construction labor-saving and simple.

[0006] The technical solution adopted by the present invention to solve the above-mentioned problem is: a self-locking prestressed anchoring system, one end of which is a pre-expanded self-locking anchoring structure, the pre-expanded self-locking anchoring structure comprising an embedded part and a cable assembly, the embedded part comprising an embedded pipe, a lower anchor pad and a protective cover which are buried together in the embedded channel and axially penetrated, the embedded pipe is arranged at the front end of the lower anchor pad, the protective cover is arranged at the rear end of the lower anchor pad, a circumferentially arranged multi-petal slider is arranged in the protective cover, the multi-petal slider can be radially contracted under the extrusion of the elastic body, and a temporary expansion positioning piece is further arranged on the inner ring of the multi-petal slider, so that the inner ring of the multi-petal slider forms a reserved hole for the cable assembly to penetrate from the embedded channel into the deep part of the protective cover; the expansion positioning piece can be pushed down by the inserted cable assembly to release the temporary expansion effect on the multi-petal slider, so that the multi-petal slider forms an embracing locking on the cable assembly.

[0007] The other end of the self-locking prestressed anchor system is the tensioning end. The anchor embedded parts arranged at the tensioning end include an embedded pipe, an upper anchor pad, a tensioning anchor and an anchor protection cover that are pre-buried together.

[0008] Furthermore, the outer ring of the embedded pipe is sleeved with a spiral rib, and the lower end of the spiral rib abuts against the lower anchor plate.

[0009] Furthermore, the protective cover has an annular step, the multi-petal slider is supported on the step, and the multi-petal slider slides along the extension surface of the step.

[0010] Preferably, the extension surface of the step extends radially or extends obliquely relative to a center line.

[0011] Preferably, guide strips or guide grooves are provided on the sliding contact surfaces of the multi-petal slider and the step to match each other, and the cooperation of the guide strips and the guide grooves constitutes a guide for the multi-petal slider to slide on the step.

[0012] Preferably, the elastic body is a compression spring, one end of which acts on the slider of the multi-petal slider and the other end of which acts on the inner wall of the protective cover.

[0013] Preferably, the expansion positioning member is an annular positioning ring, which is placed on the inner ring of the multi-petal slider to expand the slider outward; or the expansion positioning member is an annular member with multiple positioning pins, which are circumferentially erected on the connecting plate, and the multiple positioning pins act on the multi-petal slider to resist contraction.

[0014] Preferably, the cable assembly comprises a prestressed steel wire bundle and an anchor head arranged at the end of the prestressed steel wire bundle, and the axially retracted multi-petal slider is pressed against the end surface of the anchor head to form a limit for the retraction of the cable assembly.

[0015] This application also provides a construction method for the self-locking prestressed anchor system, the steps are as follows:

[0016] A. Assembly and installation of embedded parts:

[0017] 1) Installation of embedded parts of the self-locking anchoring structure with pre-expansion at the lower end: install the elastic body and the multi-petal slider into the protective cover, temporarily install the expansion positioning piece on the inner ring of the multi-petal slider, and expand the multi-petal slider to leave a reserved hole; axially connect the lower anchor plate and the protective cover into one piece, put on the spiral reinforcement, connect the embedded pipe, and embed the whole into the embedded channel of the precast concrete component; the lower anchor plate and the protective cover are respectively provided with grouting ports, and the grouting pipe is led out from the precast concrete component through the grouting ports so as to grout and seal the anchor after the prestressed steel strand is tensioned;

[0018] 2) Installation of upper anchor embedded parts: Assemble the upper anchor pad, tension anchor, spiral reinforcement and embedded pipe, and bury them together in the prefabricated or cast-in-place concrete component;

[0019] B. Install cable assembly and tension

[0020] 1) Make cable assembly: cut the prestressed steel bundle according to the length required by the project, install the anchor head at the lower end of the steel bundle, and anchor the lower end of the prestressed steel bundle to the anchor head;

[0021] 2) At the construction site, the end of the cable assembly with the anchor head installed is inserted into the embedded pipe of the pre-expanded self-locking anchoring structure at the lower end. When the anchor head passes through the multi-petal slider, the anchor head pushes the expansion positioning piece downward. The multi-petal slider without the expansion positioning piece is retracted toward the prestressed steel bundle under the action of the elastic body, radially hugging the prestressed steel bundle while axially resisting the end face of the anchor head, forming a limit for the upward retraction of the cable assembly;

[0022] 3) Install the upper end of the cable assembly into the tensioning anchor, tension the prestressed steel strand, and then lock and anchor it;

[0023] 4) Install the anchor protection cover at the tail of the tensioning anchor and perform grouting to complete the construction of the self-locking prestressed anchor system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is an overall schematic diagram of the pre-expanded self-locking anchoring structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the cable assembly of the present invention;

