Prestressed anchor cable tension stress compensation device and construction method

Abstract

The invention discloses a prestressed anchor cable tension stress compensation device and a construction method, and relates to the technical field of anchor cable tension. The compensation problem is solved; the structure specifically comprises a concrete cushion layer, a fixed end is arranged on the inner wall of the concrete cushion layer, a plurality of anchor cables are limited on the inner wall of the fixed end, a hydraulic force application mechanism is arranged on one side of each anchor cable, and a limiting lock catch is arranged on the outer wall, located on one side of the hydraulic force application mechanism, of the fixed end; the axis of the anchor cable, the axis of the fixed end and the pulling force direction of the hydraulic force application mechanism are parallel and all perpendicular to the bearing face of the concrete cushion layer, the hydraulic force application mechanism comprises a shell fixed to the bearing face of the concrete cushion layer and a hydraulic oil cylinder fixed to the inner side of the shell, and the inner wall of the hydraulic oil cylinder is in sliding fit with a hydraulic piston. Graded tensioning and regulation of the pre-stressed anchor cable can be achieved, the final pre-stress is compensated before pre-stress construction is finished, and the situation of stress loss can be effectively avoided.

Description

Technical Field

[0001] The invention relates to the technical field of anchor cable tensioning, and in particular to a prestressed anchor cable tensioning stress compensation device and a construction method. Background Art

[0002] Prestressed anchor cable is a reinforcement technology used in geotechnical engineering. It is mainly used in foundation pit support, slope stabilization, tunnel support, dam reinforcement and other projects. Specifically, prestress is applied in the anchor cable to enhance the rigidity, stability and bearing capacity of the structure.

[0003] Existing prestressing technologies are mostly applied once, which is prone to cause prestress loss. After the prestress loss occurs, the existing devices cannot compensate for the lost stress. The loss of prestress is a complex process with many aspects, which may be caused by tension locking, relaxation of anchor cable materials, creep of geological surrounding rocks, temperature changes and other factors.

[0004] To this end, the present invention provides a prestressed anchor cable tensioning stress compensation device and a construction method. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a prestressed anchor cable tensioning stress compensation device and a construction method.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A prestressed anchor cable tensioning stress compensation device comprises a concrete cushion layer;

[0008] The inner wall of the concrete cushion layer is provided with a fixed end, the inner wall of the fixed end is limited by a plurality of anchor cables, a hydraulic force mechanism is provided on one side of the anchor cables, and a limited lock is provided on the outer wall of the fixed end located on the side of the hydraulic force mechanism.

[0009] Preferably, the axis of the anchor cable, the axis of the fixed end and the pulling direction of the hydraulic force applying mechanism are parallel and perpendicular to the bearing surface of the concrete cushion layer.

[0010] Furthermore: the hydraulic force mechanism includes an outer shell fixed to the bearing surface of the concrete cushion layer and a hydraulic cylinder fixed to the inner side of the outer shell, the inner wall of the hydraulic cylinder is slidably fitted with a hydraulic piston, the inner wall of the hydraulic piston is fixed with a hydraulic pull rod, the hydraulic pull rod is connected to the end of the anchor cable, and the outer wall of one side of the hydraulic cylinder is provided with a cylinder hole connected to the inner cavity of the hydraulic cylinder.

[0011] On the basis of the above-mentioned solution: a caliper for reading the position of the hydraulic pull rod is arranged at the end of the housing.

[0012] A better solution among the above solutions is: the hydraulic pull rod is connected to the anchor cable through a tension sensor, and the hydraulic force application mechanism is connected to a hydraulic controller 1, and the tension sensor is electrically connected to the hydraulic controller 1.

[0013] As a further solution of the present invention: the tension sensor is composed of one or more strain gauges.

[0014] A construction method for a prestressed anchor cable tensioning stress compensation device comprises the following steps:

[0015] S1: Concrete cushion construction: after the anchor cable grouting construction is completed, the concrete cushion is constructed on the free end of the anchor cable to ensure that the bearing surface of the concrete cushion is perpendicular to the direction of prestressing;

[0016] S2: Install the tension sensor, install the limit lock buckle on the anchor bar of the anchor cable, and connect the other end of the limit lock buckle to the hydraulic pull rod;

[0017] S3: Pre-tensioning of anchor cables, start hydraulic controller 1, and set pre-tensioning force F0 to tension the anchor cables. Keep the tension for 60 minutes to make the pre-tensioning stress offset the stress loss in the production of anchor cable materials and tensioning and locking stages;

[0018] S4: monitor the loss of prestress F0′, monitor the stress loss value after the pre-tensioning by the tension sensor, and monitor the elongation of the anchor cable by the caliper;

[0019] S5: Cyclic multi-stage tensioning, setting the prestressing gradient F n ′, each time the tensioning is increased by a gradient value until the prestressing design value F is reached, and the tensioning stress loss and tensioning length in the process are monitored at the same time;

[0020] S6: Prestress compensation: monitor the loss of prestress within 60 minutes after tensioning is completed;

[0021] S61: If the final prestress loss is less than kF, the construction is terminated;

[0022] S62: If the loss of final prestress is greater than kF, the tensioning cycle continues until the final prestress is less than kF.

