A design method for an asymmetric inclined arch cable-stayed landscape bridge

Abstract

This application relates to the field of landscape bridge design, specifically disclosing a design method for an asymmetric inclined arch cable-stayed landscape bridge, comprising the following steps: a. simulating and determining component parameters; b. generating a finite element structural analysis model; c. performing structural analysis calculations; d. exporting the calculation results of the model family (#imgabs0#); e. exporting the calculation results of the model family (#imgabs1#); f. verifying the structural model; and g. optimizing component cross-sections and verifying bearing capacity. By applying this design method, the human input in the design process can be significantly reduced, and digital means can be used to perform rapid and efficient parametric iterative design of the target design bridge. This method strives to find the optimal solution during the design process, reducing the designer's time and cost, improving efficiency, and achieving good economic and social benefits.

Description

Technical Field

[0001] The present application relates to the field of landscape bridge design, and in particular to a design method for an asymmetric inclined arch cable-stayed landscape bridge. Background Art

[0002] With the development of the economy and society, the purpose of bridge construction has expanded beyond simply satisfying transportation needs. Designers are now focusing on designing landscape bridges that not only fulfill their functional needs but also reflect the city's economic and technological development. Guided by aesthetic design principles, landscape bridges are created by integrating art and structure, taking into account engineering conditions and regional characteristics. Landscape bridges come in a variety of forms, with arch cable-stayed bridges, inclined column-tower cable-stayed bridges, and inclined arch cable-stayed landscape bridges being the most commonly used in engineering.

[0003] For example, the patent for invention with the authorization announcement number CN106592407A, titled "A Bridge Design Method for a Cable-Stayed-Arch Bridge System," includes the following steps:

[0004] (1) According to the span, width and load requirements of the arch bridge, the arch rib span ratio is determined to be 1 / 5-1 / 3 and the number of cables in the bridge facade is determined to be 12;

[0005] (2) Divide the main beam into 7 equal parts along the span direction, and select 6 hanging points on the main beam in sequence: point A, point B, point C, point D, point E, and point F. At the same time, divide the arch rib into 8 equal parts along the horizontal direction, and select 7 hanging points on the arch rib in sequence;

[0006] (3) Cable arrangement: Connect points A, B, C, D, E and F on the main beam to the hanging points on the arch rib in sequence through cables.

[0007] Regarding the above-mentioned related technologies, the inventors believe that the design process of cable-stayed bridges (landscape bridges) is usually carried out in a manual and mechanized manner, and the processes of finding the shape, scheme design, and in-depth design are carried out in sequence. During the operation, the scheme comparison is not carried out through an iterative parametric method. The design method is inefficient and usually cannot effectively screen out the optimal solution. Summary of the Invention

[0008] In order to improve the problems of difficult shape finding and structural optimization of inclined arch cable-stayed landscape bridges, the present application provides a design method for an asymmetric inclined arch cable-stayed landscape bridge.

[0009] This application provides a design method for an asymmetric inclined arch cable-stayed landscape bridge, which adopts the following technical solutions:

[0010] A design method for an asymmetric inclined arch cable-stayed landscape bridge, comprising:

[0011] a. Simulate and determine component parameters;

[0012] b. Generate finite element structural analysis model;

[0013] c. Structural analysis and calculation;

[0014] d. Export the calculation results of the model family (α);

[0015] e. Export the calculation results of the model family (n);

[0016] f. Structural model testing;

[0017] g. Component section optimization and bearing capacity verification.

[0018] Optionally, the step a) simulating and determining component parameters specifically includes the following steps:

[0019] Step S1: Based on the design data, a preliminary architectural design of the landscape bridge is performed. The distance between the bridge end supports of the landscape bridge, i.e., the span l of the bridge, is determined according to actual needs and landscape effects, and the axis y1(x) of the bridge deck curvature is determined.

