Road surface axle load conversion method and system based on heavy traffic, and readable storage medium

Abstract

The invention provides a road surface axle load conversion method and system based on heavy traffic and a computer readable storage medium, and the method comprises the steps: firstly determining the ground contact area and pressure of a tire of a heavy vehicle to calculate the ground contact pressure, and building a finite element model of a road surface structure; fitting is carried out based on the grounding pressure intensity and a pavement structure finite element model to obtain two types of axle load conversion coefficients under different axle loads, and then conversion is carried out according to the two types of axle load conversion coefficients to obtain two vehicle equivalent design axle load conversion coefficient expressions; therefore, a basis is provided for special design of the asphalt pavement under the conditions of heavy traffic and extra-heavy traffic, and the application requirements of increasing heavy-load and overload vehicles on the current road are met.

Description

Technical Field

[0001] This invention relates to the field of road transport construction technology, and more particularly to an axle load conversion method, and more specifically, to a road axle load conversion method and system based on heavy traffic, as well as a computer-readable storage medium. Background Technology

[0002] Due to a significant increase in traffic volume and the increasing weight of vehicles, overloading of freight trucks has become increasingly serious, severely impacting road surface structure. In recent years, influenced by the rising proportion of heavy-duty vehicles, asphalt roads have commonly exhibited early-stage defects after opening to traffic, with rutting being particularly prominent. Rutting not only affects driving comfort and safety but also increases subsequent maintenance and operation costs, and may even shorten the road's lifespan.

[0003] The rapid increase in heavy-duty vehicles has brought new challenges to the design, construction, and maintenance of asphalt roads in my country. Current asphalt pavement design methods in my country are based on standard axle loads and use allowable deflection and allowable stress as design indicators. There are no specific designs for asphalt pavements under heavy or extremely heavy traffic conditions. This makes it impossible to meet the application requirements of the ever-increasing number of heavy and overloaded vehicles.

[0004] Numerous achievements have been made regarding axle load conversion methods. CN111209667B - An axle load conversion method based on equivalent failure of asphalt pavement shear fatigue. However, while the above conversion method has been demonstrated in light-load traffic axle load conversion, it is not applicable to heavy-load traffic.

[0005] Therefore, there is an urgent need for a road axle load conversion scheme based on heavy traffic that can serve as a demonstration application in heavy traffic axle load conversion. Summary of the Invention

[0006] In view of the above problems, the purpose of this invention is to provide a method, system and computer-readable storage medium for road axle load conversion based on heavy traffic, so as to solve the problem that the existing axle load conversion methods are only for light traffic and lack axle load conversion for heavy traffic.

[0007] This invention provides a method for converting road axle loads based on heavy traffic, comprising:

[0008] Determine the tire contact area and pressure of heavy-duty vehicles to calculate the contact pressure, and establish a finite element model of the road structure;

[0009] The axle load conversion coefficient under different axle loads is obtained by fitting the ground pressure and the finite element model of the road structure.

[0010] The axle load conversion factor is used to obtain the vehicle equivalent design axle load conversion factor expression.

[0011] Preferably, fitting is performed based on the grounding pressure and the finite element model of the road structure to obtain axle load conversion coefficients under different axle loads, including:

[0012] Based on the grounding pressure and the finite element model of the pavement structure, axle load conversion models are established based on the permanent deformation of the asphalt mixture layer and the compressive strain of the top surface of the subgrade, respectively, to obtain the axle load conversion coefficients for permanent deformation and compressive strain under different axle loads.

[0013] Preferably, obtaining the axle load conversion factor for the permanent deformation includes:

[0014] According to the design specifications for asphalt pavement, the permanent deformation of each layer of the pavement is obtained when the permanent deformation of the asphalt mixture layer is used as the design index.

[0015] Based on the permanent deformation of each layer of the road surface, an axle load conversion model equivalent to the permanent deformation of the asphalt mixture layer is obtained.

[0016] Based on the grounding pressure and the finite element model of the road structure, the tensile stress at the bottom of the layer corresponding to different axle loads under different layer thicknesses on the road mixture layer is obtained, and the tensile stress at the bottom of the layer is substituted into the axle load conversion model to obtain the axle load conversion coefficients corresponding to different axle loads under different layer thicknesses on the road mixture layer.

