Parametric design method for multi-tower partial cable-stayed bridge of high-speed railway

Abstract

The invention relates to the technical field of bridge engineering, in particular to a parameterized design method for a multi-tower partial cable-stayed bridge of a high-speed railway, which comprises the following steps of: establishing a function relation of related design parameters according to a proposed main span sequence to obtain a reasonable side-mid span ratio, high span ratio and tower span ratio scheme; and according to comprehensive comparison and selection of a main bridge construction cost calculation formula and engineering technology difficulty, data processing is carried out by using a normalization and weighted average method, and an optimal scheme is determined. The method has the advantages that a theoretical basis is provided in the whole scheme design, man-made subjective decisions are reduced, and the refinement degree and rationality of the design are improved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, and in particular to a parametric design method for a high-speed railway multi-tower partial cable-stayed bridge. Background Art

[0002] The partial cable-stayed bridge is a composite bridge system between the continuous beam or continuous rigid frame bridge and the traditional cable-stayed bridge. It is a structural system in which the main beam and the cable jointly bear the vertical load. Due to the unique force mechanism of the partial cable-stayed bridge, its basic structural parameters are different from those of the general cable-stayed bridge and the beam bridge. In addition, the height of the bridge tower, the cross-sectional form of the main beam, and the side and middle spans are all important parameters that affect the mechanical characteristics of the partial cable-stayed bridge structure, and are also important indicators for evaluating the mechanical performance of the partial cable-stayed bridge, which has great research value.

[0003] In the general design process of multi-tower partially cable-stayed bridges, most of the current research on the optimization design of partially cable-stayed bridges is limited to the optimization of cable force and local component optimization, but the above optimization effects are limited and non-optimal situations are prone to occur. Summary of the invention

[0004] The purpose of the present invention is to provide a parametric design method for a high-speed railway multi-tower partial cable-stayed bridge based on the above-mentioned deficiencies in the prior art, which is used to optimize important parameters such as the side-to-mid-span ratio, tower-span ratio and high-span ratio of a large-span multi-tower partial cable-stayed bridge, and provide a theoretical basis for the design scheme, thereby reducing the situation in which the design parameters in the prior art are prone to non-optimal conditions, reducing the influence of the subjective experience of designers, and improving the refinement and rationality of the design.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] A parametric design method for a high-speed railway multi-tower partially cable-stayed bridge, characterized in that it comprises the following steps:

[0007] According to the design influencing conditions of the multi-tower cable-stayed bridge of the high-speed railway, the initial value of the main bridge length L is preliminarily determined according to the height from the ground line to the bridge deck and the conditions of crossing the waterway, deep water area and traffic line. t ;

[0008] The main span L of the multi-tower cable-stayed bridge of the high-speed railway is proposed. i The value sequence of ;

[0009] According to the proposed initial value of the main bridge length L t and the proposed main span L i Sequence, combining the topographic conditions of the bridge site and the navigation requirements, calculate the sequence of the number of main spans;

[0010] Combined with the main span L iThe value sequence of the side span ratio coefficient is used to determine the side span length, and the main bridge length L is adjusted according to the arrangement of the main span length and the side span length. ti ;

[0011] According to the main span L i The value sequence of calculates the bridge tower height;

[0012] Combined with the main span L i The value sequence of and the design requirements of high-speed railways as well as the cross-sectional form of the main beam determine the cross-sectional height of the main beam;

[0013] According to the main span L i The value sequence of is combined with the railway line elevation and beam height, and assuming that the foundation cap is located at the ground line, the pier height and underwater depth under each scheme are determined;

[0014] Calculate the total cost based on all design options for main span sequence, side span length, tower height and pier height;

[0015] Calculate the engineering and technical difficulty of different solutions;

[0016] Taking into account the total construction cost and engineering technical difficulty, the optimal solution for the multi-tower partial cable-stayed bridge of the high-speed railway is determined.

[0017] The design influencing conditions include the topographic conditions of the bridge site, hydrological conditions, navigation requirements, crossing traffic lines, railway grade and design speed, and railway line elevation.

[0018] The main span of the multi-tower cable-stayed bridge on a high-speed railway is L i The value sequence of is: L0, L0+10, L0+20, L0+30, ..., 350; where L0 represents the minimum span of the main span, which is the larger value of the minimum width limit of the channel and 200m; each item in the sequence represents different main span values, expressed as L i Indicates that L i The subscript i represents the i-th item in the main span sequence, i=1, 2, 3, 4,...; that is: L1=L0, L2=L0+10, L3=L0+20...

