A structure and method for improving the crack resistance of the joint section of a simply supported and then continuous bridge

Abstract

The present invention discloses a structure and method for improving the crack resistance of a bridge joint section that is simply supported first and then continuous. The structure includes: a bridge pier; a first precast concrete beam and a second precast concrete beam erected on the bridge pier, the first precast concrete beam having a first stress-bearing steel bar extension section in the tension zone, the second precast concrete beam having a second stress-bearing steel bar extension section in the tension zone, the first stress-bearing steel bar having a second stress-bearing steel bar extension section, the first stress-bearing steel bar extension section and the second stress-bearing steel bar extension section connected; an isolator, the isolator being arranged outside the first stress-bearing steel bar extension section and the second stress-bearing steel bar extension section; a cast-in-place concrete joint section, the cast-in-place concrete joint section being arranged on the bridge pier and being cast by high-performance concrete between the first precast concrete beam and the second precast concrete beam. The structure for improving the crack resistance of a bridge joint section that is simply supported first and then continuous has good crack resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and in particular to a structure for improving the anti-cracking performance of a simply-supported-then-continuous bridge joint section and a construction method for the structure for improving the anti-cracking performance of a simply-supported-then-continuous bridge joint section. Background Art

[0002] At present, the construction of urban rail transit in my country is developing rapidly. One of the design and construction methods of rail transit bridges is to simply support first and then make it continuous to obtain better smoothness and comfort. However, during the service stage, under the action of vehicle load, the top of the cast-in-place concrete joint section is tensile and prone to cracking. The tensile zone of the cast-in-place concrete joint section has poor crack resistance. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to propose a structure for improving the crack resistance of a bridge joint section that is first simply supported and then continuous, wherein the cast-in-place concrete joint section of the structure for improving the crack resistance of a bridge joint section that is first simply supported and then continuous has good crack resistance.

[0004] The present invention also proposes a construction method for improving the crack resistance of a simply supported and then continuous bridge joint section.

[0005] According to the first aspect of the present invention, a structure for improving the crack resistance of a simply supported and then continuous bridge joint section comprises: a bridge pier; a first precast concrete beam and a second precast concrete beam, wherein the first precast concrete beam and the second precast concrete beam, one end of each of which is adjacent to each other, are both mounted on the bridge pier; a first stress-bearing steel bar is provided in a tension zone of the first precast concrete beam, and one end of the first stress-bearing steel bar adjacent to the second precast concrete beam extends out of the end of the first precast concrete beam to form an extended section of the first stress-bearing steel bar; a second stress-bearing steel bar is provided in a tension zone of the second precast concrete beam, and one end of the second stress-bearing steel bar adjacent to the first precast concrete beam extends out of the second precast concrete beam The end of the precast concrete beam is used to form a second stressed steel bar extension section, and the first stressed steel bar extension section and the second stressed steel bar extension section are connected; an isolation member, which is arranged on the outside of the first stressed steel bar extension section and the second stressed steel bar extension section; a cast-in-place concrete combining section, which is arranged on the pier and is formed between the first precast concrete beam and the second precast concrete beam by casting high-performance concrete, and the first stressed steel bar extension section, the second stressed steel bar extension section and the isolation member are embedded in the cast-in-place concrete combining section, wherein the elastic modulus of the isolation member is lower than the elastic modulus of the cast-in-place concrete combining section.

[0006] According to the structure of improving the crack resistance of the simply supported and then continuous bridge joint section of the present invention, the stress of the concrete can be effectively reduced by partially destroying the bond between the steel bars and the concrete through the isolation piece, and at the same time, high-performance concrete is locally used to improve its crack resistance.

[0007] In addition, the structure for improving the crack resistance of the simply supported and then continuous bridge joint section according to the embodiment of the present invention may also have the following additional technical features:

[0008] According to an embodiment of the present invention, the isolation member is a rubber member.

[0009] According to an embodiment of the present invention, the isolation piece is a polyethylene plastic piece.

[0010] According to one embodiment of the present invention, the cast-in-place concrete connecting section is formed by pouring ECC concrete.

[0011] According to one embodiment of the present invention, the cast-in-place concrete connecting section is formed by pouring UHPC concrete.

[0012] According to one embodiment of the present invention, the isolation member is constructed as a sleeve, and an opening is arranged on the tube wall of the sleeve, the opening extends along the axial direction of the sleeve and penetrates the sleeve in the axial direction, and the sleeve is suitable for being buckled on the outer side of the first stressed steel bar extending section and the second stressed steel bar extending section through the opening.