[0017] The least squares method was used to fit the axle load conversion coefficients corresponding to different axle loads under different layer thicknesses on the pavement mixture layer to obtain the axle load conversion coefficient for permanent deformation.

[0018] Preferably, obtaining the compressive strain axial load conversion factor includes:

[0019] According to the design specifications for asphalt pavement of highways, a calculation model is obtained for the allowable vertical compressive strain of the top surface of the subgrade when the compressive strain of the top surface of the subgrade is used as the design index.

[0020] The roadbed top surface compressive strain under different axle loads is obtained based on the ground pressure and the finite element model of the road structure. The roadbed top surface compressive strain under different axle loads is then substituted into the calculation model of the allowable vertical compressive strain of the roadbed top surface to obtain the axle load conversion coefficient based on the equivalent principle of roadbed top surface compressive strain under different axle loads.

[0021] The least squares method was used to fit the axle load conversion coefficients based on the compressive strain equivalent principle of the roadbed top surface under different axle loads to obtain the compressive strain axle load conversion coefficients.

[0022] Preferably, the conversion is performed based on the axle load conversion factor to obtain the vehicle equivalent design axle load conversion factor expression, including:

[0023] A heavy-load cycle conversion coefficient model is established based on the aforementioned highway asphalt pavement design specifications.

[0024] The axle load conversion factor for permanent deformation is substituted into the preset formula for the equivalent design axle load conversion factor for a specific axle type in a specific axle load range and the axle load conversion model based on the equivalent permanent deformation of the asphalt mixture layer to obtain the equivalent design axle load conversion factor formula; the equivalent design axle load conversion factor formula is substituted into the heavy load conversion factor model to obtain the expression for the vehicle equivalent design axle load conversion factor for permanent deformation.

[0025] Preferably, the conversion is performed based on the axle load conversion factor to obtain the vehicle equivalent design axle load conversion factor expression, including:

[0026] A heavy-load cycle conversion coefficient model is established based on the aforementioned highway asphalt pavement design specifications.

[0027] The compressive strain axle load conversion factor is substituted into the preset formula for the equivalent design axle load conversion factor of a specific axle type in a specific axle load range and the calculation model of the allowable vertical compressive strain on the top surface of the roadbed to obtain the equivalent design axle load conversion factor formula; the equivalent design axle load conversion factor formula is substituted into the heavy load cycle conversion factor model to obtain the expression for the compressive strain vehicle equivalent design axle load conversion factor.

[0028] This invention also provides a road axle load conversion system based on heavy traffic, implementing the road axle load conversion method based on heavy traffic as described above, including:

[0029] The data storage module is used to determine the tire contact area and pressure of heavy-duty vehicles to calculate the ground pressure and to establish a finite element model of the road structure.

[0030] The data conversion module is used to fit the grounding pressure and the finite element model of the road structure to obtain the axle load conversion coefficient under different axle loads.

[0031] The standard conversion module is used to convert the axle load according to the axle load conversion factor to obtain the vehicle equivalent design axle load conversion factor expression.

[0032] Preferably, the data conversion module includes:

[0033] The permanent deformation coefficient calculation unit is used to establish an axle load conversion model based on the permanent deformation of the asphalt mixture layer of the pavement according to the ground pressure and the finite element model of the pavement structure, and to obtain the axle load conversion coefficient of permanent deformation under different axle loads.

[0034] The compressive strain coefficient calculation unit is used to establish an axle load conversion model based on the compressive strain of the roadbed top surface of the road surface according to the ground pressure and the finite element model of the road structure, and to obtain the compressive strain axle load conversion coefficient under different axle loads.

[0035] Preferably, the standard conversion module includes:

[0036] The permanent deformation equivalent conversion unit establishes a heavy-load cycle conversion coefficient model based on the highway asphalt pavement design specifications; it substitutes the permanent deformation axle load conversion coefficient into a preset formula for the equivalent design axle load conversion coefficient for a specific axle type in a specific axle load range and into the axle load conversion model based on the equivalent permanent deformation of the asphalt mixture layer to obtain the equivalent design axle load conversion coefficient formula; it then substitutes the equivalent design axle load conversion coefficient formula into the heavy-load cycle conversion coefficient model to obtain the expression for the vehicle equivalent design axle load conversion coefficient for permanent deformation.

