Bridge structure model test steel beam external prestress tension protection device and method

Abstract

The present application relates to a kind of bridge structure model test steel beam external prestress tension protection device and method. In the process of external prestress tension test, external prestress beam suddenly breaks or slips and can endanger personnel and equipment safety. The device includes external prestress protection pipe, external prestress steel beam is inserted in the external prestress protection pipe;External prestress protection pipe is provided with external prestress anchor plate at both ends, and external prestress steel beam is anchored through anchor nut from external prestress anchor plate at both ends;The inner wall of external prestress protection pipe is provided with annular transverse positioning stiffener, and external prestress steel beam is located in the transverse positioning stiffener. When external prestress tension is carried out in test, the device can effectively prevent prestress steel beam from suddenly breaking or slipping, and protect on-site personnel and equipment;The component used adopts standard size, and is mechanically connected between components, can be built by assembly type installation mode, is easy to install and disassemble, and can be reused.

Description

Technical Field

[0001] This invention relates to the field of bridge structural model testing technology, specifically to a protective device and method for external prestressing tensioning of steel strands in bridge structural model testing. Background Technology

[0002] As the service life of long-span concrete bridges increases, due to concrete shrinkage and creep, steel strand relaxation, and corrosion, concrete bridges commonly exhibit increased mid-span deflection and reduced load-bearing capacity, posing significant safety risks to their continued use. To address these issues, reinforcement treatment is generally necessary, and external prestressing is one of the commonly used reinforcement methods for long-span bridge structures. To understand the application process of external prestressing, it is necessary to conduct concrete bridge structural model tests in the early stages of construction. The test model uses a portion of an actual bridge, which mostly bears axial compressive stress in real bridges; therefore, it is often necessary to simulate this axial compressive stress in the model tests.

[0003] In model tests, external prestressing is a common method for applying axial compressive stress. However, during the external prestressing tensioning process in old bridge reinforcement and model tests, sudden fracture or slippage of the prestressed steel strands can occur due to factors such as the quality of the prestressed steel strands, improper control of the tension force, non-standard tensioning, and uneven prestressing. This sudden fracture or slippage is a brittle failure without obvious warning, affecting the safety of the test and endangering the safety of personnel and equipment.

[0004] Therefore, it is necessary to propose a protection method to overcome the above-mentioned defects. Summary of the Invention

[0005] The purpose of this invention is to provide a protective device and method for external prestressing tensioning of steel strands in bridge structural model tests, so as to solve the problem of sudden breakage or slippage of external prestressing strands endangering the safety of personnel and equipment during the test.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A protective device for external prestressing tensioning of steel strands in bridge structural model tests, the device comprising an external prestressing protective tube, wherein an external prestressing steel strand is inserted into the external prestressing protective tube;

[0008] The external prestressed protective pipe is provided with external prestressed anchor plates at both ends, and the two ends of the external prestressed steel strands pass through the external prestressed anchor plates and are anchored by anchor nuts.

[0009] The inner wall of the external prestressed protective pipe is provided with annular transverse positioning stiffening ribs, and the external prestressed steel strands are located inside the transverse positioning stiffening ribs.

[0010] Furthermore, the external prestressed protective pipe includes several general segments, and the end edges of the general segments are provided with longitudinal connecting flanges, and the longitudinal connecting flanges are provided with longitudinal connecting bolt holes;

[0011] The longitudinal connecting flanges of adjacent general-purpose segments are connected and fixed to each other by inserting bolts into the longitudinal connecting bolt holes.

[0012] Furthermore, the general segment is composed of two semicircular tubes, and the outer wall of the semicircular tubes is provided with radial longitudinal stiffening ribs;

[0013] The longitudinal stiffening rib located at the end of the semi-circular tube is provided with a transverse connecting bolt hole. The two semi-circular tubes are joined together, and bolts are inserted into the transverse connecting bolt holes to connect and fix them to each other.

[0014] Furthermore, the universal segment is divided into multiple models according to different lengths, and multiple different models of the universal segment are connected to form the external prestressed protective pipe.

[0015] Furthermore, the external prestressed protective pipe also includes an adjustable-size segment, which includes an outer tube and an inner tube, with the inner tube inserted into the outer tube and moving longitudinally.

[0016] Furthermore, one end of the inner tube is inserted into the outer tube, and the other end is provided with a longitudinal connecting flange.

[0017] Furthermore, the outer tube is composed of two semi-circular outer tubes, and the outer wall of the semi-circular outer tubes is provided with radial longitudinal stiffening ribs;

[0018] A transverse connecting bolt hole is provided on the longitudinal stiffening rib located at the end of the semi-circular outer tube. Two semi-circular outer tubes are joined together, and bolts are inserted into the transverse connecting bolt hole to connect and fix them to each other.

[0019] One end of the outer tube is provided with a longitudinal connecting flange, and the longitudinal connecting flange is provided with longitudinal connecting bolt holes.

[0020] Furthermore, the outer wall of the inner tube is provided with a slide rail, and the inner wall of the outer tube is provided with a longitudinal slide groove, with the slide rail located within the longitudinal slide groove.

