Fishback type thin-walled continuous rigid frame aqueduct structure and design method thereof

Abstract

The application discloses a fish-ridge type thin-wall continuous rigid frame aqueduct structure and a design method thereof, and relates to the technical field of hydraulic engineering. The upper water conveying load-bearing structure comprises a water conveying section and a variable-height reinforcing section, and the pier column is used for supporting the water conveying section; the variable-height reinforcing section extending upwards is arranged at the position of the water conveying section opposite to the top of the pier column; the variable-height reinforcing section is symmetrically arranged along the center line of the height direction of the pier column; the neutral axis of the upper water conveying load-bearing structure at the variable-height reinforcing section region is located above the water passing section. By means of the application, the neutral axis is actively controlled to move upwards through the variable-height reinforcing section, a stress distribution mode mainly taking the water passing section as compression and the variable-height reinforcing section as tension is formed, the whole aqueduct structure is safer and more durable while the crossing capacity is reserved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water conservancy engineering, in particular to a fish-ridge thin-walled continuous rigid structure aqueduct and a design method thereof. BACKGROUND

[0002] In recent years, China's water conservancy construction has entered a boom, and is accelerating the construction of the national water network. Aqueducts are the most widely used crossing structures in water diversion projects. However, in mountainous areas, the construction of aqueducts often encounters high overhead, crossing wide and gentle valleys, highways, railways, navigable rivers, etc. The crossing capacity of simply supported beam aqueducts with a maximum span of about 40m is limited, and there is an urgent need for new aqueduct structure systems and supporting design methods that can greatly improve the crossing capacity.

[0003] Prestressed concrete continuous rigid frame bridges are one of the commonly used bridge types in the field of highways and railways. Due to the mechanical characteristics of continuous beam, consolidation of piers, beams, and foundations, etc., the crossing capacity is extremely strong, and the hanging basket construction can be used to reduce the impact on the lower part. The Caodi Slope, Xujiawan, Hegoutou, Jiaojia Aqueducts of the First Phase Project of Guizhou Central Water Conservancy Hub and the Hongshuihe Aqueduct of the Water Diversion and Irrigation Area Project of the Le'an Reservoir of the Guizhong Water Control in Guangxi refer to the size of the prestressed continuous rigid frame bridge of the highway and propose a variable box and variable cross-section prestressed continuous rigid frame aqueduct type, which increases the main span of the aqueduct structure below 25m 3 to more than 100m.

[0004] Although the variable box and variable cross-section prestressed continuous rigid frame aqueducts in the above projects have improved the crossing capacity, they basically use the highway and railway industry standards, and the water passage section is located above the load-bearing structure, resulting in the water passage section being located in the negative bending moment zone, as shown in Figure 1 Once the prestress fails or partially fails, combined with the creep of concrete, the main beam is at high risk of cracking and leakage, and the design of variable cross-section also brings certain difficulties to design and construction. Therefore, it is a problem to be solved in the field to propose a new aqueduct structure and design method that can achieve or even improve the crossing capacity of the current technical solution and make the structure safer and more durable. SUMMARY

[0005] To solve the problems of the prior art, the purpose is to provide a fish-ridge thin-walled continuous rigid structure aqueduct and a design method thereof. By using the present application, the neutral axis is actively controlled to move up by changing the height of the reinforcement section, forming a stress distribution pattern in which the water passage section is mainly in compression and the variable height reinforcement section is mainly in tension. The crossing capacity is retained while making the entire aqueduct structure safer and more durable.

[0006] The present application is implemented by the following technical solutions:

[0007] A fish-ridge thin-walled continuous rigid structure aqueduct, comprising:

[0008] The upper water conveying load-bearing structure and the pier column;

[0009] The upper water conveying load-bearing structure comprises a water conveying section and a variable-height reinforcing section, and the pier column is used for supporting the water conveying section; a variable-height reinforcing section extending upwards is arranged at a position of the water conveying section opposite to the top of the pier column; and the variable-height reinforcing section is symmetrically arranged along the center line of the height direction of the pier column.

[0010] The neutral axis of the upper water conveying load-bearing structure at the variable-height reinforcing section area is located above the water passing section.