[0020] Step S2: Based on the bridge deck axis and load, the bridge deck is equivalent to a normal straight bridge deck to obtain the equivalent bridge deck axis and bridge deck load;

[0021] Step S3: Based on the equivalent bridge deck axis and bridge deck load, calculate the height of the inclined arch and the distribution position of each cable point on the inclined arch according to the ordinary cable-stayed bridge; the calculation method of the ordinary cable-stayed bridge is to determine the vertical component of each cable according to the equivalent load on the beam and the equivalent bending moment on the beam, and then determine the horizontal component of the cable according to the bearing capacity of the cable, thereby determining the cable angle, and finally determine the optimal position of the cable top according to the cable angle and the beam span.

[0022] Step S4: Assuming that the cable strength is infinite and the number of cables is the same as that of the equivalent bridge design in step S3, the actual curved bridge deck is designed. The inclination angle range [α1, α2] of the inclined arch is calculated based on the static equilibrium of the inclined tower bridge.

[0023] The static equilibrium calculation method is as follows: assuming that the cable strength is infinite, the horizontal curved bridge deck is regarded as an arch. For each given inclination angle α of the inclined arch, it can be determined that there is only one unique cable inclination angle β. Based on the cable inclination angle β and the vertical force Fvert of the cable obtained in step S3, it can be concluded that the horizontal component of the cable is Fhorizontal = Fvertical / tanβ.

[0024] Project the inclined arch onto the bridge deck plane to obtain the horizontal sub-arch of the inclined arch. Apply F transversely to the horizontal sub-arch model of the inclined arch to calculate whether it meets the ultimate bearing capacity state. The minimum α value that can meet the bearing capacity of the horizontal sub-arch is α1.

[0025] The arch model formed by the transverse action F on the bridge deck plane is calculated to determine whether it meets the ultimate bearing capacity of the bridge deck. The maximum α value that can meet the bearing capacity of the bridge deck is α2.

[0026] Step S5: Based on the inclination angle range of the inclined arch described in S4, in the first design analysis, it is assumed that the inclination angle α of the inclined arch to the horizontal plane is the maximum allowable inclination angle α2;

[0027] Step S6: Divide the bridge deck and the inclined arch into n segments evenly according to their horizontal projection lengths, where n ranges from 1 to n². The upper limit of the number of segments, n², is determined by the minimum spacing allowed by construction operations and engineering experience. In the first design analysis, it is assumed that n = n².

[0028] Step S7: According to the segmentation method of step S6, the endpoints of each bridge deck and inclined arch on the same horizontal plane are used as the cable endpoints to determine the number of cables; the cable cross-section is preliminarily selected based on engineering experience. Under normal circumstances, the diameter of the cable cross-section is generally 10 cm. The size of the cable cross-section is directly related to the length and weight of the bridge deck and the number of cables. For example, a cable with a diameter of 12 cm has an axial force of 500 tons, and a cable with a diameter of 7 cm has an axial force of 200 tons.

[0029] Optionally, the step b) generating a finite element structural analysis model specifically includes the following steps:

[0030] Step S8: Determine the spatial coordinates of each component endpoint based on the component parameters in steps S2-S7, and compile the spatial position, physical properties, cross-sectional attributes, and structural boundary condition information of each component into a command file that can be recognized by the finite element analysis software;

[0031] Step S9: According to the command file with preliminary design model information recorded in step S8, the command file is read in the finite element analysis software, and the curved bridge deck and the inclined arch are divided into n sections on average according to the calculated span l of the landscape bridge and the inclination f1 of the curved bridge deck plane, the inclination angle α of the inclined arch, and the inclination f2 of the inclined arch plane. The end points of each section are connected to determine the position of the cable, the component cross-section information, component material information, and structural boundary conditions are read, and a finite element structural analysis model is generated. The structural force analysis and calculation are performed according to the uniformly distributed pedestrian load on the bridge deck.