[0019] The formula for calculating the number of main spans is:

[0020] For different values ​​in the main span sequence, the corresponding number of main spans n is calculated according to this formula. i :n1,n2,n3,......;

[0021] Where n is the number of main spans, which is rounded down; L t is the initial value of the main bridge length; L i The value in the main span sequence.

[0022] The calculation formula of the side span is:

[0023] L si =ξL i ; For each item in the value sequence of the main span, take the low, medium and high values ​​of ξ according to the side span calculation formula and then determine the side span L respectively si1 , L si2 , L si3 Three options:

[0024] Where, L si is the side span diameter; ξ is the side-to-mid span ratio coefficient, ranging from 0.55 to 0.60, preferably 0.55, 0.575, and 0.60; L i The value in the main span sequence.

[0025] The calculation formula of the bridge tower height is:

[0026] Among them, ψ is determined by whether the main tower and the side tower are of equal height. When the main tower and the side tower are of equal height, ψ is 2.5. When the main tower and the side tower are of unequal height, ψ of the side tower is 1.5 and ψ of the main tower is 2.0.

[0027] In the formula, H i is the bridge tower height; L i is the value in the main span sequence; ψ is the value coefficient; μ represents the influence coefficient of the cable on the bridge tower height, which is calculated by the number of cable-stayed cables tensioned on a single bridge tower and the angle between the side cable of the cable and the main beam.

[0028] The calculation formula of the main beam section height is:

[0029]

[0030] In the formula, h i is the main beam section height; b is the bridge deck width, which is determined according to the standard track gauge of high-speed railways, the number of tracks, and the width of the maintenance channel; γ is determined according to the location of the section, the section at the pier top is 3.6, the section at the mid-span is 1.8, and the section between the pier top and the mid-span is determined according to a linear change; λ is determined according to the cross-sectional form of the main beam.

[0031] The calculation formula of the total cost is:

[0032] S i =c1k1bh i L ti +c2(n i +1)H i +c3(n i +3)G i+rk2(n i +1)tl i ;

[0033] In the formula, S i represents the total cost of different schemes; c1 represents the comprehensive cost of the main bridge concrete; c2 represents the average comprehensive cost of the bridge tower per meter; c3 represents the average comprehensive cost of the bridge pier per meter; r represents the average comprehensive cost of the cable per meter; t represents the number of cables on a single bridge tower; l i represents the length of the side cable, which is determined according to the angle between the side cable and the main beam and the height of the bridge tower; c1, c2, c3 and r are determined according to the actual concrete cost, steel strand cost, material transportation conditions and structural size parameters; k1 represents the reduction coefficient of the main beam cross-sectional area, which is 0.6 considering that the main beam adopts a variable cross-section; k2 represents the reduction coefficient of the length of the inclined cable, which is 0.6 considering that it is uniformly calculated according to the side cable length.

[0034] The calculation formula of the engineering technical difficulty is:

[0035] β i =A i ×B i ×C i ×D i ;

[0036] In the formula, β i Engineering technical difficulty; Engineering A i Indicates the main span influence coefficient; B i Indicates the influence coefficient of bridge tower height; C i Indicates the influence coefficient of pier height; D i Indicates the influence coefficient of bridge foundation type; the specific determination method of each coefficient in the formula is: establish the main span L i With A i A is a nonlinear function of i According to the main span value, A i ∈(0,1]; establish the bridge tower height H i With B i The nonlinear function B i According to the height of the bridge tower, B i ∈(0,1]; Establish the bridge pier height G i With C i The nonlinear function, C i According to the height of the bridge pier, C i ∈(0,1]; D i Values ​​are taken based on the foundation type: if the foundation type is pile foundation, D i Take 1.0; the foundation type is pipe column foundation, D i Take 1.1; the foundation type is caisson foundation, D i Take 1.2.

[0037] Normalize the total cost of the design solution: Map the result to (0,1]; then normalize the total cost coefficient φ i and engineering technology difficulty coefficient β i Perform weighted averaging and establish a solution decision formula: Among them, φ i represents the cost coefficient of each design scheme obtained after normalization; β i Indicates the engineering technology difficulty coefficient; Represents the weight coefficient, which is adjusted according to local terrain conditions, transportation conditions and material supply; ε i represents the decision coefficient of the scheme; S i represents the sample value of the total construction cost, S imax Indicates the maximum value of the total cost sample. According to this formula, the decision coefficient ε of different schemes is calculated i , take ε i For smaller values, 2-3 preferred design plans will be formulated.