[0026] Figure 3 It is a structural schematic diagram of the embedded part of the pre-expanded self-locking anchoring structure of the present invention;

[0027] Figure 4 Another structural schematic diagram of the embedded part of the pre-expanded self-locking anchoring structure of the present invention;

[0028] Figure 5 It is a schematic diagram of the structure of the protective cover of the present invention;

[0029] Figure 6 for Figure 5 A-direction view;

[0030] Figure 7 It is a schematic diagram of the structure of a three-petal slider;

[0031] Figure 8 for Figure 7 B-direction view;

[0032] Fig. 9 is a schematic diagram of the structure of an annular positioning ring as an expansion positioning member;

[0033] Fig.10 A schematic diagram of the structure of a ring-shaped member having a plurality of positioning pins as an expansion positioning member;

[0034] Fig.11 for Fig.10 C-direction view;

[0035] Fig.12 It is a schematic diagram of the overall structure of the self-locking prestressed anchoring system of the present invention;

[0036] In the figure: Ⅰ-cable assembly, Ⅱ-embedded component assembly;

[0037] 1-anchor head, 2-prestressed steel bundle, 3-protective cover, 301-sealing ring installation groove, 302-installing expansion positioning piece pin hole, 303-slider installation base plate, 4-three-petal slider, 401-guide groove, 402-installing elastomer positioning hole, 403-installing expansion positioning piece positioning groove, 5-elastic body, 6-bolt, 7-sealing ring, 8-lower anchor plate, 9-spiral reinforcement, 10-embedded pipe or preformed channel, 11-precast concrete, 12-grouting pipe one, 13-grouting pipe two, 14-expansion positioning piece, 141-annular positioning ring, 142-annular piece with multiple positioning pins, 1421-positioning pin, 1422-connecting plate, 15-guide strip, 16-upper anchor plate, 17-tensioning end anchor, 18-anchor protection cover. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below with reference to the accompanying drawings. Example 1

[0039] like Figure 1As shown, a pre-expanded self-locking prestressed anchoring structure includes a cable assembly I and an embedded component assembly II, wherein the embedded component assembly II includes a protective cover 3, a three-petal slider 4, an elastic body 5, an expansion positioning piece 14, a lower anchor pad 8, a spiral rib 9 and an embedded pipe 10; the cable assembly I includes an anchor head 1 and a prestressed steel bundle 2, wherein the prestressed steel bundle 2 is anchored in the anchor head 1, and the anchor head 1 covers the end of the prestressed steel bundle 2. When in use, the lower anchor pad 8 is combined with the protective cover 3 by bolts, and is embedded in a precast concrete block 11 together with the spiral rib 9 and the embedded pipe 10, wherein the three-petal slider 4 is always in an expanded state under the action of the elastic body 5 and the expansion positioning piece 14, i.e., a reserved hole is reserved in the inner circle of the three-petal slider 4 for the anchor head 1 to pass through smoothly, and one end of the cable assembly I with the anchor head 1 passes through the embedded pipe 10, and when it passes through the three-petal slider 4, it touches the expansion positioning piece 14 and causes it to fall off. Fall into the protective cover 3. At this time, under the action of the elastic body 5, the three-petal slider 4 radially contracts and clamps the prestressed steel bundle, and at the same time axially contacts the end face of the anchor head 1, so that the cable assembly I cannot retract, thereby forming a self-locking prestressed anchoring structure.

[0040] like Figure 5 , Figure 6 As shown, the protective cover 3 is a closed cylinder, the upper part of which is connected to the lower anchor plate 8. When in use, the three-petal slider 4, the elastic body 5, and the expansion positioning member 14 constituting the self-locking mechanism are installed in the protective cover 3 and embedded in the precast concrete component. After the concrete is poured, an internal space is formed, so that the cable assembly I can pass through it.

[0041] like Figure 7 , Figure 8 As shown, the three-petal slider 4 is an annular plate-like component. In order to enable its inner circle to achieve the functions of expansion and gathering, it is separated into multiple identical petal sliders, and a countersunk hole 402 for installing the elastic body 5 is provided in the radial direction of the outer circle; in this embodiment, the three-petal slider 4 is composed of three-petal sliders. As a variation of the embodiment of the present invention, the number of slider petals constituting the three-petal slider 4 can also be increased or decreased, consisting of 2-4 petals, 5 petals or m petals, and the value range of m is: m is any integer between 2-36.

[0042] The function of the expansion positioning member 14 is to keep the inner ring of the three-petal slider 4 in an expanded state before the cable assembly is inserted, so as to facilitate the insertion and installation of the cable assembly I. The first implementation structure of the expansion positioning member 14 is as follows: Figure 3 As shown, the expansion positioning member 14 can be used as Figure 7 The structure of the annular positioning ring 141 shown in the figure is matched with the present embodiment. A mounting groove 403 (such as Figure 8 According to the technical concept of the present invention, the structure of the annular positioning ring 141 is not limited to the following: Figure 7 The round bar material shown can also be made of an annular column or cylinder structure.