[0037] The compressive strain equivalent conversion unit is used to establish a heavy-load cycle conversion coefficient model according to the highway asphalt pavement design specification; to substitute the compressive strain axle load conversion coefficient into the preset formula for the equivalent design axle load conversion coefficient of a specific axle type in a specific axle load range and the calculation model of the allowable vertical compressive strain of the roadbed top surface, so as to obtain the equivalent design axle load conversion coefficient formula; and to substitute the equivalent design axle load conversion coefficient formula into the heavy-load cycle conversion coefficient model, so as to obtain the compressive strain vehicle equivalent design axle load conversion coefficient expression.

[0038] In addition, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the road axle load conversion method based on heavy traffic as described above.

[0039] As can be seen from the above technical solution, the method, system, and computer-readable storage medium for road axle load conversion based on heavy traffic provided by this invention calculates the ground pressure by determining the tire contact area and pressure of heavy-duty vehicles, and establishes a finite element model of the road structure. Then, based on the ground pressure and the finite element model of the road structure, axle load conversion coefficients under two different types of axle loads are obtained. Subsequently, the conversion coefficients of the two types of axle loads are used to obtain the equivalent design axle load conversion coefficient expressions for two types of vehicles. This provides a basis for the special design of asphalt pavements under heavy traffic and extra-heavy traffic conditions, and meets the application requirements of the increasing number of heavy-duty and overloaded vehicles on current roads. Attached Figure Description

[0040] Other objects and results of the invention will become more apparent and readily understood by referring to the following description taken in conjunction with the accompanying drawings, and with a more complete understanding of the invention. In the drawings:

[0041] Figure 1This is a flowchart of a method for converting road axle loads based on heavy traffic, according to an embodiment of the present invention.

[0042] Figure 2 This is a schematic diagram of the fitting permanent deformation axle load conversion coefficient for the road axle load conversion method based on heavy traffic according to an embodiment of the present invention.

[0043] Figure 3 This is a schematic diagram of the fitting compressive strain axle load conversion coefficient of the pavement axle load conversion method based on heavy traffic according to an embodiment of the present invention.

[0044] Figure 4 This is a system block diagram of a road axle load conversion system based on heavy traffic according to an embodiment of the present invention. Detailed Implementation

[0045] The existing standard axle load conversion method is no longer suitable for heavy-duty traffic.

[0046] To address the aforementioned problems, this invention provides a method, system, and computer-readable storage medium for converting road axle loads based on heavy traffic. Specific embodiments of this invention will be described in detail below with reference to the accompanying drawings.

[0047] To illustrate the method and system for converting road axle loads based on heavy traffic provided by this invention, Figures 1-4 The embodiments of the present invention are illustrated by way of example.

[0048] The following description of exemplary embodiments is merely illustrative and is in no way intended to limit the invention or its application or use. Techniques and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques and equipment should be considered part of the specification.

[0049] like Figure 1 As shown, this invention provides a method for converting road axle loads based on heavy traffic, which mainly includes the following steps:

[0050] S1: Determine the tire contact area and pressure of heavy-duty vehicles to calculate the contact pressure and establish a finite element model of the road structure;

[0051] S2: Fit the grounding pressure and the finite element model of the road structure to obtain the axle load conversion coefficient under different axle loads;

[0052] S3: Calculate the equivalent design axle load conversion factor based on the axle load conversion factor to obtain the vehicle equivalent design axle load conversion factor expression.

[0053] Step S1 involves determining the tire contact area and pressure of the heavy-duty vehicle to calculate the contact pressure and establishing a finite element model of the road structure.

[0054] In this embodiment, the heavy-load formula method is used to calculate the tire ground contact pressure. This method shows that tire pressure increases with axle load, and under heavy load conditions, the tire pressure and ground contact pressure are very close. At this time, the relationship between the tire ground contact pressure p and the axle load P is p1 / p2 = (P1 / P2). 0.65 (Formula 1);

[0055] A finite element model of the pavement structure is established. Specifically, in this embodiment, finite element software is used to establish a typical semi-rigid pavement structure model to analyze the mechanical response of the pavement structure under different axle loads.

[0056] More specifically, this invention uses ABAQUS finite element software to establish a typical semi-rigid pavement structure model and analyzes the mechanical response of the pavement structure under different axle loads.