[0032] Optionally, the structural analysis calculation c specifically includes the following steps:

[0033] Step S10: Read the command stream of the model building and analysis process in the finite element analysis software according to the operation steps described in steps S1-S9, and generate a new command file;

[0034] Optionally, the calculation results of d and deriving the model family (α) specifically include the following steps:

[0035] Step S11: According to the structural analysis calculation steps S9-S10, based on the calculation results, if there are cables under pressure or without pressure, first reduce the inclination angle α of the skew arch, re-assign the values and generate a data file containing the analysis model command stream, iteratively execute step S9 for the group of model families (α), and derive the calculation results of the model family (α);

[0036] Step S12: according to the analysis result of step S9, the cable tension thresholds [T1, T2] are set, where the upper limit T1 and the lower limit T2 of the threshold are determined by the cable material, the initially selected cross-sectional form, and the actual stress conditions;

[0037] When the results derived from the finite element analysis show that all cables are subjected to tension and the tension is within the threshold range, the preliminary structural model is considered to meet the structural stress requirements. The model with the smallest cable tension variance is selected from the calculation results of this model family (α), and its parameter α is used as the theoretical optimal skew arch inclination angle.

[0038] Optionally, the step e. deriving the calculation results of the model family (n) specifically includes the following steps:

[0039] Step S13: If the finite element calculation results derived from steps S9-S12 cannot meet the requirements of step S12, then a new model family (n) is reconstructed by adjusting the number n of bridge deck and inclined arch segments. The approximate convergence parameter α described in step S12 is known, n is reassigned, and a data file containing an analysis model command stream is generated. Step S9 is iteratively executed on the new model family (n). When the cables are all subjected to tension in the results derived from the finite element analysis, and the tension is within the threshold range, it is considered that the preliminary structural model meets the structural force requirements. The model with the smallest cable tension variance is selected from the calculation results of the model family (n), and its parameter n is used as the theoretical optimal number of cables.

[0040] Step S14: If the finite element calculation results derived from steps S9-S13 cannot meet the requirements of steps S12 and S13, the arch axis y1(x) in the curved bridge deck plane and the arch axis y2(x) in the inclined arch plane in step S9 are manually corrected according to the difference in the calculation results, and steps S9-S14 are re-executed.

[0041] Optionally, the structural model test f specifically includes the following steps:

[0042] Step S15: Based on the structural model of steps S9-S14, check whether the structural model meets reasonable usage requirements based on engineering experience and construction feasibility conditions on the basis of reasonable force. If not, manually correct the characteristic parameters of the inclined arch cable-stayed landscape bridge and execute steps S9-S14.

[0043] Optionally, the g, component cross-section optimization and bearing capacity verification, specifically include the following steps:

[0044] Step S16: Based on the structural model described in step S15, if the structure meets the actual use requirements, the component cross-section is further optimized to complete the necessary design process for bearing capacity verification.

[0045] Optionally, in step S2, the method of equivalent bridge deck axis and bridge deck load is: project the bridge deck axis on the bridge deck plane and the load on the bridge deck onto the vertical plane, the projection of the bridge deck axis on the vertical plane, i.e., the equivalent bridge deck axis, is the intersection line of the bridge deck plane and the vertical plane, and the projection of the load, i.e., the equivalent load, is q'(x)=∫q(x)dy.

[0046] Optionally, in step S4, the inclination angle range [α1, α2] is limited by factors such as the type of bridge, construction location, navigation requirements, and load conditions, and is first preliminarily determined by site conditions. The calculation of the inclination angle range [α1, α2] must simultaneously meet the requirements of earthquake resistance, wind resistance, stability, and deformation under current specifications.

[0047] In summary, the beneficial technical effects of this application are as follows: This design method improves the shortcomings of traditional landscape bridge design, such as difficulty in bridge form finding, improper structural stress, and waste of excess materials. By applying this design method, the human input in the design process can be greatly reduced. Digital means are used to perform rapid and efficient parametric iterative design of the target bridge design, striving to find the optimal solution during the design process, reducing the designer's time and cost, improving efficiency, and achieving good economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a structural diagram of the asymmetric inclined arch cable-stayed landscape bridge in this application;

[0049] Figure 2 A side view diagram of the asymmetric inclined arch cable-stayed landscape bridge of this application;

[0050] Figure 3 A design flow chart for simulating and determining component parameters in this application;

[0051] Figure 4 Generate a finite element structural analysis model and a flowchart of structural analysis calculations for this application;

[0052] Figure 5 A schematic diagram showing the distribution of the equivalent bridge deck axis and bridge deck load for the asymmetric inclined arch cable-stayed landscape bridge in this application;

[0053] Figure 6 This is the component parameter analysis diagram of the asymmetric inclined arch cable-stayed landscape bridge for this application.