[0013] According to one embodiment of the present invention, the isolation member includes a first sub-isolator and a second sub-isolator formed in an arc shape, the first sub-isolator and the second sub-isolator are both arranged on the outside of the first stressed steel bar extending section and the second stressed steel bar extending section, and the first sub-isolator and the second sub-isolator are connected to splice to form a sleeve.

[0014] According to an embodiment of the present invention, the isolation member is formed as a flexible membrane, and the flexible membrane is wrapped around the outer sides of the first stressed steel bar extended section and the second stressed steel bar extended section.

[0015] According to the second aspect of the present invention, the construction method of the structure for improving the crack resistance of the first simply supported and then continuous bridge joint section is the structure for improving the crack resistance of the first simply supported and then continuous bridge joint section according to the first aspect of the present invention, and the construction method comprises the following steps:

[0016] S01: erecting the first precast concrete beam and the second precast concrete beam on the bridge pier;

[0017] S02: connecting the first stressed steel bar extension section and the second stressed steel bar extension section together;

[0018] S03: Arranging the isolation member on the outer sides of the first stressed steel bar extended section and the second stressed steel bar extended section;

[0019] S04: installing a template for casting the cast-in-place concrete joining section between the first precast concrete beam and the second precast concrete beam, and casting concrete to form the cast-in-place concrete joining section.

[0020] According to the construction method of the structure for improving the crack resistance of the simply supported and then continuous bridge joint section according to the embodiment of the present invention, the cast-in-place concrete joint section of the structure for improving the crack resistance of the simply supported and then continuous bridge joint section formed by the construction method has good crack resistance in the tensile zone.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 is a schematic structural diagram of a structure for improving the crack resistance of a simply-supported-then-continuous bridge joint section according to an embodiment of the present invention;

[0024] Figure 2 yes Figure 1 The cross-sectional view along line AA of the structure shown in FIG. 1 for improving the crack resistance of the simply supported then continuous bridge joint segment.

[0025] Reference numerals:

[0026] Improve the crack resistance of the joint section of the simply supported and then continuous bridge structure 100;

[0027] Pier 1;

[0028] A first precast concrete beam 2; a first stress-bearing steel bar 21; a first stress-bearing steel bar extension section 211;

[0029] A second precast concrete beam 3; a second stress-bearing steel bar 31; a second stress-bearing steel bar extension section 311;

[0030] Isolation member 4;

[0031] Cast-in-place concrete joint section 5. DETAILED DESCRIPTION

[0032] 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.

[0033] Reference below Figure 1-Figure 2 A structure 100 for improving the crack resistance of a simply-supported-then-continuous bridge joint section according to an embodiment of the first aspect of the present invention is described.

[0034] refer to Figure 1-Figure 2 As shown, the structure 100 for improving the crack resistance of the simply supported and then continuous bridge joint section according to an embodiment of the present invention includes: a pier 1, a first precast concrete beam 2, a second precast concrete beam 3, an isolation member 4 and a cast-in-place concrete joint section 5.

[0035] The first precast concrete beam 2 and the second precast concrete beam 3 are both mounted on the pier 1 at one end adjacent to each other. Specifically, Figure 1 As shown in the figure, the first precast concrete beam 2 and the second precast concrete beam 3 both extend in the left-right direction, the first precast concrete beam 2 is arranged on the left side of the second precast concrete beam 3, and the right end of the first precast concrete beam 2 and the left end of the second precast concrete beam 3 are both mounted on the pier 1. The first precast concrete beam 2 is provided with a first stress-bearing steel bar 21 in the tension zone, and one end of the first stress-bearing steel bar 21 adjacent to the second precast concrete beam 3 extends out of the end of the first precast concrete beam 2 to form a first stress-bearing steel bar extension section 211, the second precast concrete beam 3 is provided with a second stress-bearing steel bar 31 in the tension zone, and one end of the second stress-bearing steel bar 31 adjacent to the first precast concrete beam 2 extends out of the end of the second precast concrete beam 3 to form a second stress-bearing steel bar extension section 311, and the first stress-bearing steel bar extension section 211 and the second stress-bearing steel bar extension section 311 are connected to form a multi-span simply supported stress-bearing system.

[0036] It can be understood that the structure 100 for improving the crack resistance of the simply supported and then continuous bridge joint section includes multiple precast concrete beams, and the number of precast concrete beams can be two, or three, four or more. The "first precast concrete beam 2" and the "second precast concrete beam 3" in the present application refer to two precast concrete beams adjacent to each other among the multiple precast concrete beams. The precast concrete beam on the left side of any two adjacent precast concrete beams can be called the "first precast concrete beam 2", and the precast concrete beam on the right side can be called the "second precast concrete beam 3".

