Modular construction design method for cast-in-place triangular brackets of bridges

Abstract

The invention discloses a modular construction design method for cast-in-place triangular brackets of bridges, comprising: S1. constructing a triangular bracket component library and a transverse connection component library; S2. constructing a transverse distribution ratio coefficient table; S3. determining the number of triangular brackets required for construction and the distance between adjacent triangular brackets, and using the number of pieces m and the distance b as search conditions to search for the transverse distribution ratio coefficient of each triangular bracket from the transverse distribution ratio coefficient table; S4. calculating the design load of each triangular bracket according to the transverse distribution ratio coefficient of each triangular bracket; S5. selecting m triangular brackets from the triangular bracket component library according to the screening conditions; S6. using the distance b as the search condition to select a number of transverse connections from the transverse connection component library; S7. assembling and constructing the m triangular brackets and the number of transverse connections. The invention can realize the standardized design of triangular brackets, so that the utilization rate of triangular brackets is high and the consumables are small.

Description

Technical Field

[0001] The invention relates to the field of civil engineering, and in particular to a modular construction design method for a cast-in-place triangular bracket of a bridge. Background Art

[0002] The triangular bracket method is often used in the construction of block 0 of high pier cantilever continuous beam (rigid frame). The triangular bracket usually needs to be designed, calculated, processed and manufactured independently, which leads to uneven economy and safety. The difference is large, and most of the triangular brackets are used once, and the reuse rate is low.

[0003] How to effectively solve the deficiencies in the construction design of triangular brackets and improve the standardization, assembly and recycling of brackets is a technical problem worthy of research and exploration. Therefore, in order to solve the above problems, a modular construction design method for cast-in-place triangular brackets for bridges is needed. Summary of the invention

[0004] In view of this, the purpose of the present invention is to overcome the defects in the prior art and provide a modular construction design method for cast-in-place triangular brackets for bridges, which can achieve standardized design of triangular brackets and increase the utilization rate of the triangular brackets and reduce consumables.

[0005] The modular construction design method of the cast-in-place triangular bracket of a bridge of the present invention comprises the following steps:

[0006] S1. Construct a triangular bracket component library and a horizontal connection component library;

[0007] S2. Constructing a lateral distribution ratio coefficient table of the triangular bracket;

[0008] S3. Determine the number of triangular brackets m and the distance b between adjacent triangular brackets required for construction, and use the number of triangular brackets m and the distance b as search conditions to find the lateral distribution ratio coefficient of each triangular bracket from the lateral distribution ratio coefficient table;

[0009] S4. Perform uniform load analysis on the supported object and calculate the design load of each triangular bracket according to the lateral distribution ratio coefficient of each triangular bracket;

[0010] S5. Select m target triangular brackets from the triangular bracket component library according to the screening conditions;

[0011] S6. Using the distance b as a search condition, select a number of target horizontal connections from the horizontal connection component library;

[0012] S7. Assemble and construct m target triangular brackets and several target lateral connections.

[0013] Furthermore, a triangular bracket component library is constructed, including:

[0014] Taking the casting length and design bearing capacity of the triangular bracket as design parameters, several triangular brackets are designed;

[0015] Conduct mechanical analysis on several types of triangular brackets to determine the cross-sectional dimensions and rod models required for the design;

[0016] Design a standardized design drawing of the triangular bracket according to the cross-sectional dimensions and rod model;

[0017] According to the design drawings, corresponding triangular bracket components are processed to form a triangular bracket component library.

[0018] Furthermore, a lateral distribution ratio coefficient table of the triangular bracket is constructed, specifically including:

[0019] S21. The number of triangular brackets and the distance between adjacent triangular brackets are used as design variables, and the design variables are initialized;

[0020] S22. Perform simplified load analysis on the supported target object to obtain uniformly distributed loads on the concrete top and bottom plates and uniformly distributed loads on the concrete web plates;

[0021] S23. According to the rigid beam method, the reaction force of each main beam is obtained by assuming and analyzing the effect between the transverse connection and each triangular bracket;

[0022] S24. Calculate the lateral distribution ratio coefficient of each triangular bracket according to the reaction force of each main beam;

[0023] S25. Change the value of the design variable, repeat steps S22-S24, obtain the lateral distribution ratio coefficient of each triangular bracket under different design variables, and form a lateral distribution ratio coefficient table of the triangular bracket.