[0038] Table 1 Weight coefficient table

[0039]

[0040] In the present invention, the engineering technology difficulty coefficient calculation formula is, where A i Determined according to the main span influence coefficient relationship diagram, see Figure 3 ; B i Determined according to the bridge tower height influence coefficient relationship diagram, see Figure 4 ; C i Determined according to the relationship diagram of the influence coefficient of pier height, see Figure 5 .

[0041] The advantages of the present invention are as follows: according to the proposed main span sequence, a functional relationship of relevant design parameters is established to obtain reasonable side-to-middle span ratio, high span ratio and tower span ratio schemes; and according to the main bridge cost calculation formula and comprehensive comparison of engineering technical difficulty, data processing is performed using normalization and weighted average methods to determine the optimal scheme; a theoretical basis is provided in the entire scheme design, human subjective decision-making is reduced, and the refinement and rationality of the design are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a flow chart of the method of the present invention;

[0043] Figure 2 This is a schematic diagram of the structure of a high-speed railway multi-tower partial cable-stayed bridge involved in the present invention;

[0044] Figure 3It is a curve diagram of the main span influence coefficient of the multi-tower partial cable-stayed bridge in the present invention;

[0045] Figure 4 A curve diagram of the influence coefficient of the tower height of a multi-tower cable-stayed bridge in the present invention;

[0046] Figure 5 It is a curve diagram of the influence coefficient of the pier height of the multi-tower partial cable-stayed bridge in the present invention. DETAILED DESCRIPTION

[0047] The features of the present invention and other related features are further described in detail below through embodiments in conjunction with the accompanying drawings to facilitate understanding by those skilled in the art:

[0048] like Figure 1-5 As shown in the figure, the marks 1-3 and the letters represent: main beam 1, foundation 2, ground line 3, L i Indicates the main span of the bridge, L si represents the side span of the bridge, H i Indicates the bridge tower height, G i represents the height of the pier, and α represents the angle between the side cable and the main beam.

[0049] Example: Figures 1 to 5 As shown, this embodiment takes a high-speed railway multi-tower partial cable-stayed bridge as an example to illustrate the parametric design method of the present invention. The situation of the high-speed railway multi-tower partial cable-stayed bridge is as follows:

[0050] The railway grade is high-speed railway; the number of main lines is double; the line spacing is 5m; the design speed is 350km / h; the design live load is ZK live load; the cable tower adopts the upright bridge tower form, and the horizontal double cable plane is arranged; the main beam material is C55; the top elevation of the pedestal is about 111.5m; the railway line elevation is 150m; the bridge is located in a deep reservoir environment, with an average water depth of about 40m and the deepest dam site is about 70m; the reservoir area is navigable all year round, classified as a Class VI waterway, with a navigation limit requirement of 25×6.0m and a maximum navigation water level of 117.15m; the foundation type is pile foundation; the economically reasonable bridge design scheme is determined by the method in this paper.

[0051] like Figure 1 As shown, the parametric design method for a high-speed railway multi-tower partial cable-stayed bridge in this embodiment includes the following steps:

[0052] 1) The bridge is a high-speed railway multi-tower cable-stayed bridge with a design speed of 350km / h, a railway line elevation of about 150m, a cap top elevation of about 111.5m, located in a deep reservoir environment, with a water width of about 900m, and the highest navigable water level of the reservoir is 117.15m, an average water depth of about 40m, and the deepest point of the dam site is about 70m. The initial value of the main bridge length L is preliminarily determined. t =950m.

[0053] 2) According to the fact that the reservoir area is open to navigation all year round, it is classified as a Class VI waterway, and the navigation limit requirement is 25×6.0=150m. The minimum span of the main span can be determined as L0=max{150,200}=200m. The main span of the multi-tower cable-stayed bridge of the high-speed railway is proposed as L i Value sequence:

[0054] 200, 210, 220, 230, 240, ..., 350;

[0055] 3) According to the main span L i Value sequence and initial value of main bridge length L t =950m, substitute into the formula Calculate the main span number sequence n i : 4, 4, 4…, 3, 3, 3…, 2, 2. Calculation example: Round down n1=4; the specific calculation results are shown in Table 2.