[0011] In the prior art, the water passing section is located above the load-bearing structure, which leads to the problem that the water passing section is located in the negative bending moment area, and once the prestress fails, the main beam is at a huge risk of cracking and leakage. The present application provides a fish-ridge type thin-walled continuous rigid frame aqueduct structure and a design method thereof. By actively controlling the upward movement of the neutral axis through the variable-height reinforcing section, a stress distribution mode in which the water passing section is mainly in compression and the variable-height reinforcing section is mainly in tension is formed, so that the entire aqueduct structure is safer and more durable while the crossing capacity is retained. In the specific scheme, from top to bottom, the upper water conveying load-bearing structure, the pier column and the foundation structure are sequentially arranged. The upper water conveying load-bearing structure comprises a water conveying section. In view of the stress characteristics of the aqueduct structure during construction and operation, a variable-height reinforcing section is added to the upper side of the water conveying section. The variable-height reinforcing section is mainly arranged at a position corresponding to the pier column, so as to realize the upward and downward distribution of the variable-height reinforcing section and the pier column. In this way, by actively controlling the centroid of the variable-height reinforcing section section, the upward movement of the neutral axis is realized, so that the neutral axis is located above the water passing section. Thus, a stress distribution mode in which the water passing section is mainly in compression and the variable-height reinforcing section is mainly in tension is formed. Specifically, the variable-height reinforcing section adopts a longitudinal gradually changing section design, which is similar to a fish-ridge shape. The height change function of the variable-height reinforcing section is positively correlated with the aqueduct bending moment envelope diagram, so that the structural bending stiffness and the bending moment demand are spatially matched. Under the synergistic action of the prestress system, the maximum tensile stress of the water passing section is reduced to within the allowable range of the design specification, so that the aqueduct is not prone to cracking, and the entire aqueduct structure is safer and more durable while the crossing capacity is retained. In addition, a pier column structure with appropriate stiffness can be selected according to the span and height of the aqueduct. The longitudinal stiffness of the pier column is reduced as much as possible under the premise of meeting the requirements of the stability of the aqueduct during construction and operation, so as to adapt to the horizontal displacement caused by factors such as temperature change, concrete shrinkage and creep. The transverse stiffness of the pier column is appropriately large, so as to adapt to the distortion and displacement of the aqueduct under the action of transverse unbalanced load or wind load, seismic load and the like. From the structure shape, a double-column thin-walled pier or a double-column solid pier, a single-column thin-walled pier or a single-column solid pier can be selected, and a V-shaped pier or a Y-shaped pier can also be selected. The foundation structure comprises a shallow foundation such as a plate foundation and a deep foundation such as a pile foundation and a caisson.

[0012] Further optimization, the highest point of the variable height reinforcing section is located on the center line of the pier column height direction, and the highest point on both sides is connected with the water conveying section through a straight line, a circular arc or a gentle curve. Preferably, the circular arc connection mode is adopted.

[0013] Further optimization, the highest point of the variable height reinforcing section is located on the center line of the pier column height direction, and the highest point on both sides is connected with the water conveying section through a straight line, a circular arc or a gentle curve. Preferably, the circular arc connection mode is adopted.

[0014] Further optimization, the highest point of the variable height reinforcing section is located on the center line of the pier column height direction, and the highest point on both sides is connected with the water conveying section through a straight line, a circular arc or a gentle curve. Preferably, the circular arc connection mode is adopted.

[0015] Further optimization, the variable height reinforcing section and the water conveying section are integrally formed.

[0016] Further optimization, a plurality of pier columns are sequentially supported along the length direction of the water conveying section, and the water conveying section is provided with a variable height reinforcing section corresponding to each pier column.

[0017] Further optimization, the upper water conveying load-bearing structure is a continuous aqueduct made of concrete or prestressed concrete with an equal cross-section single-box single-chamber or double-box double-chamber structure.

[0018] Further optimization, the water passing section of the upper water conveying load-bearing structure is in a rectangular, U-shaped, circular or trapezoidal shape.

[0019] Further optimization, the top surface of the upper water conveying load-bearing structure is made of weather-resistant steel, stainless steel plate or other materials to form a combined structure with the aqueduct concrete.

