Elastic cable mat rockfill structure and construction method and design method thereof

Abstract

The application relates to a flexible cable cushion stone structure, which comprises a first reinforcing bar area formed by binding a plurality of first reinforcing bars on a lower beam of a main tower of a cable-stayed bridge; a pre-buried pipe installed in the first reinforcing bar area, wherein a flexible cable is arranged in the pre-buried pipe; anchor cushion plates installed at two ends of the pre-buried pipe; a plurality of rows of perforated steel plates installed on the lower beam; through reinforcing bars penetrating through the perforated steel plates; and a cushion stone concrete area formed by pouring cushion stone concrete into the first reinforcing bar area. The application provides a flexible cable cushion stone structure, a construction method and a design method of the flexible cable cushion stone structure. The perforated steel plates and the through reinforcing bars penetrating through the perforated steel plates are installed on the lower beam, the perforated steel plates and the through reinforcing bars penetrating through the perforated steel plates ensure that the flexible cable cushion stone structure itself can bear the shearing force of the flexible cable, and the shearing force of the flexible cable can be transmitted to the lower beam in a vertical direction, so that the problem of the reduction of the shearing bearing capacity caused by the post-pouring of the cushion stone concrete is solved.

Description

Technical Field

[0001] This application relates to the field of bridge engineering technology, and in particular to an elastic cable-stayed stone structure, its construction method, and design method. Background Technology

[0002] To reduce seismic response, long-span cable-stayed bridges generally employ a fully floating system. Under external loads, these bridge systems are prone to significant longitudinal displacement at the beam ends. To accommodate bridge deformation, large-scale beam-end expansion joints are required. However, large-scale beam-end expansion joints are difficult to manufacture, and the joints themselves often become a major reason for speed limits on high-speed railway bridges.

[0003] In related technologies, longitudinal elastic cable restraint systems are often used to control beam end displacement without significantly increasing seismic response. In longitudinal elastic cable restraint systems, the elastic cables are usually fixed to the lower crossbeam of the main tower of the cable-stayed bridge through elastic cable bearing structures.

[0004] The elastic cable pad stone structure, located on the lower crossbeam of the main tower of the cable-stayed bridge, is subject to the longitudinal shear force transmitted by the elastic cable and is an important load-bearing component. To ensure the load-bearing performance of the concrete and the construction quality, during construction, the elastic cable pad stone structure (such as the embedded pipe and anchor plate with built-in elastic cable) is generally hoisted as a whole to the position of the lower crossbeam of the main tower of the cable-stayed bridge. Then, the lower crossbeam and the elastic cable pad stone concrete are cast in one piece on site, thereby fixing the elastic cable to the lower crossbeam.

[0005] When on-site construction space is limited and it is difficult to pour the lower crossbeam and elastic cable pad concrete in one piece, it is often necessary to pour the elastic cable pad concrete later. However, the later-poured concrete will have a significant impact on its shear resistance. Summary of the Invention

[0006] This application provides an elastic cable pad structure, its construction method, and design method to solve the technical problems in related technologies where the shear resistance of the elastic cable pad is affected by the limited on-site construction space and the post-casting of the elastic cable pad concrete.

[0007] The first aspect of this application provides an elastic cable cushion structure, which includes:

[0008] The first reinforcement zone is formed by binding several first reinforcement bars to the lower crossbeam of the cable-stayed main tower;

[0009] An embedded pipe is installed within the first reinforcing steel zone, and the embedded pipe contains an elastic cable.

[0010] Anchor plates are installed at both ends of the pre-embedded pipe;

[0011] Perforated steel plates, and several rows of the perforated steel plates are installed on the lower crossbeam;

[0012] A through-bar, wherein the through-bar penetrates the perforated steel plate;

[0013] The pad concrete zone is formed by pouring pad concrete into the first reinforcement zone.

[0014] In some embodiments, several rows of perforated steel plates are evenly spaced.

[0015] In some embodiments, the perforated steel plate is a comb-shaped perforated steel plate.

[0016] In some embodiments, a plurality of second reinforcing bars are tied to the lower crossbeam to form a second reinforcing bar zone;

[0017] The perforated steel plate includes a comb plate and a plurality of comb teeth disposed on one side of the comb plate. The comb plate has a plurality of through holes for the through reinforcing bars to pass through, and the comb teeth are inserted into the second reinforcing bar area.

[0018] In some embodiments, the spacing of the comb teeth is the same as the spacing of the second reinforcing bar on the lower crossbeam.

[0019] In some embodiments, the gaps between the comb teeth are 2mm-5mm larger than the diameter of the second reinforcing bar on the lower crossbeam.