[0056] 4) Determine the side span:

[0057] The side span calculation formula is proposed: L sim =ξ m L i , ξ is taken as low, medium and high values ​​as ξ1=0.55, ξ2=0.575, ξ3=0.60; according to the main span sequence, the side span scheme is obtained according to this formula.

[0058] Calculation example:

[0059] L s11 =ξ1L1=0.55×200=110m,

[0060] L s21 =ξ2L1=0.575×200=115m,

[0061] ...L s12 =ξ1L1=0.55×210=115.5m,

[0062] L s22 =ξ2L2=0.575×210=120.75m,

[0063] ...L s13 =ξ1L3=0.55×220=121m,

[0064] L s23 =ξ2L3=0.575×220=126.5m,……The other calculation results are shown in Table 2.

[0065] Adjust the length of the main bridge according to the span of the middle span and the side span: Lti =n i ×L i +2×L sim . Calculation example: L t1 =4×200+2×110=1020m, L t2 =4×210+2×115.5=1071m,…; The rest of the calculation results are shown in Table 3.

[0066] 5) Determine the bridge tower height: According to the bridge tower height calculation formula Substitute the main span sequence to calculate the bridge tower height H i Calculation example: Main side tower equal height design ψ=2, Main span L1 = 200m, substitute into the formula to calculate The rest of the calculation results are shown in Table 2.

[0067] 6) Determine the main beam section height: Taking the section at the pier top as an example, the main span is L1 = 200m. According to the main beam section form of single box double chamber, λ is 1.0; according to the railway line is double-track and the line spacing is 5.0m, the bridge deck width b = 14.1m, γ = 3.6, substitute into the formula The calculation results are: The rest of the calculation results are shown in Table 2.

[0068] 7) According to the main span sequence of the multi-tower partial cable-stayed bridge, combined with the railway line elevation, the pedestal elevation and the beam height of each scheme, and assuming that the foundation pedestal is located at the ground line, the pier height under each scheme is determined. The specific results are shown in Table 2 below.

[0069] Table 2 Main structural parameters of different design schemes for multi-tower cable-stayed bridges on high-speed railways

[0070]

[0071]

[0072] 8) Estimate the total cost of different design schemes for the whole bridge, and select one of the schemes for calculation example: main span L1 = 200m, number of main spans n1 = 4, bridge tower height H1 = 32.5m, average pier height G1 = 20.0m, bridge deck width b = 14.1m, main beam cross section adopts variable cross section, cross section area reduction factor k1 = 0.6, side cable length can be proposed as l1 = 100m according to the angle between side cable and main beam and bridge tower height, cable length reduction factor k2 = 0.6, beam height at pier top h1 = 9.5m, local C55 concrete comprehensive cost is 0.05125 million yuan / m 3The comprehensive cost of the cable-stayed cable is 162,060 yuan / t. Based on the local material transportation conditions, material prices and structural size parameters, it is estimated that the average comprehensive cost of each meter of bridge tower is 62,220 yuan, the average comprehensive cost of each meter of bridge pier is 506,400 yuan, and the average comprehensive cost of each meter of cable-stayed cable is 16,320 yuan. Substituting the above parameters into the main bridge cost formula S i =c1k1bh i L ti +c2(n i +1)H i +c3(n i +3)G i +rk2(n i +1)tl i The calculation shows that the cost of the main bridge of Scheme 1 is: S i =c1k1bh1L ti +c2(n1+1)H1+c3(n1+3)G1+rk2(n1+1)tl i =0.05152×0.6×14.1×9.5×1020+0.62217×(4+1)×32.5×5.0640×(4+3)×20+0.1632×0.6×(4+1)×108×110≈108.4728 million yuan. The total cost calculation results of the other schemes are shown in Table 3.

[0073] 9) Determine the engineering technical difficulty of different schemes, and select one of them for calculation example: main span L1 = 200m, bridge tower height H1 = 32.5m, pier height G1 = 14.5m, foundation is pile foundation; Figure 2 Main span influence coefficient curve, Figure 3 Bridge tower height influence coefficient curve, Figure 4 From the main span influence coefficient curve, we can get A1=0.80, B1=0.80, C1=0.80, D=1; then substitute A1, B1, C1, D into the formula β1=A1×B1×C1×D to calculate the engineering difficulty coefficient of this scheme: β1=0.80×0.80×0.80×1.00=0.512. The calculation results of other engineering difficulty coefficients are shown in Table 3.

