A split-type limiting device for friction testing

Abstract

This utility model discloses a split-type limiting device for friction testing, comprising: a flat anchor plate with several conical holes for steel strands to pass through; a positioning ring connected to the end of a jack; and a flat limiting plate disposed between the flat anchor plate and the positioning ring, the flat limiting plate having several through holes for steel strands to pass through. This utility model has a simple structure; the flat anchor plate, flat limiting plate, and positioning ring form a split-type structural design. This design overcomes the limitations faced by traditional circular limiting plates when performing overall tensioning of flat anchors. In particular, the flat limiting plate is designed to be detachable and can be used independently according to actual needs. This flexibility not only supports overall tensioning operations but also allows for easy switching to single-strand tensioning mode, improving the applicability and ease of operation of the equipment.

Description

Technical Field

[0001] This utility model relates to the field of flat anchoring technology, specifically a split-type limiting device for friction testing. Background Technology

[0002] In prestressed concrete structures, the flat anchorage system is widely used due to its suitability for special construction situations such as thin-walled structures and negative bending moment zones. This system uses a flat anchor as the core anchoring element, and its structural form is a variation of the wedge-type anchor. It achieves effective anchoring of the steel strand through multiple conical holes arranged in a straight line and cooperating with conical wedges.

[0003] However, in practical applications, since the common jack connection port is a circular slot structure, the limiting devices used with it are mostly circular in design, primarily for circular clamp-type anchors. Flat anchors, due to their rectangular structure, are difficult to adapt to conventional circular limiting devices. They typically require single-hole limiting and single-strand tensioning for testing or construction. This method not only increases the number of tensioning operations but also significantly reduces construction efficiency. Furthermore, in friction loss tests, because flat anchors cannot be tensioned as a whole, friction loss testing of a single steel strand is usually performed, and the overall friction loss is estimated through conversion. This indirect measurement method is not only cumbersome and inefficient but also prone to deviations in test results due to conversion errors, affecting the accuracy of prestress control in engineering projects. Therefore, a split-type limiting device for friction loss testing is proposed. Utility Model Content

[0004] The purpose of this invention is to provide a split-type limiting device for friction testing, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a split-type limiting device for friction testing, comprising: A flat anchor plate with several conical holes for steel strands to pass through; A positioning ring, which is connected to the end of the jack; and A flat limiting plate is set between the flat anchor plate and the positioning ring, and the flat limiting plate has several through holes for steel strands to pass through.

[0006] As a further embodiment of this invention: clamps are installed on the outer circumferential surface of the steel strand, the clamps being adapted to the conical holes opened on the flat anchor plate, and the number of clamps being the same as the number of conical holes.

[0007] As a further embodiment of this utility model: a positioning groove is provided on the end face of the flat limiting plate away from the positioning ring, a control groove is provided in the positioning groove, a plurality of through holes are provided in the control groove, and a connection hole is provided near the two ends of the control groove.

[0008] As a further embodiment of this utility model: the end face of the positioning ring away from the jack is provided with a centering groove, the centering groove is provided with a through groove, and the centering groove is provided with connecting threaded holes on both sides of the through groove.

[0009] As a further aspect of this utility model: the number of the through holes is five, and all five through holes overlap with the area of ​​the through groove after assembly with the positioning ring.

[0010] As a further embodiment of this utility model: the interior of the centering groove is adapted to the flat limiting plate.

[0011] As a further embodiment of this utility model, the flat anchor plate and the positioning ring are concentrically arranged.

[0012] As a further embodiment of this utility model: a positioning bolt is provided in the connecting hole of the flat limiting plate, and the end of the positioning bolt passes through the flat limiting plate and is connected to the positioning ring.

[0013] Compared with the prior art, the beneficial effects of this utility model are: The flat anchor plate, flat limiting plate, and positioning ring of this application form a split structural design. This design overcomes the limitations faced by traditional circular limiting plates when performing overall tensioning of flat anchors. In particular, the flat limiting plate is designed to be detachable and can be used individually according to actual needs. This flexibility not only supports overall tensioning operations but also allows for easy switching to single-anchor tensioning mode, improving the applicability and ease of operation of the equipment. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the split-type limiting device of this utility model; Figure 2 This is a schematic diagram of the combination of the flat anchor plate and the flat limiting plate of this utility model; Figure 3 This is a schematic diagram of the flat limiting plate and positioning ring combination of this utility model; Figure 4 This is a schematic diagram of the flat limiting plate of this utility model; Figure 5 This is a schematic diagram of the positioning ring of this utility model; Figure 6 This is a schematic diagram of the assembly of the five steel strands of this utility model; Figure 7 This is a schematic diagram of the assembly of the four steel strands of this utility model; Figure 8 This is a schematic diagram of the assembly of the three steel strands of this utility model; In the diagram: 1. Flat anchor plate; 2. Clip; 3. Steel strand; 4. Flat limiting plate; 4-1. Positioning groove; 4-2. Control groove; 4-3. Through hole; 4-4. Connecting hole; 5. Positioning ring; 5-1. Centering groove; 5-2. Through groove; 5-3. Connecting threaded hole; 6. Positioning bolt; 7. Jack. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] Please see Figure 1-8 In this embodiment of the present invention, a split-type limiting device for friction testing includes: Flat anchor plate 1, on which a plurality of conical holes are formed for steel strands 3 to pass through; Positioning ring 5, which is connected to the end of jack 7; and A flat limiting plate 4 is set between the flat anchor plate 1 and the positioning ring 5. The flat limiting plate 4 has several through holes 4-3 for the steel strands 3 to pass through.