[0020] The second aspect of this application provides a construction method for an elastic cable-stayed stone structure, comprising:

[0021] Several second reinforcing bars are tied at the lower crossbeam position of the main tower of the cable-stayed structure to form a second reinforcing bar zone;

[0022] Several rows of perforated steel plates are inserted in the second reinforcing bar area, and through reinforcing bars pass through the perforated steel plates;

[0023] A portion of the first reinforcing steel is pre-embedded and tied in the second reinforcing steel zone;

[0024] Concrete is poured in the second reinforced zone to form the lower crossbeam;

[0025] The remaining first reinforcing bars are tied to form a first reinforcing bar area, and a pre-embedded pipe with built-in elastic cable and anchor plates at both ends of the pre-embedded pipe are installed in the first reinforcing bar area.

[0026] Pour concrete for the pad stone in the first reinforced steel zone to form the pad stone concrete zone, thus completing the construction of the elastic cable pad stone structure.

[0027] A third aspect of this application provides a design method for an elastic cable cushion stone structure, comprising:

[0028] A finite element model of a cable-stayed bridge was established, and loads were applied to obtain the shear design value of the elastic cable-stayed bridge structure.

[0029] Determine the diameter of the through holes in the perforated steel plate and the diameter of the through reinforcing bars to obtain the design value of the shear bearing capacity of a single through hole and the total number of through holes;

[0030] Determine the dimensions of the perforated steel plate.

[0031] In some embodiments, the design value V of the shear bearing capacity of a single through hole is obtained. pud hour,

[0032] The calculation formula is: V pud =1.4 (d) 2 -d s 2 f cd +1.2d s 2 f sd ;

[0033] Where d is the diameter of the through hole in the perforated steel plate, d s f is the diameter of the through-bar. cd f is the design value of the axial compressive strength of the elastic cable pad concrete. sd This is the design value for the tensile strength of the through-bar reinforcement.

[0034] In some embodiments, determining the dimensions of the perforated steel plate includes:

[0035] The minimum edge spacing between two adjacent through holes in the perforated steel plate is determined according to the stress requirements;

[0036] Determine the center distance between two adjacent through holes in the perforated steel plate;

[0037] The number of openings in a single perforated steel plate is determined by the length of the perforated steel plate and the center distance between two adjacent through holes.

[0038] The number of perforated steel plates is determined based on the number of holes in a single perforated steel plate and the total number of through holes.

[0039] The beneficial effects of the technical solution provided in this application include:

[0040] This application provides an elastic cable pad stone structure, in which perforated steel plates and through-steel bars are installed on the lower crossbeam. The perforated steel plates and through-steel bars ensure that the elastic cable pad stone structure itself can withstand the shear force of the elastic cables and can transfer the shear force of the elastic cables longitudinally downward to the lower crossbeam, thereby solving the problem of reduced shear bearing capacity caused by post-casting of pad stone concrete. Since the shear bearing capacity is guaranteed, the anchor plates, embedded pipes and pad stone concrete in the elastic cable pad stone structure can all be constructed later, reserving construction space, reducing the number of times construction equipment needs to be changed and shortening the project period. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the elastic cable pad stone structure in the longitudinal direction of a bridge according to an embodiment of the present invention.

[0043] Figure 2 This is a schematic diagram of the transverse structure of an elastic cable pad stone structure in one embodiment of the present invention.

[0044] Figure 3 This is a schematic diagram of the reinforcement arrangement along the bridge direction in an embodiment of the elastic cable pad stone structure.

[0045] Figure 4 This is a schematic diagram of the transverse reinforcement arrangement of an elastic cable-stayed stone structure in one embodiment of the present invention.

[0046] Figure 5 This is a schematic diagram of the structure of a perforated steel plate in one embodiment of the present invention.

[0047] Figure 6 This is a flowchart illustrating the construction steps of an elastic cable pad stone structure according to an embodiment of the present invention.

[0048] Figure 7 This is a flowchart illustrating the design steps of an elastic cable cushion stone structure according to an embodiment of the present invention.

[0049] Figure label:

[0050] 1. Elastic cable pad stone structure; 11. First reinforcing bar; 12. Embedded pipe; 13. Anchor plate; 14. Perforated steel plate; 141. Comb plate; 142. Comb teeth; 143. Through hole; 15. Through reinforcing bar; 16. Pad stone concrete; 2. Lower crossbeam. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0052] like Figures 1 to 4 As shown, where, Figure 1This is a schematic diagram of the elastic cable pad stone structure in the longitudinal direction of a bridge according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the transverse structure of an elastic cable pad stone structure in one embodiment of the present invention. Figure 3 This is a schematic diagram of the reinforcement arrangement along the bridge direction in an embodiment of the elastic cable pad stone structure. Figure 4 This is a schematic diagram of the transverse reinforcement arrangement of an elastic cable-stayed stone structure in one embodiment of the present invention.