[0024] Furthermore, the design load P of each triangular bracket is determined according to the following formula: i :

[0025] P i =m gi (t1+t2)·l·ρ·B+m qi (h-t1-t2)·l·ρ·t3;

[0026] Among them, m gi is the lateral distribution ratio coefficient under the uniform load of the top and bottom plates, t1 is the thickness of the top plate, t2 is the thickness of the bottom plate, l is the casting length of the supported target, ρ is the concrete density, B is the length of the uniform load of the top and bottom plates, m qi is the lateral distribution proportional coefficient under the uniformly distributed load on the web, h is the beam height, and t3 is the web thickness.

[0027] Furthermore, the screening condition is: P ≥ P i, L≥l; where P is the design bearing capacity of the triangular bracket, L is the casting length of the triangular bracket, and l is the casting length of the supported target object.

[0028] The beneficial effects of the present invention are as follows: the modular construction design method of the cast-in-place triangular bracket of a bridge disclosed by the present invention transforms the design and processing of the general space triangular bracket from a single product idea to a modular standardized product design and processing, and respectively establishes a dual-modulus standard single-piece triangular bracket component library and a standard transverse connection component library. According to actual construction parameters, suitable components are selected from the component library for on-site installation, and after the construction is completed, they can be dismantled and put back into the component library for next use, thereby realizing the modular construction design of the cast-in-place triangular bracket of the bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0030] Figure 1 This is a schematic diagram of the arrangement of the cast-in-situ triangular bracket of the bridge of the present invention;

[0031] Figure 2 It is a computational mechanics schematic diagram of a single-piece triangular bracket of the present invention;

[0032] Figure 3 It is a schematic diagram of the catalog of standard design drawings of the modular triangular bracket of the present invention;

[0033] Figure 4 The flowchart of the construction of the dual-module standard single-piece triangular bracket component library of the present invention;

[0034] Figure 5 It is a hypothetical schematic diagram for calculating the lateral distribution ratio coefficient of the present invention;

[0035] Figure 6 A flow chart for constructing a horizontal distribution ratio coefficient table of the present invention;

[0036] Figure 7 It is a simplified analysis diagram of the box girder cross section and load of the present invention;

[0037] Figure 8 It is a flow chart of the modular construction design method of the present invention. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with the accompanying drawings, as shown in the drawings:

[0039] The modular construction design method of the cast-in-place triangular bracket of a bridge of the present invention comprises the following steps:

[0040] S1. Construct a triangular bracket component library and a horizontal connection component library;

[0041] S2. Constructing a lateral distribution ratio coefficient table of the triangular bracket;

[0042] S3. Determine the number of triangular brackets m and the distance b between adjacent triangular brackets required for construction, and use the number of triangular brackets m and the distance b as search conditions to find the lateral distribution ratio coefficient of each triangular bracket from the lateral distribution ratio coefficient table;

[0043] S4. Perform uniform load analysis on the supported target object, and calculate the design load of each triangular bracket according to the lateral distribution ratio coefficient of each triangular bracket; in this embodiment, the supported target object is a cast-in-place box girder;

[0044] S5. Select m target triangular brackets from the triangular bracket component library according to the screening conditions;

[0045] S6. Using the distance b as a search condition, select a number of target horizontal connections from the horizontal connection component library;

[0046] S7. Assemble and construct m target triangular brackets and several target lateral connections.

[0047] The triangular bracket modular construction design method of the present invention carries out professional drawing design and model calculation and analysis, has good safety performance, and establishes a relatively complete dual-module standard single-piece triangular bracket component library and a standard transverse connection component library. The triangular bracket has a short installation time, and the components can be flexibly combined. After the triangular bracket is constructed, the bracket can be removed simply, conveniently, safely, reliably, quickly and efficiently. After removal, the bracket can be put back into the component library for recycling and reuse, with high utilization rate and less consumables.

[0048] In this embodiment, in step S1, a triangular bracket component library is constructed, such as Figure 4 As shown, specifically including:

[0049] According to the construction requirements of cast-in-place triangular brackets for general bridges, the casting length L and design bearing capacity P of the single triangular bracket are graded according to the modulus. For example, when the casting length is 2m and the casting weight is 100KN, the double modulus model LP of the single triangular bracket is 2-100;

[0050] According to the dual-module model of the triangular bracket, the design calculation of the single-piece triangular bracket can be carried out. The mechanical diagram is as follows Figure 2 As shown in the figure, the main members are hinged and it is assumed to be a truss structure that only bears axial force. The following formula can be obtained:

[0051]

[0052] Where: [σ i ] is the allowable stress value of the corresponding member; A iis the cross-sectional area of ​​the corresponding rod; N i is the axial force of the corresponding rod.