[0017] Specifically, the flat anchor plate 1 and the positioning ring 5 are concentrically arranged. Clamping pieces 2 are installed on the outer circumference of the steel strand 3. The number of clamping pieces 2 is consistent with the number of tapered holes opened on the flat anchor plate 1, and each clamping piece 2 is matched with one tapered hole, achieving a one-to-one correspondence. The number of threading holes 4-3 is not limited, but in this embodiment, it is preferably set to five. The spacing between the five threading holes 4-3 is equal, and the center distance between adjacent threading holes 4-3 is the same. After assembly with the positioning ring 5, the position of each threading hole 4-3 corresponds to the through groove 5-2 area on the positioning ring 5, and the flat anchor plate 1, the flat limiting plate 4, and the positioning ring 5 are all movably connected.

[0018] When using this limiting fixture to conduct an overall friction test on a 5-hole flat limiting plate, first assemble and connect the flat limiting plate 4 and the positioning ring 5. During the test, install the flat anchor plate 1, the clamping piece 2, the flat limiting plate 4 and the positioning ring 5 assembly in sequence, and use the jack 7 to perform the tensioning operation.

[0019] When using this limiting fixture to conduct an overall friction test on a 4-hole flat limiting plate, the flat limiting plate 4 and the positioning ring 5 are not assembled and connected. During the test, the flat anchor plate 1, the clamping piece 2, and the flat limiting plate 4 are installed in sequence. After the steel strand 3 passes through the flat anchor plate 1 and the clamping piece 2, it passes through the first four holes of the flat limiting plate 4 in sequence. Then, the positioning ring 5 is installed. The axis of the positioning ring 5 is located at the center point of the flat anchor plate 1 and is eccentric to the flat limiting plate 4. The eccentric distance is equal to half the hole spacing of the flat anchor plate 1. Then, the tensioning operation is performed using the jack 7.

[0020] This limiting fixture is used for single-strand tensioning of a 4-hole flat limiting plate. During construction, there is no need to use the positioning ring 5. After installing the flat anchor plate 1 and the clamping plate 2, the flat limiting plate 4 is installed directly. The steel strand 3 passes through the flat anchor plate 1 and the clamping plate 2, and then passes through the first four holes of the flat limiting plate 4 in sequence. Then, the jack 7 is installed to carry out the single-strand tensioning operation (the above tensioning operations are all existing technologies and will not be described in detail here).

[0021] The aforementioned technical solution provides a limiting fixture comprising a flat anchor plate 1, a flat limiting plate 4, and a positioning ring 5. These components are connected in a movable manner to form a modular structure. This design overcomes the limitations of traditional circular limiting plates when tensioning flat anchors as a whole. In particular, the flat limiting plate 4 is detachable and can be used independently according to actual needs. This flexibility not only supports overall tensioning operations but also allows for easy switching to single-anchor tensioning mode, improving the applicability and ease of operation of the equipment.

[0022] Please see Figure 1 In one embodiment, preferably, the end face of the flat limiting plate 4 away from the positioning ring 5 is provided with a positioning groove 4-1, a control groove 4-2 is provided in the positioning groove 4-1, a plurality of through holes 4-3 are provided in the control groove 4-2, and a connecting hole 4-4 is provided near the two ends of the control groove 4-2.