[0020] Further optimization, the upper water conveying load-bearing structure and the pier foundation structure can be designed according to the actual situation on site to achieve a good engineering landscape effect.

[0021] Further optimization:

[0022] The application also provides a design method of a fish-ridge type thin-wall continuous rigid aqueduct structure, which comprises the following steps:

[0023] S1: determining the span scheme of the fish-ridge type continuous rigid aqueduct structure according to external conditions; the span scheme comprises determining the maximum span and the minimum span of the pier column and the fish-ridge type continuous rigid aqueduct structure ;

[0024] S2: determining the size parameters and the cross-sectional type of the upper water conveying load-bearing structure according to hydraulics and engineering experience;

[0025] S3: then determining the ideal state of the fish-ridge size optimization model in accordance with the engineering​ , , and hy; wherein, hy is the center height of the variable height reinforcing section; and are the lengths from the center of the variable height reinforcing section to the two ends, respectively; is the distance from one end of the variable height reinforcing section to the end of the water conveying section on one side; is the distance from the other end of the variable height reinforcing section to the end of the water conveying section on the other side;

[0026] S4: Based on the preliminary scheme determined in steps S1-S3, the linear type of the variable height reinforcing section, the prestressed steel beam arrangement scheme, the construction sequence and the temporary support type are determined, respectively;

[0027] S5: Then, a three-dimensional finite element model of the fishback type continuous rigid frame aqueduct structure is established for structure simulation, and through stress control, the values of , , , and hy are continuously optimized and adjusted until the stress and deformation meet the requirements of the concrete design specification, so as to determine the parameters of the upper water conveying and bearing structure;

[0028] S6: Finally, the detailed structure design of the aqueduct and the design of the lower foundation are completed according to engineering experience and relevant specifications.

[0029] Further optimization, in the step S4, the prestressed steel beam arrangement scheme is preliminarily determined according to the load balance method and distribution law, wherein, is the self-weight load bending moment, is the water load bending moment, is the bending moment under the combined action of self-weight and water load.

[0030] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0031] The fishback type thin-walled continuous rigid frame aqueduct structure and the design method thereof provided by the present application adopt the present scheme, actively control the upward movement of the neutral axis through the variable height reinforcing section, form a stress distribution mode in which the water passing section is mainly in compression and the variable height reinforcing section is mainly in tension, and make the entire aqueduct structure safer and more durable while retaining the crossing capacity. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation to the scope, and other related drawings can also be obtained by those of ordinary skill in the art without any creative effort based on these drawings. In the drawings:

[0033] Figure 1 A schematic diagram of the prior art aqueduct design;

[0034] Figure 2 A schematic diagram of the fish-ridge type continuous rigid aqueduct structure provided by the present application;

[0035] Figure 3 A perspective view of the fish-ridge type continuous rigid aqueduct structure provided by the present application;

[0036] Figure 4 A normal stress distribution diagram of the fish-ridge type continuous rigid aqueduct structure provided by the present application;

[0037] Figure 5 A schematic diagram of various section forms of the fish-ridge type continuous rigid aqueduct structure provided by the present application;

[0038] Figure 6 A prestressed steel beam distribution diagram of the fish-ridge type continuous rigid aqueduct structure provided by the present application;

[0039] Figure 7 A working condition design diagram of the fish-ridge type continuous rigid aqueduct structure provided by the present application under automatic load;

[0040] Figure 8 A working condition design diagram of the fish-ridge type continuous rigid aqueduct structure provided by the present application under water load;

[0041] Figure 9 A rotational stiffness calculation design diagram of the fish-ridge type continuous rigid aqueduct structure provided by the present application;

[0042] Figure 10 A section size diagram of the upper water conveying bearing structure provided by the present application;

[0043] Figure 11 A normal stress distribution schematic diagram of the fish-ridge type continuous rigid aqueduct structure provided by the present application;

[0044] Figure 12 A normal stress distribution schematic diagram of the fish-ridge type continuous rigid aqueduct structure provided by the present application.

[0045] The marks in the drawings and the corresponding names of the parts are as follows:

[0046] 1 - upper water-carrying load-bearing structure, 101 - variable-height reinforcing section, 102 - prestressed steel tendon, 103 - water-carrying section, 2 - pier column. DETAILED DESCRIPTION

[0047] In order to make the objectives, technical solutions and advantages of the present application clearer, further detailed description of the present application is made below in combination with examples and drawings, the illustrative embodiments of the present application and the description thereof are only used to explain the present application and do not limit the present application.