[0053] According to the mechanical diagram of the monolithic triangular bracket ( Figure 2 ) can be used to calculate the axial force of the corresponding rod:

[0054]

[0055]

[0056] That is, the cross section and stress of the rod should meet the following requirements:

[0057]

[0058]

[0059] According to the mechanical diagram ( Figure 2 ), as well as the cross-sectional design requirements of the main members (Formula (4), Formula (5)), select the appropriate steel type and combination form. Through the above calculation combination, a complete set of modular triangular bracket standard design drawings can be designed based on the dual-module model of the single-piece triangular bracket. Among them, the catalog of modular triangular bracket standard design drawings is as follows Figure 3 shown.

[0060] Once the dual-module model of the single-piece triangular bracket is known, the corresponding standard design drawing of the modular triangular bracket can be found. The drawing includes the overall layout drawing and engineering quantity table of the triangular bracket of this model, as well as the structural drawings and models of each rod.

[0061] Components corresponding to various dual-modulus models are processed according to the standard design drawings of the modular triangular bracket, and the components are placed in a dual-modulus standard single-piece triangular bracket component library to form a triangular bracket component library.

[0062] In this embodiment, the transverse layout parameters m and b of a single triangular bracket are modularized according to the general range of bridge width. Among them, m represents the number of triangular brackets arranged, and b represents the spacing between two adjacent triangular brackets. The modulus of m is 1, and the modulus of b is 0.5. When the number of arranged pieces m is 2 and the adjacent spacing b is 2.5m, the transverse layout parameter mb is 2-2.5m. In step S1, a standard transverse connection is designed according to the modulus b, and each standard transverse connection is processed using existing technology and placed in a standard transverse connection component library to form a transverse connection component library.

[0063] In this embodiment, in step S2, a lateral distribution ratio coefficient table of the triangular bracket is constructed, such as Figure 6 As shown, specifically including:

[0064] S21. The number of triangular brackets and the distance between adjacent triangular brackets are used as design variables, and the design variables are initialized;

[0065] S22. The pouring weight of concrete is normalized and assumed to be Figure 5 As shown in the figure, the concrete top and bottom plate loads are simplified to a uniformly distributed load of g = 1 kN / m and a length of B; the concrete web load is simplified to a uniformly distributed load of q = 1 kN / m and a length of t.

[0066] S23. According to the rigid beam method, the reaction force of each main beam is obtained by assuming the interaction between the transverse connection and each triangular bracket. Specifically, when the uniformly distributed load is 1, the reaction force of each main beam can be obtained:

[0067]

[0068] Among them, the rigid beam method adopts the existing technology and will not be described in detail here.

[0069] S24. According to the reaction force of each main beam, the lateral distribution ratio coefficient of each triangular bracket is calculated; specifically, the lateral distribution ratio coefficient is:

[0070]

[0071] According to formula (7.1) and formula (7.2), the lateral distribution ratio coefficient of each triangular bracket can be calculated;

[0072] S25. Change the value of the design variable, repeat steps S22-S24, obtain the lateral distribution ratio coefficient of each triangular bracket under different design variables, and form a lateral distribution ratio coefficient table of the triangular bracket. As shown in the following table: Table 1 is a lateral distribution ratio coefficient table under the action of uniformly distributed load g=1, and Table 2 is a lateral distribution ratio coefficient table under the action of uniformly distributed load q=1 on the left and right webs.

[0073] Table 1

[0074]

[0075] Table 2

[0076]

[0077] It should be noted that the lateral distribution of the triangular bracket meets the symmetry condition. In the proportional coefficients of Table 1 and Table 2, if the number of triangular bracket pieces is 2, only the coefficient corresponding to one piece is listed, and the other piece is the same as this piece, so it is not listed. Similarly, if the number of triangular bracket pieces is 3, the coefficients corresponding to the triangular brackets on both sides are the same, so the other side is not listed.

[0078] In this embodiment, in step S4, when the triangular bracket is constructed for the cast-in-place box girder, the box girder cross section and load need to be simplified, and the flange plate part is not considered. The simplified diagram is as follows: Figure 7 shown.

[0079] Through simplified analysis, the uniform load g can be expressed as: g = (t1 + t2) · l · ρ; the uniform load q can be expressed as: q = (h-t1-t2) · l · ρ;

[0080] By looking up the lateral distribution ratio coefficient table of the triangular bracket (Table 1, Table 2), the corresponding lateral distribution ratio coefficient under the action of uniformly distributed load g = 1 is found to be m g1 、m g2 ; The lateral distribution proportional coefficients under the action of uniformly distributed load q=1 on the left and right webs are mq1 and mq2.