[0053] This application provides an elastic cable pad structure 1, which is arranged on the lower crossbeam 2 of the main cable tower.

[0054] Elastic cable pad stone structure 1 includes:

[0055] The first reinforcement zone is formed by binding several first reinforcement bars 11 to the lower crossbeam 2 of the cable-stayed main tower;

[0056] The embedded pipe 12 is installed in the first reinforcement zone 11, and the embedded pipe 12 has an internal elastic cable.

[0057] Anchor plates 13 are installed at both ends of the pre-embedded pipe 12;

[0058] Perforated steel plate 14, several rows of perforated steel plates 14 are installed on the lower crossbeam 2;

[0059] Through-through steel bar 15, through-through steel bar 15 penetrates through perforated steel plate 14;

[0060] The pad concrete zone is formed by pouring pad concrete 16 into the first reinforcement zone.

[0061] This application provides an elastic cable pad stone structure, in which a perforated steel plate and a through-bar reinforcing bar are installed on the lower crossbeam. The perforated steel plate and the through-bar reinforcing bar ensure that the elastic cable pad stone structure itself can withstand the shear force of the elastic cable and can transfer the shear force of the elastic cable to the lower crossbeam longitudinally, thereby solving the problem of reduced shear bearing capacity caused by post-casting of pad stone concrete. Since the shear bearing capacity is guaranteed, the anchor plate, embedded pipe and pad stone concrete in the elastic cable pad stone structure can be constructed later, leaving space for construction operations, reducing the number of times construction equipment needs to be changed and shortening the project period.

[0062] Several second reinforcing bars (not shown in the figure) are tied to the lower crossbeam 2 to form a second reinforcing bar zone. The second reinforcing bars are ordinary reinforcing bars.

[0063] like Figure 3 and Figure 4 As shown, several first reinforcing bars 11 are tied together in a crisscross pattern to form the first reinforcing bar area. The first reinforcing bars 11 are ordinary reinforcing bars.

[0064] The embedded pipe 12 has an internal elastic cable, and the anchor plates 13 are installed at both ends of the embedded pipe 12. The anchor plates 13 tension the elastic cable to distribute the concentrated force at the anchoring position.

[0065] The first reinforcing bar 11, the embedded pipe 12, the anchor plate 13, and the pad concrete 16 are existing technologies and will not be described in detail here.

[0066] Several rows of perforated steel plates 14 are installed on the lower crossbeam 2, with some inserted into the lower crossbeam 2 and others located in the concrete pad area. The height of both parts is not less than 30cm to ensure the smooth transmission of the elastic cable shear force.

[0067] In some embodiments, a plurality of rows of perforated steel plates 14 are evenly spaced. Of course, in other embodiments, the spacing, length, and position of the plurality of rows of perforated steel plates 14 can be adjusted according to the actual construction conditions.

[0068] Preferably, when multiple rows of perforated steel plates 14 are arranged, the distance between two adjacent perforated steel plates 14 is not less than three times the height of the portion of the plate located in the concrete pad.

[0069] like Figure 5 As shown, Figure 5 This is a schematic diagram of the structure of a perforated steel plate in one embodiment of the present invention.

[0070] In some embodiments, the perforated steel plate 14 is a comb-shaped perforated steel plate. This facilitates insertion onto the lower crossbeam 2 and ensures smooth transmission of the elastic cable shear force.

[0071] In some embodiments, the perforated steel plate 14 includes a comb plate 141 and a plurality of comb teeth 142 disposed on one side of the comb plate 141. The comb plate 141 has a plurality of through holes 143 for the through reinforcing bars 15 to pass through, and the comb teeth 142 are inserted into the second reinforcing bar area.

[0072] In some embodiments, the spacing between adjacent comb teeth 142 is the same as the spacing between adjacent second reinforcing bars in the transverse direction of the lower crossbeam 2.

[0073] In some embodiments, the tooth gaps of adjacent comb teeth 142 are 2mm-5mm larger than the diameter of the second reinforcing bar in the transverse direction of the lower crossbeam 2.

[0074] According to the above scheme, it is convenient to insert the perforated steel plate 14 into the lower crossbeam 2.

[0075] In some embodiments, the diameter of the through hole 143 of the perforated steel plate 14 is not less than the sum of the diameter of the through reinforcing bar 15 and the maximum aggregate size of the pad concrete 16.