[0048] Example 1: The present example 1 provides a fish-ridge type thin-walled continuous rigid frame aqueduct structure, as shown in Figures 2-6 , which comprises:

[0049] an upper water-carrying load-bearing structure 1 and a pier column 2;

[0050] The upper water-carrying load-bearing structure 1 comprises a water-carrying section 103 and a variable-height reinforcing section 101, and the pier column 2 is used to support the water-carrying section 103; a variable-height reinforcing section 101 extending upward is arranged at a position of the water-carrying section 103 opposite to the top of the pier column 2; the variable-height reinforcing section 101 is arranged symmetrically along the center line of the height direction of the pier column 2.

[0051] The neutral axis of the upper water-carrying load-bearing structure 1 at the variable-height reinforcing section 101 area is located above the water cross section.

[0052] Compared with the prior art, the water passing section is located in the negative bending moment area, and once the prestress fails, the main beam is at a huge risk of cracking and leakage, and the fish-ridge thin-walled continuous rigid frame aqueduct structure and the design method thereof are provided, and the height of the variable height reinforcing section 101 is actively controlled to move the neutral axis upward, a stress distribution mode in which the water passing section is mainly in compression and the variable height reinforcing section 101 is mainly in tension is formed, and the whole aqueduct structure is safer and more durable while the crossing capacity is reserved. In the specific scheme, from top to bottom, the upper water conveying load-bearing structure 1, the pier column 2 and the foundation structure are sequentially arranged, the upper water conveying load-bearing structure 1 comprises the water conveying section 103, and based on the stress characteristics of the aqueduct structure during construction and operation, the variable height reinforcing section 101 is arranged on the upper side of the water conveying section 103, the variable height reinforcing section 101 is mainly arranged at the position corresponding to the pier column 2, and the variable height reinforcing section 101 and the pier column 2 are arranged in a top-and-bottom mode, so that the neutral axis is moved upward by actively controlling the section centroid of the variable height reinforcing section 101, and the neutral axis is located above the water passing section, so that the stress distribution mode in which the water passing section is mainly in compression and the variable height reinforcing section 101 is mainly in tension is formed. Specifically, the variable height reinforcing section 101 adopts a longitudinal gradually changing cross-section design, is similar to a fish-ridge, and the height change function of the variable height reinforcing section 101 is positively correlated with the aqueduct bending moment envelope diagram, so that the structural bending stiffness and the bending moment demand are spatially matched, and under the synergistic action of the prestress system, the maximum tensile stress of the water passing section is reduced to the allowable range of the design specification, so that the aqueduct is not easy to crack, the whole aqueduct structure is safer and more durable while the crossing capacity is reserved. In addition, the pier column 2 structure with appropriate stiffness can be selected according to the span and height of the aqueduct, the longitudinal stiffness of the pier column 2 is reduced as much as possible under the premise of meeting the requirements of the stability of the aqueduct during construction and operation, so as to adapt to the horizontal displacement caused by factors such as temperature change, concrete shrinkage and creep. The transverse stiffness of the pier column 2 is appropriately large, so as to adapt to the distortion and displacement of the aqueduct under the action of transverse unbalanced load or wind load, seismic load and the like. From the structure shape, a double-column thin-walled pier or a double-column solid pier, a single-column thin-walled pier or a single-column solid pier can be selected, and a V-shaped pier or a Y-shaped pier can also be selected. The foundation structure comprises a shallow foundation such as a plate foundation, a pile foundation and a deep foundation such as a caisson.

[0053] In the embodiment, the highest point of the variable height reinforcing section 101 is located on the center line in the height direction of the pier column 2, and the highest point is connected to the water conveying section 103 through a straight line, a circular arc or a gentle curve.

[0054] In the embodiment, the highest point of the variable height reinforcing section 101 is connected to the water conveying section 103 through a curve.

[0055] In the embodiment, Figure 6As shown, a plurality of prestressed steel strands 102 are arranged in the variable-height reinforcing section 101, and the prestressed steel strands 102 are arranged along the length direction of the top surface of the variable-height reinforcing section 101.