[0021] Furthermore, a limiting device is provided between the outer tube and the inner tube.

[0022] On the other hand, a method for protecting steel strands under external prestressing tension in bridge structural model tests is provided, the method being implemented based on the aforementioned device, including:

[0023] Cast concrete beams;

[0024] Install external prestressed steel strands;

[0025] Install external prestressed protective pipes;

[0026] Tensioning and anchoring solid external prestressed steel strands;

[0027] Adjust the adjustable size segment.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] This invention provides a protective device and method for external prestressing tensioning of steel strands in bridge structural model tests. During external prestressing tensioning in the test, it effectively prevents sudden breakage or slippage of the prestressed steel strands, protecting on-site personnel and equipment. The components used in the device are of standard dimensions and mechanically connected, allowing for assembly via a modular installation method. Installation and disassembly are convenient, and the device can be reused multiple times. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a structural diagram of the device of the present invention.

[0032] Figure 2 This is a structural diagram of a general segment.

[0033] Figure 3 This is a cross-sectional structural diagram of the device of the present invention.

[0034] Figure 4 This is a diagram of the end structure of a general segment.

[0035] Figure 5 This is an elevation view of the adjustable-size segment.

[0036] Figure 6 This is a cross-sectional structural diagram of an adjustable-size segment.

[0037] The diagram is labeled as follows:

[0038] 1-External prestressed protective pipe, 2-Transverse connecting bolt hole, 3-Longitudinal connecting flange, 4-Longitudinal stiffening rib, 5-External prestressed steel strand, 6-External prestressed anchor plate, 7-Transverse positioning stiffening rib, 8-Longitudinal connecting bolt hole, 10-Anchor nut.

[0039] A - Freely expandable section, B - Fixed section. Detailed Implementation

[0040] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0041] In the description of this invention, it should be understood that the terms "top", "bottom", "inner", "outer", "longitudinal", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "setting," etc., should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] In a specific implementation, the length direction of the external prestressed protective pipe 1 is defined as longitudinal, and the direction perpendicular to the longitudinal direction is defined as transverse.

[0044] like Figure 1 This invention provides a protective device for external prestressing tensioning of steel strands in bridge structural model tests. The device includes an external prestressing protective pipe 1, into which external prestressing steel strands 5 are inserted. External prestressing anchor plates 6 are provided at both ends of the external prestressing protective pipe 1, and the two ends of the external prestressing steel strands 5 pass through the external prestressing anchor plates 6 and are anchored by anchoring nuts 10.

[0045] The inner wall of the external prestressed protective pipe 1 is provided with annular transverse positioning stiffening ribs 7, and the external prestressed steel strands 5 are located within the transverse positioning stiffening ribs 7. The transverse positioning stiffening ribs 7 can prevent the external prestressed protective pipe 1 from contacting the external prestressed steel strands 5 due to inconsistent deflection, thus preventing frictional loss of the external prestressed steel strands 5 and affecting the prestressing effect. It can also ensure the relative position between the external prestressed protective pipe 1 and the external prestressed steel strands 5.

[0046] The external prestressed protective pipe 1 includes several general-purpose segments. The end edges of the general-purpose segments are provided with longitudinal connecting flanges 3, and the longitudinal connecting flanges 3 are provided with longitudinal connecting bolt holes 8. The longitudinal connecting flanges 3 of adjacent general-purpose segments are connected and fixed to each other by inserting bolts into the longitudinal connecting bolt holes 8.

[0047] like Figure 2-4 The general-purpose segment consists of two semi-circular tubes, using two semi-circular aluminum alloy tubes of a certain thickness to reduce weight; the thickness can be 3mm. The outer wall of the semi-circular tubes is provided with radial longitudinal stiffening ribs 4, spaced at 60° intervals. Transverse connecting bolt holes 2 are provided on the longitudinal stiffening ribs 4 at the ends of the semi-circular tubes. The two semi-circular tubes are joined together, and bolts are inserted into the transverse connecting bolt holes 2 to connect and fix them together.

[0048] Because the thickness of the transverse positioning stiffening rib 7 is small, the friction between it and the external prestressed steel strand 5 is negligible, and therefore, it has no effect on the application of external prestress.

[0049] For ease of assembly and disassembly and versatility, the protective device uses a standard length, with each pair of sections connected by bolts via flanges. The universal sections are available in multiple models based on length, such as 50cm, 100cm, and 200cm standard sections. Multiple universal sections of different models can be connected to form an external prestressed protective pipe 1.

[0050] like Figure 5-6 The external prestressed protective pipe 1 also includes adjustable-size segments, which include an outer pipe and an inner pipe. The inner pipe is inserted into the outer pipe and moves longitudinally. The fixed length is 100cm, and the maximum free extension is 50cm, that is, the fixed section B is 100cm long and the free extension section A is 50cm long. The inner pipe is 2mm thick, one end is inserted into the outer pipe, and the other end is provided with a longitudinal connecting flange 3. The outer pipe is 3mm thick and consists of two semi-circular outer pipes. The outer wall of the semi-circular outer pipe is provided with radial longitudinal stiffening ribs 4. The longitudinal stiffening ribs 4 located at the ends of the semi-circular outer pipes are provided with transverse connecting bolt holes 2. The two semi-circular outer pipes are joined together, and bolts are inserted into the transverse connecting bolt holes 2 to connect and fix them to each other. One end of the outer pipe is provided with a longitudinal connecting flange 3, and the longitudinal connecting flange 3 is provided with longitudinal connecting bolt holes 8.