[0043] Another structural solution of the expansion positioning member 14 is as follows Figure 4 As shown, the expansion positioning member 14 can be used as Figure 8 The structure of the ring member 142 with multiple pins shown in the figure is matched with the implementation scheme, and a pin hole 302 (such as Figure 5 , Figure 6 shown).

[0044] In order to allow the slider to be accurately radially retracted, a guide groove 401 is provided on the bottom surface of the three-petal slider 4, and an annular step is formed on the protective cover 3. The extension surface of the step is perpendicular to the central axis. The slider is axially supported on the step surface, and a guide strip 15 matching the guide groove is provided on the extension surface.

[0045] The protective cover 3 and the lower anchor plate 8 should ensure a reliable sealing connection. The protective cover 3 and the lower anchor plate 8 are connected by flanges. A sealing ring installation groove 301 is provided on the flange installation surface of the protective cover 3, and an elastic sealing ring 7 is provided in the sealing ring installation groove 301.

[0046] Compared with the technology of the patent publication with publication number 102535755A, the advantages of the pre-expanded self-locking prestressed anchor structure of the present application are:

[0047] (1) The multi-petal slider adopts an expansion positioning piece, which gives it a temporary expansion function, so that the slider is in the expanded "normally open" state, which saves labor and time during cable threading construction and meets the actual needs of the project; and there is no need to set a guide head at the end of the cable assembly, which simplifies the structure. Example 2

[0048] The pre-expanded self-locking anchoring structure involved in Example 1 serves as the lower end of the self-locking prestressed anchoring system, and the upper end of the self-locking prestressed anchoring system is the tensioning end. The anchor embedded parts of the tensioning end include embedded pipes, an upper anchor pad 16, a tensioning end anchor 17 and an anchor protection cover 18 that are pre-buried together. The tensioning end anchor 17 is a known anchor with a wire dividing plate. After the steel wires of the prestressed steel bundle are divided, they are inserted into the wire dividing plate and a clamp is set in the wire dividing hole of the wire dividing plate to fix the steel wires, and then anchored after tensioning. Example 3

[0049] A method for installing a self-locking prestressed anchor system according to Embodiment 2 comprises the following steps:

[0050] A. Assembly and installation of embedded parts:

[0051] 1) Assemble the components of the processed embedded component assembly II with a self-locking structure, position the elastic body 5 and the three-petal slider 4 in the protective cover 3, expand the three-petal slider 4, and install the expansion positioning member 14 on the three-petal slider 4 so that the three-petal slider 4 is always in an expanded state; combine the lower anchor plate 8 and the protective cover 3 into one body through bolts, and embed them into the precast concrete 11 together with the spiral reinforcement 9 and the embedded pipe 10; the lower anchor plate 8 and the protective cover 3 are respectively provided with grouting ports 12 for leading out the grouting pipe so as to facilitate grouting and sealing after the prestressed steel strand 2 is tensioned;

[0052] 2) Install or make a reserved channel 10, during the prefabrication or pouring of the concrete component 11 in sections, make the passage channel 10 for the prestressed anchor cable by burying the embedded pipe 10 or making a reserved forming process;

[0053] 3) Installation of the anchor embedded parts at the tensioning end. The upper anchor of the self-locking prestressed anchor system is generally a conventional prestressed anchor product. The upper anchor pad 16, spiral reinforcement 9 and embedded pipe 10 of the upper anchor are embedded in the prefabricated or cast-in-place concrete component 11.

[0054] B. Install cable assembly and tension

[0055] 1) Making and installing the cable assembly I: according to the length required by the project, the prestressed steel bundle 2 is cut, the anchor head 1 is installed at one end of the steel bundle, and the steel bundle 2 is anchored on the anchor head 1 after anchoring (or anchoring) treatment; at the construction site, the end of the cable assembly I installed with the anchor head 1 is passed through the above-mentioned upper anchor pad 16, through the pre-buried pipe 10, and when it reaches the three-petal slider 4 with a self-locking structure, the anchor head touches the expansion positioning piece 14 and causes it to fall off. At this time, under the action of the elastic body 5, the three-petal slider 4 is closed and tightly holds the prestressed steel bundle, and the axial direction forms a limit with the anchor head 1, so that the cable assembly I cannot retract, thereby forming a self-locking prestressed anchoring component;

[0056] 2) Install the tensioning end anchor 17 at the upper end of the cable assembly, insert the steel wire of the prestressed steel bundle into the wire dividing plate after the wire is divided, and set a clamp in the wire dividing hole of the fan plate to fix the steel wire, anchor it after tensioning, and lock the anchor;

[0057] 3) Install the anchor protection cover 18 and perform grouting. At this point, the installation and construction of the single-beam self-locking prestressed anchor system is completed.