[0054] Explanation of reference numerals: 1, curved bridge body; 11, curved bridge deck; 12, curved beam; 13, bridge handrail; 14, bridge railing;

[0055] 2. Bridge end support; 3. Support pier; 4. Inclined arch; 5. Cable. DETAILED DESCRIPTION

[0056] The following is combined with Figure 1-6 This application is described in further detail.

[0057] The embodiment of the present application discloses an asymmetric inclined arch cable-stayed landscape bridge. Figure 1 , Figure 2 The asymmetric inclined arch cable-stayed landscape bridge includes a curved bridge body 1, a bridge end support 2, a supporting pier 3, an inclined arch 4, and a cable 5. The curved bridge body 1 is connected to the road through an approach bridge. The connection point between the approach bridge (not shown) and the curved bridge body 1 is located at the top of the bridge end support 2.

[0058] The two ends of the curved bridge body 1 are connected to the bridge end supports 2 respectively. The bridge end supports 2 are giant concrete piers, which are rigidly connected to the bridge body and the bridge arch to resist bending moments.

[0059] The axis of the curved bridge body 1 is a curve, and the axis of the curved bridge body 1 is biased toward one side of the line connecting the two bridge end supports 2. The crossbeam at the bottom of the curved bridge body 1 is a trapezoidal cross-section beam to improve the torsion resistance of the curved bridge body 1 itself. The side of the curved bridge body 1 close to the inclined arch 4 is connected to the inclined arch 4 through a cable 5, and the supporting pier 3 is supported at the bottom of the curved bridge body 1;

[0060] The curved bridge body 1 mainly includes a curved bridge deck 11, a curved beam 12 supporting the curved bridge deck 11, bridge handrails 13 arranged on both sides of the curved bridge deck 11, and bridge railings 14 connected to the bridge handrails 13.

[0061] The two arch feet of the inclined arch 4 are connected to the bridge end support 2, and the fixing points of the cables 5 are arranged on the inclined arch 4; the cables 5 are multiple large steel cables, the first ends of which are connected to the inclined arch 4, and the second ends of which are connected to one side of the curved bridge body 1. Among them, the closer the connection point of the cable with the curved bridge body 1 is to the bridge end support 2, the lower the fixing point of its other end on the inclined arch 4.

[0062] Furthermore, in order to achieve rapid and efficient parametric iterative design of the above-mentioned asymmetric inclined arch cable-stayed landscape bridge, this embodiment discloses a design method for the asymmetric inclined arch cable-stayed landscape bridge, which is specifically as follows:

[0063] Reference Figure 3 , Figure 4 A design method for an asymmetric inclined arch cable-stayed landscape bridge comprises the following steps:

[0064] a. Simulate and determine component parameters, including the following steps:

[0065] Step S1: Based on the design data, conduct a preliminary architectural design of the landscape bridge, examine whether the design site is suitable for the use of a tilted tower cable-stayed landscape bridge, determine the distance between the bridge end supports, i.e., the span l of the bridge, and determine the axis y1(x) of the bridge deck curvature based on actual needs and landscape effects;

[0066] Step S2: Refer to Figure 5 , Figure 6 According to the bridge deck axis and load, the bridge deck is equivalent to an ordinary straight bridge deck to obtain the equivalent bridge deck axis and bridge deck load; the method of equivalent bridge deck axis and bridge deck load is: project the bridge deck axis and the load on the bridge deck on the bridge deck plane onto the vertical plane, the projection of the bridge deck axis on the vertical plane, that is, the equivalent bridge deck axis, is the intersection line of the bridge deck plane and the vertical plane, and the projection of the load, that is, the equivalent load, is q'(x)=∫q(x)dy.

[0067] Step S3: Based on the equivalent bridge deck axis and bridge deck load, calculate the height of the inclined arch and the distribution position of each cable point on the inclined arch according to the ordinary cable-stayed bridge; the calculation method of the ordinary cable-stayed bridge is to determine the vertical component of each cable according to the equivalent load on the beam and the equivalent bending moment on the beam, and then determine the horizontal component of the cable according to the bearing capacity of the cable, thereby determining the cable angle, and finally determine the optimal position of the cable top according to the cable angle and the beam span.