[0056] In the embodiment, the variable-height reinforcing section 101 and the water conveying section 103 are integrally formed.

[0057] In the embodiment, a plurality of piers 2 are sequentially arranged along the length direction of the water conveying section 103, and the variable-height reinforcing section 101 is arranged at each pier 2.

[0058] In the embodiment, as shown, Figure 5 the upper water conveying load-bearing structure 1 is a continuous aqueduct made of concrete or prestressed concrete with an equal cross-section single-box single-cell or double-box double-cell structure.

[0059] In the embodiment, as shown, Figure 5 the water passing section of the upper water conveying load-bearing structure 1 is in a rectangular, U-shaped, circular or trapezoidal shape.

[0060] Embodiment 2: The embodiment 2 is further optimized on the basis of the embodiment 1, as shown, Figures 2-12 a design method of a fish-ridge type thin-wall continuous rigid aqueduct structure is provided, which comprises the following specific steps:

[0061] 1. Preliminary determination of the span of the fish-ridge type continuous rigid aqueduct. First, collect the external conditions that have an influence on the arrangement of the supporting structure below the aqueduct, such as railways, highways, buildings, river channels and the like, and then select the supporting structure pier position and determine the maximum span and the minimum span according to the limiting conditions to preliminarily determine the span scheme of the aqueduct. The span is preferably arranged symmetrically, and the space below the building is not necessarily occupied to save the cost of land acquisition and demolition and highlight the advantages of the hanging basket construction.

[0062] 2. Determine the internal size of the aqueduct according to the aqueduct hydraulics calculation, and preliminarily determine the size of the aqueduct concrete structure according to engineering experience. The wall thickness can be 35-100 cm according to the general wall thickness t, as shown, Figure 5 the cross-sectional type can be selected from U-shaped, circular, egg-shaped, rectangular and the like, or can be arranged in multiple grooves.

[0063] 3. Select and determine the fish-ridge size according to the fish-ridge size optimization model of the present application. , , , hy. Wherein, as shown, Figure 7As shown, one pier column 2 and the upper water conveying section 103 form a unit, and the water conveying section 103 at the two ends is intercepted as the midpoint between the pier column 2 and the adjacent pier column 2; hy is the center height of the variable-height reinforcing section 101; and respectively the length from the center of the variable-height reinforcing section 101 to the two ends; is the distance from one end of the variable-height reinforcing section 101 to the end of the water conveying section 103 on one side; is the distance from the other end of the variable-height reinforcing section 101 to the end of the water conveying section 103 on the other side; in this way, the parameter design of a plurality of units can be quickly calculated.

[0064] 4. Draw the preliminary scheme structure of the fish-ridge type continuous rigid frame aqueduct according to the above arrangement parameters, and the straight line, circular arc or gentle curve is adopted to connect between the main beams of the fish-ridge structure, and the circular arc connection mode is preferably selected, and the circular arc or other curve such as hyperbolic curve can be selected for the transition at the top according to the modeling requirements.

[0065] 6. The arrangement scheme of the prestressed steel beam 102 is preliminarily determined according to the load balance method and distribution law, wherein, is the self-weight load bending moment, is the water load bending moment, is the bending moment under the combined action of the self-weight and water load.

[0066] 7. The construction scheme is preliminarily designed according to the length of each section of 3-5 m, and the construction sequence and temporary support form are determined.

[0067] 8. The three-dimensional finite element model is established to carry out structure simulation. The stress control principle is that the inner surface of the 1-3 grade aqueduct is controlled to not appear cracks according to the strict requirements, the outer surface is controlled to not appear cracks according to the general requirements, and the 4-5 grade aqueduct is controlled to not appear cracks according to the general requirements.

[0068] 9. According to the simulated structure, the values of the aqueduct , , , and hy are continuously optimized and adjusted until the stress and deformation meet the requirements of the concrete design specification, and the aqueduct upper structure is determined.

[0069] 10. Finally, the aqueduct detailed structure design and the lower foundation design are completed according to the engineering experience and the related specifications.