[0023] Specifically, the bottom surface of the positioning groove 4-1 is flat, with a groove width of 50mm; the control groove 4-2 has a groove width of 32mm and is set parallel to the positioning groove 4-1, with a parallel distance of 8mm between them. This distance is the effective limiting distance of the flat limiting plate 4; the bottom surface of the control groove 4-2 is provided with five cylindrical through holes 4-3 with the same axial orientation and a hole diameter of 18mm. Their axes are perpendicular to the bottom surface of the control groove 4-2, and the five through holes 4-3 are arranged in a straight line. The connecting hole 4-4 is a circular stepped hole used for the installation of the positioning bolt 6. It is designed for the largest specification of 5-hole flat anchors in conventional flat anchors. When tensioning flat anchors with other hole numbers as a whole, the positioning bolt 6 is removed, and the centering is achieved by sliding the flat limiting plate 4 in the centering groove 5-1 in the positioning ring 5.

[0024] Please see Figure 1In one embodiment, preferably, the end face of the positioning ring 5 away from the jack 7 is provided with a centering groove 5-1, a through groove 5-2 is provided in the centering groove 5-1, and connecting threaded holes 5-3 are provided on both sides of the centering groove 5-1 located in the through groove 5-2.

[0025] Specifically, the interior of the centering groove 5-1 is adapted to the flat limiting plate 4. The centering groove 5-1 has a depth of 5mm and a width of 51mm. The centering groove 5-1 is located at the center of the end face of the positioning ring 5. The two sides are symmetrical along the center line of the end face. A through groove 5-2 with a width of 20mm and a length of 160mm is set at the center of the centering groove 5-1. The through groove 5-2 is rectangular. The hole spacing of the two connecting threaded holes 5-3 is the same as the hole spacing between the two connecting holes 4-4 of the flat limiting plate 4.

[0026] Please see Figure 1 In one embodiment, preferably, a positioning bolt 6 is provided in the connecting hole 4-4 of the flat limiting plate 4, and the end of the positioning bolt 6 passes through the flat limiting plate 4 and is connected to the positioning ring 5.

[0027] The working principle and usage process of this utility model: Before the overall friction test of the flat anchor plate, the flat limiting plate 4 and the positioning ring 5 are assembled and connected in advance using positioning bolts 6. Specifically, the centering grooves 5-1 of the flat limiting plate 4 and the positioning ring 5 fit together, and the axis of the through hole 4-3 located at the center position on the flat limiting plate 4 coincides with the overall axis of the positioning ring 5 to ensure the balance of force on the limiting fixture during later use; the positioning bolts 6 are passed through the connecting hole 4-4 and the connecting threaded hole 5-3 in sequence to complete the assembly and connection of the flat limiting plate 4 and the positioning ring 5.

[0028] During the experiment, flat anchor plate 1, clamp 2, steel strand 3, and pre-embedded components under the anchor were pre-installed. Then, steel strand 3 was passed through the through hole 4-3, through groove 5-2, and jack 7 in sequence. The positioning ring 5 was placed in the groove at the end of jack 7. The centering was achieved by designing the similar size between the two. Then, the steel strand was tensioned. After the oil returned, the friction loss data was calculated by the difference in anchoring force at both ends of the anchoring system after the steel strand 3 retracted. The operation steps for tensioning the flat anchor are the same as the above experimental steps.

[0029] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0030] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A split type stopper for a friction test, characterized by comprising: a first stopper member; a second stopper member; and a connecting member for connecting the first stopper member and the second stopper member. include: A flat anchor plate having several conical holes through which steel strands pass; A positioning ring, which is connected to the end of the jack; as well as A flat limiting plate is set between the flat anchor plate and the positioning ring, and the flat limiting plate has several through holes for steel strands to pass through.

2. The split stopper for a friction test according to claim 1, wherein The outer circumferential surface of the steel strand is fitted with clips that are adapted to the conical holes opened on the flat anchor plate, and the number of clips is the same as the number of conical holes.

3. The split stopper for a friction test according to claim 1, wherein The flat limiting plate has a positioning groove on the end face away from the positioning ring. A control groove is formed in the positioning groove. Several through holes are formed in the control groove. A connection hole is formed near the two ends of the control groove.

4. The split stopper for a friction test according to claim 1, wherein The positioning ring has a centering groove on its end face away from the jack, and a through groove is formed in the centering groove. Connecting threaded holes are formed on both sides of the centering groove located in the through groove.

5. The split stopper for friction testing according to claim 4, wherein The number of the through holes is five, and all five through holes overlap with the area of ​​the through groove after assembly with the positioning ring.

6. The split stopper for friction testing according to claim 4, wherein The interior of the centering groove is adapted to the flat limiting plate.

7. The split stopper for friction testing according to claim 1, wherein The flat anchor plate and the positioning ring are concentrically arranged.

8. The split stopper for friction testing according to claim 3, wherein A positioning bolt is provided in the connecting hole of the flat limiting plate, and the end of the positioning bolt passes through the flat limiting plate and is connected to the positioning ring.

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