[0068] Step S4: Assuming that the strength of the cable 5 is infinite, the number of cables 5 is the same as that of the equivalent bridge design in step S3, and the actual curved bridge deck is designed. The inclination angle range [α1, α2] of the inclined arch 4 is obtained based on the static equilibrium calculation of the inclined tower bridge;

[0069] The static equilibrium calculation method is as follows: assuming that the strength of the cable 5 is infinite, the horizontal curved bridge deck is regarded as an arch. For each given inclination angle α of the inclined arch, it can be determined that there is only one unique cable inclination angle β. Based on the cable inclination angle β and the vertical force Fvert of the cable 5 obtained in step S3, it can be concluded that the horizontal component of the cable 5 is Fhorizontal = Fvertical / tanβ.

[0070] Project the inclined arch 4 onto the bridge deck plane to obtain the horizontal sub-arch of the inclined arch 4. Apply F transversely to the horizontal sub-arch model of the inclined arch 4 to calculate whether it meets the ultimate bearing capacity state. The minimum α value that can meet the bearing capacity of the horizontal sub-arch is α1.

[0071] The arch model formed by the transverse action F on the bridge deck plane is calculated to determine whether it meets the ultimate bearing capacity of the bridge deck. The maximum α value that can meet the bearing capacity of the bridge deck is α2.

[0072] The inclination angle range [α1, α2] is limited by factors such as the bridge type, construction location, navigation requirements, and load conditions. It is first preliminarily determined by site conditions. The calculation of the inclination angle range [α1, α2] must simultaneously meet the requirements of earthquake resistance, wind resistance, stability, and deformation under the current specifications.

[0073] Step S5: Based on the inclination angle range of the inclined arch 4 described in S4, in the first design analysis, it is assumed that the inclination angle α of the inclined arch 4 and the horizontal plane is the maximum allowable inclination angle α2;

[0074] Step S6: Divide the deck and the inclined arch 4 of the curved bridge body 1 into n segments according to their horizontal projection lengths. The value of n ranges from [1, n²], where the upper limit n² of the number of segments is determined by the minimum spacing allowed by construction operations and engineering experience. In the first design analysis, it is assumed that n = n².

[0075] Step S7: According to the segmentation method of step S6, the endpoints of each bridge deck section and the inclined arch 4 on the same horizontal plane are used as the cable endpoints, the number of cables 5 is determined, and the cross-section of the cables 5 is preliminarily selected based on engineering experience.

[0076] The cable cross-section is preliminarily selected based on engineering experience. Under normal circumstances, the diameter of the cable cross-section is generally 10 cm. The size of the cable cross-section is directly related to the length and weight of the bridge deck and the number of cables. For example, a cable 5 with a diameter of 12 cm has an axial force of 500 t, and a cable 5 with a diameter of 7 cm has an axial force of 200 t.

[0077] b. Generate a finite element structural analysis model, which specifically includes the following steps:

[0078] Step S8: Determine the spatial coordinates of the endpoints of each component based on the component parameters in steps S2-S7, and compile the spatial position, physical properties, cross-sectional attributes, and structural boundary condition information of each component into a command file that can be recognized by finite element analysis software such as ANSYS or MIDAS;

[0079] Step S9: According to the command file with preliminary design model information recorded in step S8, the command file is read in the finite element analysis software, and the curved bridge deck and the inclined arch are divided into n sections on average according to the calculated span l of the landscape bridge and the inclination f1 of the curved bridge deck plane, the inclination angle α of the inclined arch, and the inclination f2 of the inclined arch plane. The end points of each section are connected to determine the position of the cable, the component cross-section information, component material information, and structural boundary conditions are read, and a finite element structural analysis model is generated. The structural force analysis and calculation are performed according to the uniformly distributed pedestrian load on the bridge deck.