[0070] In the above steps, the fish-ridge size optimization model in the third point is:

[0071] First, the conditions are set , , ; then the maximum double cantilever and only considering the self-weight action are calculated respectively 、 、 、 Self-weight bending moment of each segment , Total length of water conveying section 103, Maximum value of design span in the middle of the span, Minimum value of design span in the middle of the span, Material volume of the upper water conveying load-bearing structure 1, Total width of the upper water conveying load-bearing structure 1, Height of the water conveying section 103 below the variable-height reinforcing section 101, Thickness of the side wing plate, Distance between the two wing plates, Thickness of the bottom web plate, Maximum height of the variable-height reinforcing section 101; as shown in Figure 7 Wherein:

[0072] ;

[0073] In the above formula, Self-weight load, Distance between the side end of the water conveying section 103 and any point thereof, L is the total length of the water conveying section 103, Peak value of triangular distribution load generated by the self-weight of the fishback.

[0074] Subsequently, under the working condition of water passing and only considering the water load, the water load bending moment of each segment is calculated respectively 、 、 、 Self-weight bending moment of each segment ; as shown in Figure 8 Wherein:

[0075] ;

[0076] In the above formula, μ BA Bending moment distribution coefficient of the side span, M is the distributed bending moment, Water load, μ BC Bending moment distribution coefficient of the middle span.

[0077] In the process of calculating the above bending moments, the following steps are also included:

[0078] 1、 Figure 9 A rigid arm constraint is applied to the middle structure at point B, and the basic system of displacement method is obtained. BA is a single-span beam with one end fixed and one end simply supported, BC is a single-span beam with one end fixed and one end oriented, and BD is a single-span beam with both ends fixed.

[0079] 2. Fixed-end moment: the end moment of the member caused by external load in the displacement method basic system, as shown in the following formula, the following part is positive in tension.

[0080] 3. Rotational stiffness calculation: as follows: , , . , , , is a variable cross-section; in the formula: is the side span member stiffness, is the midspan member stiffness, is the pier column 2 member stiffness, is the BA bar rotational stiffness, is the BC bar rotational stiffness, is the BD bar rotational stiffness, is the calculated value, is the calculated value, is the calculated value.

[0081] 4. Distribution coefficient: μ BA = , μ BC = , μ BD = , μ BA is the BA bar distribution coefficient, μ BC is the BC bar distribution coefficient, μ BD is the BD bar distribution coefficient.

[0082] 5. Distribution and transmission: distribute the unbalanced moment to each member and transmit it to the far end.

[0083] 6. Final moment: add the fixed-end moment and the distributed or transmitted moment according to the superposition principle to obtain the final end moment.

[0084] wherein the fixed-end moment:

[0085] ;

[0086] distributed moment: ;

[0087] Moment distribution process:

[0088] ;

[0089] wherein, , according to the above formula, the self-weight moment and the water load moment can be obtained, and finally according to the function and substituting Thus the optimal ; wherein is the support reaction force of point A.

[0090] In the above formula, the fixed-end bending moment refers to fixing the rotation joint as the basic system of displacement method, and the bar end bending moment generated by the external load on the basic system. is the fixed-end bending moment of point A of AB bar, is the fixed-end bending moment of point B of BA bar, is the fixed-end bending moment of point B of BC bar, is the fixed-end bending moment of point C of CB bar, is the fixed-end bending moment of point B of BD bar;

[0091] M is the unbalanced moment, the unbalanced moment is the sum of the fixed-end bending moments of the bars connected to the rotation joint, and its value is equal to the rigid arm reaction moment. is the bending moment value of point B of BA bar after bending moment distribution, is the bending moment value of point B of BC bar after bending moment distribution, is the bending moment value of point B of BD bar after bending moment distribution, is the bending moment value of point C of CB bar after bending moment distribution, is the bending moment value of point D of DB bar after bending moment distribution. The distribution process is shown in the following table:

[0092] Bending moment distribution process table

[0093]

[0094] By using the above scheme, the neutral axis is actively controlled to move up by the variable height reinforcing section 101, forming a stress distribution mode in which the water passing section is mainly in compression and the variable height reinforcing section 101 is mainly in tension, that is, by adjusting the variable height fishback structure at the top of the aqueduct and the prestressed steel beam, it is relatively easy to keep the water passing section in compression stress, and at the same time, the entire aqueduct structure is safer and more durable while retaining the crossing capacity.