[0037] The isolation member 4 is arranged on the outside of the first stressed steel bar extension section 211 and the second stressed steel bar extension section 311. The cast-in-place concrete connecting section 5 is arranged on the pier 1 and is formed between the first precast concrete beam 2 and the second precast concrete beam 3 by casting high-performance concrete. The first stressed steel bar extension section 211, the second stressed steel bar extension section 311 and the isolation member 4 are embedded in the cast-in-place concrete connecting section 5, wherein the elastic modulus of the isolation member 4 is lower than the elastic modulus of the cast-in-place concrete connecting section 5.

[0038] The cast-in-place concrete joint section 5 serves to connect the first precast concrete beam 2 and the second precast concrete beam 3, thereby realizing the system conversion from simple support to continuous support. By setting the isolator 4 on the outside of the first stress-bearing steel bar extension section 211 and the second stress-bearing steel bar extension section 311, the bonding effect of the connection interface between the first stress-bearing steel bar extension section 211 and the second stress-bearing steel bar extension section 311 and the cast-in-place concrete joint section 5 can be destroyed. By partially releasing the bonding between the steel bar and the concrete at the key position, the tensile force that should be borne by the concrete and the steel bar is transferred to the steel bar, which greatly reduces the tensile stress of the cast-in-place concrete joint section 5 in the negative bending moment zone and improves the crack resistance of the tensile zone of the cast-in-place concrete joint section 5.

[0039] Among them, the isolation piece 4 is low-priced, suitable for mass production in factories, and does not require additional processes during the construction phase. It only needs to be buckled on the tensile steel bars of the cast-in-place concrete joint section 5, which makes it easy to ensure the quality of the project.

[0040] According to the embodiment of the present invention, the structure 100 for improving the crack resistance of the simply supported and then continuous bridge joint section, through the new ideas of "combining resistance and release" and "making the best use of resources", partially releases the bonding force between the steel bars in the tension zone and the cast-in-place concrete joint section 5 to reduce the tensile stress in the concrete of the cast-in-place concrete joint section 5, thereby improving the crack resistance of the tensile zone of the cast-in-place concrete joint section 5, and is easy to construct and low in cost.

[0041] In an optional embodiment of the present invention, the isolation member 4 is a rubber member, that is, the isolation member 4 is made of a rubber material, and the elastic modulus of the rubber material is much lower than that of the concrete material.

[0042] In another optional embodiment of the present invention, the isolation member 4 is a polyethylene plastic member, that is, the isolation member 4 is made of polyethylene plastic material, and the elastic modulus of the polyethylene plastic material is much lower than that of the concrete material.

[0043] Preferably, the cast-in-place concrete joint section 5 is formed by casting high-performance concrete, which refers to concrete with higher tensile strength than ordinary concrete. For example, the cast-in-place concrete joint section 5 is formed by casting ECC concrete or the cast-in-place concrete joint section 5 is formed by casting UHPC concrete. By casting the cast-in-place concrete joint section 5 by high-performance concrete, the tensile performance of the cast-in-place concrete joint section 5 can be further improved.

[0044] In one embodiment of the present invention, the spacer 4 is configured as a sleeve, and an opening is provided on the wall of the sleeve, the opening extends along the axial direction of the sleeve and penetrates the sleeve in the axial direction, and the sleeve is suitable for being buckled through the opening on the outside of the first stressed steel bar extension section 211 and the second stressed steel bar extension section 311. This facilitates the spacer 4 to be arranged on the outside of the first stressed steel bar extension section 211 and the second stressed steel bar extension section 311.

[0045] In one embodiment of the present invention, the isolator 4 includes a first sub-isolator and a second sub-isolator formed in an arc shape, and the first sub-isolator and the second sub-isolator are both arranged outside the first stressed steel bar extension section 211 and the second stressed steel bar extension section 311, and the first sub-isolator and the second sub-isolator are connected to form a sleeve. This makes it convenient to arrange the isolator 4 outside the first stressed steel bar extension section 211 and the second stressed steel bar extension section 311. Among them, the connection method of the first sub-isolator and the second sub-isolator can be arbitrarily selected according to needs. For example, the first sub-isolator and the second sub-isolator can be connected by rope binding, or can be connected by threaded fasteners, or can be connected by glue bonding, etc.

[0046] In one embodiment of the present invention, the isolation member 4 is formed as a flexible membrane, such as a rubber membrane or a plastic membrane, and the flexible membrane is wrapped around the outside of the first stress-bearing steel bar extension section 211 and the second stress-bearing steel bar extension section 311. This facilitates the isolation member 4 to be disposed outside the first stress-bearing steel bar extension section 211 and the second stress-bearing steel bar extension section 311.