[0074] 10) Comprehensively consider the total cost and engineering technical difficulty to determine the preferred solution. Select one of the solutions for calculation example: the total cost of a solution is S1≈108.4728 million yuan, the engineering difficulty coefficient is β1=0.512, and the maximum total cost of all solutions is S max ≈118.288 million yuan, Normalize the total cost: Then use the weighted average to calculate the decision coefficient of the solution The calculation results of decision coefficients for other options are shown in Table 3.

[0075] Table 3 Total cost and engineering technical difficulty coefficient of different design schemes for multi-tower cable-stayed bridges on high-speed railways

[0076]

[0077]

[0078] According to the decision coefficients of each scheme in Table 3, take ε i The smaller value and considering the different main spans, the optimal scheme is proposed. After comparison, Scheme 13 (ε i value is 0.726) and Scheme 16 (ε i The value is 0.746) can be formulated as the preferred solution, and the specific solution is as follows:

[0079] Scheme 13: The span arrangement is: (132+3×240+132)m, the bridge tower height is 36.7m, the main beam height is 5.1m-10.2m, and the pier height is 19.3m.

[0080] Scheme 16: The span arrangement is: (137.5+3×250+137.5)m, the bridge tower height is 37.7m, the main beam height is 5.2m-10.4m, and the pier height is 19.1m.

[0081] Although the above embodiments have described in detail the concepts and embodiments of the present invention with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and changes can still be made to the present invention without departing from the scope of the claims, so they are not described one by one here.

Claims

1. A parametric design method for a high-speed railway multi-tower partially cable-stayed bridge, characterized in that: The steps include: According to the design influencing conditions of the multi-tower cable-stayed bridge of the high-speed railway, the initial value of the main bridge length L is preliminarily determined according to the height from the ground line to the bridge deck and the conditions of crossing the waterway, deep water area and traffic line. t ; The main span L of the multi-tower cable-stayed bridge of the high-speed railway is proposed. i The value sequence of ; According to the proposed initial value of the main bridge length L t and the proposed main span L i Sequence, combining the topographic conditions of the bridge site and the navigation requirements, calculate the sequence of the number of main spans; Combined with the main span L i The value sequence of the side span ratio coefficient is used to determine the side span length, and the main bridge length L is adjusted according to the arrangement of the main span length and the side span length. ti ; According to the main span L i The value sequence of calculates the bridge tower height; Combined with the main span L i The value sequence of and the design requirements of high-speed railways as well as the cross-sectional form of the main beam determine the cross-sectional height of the main beam; According to the main span L i The value sequence of is combined with the railway line elevation and beam height, and assuming that the foundation cap is located at the ground line, the pier height and underwater depth under each scheme are determined; Calculate the total cost based on all design options for main span sequence, side span length, tower height and pier height; Calculate the engineering and technical difficulty of different solutions; Taking into account the total construction cost and engineering technical difficulty, the optimal solution for the multi-tower partial cable-stayed bridge of the high-speed railway is determined.

2. The parametric design method for a high-speed railway multi-tower partially cable-stayed bridge according to claim 1, characterized in that: The design influencing conditions include the topographic conditions of the bridge site, hydrological conditions, navigation requirements, crossing traffic lines, railway grade and design speed, and railway line elevation.

3. The parametric design method for a high-speed railway multi-tower partially cable-stayed bridge according to claim 1, characterized in that: The main span of the multi-tower cable-stayed bridge on a high-speed railway is L i The value sequence of is: L0, L0+10, L0+20, L0+30, ..., 350; where L0 represents the minimum span of the main span, which is the larger value of the minimum width limit of the channel and 200m; each item in the sequence represents different main span values, expressed as L i Indicates that L i The subscript i represents the i-th item in the main span sequence, i=1, 2, 3, 4,...; that is: L1=L0, L2=L0+10, L3=L0+20...

4. The parametric design method for a high-speed railway multi-tower partially cable-stayed bridge according to claim 1, characterized in that: The formula for calculating the number of main spans is: For different values ​​in the main span sequence, the corresponding number of main spans n is calculated according to this formula. i :n1,n2,n3,......; Where n is the number of main spans, which is rounded down; L t is the initial value of the main bridge length; L i The value in the main span sequence.