[0076] In some embodiments, the thickness of the perforated steel plate 14 is not less than 12 mm, and the through steel bar 15 is a threaded steel bar with a diameter of not less than 12 mm, in order to meet the structural and stress requirements.

[0077] like Figure 6 As shown, Figure 6 This is a flowchart illustrating the construction steps of an elastic cable pad stone structure according to an embodiment of the present invention.

[0078] The second aspect of this application provides a construction method for an elastic cable-stayed stone structure, which includes the following steps:

[0079] Step S1: Tie several second reinforcing bars at position 2 of the lower crossbeam of the main tower of the cable-stayed cable to form a second reinforcing bar zone;

[0080] Step S2: Several rows of perforated steel plates 14 are inserted into the second reinforcing bar area, and through reinforcing bars 15 penetrate the perforated steel plates 14.

[0081] Step S3: Pre-embed and tie a portion of the first reinforcing bar 11 in the second reinforcing bar area;

[0082] Step S4: Pour concrete in the second reinforcement zone to form the lower crossbeam 2;

[0083] Step S5: Tie the remaining first reinforcing bars 11 to form the first reinforcing bar area, and at the same time install the embedded pipe 12 with built-in elastic cable and the anchor plate 13 at both ends of the embedded pipe 12 in the first reinforcing bar area.

[0084] Step S6: Pour the pad stone concrete 16 in the first reinforcement zone to form the pad stone concrete zone and complete the construction of the elastic cable pad stone structure 1.

[0085] In steps S3 and S5, the first reinforcing bar 11 is tied twice to form the first reinforcing bar area. The ratio of the two tyings is based on the principle that the first tying of the first reinforcing bar 11 does not affect the construction of other processes.

[0086] After the lower crossbeam 2 is formed in step S4, depending on the construction space, the process that conflicts with the pouring of the pad concrete can be carried out first, such as the steel beam jacking process. After the steel beam jacking process is completed, step S5 can be carried out. This ensures the shear bearing capacity, reserves construction space, reduces the number of times construction equipment needs to be changed, and shortens the project period.

[0087] like Figure 7 As shown, Figure 7 This is a flowchart illustrating the design steps of an elastic cable cushion stone structure according to an embodiment of the present invention.

[0088] A third aspect of this application provides a design method for an elastic cable cushion stone structure, which includes the following steps:

[0089] Step S1: Establish a finite element model of the cable-stayed bridge and apply loads to obtain the shear design value V of the elastic cable pad structure 1. d .

[0090] Specifically, the finite element model of a cable-stayed bridge is the spatial truss finite element model of a cable-stayed bridge.

[0091] Step S2: Determine the diameter of the through hole 143 on the perforated steel plate 14 and the diameter of the through reinforcing bar 15 to obtain the design value V of the shear bearing capacity of a single through hole 143. pud And the total number of through holes 143, N0.

[0092] Specifically, the diameter of the through hole 143 on the perforated steel plate 14 and the diameter of the through reinforcing bar 15 are determined according to the structural requirements.

[0093] In some embodiments, the design value V of the shear bearing capacity of a single through hole is obtained. pud hour,

[0094] The calculation formula is: V pud =1.4 (d) 2 -d s 2 f cd +1.2d s 2 f sd ;

[0095] Where d is the diameter of the through hole in the perforated steel plate, d s f is the diameter of the through-bar. cd f is the design value of the axial compressive strength of the elastic cable pad concrete. sd This is the design value for the tensile strength of the through-bar reinforcement.

[0096] When obtaining the total number N0 of through holes 143,

[0097] The calculation formula is: N0 = V d / V pud .

[0098] Step S3: Determine the dimensions of the perforated steel plate 14.

[0099] In some embodiments, step S3, determining the dimensions of the perforated steel plate 14, includes:

[0100] The minimum edge spacing e between two adjacent through holes 143 of the perforated steel plate 14 is determined according to the stress requirements. c ;

[0101] The calculation formula is: e c =V pud / (t •f vd ),

[0102] Where t is the thickness of the perforated steel plate, f vd This represents the design value for the shear strength of the perforated steel plate.

[0103] Determine the center distance e between two adjacent through holes 143 of the perforated steel plate 14. i ;

[0104] Specifically, the center distance e between two adjacent through holes 143 of the perforated steel plate 14 is taken as follows: i It is 3 times the spacing of the first reinforcing bar 11, and satisfies e. i ≥e c Construction is convenient.

[0105] The length of the perforated steel plate 14 and the center distance e between two adjacent through holes 143 i Determine the number N of openings in a single perforated steel plate 14. i ;

[0106] Specifically, the calculation formula is: N i =L1 / e i ;

[0107] Where L1 is the longitudinal length of the perforated steel plate.