[0080] c. Structural analysis and calculation, specifically including the following steps:

[0081] Step S10: According to the operation steps described in steps S1-S9, the command stream of the model establishment and analysis process in the finite element analysis software is read to generate a new command file; the main control parameters are the calculated span l of the landscape bridge, the inclination f1 in the curved bridge deck plane, the inclination f2 in the inclined arch plane, the inclination angle α of the inclined arch plane, and the number of horizontal segments n of the bridge deck and inclined arch (where n also represents the number of cables of the inclined arch cable-stayed landscape bridge). When one of the above main parameters is different and the other parameters are the same, the series of models is called a model family. The cross-sectional dimensions, physical properties, boundary conditions and other information of the components within the model family can vary to a certain extent, and are reasonably designed based on the calculation results. That is, the characteristics of the inclined arch cable-stayed landscape bridge can be regarded as related to the function F(l,f1,f2,α,n).

[0082] d. Deriving the calculation results of the model family (α), specifically including the following steps:

[0083] Step S11: According to the structural analysis calculation steps S9-S10, based on the calculation results, if there are cables 5 that are under pressure or not under pressure, first reduce the inclination angle α of the skew arch, re-assign the values and generate a data file containing the analysis model command stream, iterate step S9 for the group of model families (α), and derive the calculation results of the model family (α);

[0084] Step S12: according to the analysis result of step S9, the tension thresholds [T1, T2] of the cable 5 are set. The upper limit T1 and the lower limit T2 of the threshold are determined by the material of the cable, the initially selected cross-section, and the actual stress conditions.

[0085] When the results derived from the finite element analysis show that all cables are subjected to tension and the tension is within the threshold range, the preliminary structural model is considered to meet the structural stress requirements. From the calculation results of this model family (α), the model with the smallest tension variance of cable 5 is selected, and its parameter α is used as the theoretical optimal skew arch inclination angle.

[0086] e. Export the calculation results of the model family (n), which specifically includes the following steps:

[0087] Step S13: If the finite element calculation results derived from steps S9-S12 cannot meet the requirements of step S12, then a new model family (n) is reconstructed by adjusting the number n of segments of the bridge deck and the inclined arch 4. The approximate convergence parameter α described in step S12 is known, n is reassigned, and a data file containing an analysis model command stream is generated. Step S9 is iteratively executed on the new model family (n). When the cables 5 are all subjected to tension in the results derived from the finite element analysis, and the tension is within the threshold range, it is considered that the preliminary structural model meets the structural force requirements. The model with the smallest cable tension variance is selected from the calculation results of the model family (n), and its parameter n is used as the theoretical optimal number of cables.

[0088] Step S14: If the finite element calculation results derived from steps S9-S13 cannot meet the requirements of steps S12 and S13, the arch axis y1(x) in the curved bridge deck plane and the arch axis y2(x) in the inclined arch plane in step S9 are manually corrected according to the difference in the calculation results, and steps S9-S14 are re-executed.

[0089] f. Structural model verification, including the following steps:

[0090] Step S15: Based on the structural model of steps S9-S14, check whether the structural model meets reasonable usage requirements based on engineering experience and construction feasibility conditions on the basis of reasonable force. If not, manually correct the characteristic parameters of the inclined arch cable-stayed landscape bridge and execute steps S9-S14.

[0091] g. Component cross-section optimization and bearing capacity verification, specifically including the following steps:

[0092] Step S16: Based on the structural model described in step S15, if the structure meets the actual use requirements, the component cross-section is further optimized to complete the necessary design process for bearing capacity verification.

[0093] Furthermore, it should be noted that the inclined arch 4 and the curved bridge body 1 of the inclined arch cable-stayed landscape bridge of this patent do not need to share a support, that is, the inclined arch 4 and the curved bridge section of the curved bridge body 1 are provided with separate supports. In this case, the characteristics of the inclined arch cable-stayed landscape bridge can be regarded as related to the function F(x1,x2,x3,x4,y1,y2,y3,y4,f1,f2,α,n), where (x1,y1) is the starting point of the curved bridge section, (x2,y2) is the end point of the curved bridge section, (x3,y3) is the starting point of the inclined arch, and (x4,y4) is the end point of the inclined arch. The values of the parameters (x1,x2,x3,x4,y1,y2,y3,y4) are determined according to the use requirements of the landscape bridge, the geographical conditions of construction, and the structural stress characteristics.