[0023] As a preferred embodiment of the present invention: in the step S3, F0=1 / 10F.

[0024] Meanwhile, in step S6, k is a proportional value, k=1 / 20.

[0025] The beneficial effects of the present invention are:

[0026] 1. The present invention can realize the graded tensioning and regulation of prestressed anchor cables, and compensate the final prestress before the end of prestressing construction, which can effectively avoid the situation of stress loss.

[0027] 2. The present invention has a high degree of intelligence and can monitor the prestressed loading state in real time. It is also small in size and suitable for situations where on-site construction conditions are limited. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the overall structure of a prestressed anchor cable tensioning stress compensation device proposed by the present invention;

[0029] Figure 2 A schematic diagram of a control path of a prestressed anchor cable tensioning stress compensation device proposed by the present invention;

[0030] Figure 3 A schematic diagram of the position of a prestressed anchor cable tensioning stress compensation device proposed by the present invention;

[0031] Figure 4 The present invention is a schematic flow chart of a construction method of a prestressed anchor cable tensioning stress compensation device proposed by the present invention.

[0032] In the figure: 1. Concrete cushion; 2. Limit lock; 3. Hydraulic pull rod; 4. Cylinder hole; 5. Hydraulic cylinder; 6. Hydraulic piston; 7. Caliper; 8. Housing; 9. Anchor cable; 10. Fixed end; 11. Hydraulic controller 1; 12. Tension sensor; 13. Hydraulic force mechanism. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described in detail below in conjunction with specific implementation methods.

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0035] Embodiment 1:

[0036] A prestressed anchor cable tensioning stress compensation device, such as Figure 1-Figure 3 As shown, it includes a concrete cushion layer 1, the inner wall of which is provided with a fixed end 10, the inner wall of which is limited by a plurality of anchor cables 9, a hydraulic force application mechanism 13 is provided on one side of the anchor cables 9, and a limiting lock buckle 2 is provided on the outer wall of the fixed end 10 located on the side of the hydraulic force application mechanism 13.

[0037] The axis of the anchor cable 9 , the axis of the fixed end 10 and the pulling direction of the hydraulic force applying mechanism 13 are parallel and perpendicular to the bearing surface of the concrete cushion layer 1 .

[0038] The hydraulic force mechanism 13 includes an outer shell 8 fixed to the bearing surface of the concrete cushion layer 1 and a hydraulic cylinder 5 fixed to the inner side of the outer shell 8. The inner wall of the hydraulic cylinder 5 is slidably fitted with a hydraulic piston 6. The inner wall of the hydraulic piston 6 is fixed with a hydraulic pull rod 3, which is connected to the end of the anchor cable 9.

[0039] One side outer wall of the hydraulic cylinder 5 is provided with a cylinder hole 4 which is connected with the inner cavity of the hydraulic cylinder 5 .

[0040] When oil is injected into the oil cylinder hole 4 , the hydraulic piston 6 will move due to the oil pressure, thereby driving the hydraulic pull rod 3 to move, thereby pulling the anchor cable 9 and applying prestress to the anchor cable 9 .

[0041] A caliper 7 for reading the position of the hydraulic pull rod 3 is disposed at the end of the housing 8 ; the displacement of the hydraulic pull rod 3 can be read by the caliper 7 , thereby reading the tension length of the anchor cable 9 .

[0042] The hydraulic pull rod 3 is connected to the anchor cable 9 via a tension sensor 12, and the hydraulic force applying mechanism 13 is connected to a hydraulic controller 11, and the tension sensor 12 is electrically connected to the hydraulic controller 11.

[0043] The tension sensor 12 is composed of one or more strain gauges.

[0044] The tension applied by the hydraulic pull rod 3 to the anchor cable 9 can be read by the tension sensor 12, and the tension is transmitted to the hydraulic controller 11, and the hydraulic controller 11 controls the extension and retraction of the hydraulic force applying mechanism 13 according to the tension.

[0045] Embodiment 2:

[0046] A construction method for a prestressed anchor cable tensioning stress compensation device, such as Figure 3 As shown, the following steps are included:

[0047] S1: Construction of concrete cushion layer 1. After the grouting construction of anchor cable 9 is completed, the concrete cushion layer 1 is constructed on the free end of anchor cable 9 to ensure that the bearing surface of the concrete cushion layer 1 is perpendicular to the direction of application of prestress;

[0048] S2: Install the tension sensor 12, install the limit lock buckle 2 on the anchor bar of the anchor cable 9, and connect the other end of the limit lock buckle 2 to the hydraulic pull rod 3;

[0049] S3: pre-tensioning the anchor cable 9, start the hydraulic controller 11, and set the pre-tensioning force F0 to tension the anchor cable 9, and keep it for 60 minutes after tensioning, so that the pre-tensioning stress offsets the stress loss in the anchor cable material production and tensioning locking stage;