[0051] The outer wall of the inner tube is provided with a slide rail, and the inner wall of the outer tube is provided with a longitudinal slide groove 9, with the slide rail located within the longitudinal slide groove 9.

[0052] A limiting device is installed between the outer tube and the inner tube. The limiting device can be a pin hole or a pin, which can fix the relative position of the outer tube and the inner tube so that the position of the protective device can be adjusted after the steel strand tensioning is completed.

[0053] This invention also provides a method for protecting steel strands under external prestressing tension in bridge structural model tests. The method is implemented based on the aforementioned device and includes:

[0054] S1: Casting concrete beam;

[0055] S2: Install external prestressed steel strands 5;

[0056] S3: Install external prestressed protective pipe 1;

[0057] S4: Tensioning and anchoring solid external prestressed steel strands 5;

[0058] S5: Adjust the adjustable size segment.

[0059] The device of this invention can effectively prevent sudden breakage or slippage of prestressed steel strands during external prestressing tensioning in experiments, thus protecting on-site personnel and equipment. The components used in the device are of standard dimensions and are mechanically connected, allowing for assembly via a modular installation method. Installation and disassembly are convenient, and the device can be reused multiple times.

[0060] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A protective device for external prestressing tensioning of steel strands in bridge structural model tests, characterized in that: The device includes an external prestressed protective tube (1), into which an external prestressed steel strand (5) is inserted. The external prestressed protective pipe (1) is provided with external prestressed anchor plates (6) at both ends, and the external prestressed steel strands (5) pass through the external prestressed anchor plates (6) and are anchored by anchor nuts (10). The inner wall of the external prestressed protective pipe (1) is provided with an annular transverse positioning stiffening rib (7), and the external prestressed steel strand (5) is located inside the transverse positioning stiffening rib (7). The external prestressed protective pipe (1) includes several general segments, and the end edge of the general segments is provided with a longitudinal connecting flange (3), and the longitudinal connecting flange (3) is provided with a longitudinal connecting bolt hole (8). The longitudinal connecting flanges (3) of adjacent general sections are connected and bolts are inserted into the longitudinal connecting bolt holes (8) to connect and fix them to each other; The general segment consists of two semicircular tubes, and the outer wall of the semicircular tubes is provided with radial longitudinal stiffening ribs (4). A transverse connecting bolt hole (2) is provided on the longitudinal stiffening rib (4) located at the end of the semi-circular tube. The two semi-circular tubes are joined together, and bolts are inserted into the transverse connecting bolt hole (2) to connect and fix them to each other.

2. The external prestressing tensioning protection device for steel strands in bridge structural model tests according to claim 1, characterized in that: The general-purpose segments are divided into multiple models according to different lengths, and multiple general-purpose segments of different models are connected to form the external prestressed protective pipe (1).

3. The external prestressing tension protection device for steel strands in bridge structural model tests according to claim 2, characterized in that: The external prestressed protective pipe (1) also includes an adjustable size segment, which includes an outer pipe and an inner pipe, wherein the inner pipe is inserted into the outer pipe and moves longitudinally.

4. The external prestressing tension protection device for steel strands in bridge structural model tests according to claim 3, characterized in that: One end of the inner tube is inserted into the outer tube, and the other end is provided with a longitudinal connecting flange (3).

5. The external prestressing tension protection device for steel strands in bridge structural model tests according to claim 4, characterized in that: The outer tube is composed of two semi-circular outer tubes, and the outer wall of the semi-circular outer tubes is provided with radial longitudinal stiffening ribs (4). A transverse connecting bolt hole (2) is provided on the longitudinal stiffening rib (4) located at the end of the semi-circular outer tube. The two semi-circular outer tubes are joined together, and bolts are inserted into the transverse connecting bolt hole (2) to connect and fix them to each other. One end of the outer tube is provided with a longitudinal connecting flange (3), and the longitudinal connecting flange (3) is provided with longitudinal connecting bolt holes (8).

6. The external prestressing tension protection device for steel strands in bridge structural model tests according to claim 5, characterized in that: The outer wall of the inner tube is provided with a slide rail, and the inner wall of the outer tube is provided with a longitudinal slide groove (9), and the slide rail is located in the longitudinal slide groove (9).

7. The external prestressing tension protection device for steel strands in bridge structural model tests according to claim 6, characterized in that: A limit device is provided between the outer tube and the inner tube.

8. A method for protecting steel strands under external prestressing tension in bridge structural model tests, characterized by: The method is implemented based on the apparatus of claim 7, and includes: Cast concrete beams; Install external prestressed steel strands (5); Install external prestressed protective pipe (1); Tensioning and anchoring solid external prestressed steel strands (5); Adjust the adjustable size segment.

Images