[0047] The construction method of the structure 100 for improving the crack resistance of the first simply supported and then continuous bridge joint section according to the second embodiment of the present invention is used to construct the structure 100 for improving the crack resistance of the first simply supported and then continuous bridge joint section according to the first embodiment of the present invention, and the construction method comprises the following steps:

[0048] S01: erecting the first precast concrete beam 2 and the second precast concrete beam 3 on the pier 1;

[0049] S02: Connecting the first stress-bearing steel bar extension section 211 and the second stress-bearing steel bar extension section 311 together to form a multi-span simply supported stress-bearing system;

[0050] S03: Disposing a spacer 4 outside the first stressed steel bar extension section 211 and the second stressed steel bar extension section 311 to destroy the bonding effect of the connection interface between the steel bar and the cast-in-place concrete connection section 5;

[0051] S04: installing a template for casting a cast-in-place concrete joint section 5 between the first precast concrete beam 2 and the second precast concrete beam 3, and pouring concrete to form a cast-in-place concrete joint section 5, completing the system conversion from simple support to continuous support.

[0052] According to the construction method of the structure 100 for improving the crack resistance of the simply-supported and then continuous bridge joint section according to the embodiment of the present invention, the cast-in-place concrete joint section 5 of the structure 100 for improving the crack resistance of the simply-supported and then continuous bridge joint section formed by the construction method has good crack resistance in the tensile zone.

[0053] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0054] In the description of the present invention, the features of “the first precast concrete beam 2 ” and “the second precast concrete beam 3 ” may explicitly or implicitly include one or more corresponding features.

[0055] In the description of the present invention, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0056] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] In the description of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0059] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A structure for improving the crack resistance of a bridge joint section that is simply supported and then continuous, characterized in that: include: bridge piers; a first precast concrete beam and a second precast concrete beam, wherein the first precast concrete beam and the second precast concrete beam have adjacent ends thereof both mounted on the pier, a first stress-bearing steel bar is provided in a tension zone of the first precast concrete beam, an end of the first stress-bearing steel bar adjacent to the second precast concrete beam extends out of an end portion of the first precast concrete beam to form a first stress-bearing steel bar extension section, a second stress-bearing steel bar is provided in a tension zone of the second precast concrete beam, an end of the second stress-bearing steel bar adjacent to the first precast concrete beam extends out of an end portion of the second precast concrete beam to form a second stress-bearing steel bar extension section, and the first stress-bearing steel bar extension section is connected to the second stress-bearing steel bar extension section; A spacer, the spacer is arranged outside the first stressed steel bar extended section and the second stressed steel bar extended section, the spacer includes a first sub-spacer and a second sub-spacer formed in an arc shape, the first sub-spacer and the second sub-spacer are both arranged outside the first stressed steel bar extended section and the second stressed steel bar extended section, and the first sub-spacer and the second sub-spacer are connected to form a sleeve; a cast-in-place concrete combining section, wherein the cast-in-place concrete combining section is arranged on the pier and is formed between the first precast concrete beam and the second precast concrete beam by casting high-performance concrete, wherein the first stress-bearing steel bar extending section, the second stress-bearing steel bar extending section and the spacer are embedded in the cast-in-place concrete combining section, wherein the elastic modulus of the spacer is lower than the elastic modulus of the cast-in-place concrete combining section; The isolating member is a rubber member; or, The isolating piece is a polyethylene plastic piece.

2. The structure for improving the crack resistance of the simply supported and then continuous bridge joint section according to claim 1 is characterized in that: The isolation member is formed as a flexible membrane, and the flexible membrane is wrapped around the outer sides of the first stressed steel bar extended section and the second stressed steel bar extended section.

3. The structure for improving the crack resistance of the simply supported and then continuous bridge joint section according to claim 1 is characterized in that: The cast-in-place concrete joint section is formed by pouring ECC concrete.

4. The structure for improving the crack resistance of the simply supported and then continuous bridge joint section according to claim 1 is characterized in that: The cast-in-place concrete joint section is formed by pouring UHPC concrete.

5. A construction method for improving the crack resistance of a bridge joint section that is first simply supported and then continuous, characterized in that: The structure for improving the crack resistance of the first simply supported and then continuous bridge joint section is the structure for improving the crack resistance of the first simply supported and then continuous bridge joint section according to any one of claims 1 to 4, and the construction method comprises the following steps: S01: erecting the first precast concrete beam and the second precast concrete beam on the bridge pier; S02: connecting the first stressed steel bar extension section and the second stressed steel bar extension section together; S03: Arranging the isolation member on the outer sides of the first stressed steel bar extended section and the second stressed steel bar extended section; S04: installing a template for casting the cast-in-place concrete joining section between the first precast concrete beam and the second precast concrete beam, and casting concrete to form the cast-in-place concrete joining section.

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