[0050] S4: monitoring the loss of prestress F0′, monitoring the stress loss value after the pre-tensioning by the tension sensor 12, and monitoring the elongation of the anchor cable 9 by the caliper 7;

[0051] S5: Cyclic multi-stage tensioning, setting the prestressing gradient F n ′, each time the tensioning is increased by a gradient value until the prestressing design value F is reached, and the tensioning stress loss and tensioning length in the process are monitored at the same time;

[0052] S6: Prestress compensation: monitor the loss of prestress within 60 minutes after tensioning is completed;

[0053] S61: If the final prestress loss is less than kF, the construction is terminated;

[0054] S62: If the loss of final prestress is greater than kF, the tensioning cycle continues until the final prestress is less than kF.

[0055] In the step S3, F0=1 / 10F.

[0056] In the step S6, k is a proportional value, k=1 / 20.

[0057] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A prestressed anchor cable tensioning stress compensation device, comprising a concrete cushion layer (1), characterized in that: The inner wall of the concrete cushion layer (1) is provided with a fixed end (10), the inner wall of the fixed end (10) is limited by a plurality of anchor cables (9), a hydraulic force application mechanism (13) is provided on one side of the anchor cables (9), and a limit lock buckle (2) is provided on the outer wall of the fixed end (10) located on the side of the hydraulic force application mechanism (13).

2. A prestressed anchor cable tensioning stress compensation device according to claim 1, characterized in that: The axis of the anchor cable (9), the axis of the fixed end (10) and the pulling direction of the hydraulic force applying mechanism (13) are parallel and perpendicular to the bearing surface of the concrete cushion layer (1).

3. A prestressed anchor cable tensioning stress compensation device according to claim 1, characterized in that: The hydraulic force applying mechanism (13) comprises an outer shell (8) fixed to the bearing surface of the concrete cushion layer (1) and a hydraulic cylinder (5) fixed to the inner side of the outer shell (8); the inner wall of the hydraulic cylinder (5) is slidably fitted with a hydraulic piston (6); the inner wall of the hydraulic piston (6) is fixed with a hydraulic pull rod (3); the hydraulic pull rod (3) is connected to the end of the anchor cable (9); and one side outer wall of the hydraulic cylinder (5) is provided with a cylinder hole (4) which is connected to the inner cavity of the hydraulic cylinder (5).

4. A prestressed anchor cable tensioning stress compensation device according to claim 3, characterized in that: A caliper (7) for reading the position of the hydraulic pull rod (3) is provided at the end of the housing (8).

5. A prestressed anchor cable tensioning stress compensation device according to claim 3, characterized in that: The hydraulic pull rod (3) is connected to the anchor cable (9) via a tension sensor (12), and the hydraulic force applying mechanism (13) is connected to a hydraulic controller (11), and the tension sensor (12) is electrically connected to the hydraulic controller (11).

6. A prestressed anchor cable tensioning stress compensation device according to claim 5, characterized in that: The tension sensor (12) is composed of one or more strain gauges.

7. A construction method for a prestressed anchor cable tensioning stress compensation device, which is a construction method for a prestressed anchor cable tensioning stress compensation device according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: Construction of the concrete cushion layer (1). After the grouting construction of the anchor cable (9) is completed, the concrete cushion layer (1) is constructed on the free end of the anchor cable (9) to ensure that the bearing surface of the concrete cushion layer (1) is perpendicular to the direction of application of the prestress; S2: Install the tension sensor (12), install the limit lock buckle (2) on the anchor bar of the anchor cable (9), and connect the other end of the limit lock buckle (2) to the hydraulic pull rod (3); S3: pre-tensioning the anchor cable (9), starting the hydraulic controller 1 (11), and setting the pre-tensioning force F0 to tension the anchor cable (9), and maintaining it for 60 minutes after tensioning, so that the pre-tensioning stress offsets the stress loss in the anchor cable material production and tensioning and locking stages; S4: monitoring the loss of prestress F0′, monitoring the stress loss value after the pre-tensioning by the tension sensor (12), and monitoring the elongation of the anchor cable (9) by the caliper (7); S5: Cyclic multi-stage tensioning, setting the prestressing gradient F n ′, each time the tensioning is increased by a gradient value until the prestressing design value F is reached, and the tensioning stress loss and tensioning length in the process are monitored at the same time; S6: Prestress compensation: monitor the loss of prestress within 60 minutes after tensioning is completed; S61: If the final prestress loss is less than kF, the construction is terminated; S62: If the loss of final prestress is greater than kF, the tensioning cycle continues until the final prestress is less than kF.

8. The construction method of the prestressed anchor cable tensioning stress compensation device according to claim 7 is characterized in that: In the step S3, F0=1 / 10F.

9. The construction method of a prestressed anchor cable tensioning stress compensation device according to claim 7, characterized in that: In the step S6, k is a proportional value, k=1 / 20.

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