[0081] The design load of each triangular bracket is obtained as:

[0082] P1=m g1 (t1+t2)·l·ρ·B+m q1 (h-t1-t2)·l·ρ·t3 (8.1)

[0083] P2=m g2 (t1+t2)·l·ρ·B+m q2 (h-t1-t2)·l·ρ·t3 (8.2)

[0084] Among them, m g1 With m g2 are the lateral distribution proportional coefficients under the uniform load of the top and bottom plates g=1, t1 is the thickness of the top plate, t2 is the thickness of the bottom plate, l is the casting length of the cast-in-place box girder; ρ is the concrete density, B is the length of the uniform load of the top and bottom plates, m q1 With m q2 is the lateral distribution proportional coefficient under the action of uniformly distributed load q=1 on the left and right webs, h is the beam height, and t3 is the web thickness.

[0085] In this embodiment, in step S5, the screening condition is: P ≥ P i , L≥l; where P is the design bearing capacity of the triangular bracket, L is the casting length of the triangular bracket, and l is the casting length of the cast-in-place box girder. Through the above screening conditions, each triangular bracket is screened, and the LP standard single-piece triangular bracket with the corresponding module is selected from the triangular bracket component library.

[0086] In this embodiment, in step S6, the distance b is used as a search condition to select several target transverse connections from the transverse connection component library; that is, a standard transverse connection of a corresponding module is selected from the transverse connection component library, so that the transverse connection is combined with the triangular bracket selected in step S5.

[0087] In this embodiment, in step S7, the selected standard monolithic triangular bracket and standard transverse connection are assembled and constructed. After the construction is completed, the standard monolithic triangular bracket and standard transverse connection can be removed and put back into the spare component library to be reused when selected for other projects.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A modular construction design method for cast-in-place triangular brackets for bridges, characterized in that: The steps include: S1. Construct a triangular bracket component library and a horizontal connection component library; S2. Constructing a lateral distribution ratio coefficient table of the triangular bracket; S3. Determine the number of triangular brackets m and the distance b between adjacent triangular brackets required for construction, and use the number of triangular brackets m and the distance b as search conditions to find the lateral distribution ratio coefficient of each triangular bracket from the lateral distribution ratio coefficient table; S4. Perform uniform load analysis on the supported object and calculate the design load of each triangular bracket according to the lateral distribution ratio coefficient of each triangular bracket; S5. Select m target triangular brackets from the triangular bracket component library according to the screening conditions; the screening conditions are: P ≥ P i , L≥l; where P is the design bearing capacity of the triangular bracket, P i is the design load of the triangular bracket; L is the casting length of the triangular bracket, and l is the casting length of the supported object; S6. Using the distance b as a search condition, select a number of target horizontal connections from the horizontal connection component library; S7. Assemble and construct m target triangular brackets and several target lateral connections.

2. The modular construction design method for cast-in-situ triangular brackets for bridges according to claim 1 is characterized by: Build a triangular bracket component library, including: Taking the casting length and design bearing capacity of the triangular bracket as design parameters, several triangular brackets are designed; Conduct mechanical analysis on several types of triangular brackets to determine the cross-sectional dimensions and rod models required for the design; Design a standardized design drawing of the triangular bracket according to the cross-sectional dimensions and rod model; According to the design drawings, corresponding triangular bracket components are processed to form a triangular bracket component library.

3. The modular construction design method for cast-in-situ triangular brackets for bridges according to claim 1 is characterized by: Construct the lateral distribution ratio coefficient table of the triangular bracket, including: S21. The number of triangular brackets and the distance between adjacent triangular brackets are used as design variables, and the design variables are initialized; S22. Perform simplified load analysis on the supported target object to obtain uniformly distributed loads on the concrete top and bottom plates and uniformly distributed loads on the concrete web plates; S23. According to the rigid beam method, the reaction force of each main beam is obtained by assuming and analyzing the effect between the transverse connection and each triangular bracket; S24. Calculate the lateral distribution ratio coefficient of each triangular bracket according to the reaction force of each main beam; S25. Change the value of the design variable, repeat steps S22-S24, obtain the lateral distribution ratio coefficient of each triangular bracket under different design variables, and form a lateral distribution ratio coefficient table of the triangular bracket.

4. The modular construction design method for cast-in-place triangular brackets for bridges according to claim 1 is characterized in that: Determine the design load P of each triangular bracket according to the following formula i : P i =m gi (t1+t2)·l·ρ·B+m qi (h-t1-t2)·l·ρ·t3; Among them, m gi is the lateral distribution coefficient under the uniform load of the top and bottom plates, t1 is the thickness of the top plate, t2 is the thickness of the bottom plate, l is the casting length of the supported target, ρ is the concrete density, B is the length of the uniform load of the top and bottom plates, m qi is the lateral distribution proportional coefficient under the uniformly distributed load on the web, h is the beam height, and t3 is the web thickness.

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