[0095] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A fishback-shaped thin-walled continuous rigid frame aqueduct structure, characterized in that, include: Upper water conveyance load-bearing structure (1) and pier (2); The upper water conveyance load-bearing structure (1) includes a water conveyance section and a variable height reinforcement section (101). The pier (2) is used to support the water conveyance section. A variable height reinforcement section (101) extending upward is provided at the position of the water conveyance section directly opposite the top of the pier (2). The variable height reinforcement section (101) is symmetrically arranged along the center line of the height direction of the pier (2). The neutral axis of the upper water conveyance load-bearing structure (1) in the variable height reinforced section (101) area is located above the water passage section; The variable height reinforced section (101) includes a chamber added at the top of the water conveyance section; The highest point of the variable height reinforced section (101) is transitioned by a curve; The variable height strengthening section (101) is also provided with a number of prestressed steel strands (102). The number of prestressed steel strands (102) are distributed sequentially in the height direction of the variable height strengthening section (101), and the prestressed steel strands (102) are arranged along the length direction of the top surface of the variable height strengthening section (101). The variable height reinforced section (101) and the water conveyance section are integrally formed.

2. The fishback-shaped thin-walled continuous rigid frame aqueduct structure according to claim 1, characterized in that, The highest point of the variable height reinforced section (101) is located on the center line of the height direction of the pier (2), and the two sides of the highest point are connected to the water conveyance section by straight lines, arcs or gentle curves.

3. The fishback-shaped thin-walled continuous rigid frame aqueduct structure according to claim 1, characterized in that, Several piers (2) are sequentially supported along the length of the water conveyance section, and a variable height reinforcement section (101) is provided at each of the piers (2) of the water conveyance section.

4. The fishback-shaped thin-walled continuous rigid frame aqueduct structure according to claim 1, characterized in that, The upper water conveyance load-bearing structure (1) is a continuous concrete or prestressed concrete aqueduct with a single-box single-chamber or double-box double-chamber structure of equal cross section.

5. The fishback-shaped thin-walled continuous rigid frame aqueduct structure according to claim 1, characterized in that, The water passage section of the upper water conveyance load-bearing structure (1) is rectangular, U-shaped, circular or trapezoidal.

6. The design method for a fishback-shaped thin-walled continuous rigid frame aqueduct structure according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1: Determine the span scheme of the fishback-shaped continuous rigid frame aqueduct structure based on external conditions; the span scheme includes determining the piers (2) and the maximum span of the fishback-shaped continuous rigid frame aqueduct structure. and minimum span ; S2: Determine the size parameters and cross-sectional shape of the upper water conveyance load-bearing structure (1) based on hydraulics and engineering experience; S3: Subsequently, the fishback spine size optimization model was used to determine the ideal state that conforms to engineering requirements. , , and hy; where hy is the center height of the variable height reinforcement section (101); and These are the lengths from the center of the variable height reinforced section (101) to both ends, respectively. The distance from one end of the variable height reinforced section (101) to the end of the water conveyance section on one side; The distance from the other end of the variable height reinforced section (101) to the end of the water conveyance section on the other side; S4: Based on the preliminary scheme determined in steps S1-S3, determine the alignment, prestressed steel strand arrangement, construction sequence and temporary support type of the variable height reinforced section (101); S5: Subsequently, a three-dimensional finite element model of the fishback-shaped continuous rigid frame aqueduct structure was established for structural simulation. Through stress control, the model was continuously optimized and adjusted. , , , And hy value, until the stress and deformation meet the requirements of the concrete design code, determine the parameters of the upper water conveyance load-bearing structure (1); S6: Finally, based on engineering experience and relevant specifications, complete the detailed structural design of the aqueduct and the design of its sub-foundation.

7. The design method for a fishback-shaped thin-walled continuous rigid frame aqueduct structure according to claim 6, characterized in that, In step S4, according to the load balance method and The distribution pattern has been preliminarily determined to determine the arrangement scheme of the prestressed steel strands, among which, The bending moment is due to its own weight. For water load bending moment, This is the bending moment caused by the combined action of its own weight and water load.

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