5. The parametric design method for a high-speed railway multi-tower partially cable-stayed bridge according to claim 1, characterized in that: The calculation formula of the side span is: L si =ξL i ; For each item in the value sequence of the main span, take the low, medium and high values ​​of ξ according to the side span calculation formula and then determine the side span L respectively si1 , L si2 , L si3 Three options: Where, L si is the side span diameter; ξ is the side-to-mid span ratio coefficient, with a value of 0.55-0.60; L i The value in the main span sequence.

6. The parametric design method for a high-speed railway multi-tower partially cable-stayed bridge according to claim 1, characterized in that: The calculation formula of the bridge tower height is: Among them, ψ is determined by whether the main tower and the side tower are of equal height. When the main tower and the side tower are of equal height, ψ is 2.

5. When the main tower and the side tower are of unequal height, ψ of the side tower is 1.5 and ψ of the main tower is 2.

0. In the formula, H i is the bridge tower height; L i is the value in the main span sequence; ψ is the value coefficient; μ represents the influence coefficient of the cable on the bridge tower height, which is calculated by the number of cable-stayed cables tensioned on a single bridge tower and the angle between the side cable of the cable and the main beam.

7. The parametric design method for a high-speed railway multi-tower partially cable-stayed bridge according to claim 1, characterized in that: The calculation formula of the main beam section height is: In the formula, h i is the main beam section height; b is the bridge deck width, which is determined according to the standard track gauge of high-speed railways, the number of tracks, and the width of the maintenance channel; γ is determined according to the location of the section, the section at the pier top is 3.6, the section at the mid-span is 1.8, and the section between the pier top and the mid-span is determined according to a linear change; λ is determined according to the cross-sectional form of the main beam.

8. The parametric design method for a high-speed railway multi-tower partially cable-stayed bridge according to claim 1, characterized in that: The calculation formula of the total cost is: S i =c1k1bh i L ti +c2(n i +1)H i +c3(n i +3)G i +rk2(n i +1)tl i ; In the formula, S i represents the total cost of different schemes; c1 represents the comprehensive cost of the main bridge concrete; c2 represents the average comprehensive cost of the bridge tower per meter; c3 represents the average comprehensive cost of the bridge pier per meter; r represents the average comprehensive cost of the cable per meter; t represents the number of cables on a single bridge tower; l i represents the length of the side cable, which is determined according to the angle between the side cable and the main beam and the height of the bridge tower; c1, c2, c3 and r are determined according to the actual concrete cost, steel strand cost, material transportation conditions and structural size parameters; k1 represents the reduction coefficient of the main beam cross-sectional area, which is 0.6 considering that the main beam adopts a variable cross-section; k2 represents the reduction coefficient of the length of the inclined cable, which is 0.6 considering that it is uniformly calculated according to the side cable length.

9. The parametric design method for a high-speed railway multi-tower partially cable-stayed bridge according to claim 1, characterized in that: The calculation formula of the engineering technical difficulty is: b i =A i ×B i ×C i ×D i ; In the formula, β i Engineering technical difficulty; Engineering A i Indicates the main span influence coefficient; B i Indicates the influence coefficient of bridge tower height; C i Indicates the influence coefficient of pier height; D i Indicates the influence coefficient of bridge foundation type; the specific determination method of each coefficient in the formula is: establish the main span L i With A i A is a nonlinear function of i According to the main span value, A i ∈(0,1]; establish the bridge tower height H i With B i The nonlinear function B i According to the height of the bridge tower, B i ∈(0,1]; Establish the bridge pier height G i With C i The nonlinear function, C i According to the height of the bridge pier, C i ∈(0,1]; D i Values ​​are taken based on the foundation type: if the foundation type is pile foundation, D i Take 1.0; The foundation type is pipe column foundation, D i Take 1.1; the foundation type is caisson foundation, D i Take 1.

2.

10. The parametric design method for a high-speed railway multi-tower partially cable-stayed bridge according to claim 1, characterized in that: Normalize the total cost of the design solution: Map the result to (0,1]; then normalize the total cost coefficient φ i and engineering technology difficulty coefficient β i Perform weighted averaging and establish a solution decision formula: Among them, φ i represents the cost coefficient of each design scheme obtained after normalization; β i Indicates the engineering technology difficulty coefficient; Represents the weight coefficient, which is adjusted according to local terrain conditions, transportation conditions and material supply; ε i represents the decision coefficient of the scheme; S i represents the sample value of the total construction cost, S imax Indicates the maximum value of the total cost sample. According to this formula, the decision coefficient ε of different schemes is calculated i , take ε i For smaller values, 2-3 optimal design plans will be formulated.

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