[0108] Based on the number of holes N in a single perforated steel plate 14 i The total number of through holes 143, N0, determines the number of perforated steel plates 14, m;

[0109] Specifically, the calculation formula is: m = N0 / N i .

[0110] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the method or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, "connection" 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 a connection within two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0111] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0112] The above are merely specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A flexible cable mat construction characterised in that, It comprises: The first steel bar area is formed by binding a plurality of first steel bars (11) on the lower beam (2) of the main tower of the cable-stayed bridge; The embedded pipe (12) is installed in the first steel bar area, and the embedded pipe (12) is internally provided with elastic cables; The anchor pad (13) is installed at both ends of the embedded pipe (12); A plurality of rows of the open-hole steel plates (14) are installed on the lower beam (2); The through steel bars (15) penetrate the open-hole steel plates (14); The cushion concrete area is formed by pouring the cushion concrete (16) in the first steel bar area; Part of the open-hole steel plate (14) is inserted into the lower beam (2), and the other part is located in the cushion concrete area; The open-hole steel plate (14) is a comb-tooth type open-hole steel plate; A plurality of second steel bars are bound on the lower beam (2) to form a second steel bar area; The open-hole steel plate (14) comprises a comb-tooth plate (141) and a plurality of comb teeth (142) arranged on one side of the comb-tooth plate (141), a plurality of through holes (143) for the through steel bars (15) to penetrate are distributed on the comb-tooth plate (141), and the comb teeth (142) are inserted into the second steel bar area.

2. A flexible cable mat construction as claimed in claim 1, characterised in that, The plurality of rows of the open-hole steel plates (14) are arranged at uniform intervals.

3. A flexible cable mat construction as claimed in claim 1, wherein, The spacing of the comb teeth (142) is the same as the spacing of the second steel bars on the lower beam (2).

4. A flexible cable mat construction as claimed in claim 3, wherein, The tooth gap of the comb teeth (142) is 2mm-5mm larger than the diameter of the second steel bars on the lower beam (2).

5. A construction method of an elastic cable mat rockfill structure, characterized by, The elastic cable cushion stone structure comprises: A plurality of second steel bars are bound on the lower beam (2) of the main tower of the cable-stayed bridge to form a second steel bar area; A plurality of rows of the open-hole steel plates (14) are inserted into the second steel bar area, and the through steel bars (15) penetrate the open-hole steel plates (14); A part of the first steel bars (11) is embedded and bound in the second steel bar area; The concrete is poured in the second steel bar area to form the lower beam (2); The remaining first steel bars (11) are bound to form a first steel bar area, and the embedded pipe (12) internally provided with elastic cables and the anchor pad (13) arranged at both ends of the embedded pipe (12) are installed in the first steel bar area; The cushion concrete (16) is poured in the first steel bar area to form a cushion concrete area, and the construction of the elastic cable cushion stone structure (1) is completed.

6. A method of designing a construction of an elastic cable mat stone, characterized in that, The elastic cable cushion stone structure comprises: A finite element model of the cable-stayed bridge is established, and a load is loaded to obtain a shear design value of the elastic cable cushion stone structure (1); The diameter of the through holes (143) on the open-hole steel plate (14) and the diameter of the through steel bars (15) are determined to obtain a shear bearing capacity design value of a single through hole (143) and a total number of the through holes (143); The size of the open-hole steel plate (14) is determined.

7. A method of designing a design of an elastic cord mat stone construction according to claim 6, characterized in that, Obtaining the design value V of the shear bearing capacity of a single through hole (143) pud When, The calculation formula is: V pud = 1.4(d 2 -d s 2 ) f cd + 1.2d s 2 f sd ; Wherein, d is the aperture diameter of the open steel plate, d s is the diameter of the through steel bar, f cd is the axial compressive strength design value of elastic cable mat concrete, f sd is the tensile strength design value of the through steel bar.

8. The method of designing a design of an elastic cord mat stone construction according to claim 6, characterized in that, The determination of the size of the open-hole steel plate (14) comprises: According to the stress requirement, the minimum edge distance between two adjacent through holes (143) of the open-hole steel plate (14) is determined; The center distance between two adjacent through holes (143) of the open-hole steel plate (14) is determined; The number of openings in a single perforated steel plate (14) is determined by the length of the perforated steel plate (14) and the center distance between two adjacent through holes (143); The number of perforated steel plates (14) is determined based on the number of openings in a single perforated steel plate (14) and the total number of through holes (143).

Images