[0094] During the initial analysis, it is assumed that (x1, y1) = (x3, y3) and (x2, y2) = (x4, y4). That is, during the initial analysis, the starting and ending points of the skew arch and the curved bridge segment are the same, and steps S1-S16 are executed. During the structural optimization phase, one of the values (x3, y3) and (x4, y4) is first adjusted, while the other parameters remain unchanged. The skew arch is then calculated based on static equilibrium conditions, requiring it to meet the requirements for seismic resistance, wind resistance, stability, and deformation under the prior load, with the bending moment and deformation within the skew arch being relatively minimal. Using the new starting and ending point coordinates of the skew arch as known parameters, steps S1-S16 are executed to complete the design.

[0095] In summary, this design method overcomes shortcomings in traditional landscape bridge design, such as difficulty in finding the bridge form, improper structural stress, and waste of excess materials. By applying this design method, it significantly reduces the human effort involved in the design process. By utilizing digital means, rapid and efficient parametric iterative design of the target bridge is achieved, striving to find the optimal solution during the design process, reducing the designer's time and cost, improving efficiency, and achieving significant economic and social benefits.

[0096] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A design method for an asymmetric oblique arch cable-stayed landscape bridge, characterized in that: include: a. Simulate and determine component parameters; b. Generate finite element structural analysis model; c. Structural analysis and calculation; d. Export the calculation results of the model family (α); e. Export the calculation results of the model family (n); f. Structural model testing; g. Component section optimization and bearing capacity verification; The above a. simulating and determining component parameters specifically includes the following steps: Step S1: Based on the design data, a preliminary architectural design of the landscape bridge is performed. The distance between the bridge end supports of the landscape bridge, i.e., the span l of the bridge, is determined according to actual needs and landscape effects, and the axis y1(x) of the bridge deck curvature is determined. Step S2: Based on the bridge deck axis and load, the bridge deck is equivalent to a normal straight bridge deck to obtain the equivalent bridge deck axis and bridge deck load; Step S3: Based on the equivalent bridge deck axis and bridge deck load, the height of the inclined arch and the distribution positions of the cable points on the inclined arch are calculated according to a common cable-stayed bridge; Step S4: Assuming that the cable strength is infinite and the number of cables is the same as that of the equivalent bridge design in step S3, the actual curved bridge deck is designed. The inclination angle range [α1, α2] of the inclined arch is calculated based on the static equilibrium of the inclined tower bridge. Step S5: Based on the inclination angle range of the inclined arch described in S4, in the first design analysis, it is assumed that the inclination angle α of the inclined arch to the horizontal plane is the maximum allowable inclination angle α2; Step S6: Divide the bridge deck and the inclined arch into n segments evenly according to their horizontal projection lengths, where n ranges from 1 to n². The upper limit of the number of segments, n², is determined by the minimum spacing allowed by construction operations and engineering experience. In the first design analysis, it is assumed that n = n². Step S7: According to the segmentation method of step S6, the endpoints of each bridge deck and inclined arch on the same horizontal plane are used as the cable endpoints, and the number of cables is determined; The step b) generating a finite element structural analysis model specifically includes the following steps: Step S8: Determine the spatial coordinates of each component endpoint based on the component parameters in steps S2-S7, and compile the spatial position, physical properties, cross-sectional attributes, and structural boundary condition information of each component into a command file that can be recognized by the finite element analysis software; Step S9: Based on the command file containing the preliminary design model information recorded in step S8, the command file is read into the finite element analysis software. Based on the calculated span l of the landscape bridge and the in-plane rise f1 of the curved bridge deck, the inclination angle α of the skew arch, and the in-plane rise f2 of the skew arch, the curved bridge deck and the skew arch are divided into n segments on average. The ends of each segment are connected to determine the cable positions. The component cross-sectional information, component material information, and structural boundary conditions are read to generate a finite element structural analysis model. The structural force analysis and calculation are performed according to the uniformly distributed pedestrian load on the bridge deck. The structural analysis and calculation mentioned in c) specifically includes the following steps: Step S10: According to the operation steps described in steps S1-S9, the command stream of the model establishment and analysis process in the finite element analysis software is read to generate a new command file; wherein the main control parameters are the calculated span l of the landscape bridge, the inward rise f1 of the curved bridge deck plane, the inward rise f2 of the inclined arch plane, the inclination angle α of the inclined arch plane, and the number of horizontal segments n of the bridge deck and the inclined arch; When one of the above main parameters is different and the other parameters are the same, the series of models is called a model family, and the characteristics of the inclined arch cable-stayed landscape bridge are considered to be related to the function F(l,f1,f2,α,n); The calculation results of the d and derived model family (α) specifically include the following steps: Step S11: According to the structural analysis calculation steps S9-S10, based on the calculation results, if there are cables under pressure or without pressure, first reduce the inclination angle α of the skew arch, re-assign the values and generate a data file containing the analysis model command stream, iteratively execute step S9 for the group of model families (α), and derive the calculation results of the model family (α); Step S12: according to the analysis result of step S9, the cable tension thresholds [T1, T2] are set, where the upper limit T1 and the lower limit T2 of the threshold are determined by the cable material, the initially selected cross-sectional form, and the actual stress conditions; When the results derived from the finite element analysis show that all cables are subjected to tension and the tension is within the threshold range, the preliminary structural model is considered to meet the structural stress requirements. The model with the smallest cable tension variance is selected from the calculation results of the model family (α), and its parameter α is used as the theoretical optimal skew arch inclination angle. The step e. deriving the calculation results of the model family (n) specifically includes the following steps: Step S13: If the parameter α in step 1 is known, reassign n and generate a data file containing the analysis model command stream. If the finite element calculation results derived from S9-S12 do not meet the requirements of step S12, then adjust the number of bridge deck and skew arch segments n to reconstruct a new model family (n). Iterate step S9 on the new model family (n) using the approximate convergence described in step S12. When the results derived from the finite element analysis show that all cables are subjected to tension and the tension is within the threshold range, the preliminary structural model is considered to meet the structural stress requirements. The model with the smallest cable tension variance is selected from the calculation results of the model family (n), and its parameter n is used as the theoretical optimal number of cables. Step S14: If the finite element calculation results derived from steps S9-S13 cannot meet the requirements of steps S12 and S13, the arch axis y1(x) in the curved bridge deck plane and the arch axis y2(x) in the inclined arch plane in step S9 are manually corrected according to the difference in the calculation results, and steps S9-S14 are re-executed.