Claims

1. A self-locking prestressed anchor system, one end of which is a pre-expanded self-locking anchor structure, characterized in that: The pre-expanded self-locking anchoring structure comprises an embedded part and a cable assembly, wherein the embedded part comprises an embedded pipe (10) which is embedded together in the embedded channel and axially penetrates, a lower anchor pad (8) and a protective cover (3), wherein the embedded pipe is arranged at the front end of the lower anchor pad (8), and the protective cover (3) is arranged at the rear end of the lower anchor pad (8), and a circumferentially arranged multi-petal slider is arranged in the protective cover (3), and the multi-petal slider can be radially contracted under the extrusion of the elastic body, and the inner ring of the multi-petal slider is further provided with a temporary expansion positioning The expansion positioning member (14) forms a reserved hole in the inner ring of the multi-petal slider so that the cable assembly can pass through the embedded channel into the deep part of the protective cover (3); the expansion positioning member (14) can be pushed down by the inserted cable assembly to release the temporary expansion effect on the multi-petal slider, so that the multi-petal slider can form an embracing locking on the cable assembly; the expansion positioning member (14) is an annular positioning ring (141), which is placed on the inner ring of the multi-petal slider and expands the slider outward; or the expansion positioning member (14) is A ring member (142) having a plurality of positioning pins, a plurality of positioning pins (1421) circumferentially erected on the connecting plate (1422), the plurality of positioning pins acting on the multi-petal slider to resist collapse; the protective cover (3) having a circumferential step, the multi-petal slider supported on the step, the multi-petal slider sliding along the extension surface of the step; the extension surface of the step extending radially or extending obliquely relative to the center line; guide strips ( 15) or a guide groove (401), the cooperation of the guide strip (15) and the guide groove (401) constitutes a guide for the multi-petal slider to slide on the step; the elastic body (5) is a compression spring, one end of which acts on the slider of the multi-petal slider, and the other end acts on the inner wall of the protective cover (3); the cable assembly comprises a prestressed steel wire bundle (2), and an anchor head (1) arranged at the end of the prestressed steel wire bundle (2), and the axially retracted multi-petal slider is pressed against the end face of the anchor head (1) to constitute a limit for the retraction of the cable assembly.

2. The self-locking prestressed anchor system according to claim 1, characterized in that: The other end is a tensioning end, and the anchor embedded part provided at the tensioning end comprises an embedded pipe, an upper anchor pad (16), a tensioning end anchor (17), and an anchor protection cover (18) that are embedded together.

3. The self-locking prestressed anchor system according to claim 1, characterized in that: The outer ring of the embedded pipe is sleeved with a spiral rib (9), and the lower end of the spiral rib (9) abuts against the lower anchor plate (8).

4. A construction method of the self-locking prestressed anchor system according to any one of claims 1 to 3, characterized in that: The steps are as follows A. Assembly and installation of embedded parts: 1) Installation of embedded parts of the self-locking anchoring structure with pre-expansion at the lower end: install the elastic body and the multi-petal slider into the protective cover, temporarily install the expansion positioning piece on the inner ring of the multi-petal slider, and expand the multi-petal slider to leave a reserved hole; axially connect the lower anchor plate and the protective cover into one piece, put on the spiral reinforcement, connect the embedded pipe, and embed the whole into the embedded channel of the precast concrete component; the lower anchor plate and the protective cover are respectively provided with grouting ports, and the grouting pipe is led out from the precast concrete component through the grouting ports so as to grout and seal the anchor after the prestressed steel strand is tensioned; 2) Installation of upper anchor embedded parts: Assemble the upper anchor pad, tension end anchor, spiral reinforcement and embedded pipe, and bury them together in prefabricated or cast-in-place concrete components; B. Install cable assembly and tension 1) Make cable assembly: cut the prestressed steel bundle according to the length required by the project, install the anchor head at the lower end of the steel bundle, and anchor the lower end of the prestressed steel bundle to the anchor head; 2) At the construction site, the end of the cable assembly with the anchor head installed is inserted into the embedded pipe of the pre-expanded self-locking anchoring structure at the lower end. When the anchor head passes through the multi-petal slider, the anchor head pushes the expansion positioning piece downward. The multi-petal slider without the expansion positioning piece is retracted toward the prestressed steel bundle under the action of the elastic body, radially hugging the prestressed steel bundle while axially resisting the end face of the anchor head, forming a limit for the upward retraction of the cable assembly; 3) Install the upper end of the cable assembly into the tensioning anchor, tension the prestressed steel strand, and then lock and anchor it; 4) Install the anchor protection cover at the tail of the tensioning anchor and perform grouting to complete the construction of the self-locking prestressed anchor system.

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