2. The design method of an asymmetric inclined arch cable-stayed landscape bridge according to claim 1, characterized in that: The structural model test comprises the following steps: Step S15: Based on the structural model of steps S9-S14, check whether the structural model meets reasonable usage requirements based on engineering experience and construction feasibility conditions on the basis of reasonable force. If not, manually correct the characteristic parameters of the inclined arch cable-stayed landscape bridge and execute steps S9-S14.

3. The design method of an asymmetric inclined arch cable-stayed landscape bridge according to claim 2 is characterized by: The g. Component cross-section optimization and bearing capacity verification specifically include the following steps: Step S16: Based on the structural model described in step S15, if the structure meets the actual use requirements, the component cross-section is further optimized to complete the necessary design process for bearing capacity verification.

4. The design method of an asymmetric inclined arch cable-stayed landscape bridge according to claim 1 is characterized by: In step S2, the method for equating the bridge deck axis and the bridge deck load is: Project the bridge deck axis and the load on the bridge deck on the bridge deck plane onto the vertical plane. The projection of the bridge deck axis on the vertical plane, i.e., the equivalent bridge deck axis, is the intersection of the bridge deck plane and the vertical plane. The projection of the load, i.e., the equivalent load, is q'(x) = ∫q(x)dy.

5. The design method of an asymmetric inclined arch cable-stayed landscape bridge according to claim 1 is characterized by: In step S4, the inclination angle range [α1, α2] is limited by factors such as the bridge type, construction site, navigation requirements, and load conditions. It is first preliminarily determined by site conditions. The calculation of the inclination angle range [α1, α2] must simultaneously meet the requirements of earthquake resistance, wind resistance, stability, and deformation under current specifications.

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