[0057] Furthermore, the following assumptions are introduced when establishing the ABAQUS finite element model:

[0058] 1) The structural layer is an isotropic and homogeneous elastic material with small strain and displacement, and obeys Hooke's law;

[0059] 2) The bottom layer is an elastic semi-space that extends infinitely vertically downwards and horizontally, while the upper structural layers are finite in the vertical direction but infinitely extend in the horizontal direction.

[0060] 3) The stress, strain, and displacement of the bottom layer at infinite depth and each structural layer at infinite distance in the horizontal direction all approach zero;

[0061] 4) Inter-story displacement and stress continuity between adjacent structural layers;

[0062] 5) The structural weight is not considered.

[0063] Furthermore, in this embodiment, the model's planar dimensions are 4.5m × 9m, and the subgrade depth is 6m. The X direction represents the road cross-section, the Y direction represents the driving direction, and the Z direction represents the road depth. The boundary conditions are: the two ends of the cross-section are free boundaries, the two ends along the driving direction are subject to constraints in the X and Y directions, and the bottom surface of the model is fully constrained, forming a roadbed and pavement model;

[0064] The pavement material was simulated using SOLID45 solid elements, and the material parameters are shown in the table below. To obtain results under the most unfavorable conditions, this paper uses the stress-strain analysis results of the subgrade and pavement under static load.

[0065]

[0066]

[0067] Furthermore, in this embodiment, the study of the equivalent design axle load conversion factor for a single-axle dual-wheel set defines the axle load range as 100kN-300kN. Each 20kN interval represents one load condition, for a total of 11 loading scenarios.

[0068] After completing the data preparation work, proceed to step S2, which is the process of fitting the ground pressure and the finite element model of the road structure to obtain the axle load conversion coefficient under different axle loads.

[0069] In this embodiment, axle load conversion factors under different axle loads are fitted. Specifically, axle load conversion models are established based on the permanent deformation of the asphalt mixture layer and the compressive strain of the subgrade top surface, and axle load conversion factors are fitted. That is, the axle load conversion factors under different axle loads are obtained by fitting based on the ground pressure and the finite element model of the pavement structure, including:

[0070] Based on the grounding pressure and the finite element model of the pavement structure, axle load conversion models are established based on the permanent deformation of the asphalt mixture layer and the compressive strain of the top surface of the subgrade, respectively, to obtain the axle load conversion coefficients for permanent deformation and compressive strain under different axle loads.

[0071] The process of obtaining the axle load conversion factor for the permanent deformation includes:

[0072] S211: According to the design specifications for asphalt pavement, obtain the permanent deformation of each layer of the pavement when the permanent deformation of the asphalt mixture layer is used as the design index.

[0073] S212: Obtain an axle load conversion model based on the permanent deformation of each layer of the pavement, which is equivalent to the permanent deformation of the asphalt mixture layer.

[0074] S213: Based on the grounding pressure and the finite element model of the road structure, obtain the bottom tensile stress corresponding to different axle loads under different layer thicknesses on the road mixture layer, and input the bottom tensile stress into the axle load conversion model to obtain the axle load conversion coefficient corresponding to different axle loads under different layer thicknesses on the road mixture layer.

[0075] S214: The least squares method is used to fit the axle load conversion coefficients corresponding to different axle loads under different surface layer thicknesses on the pavement mixture layer to obtain the axle load conversion coefficient for permanent deformation.

[0076] In this embodiment, an axle load conversion model based on the equivalent permanent deformation of asphalt mixture layers is established;

[0077] First, according to my country's current "Specifications for Design of Asphalt Pavement" (JTG D50), when the permanent deformation of asphalt mixture layers is used as a design index, the permanent deformation R of each layer... ai for

[0078]

[0079] Where: N e k represents the cumulative number of axle load applications. Ri T is the correction factor; pef isothermal temperature; p i h represents the vertical compressive stress on the top surface of the i-th layer. i h0 is the thickness of the i-th layer; h0 is the thickness of the rutted specimen; R oi This represents the permanent deformation amount in the rutting test.

[0080] For the same road surface structure k Ri T pef h i h0 and R oi If all parameters are the same, simplifying them to a single parameter B, then (Equation 2) can be simplified to:

[0081] Combining (Equation 1) and (Equation 3), we can obtain an axle load conversion model based on the equivalent permanent deformation of asphalt mixture layers:

[0082]

[0083] Then, based on the numerical simulation results of the ground pressure and the finite element model of the pavement structure in step S1, the thickness of the upper layer of the asphalt mixture is 10mm, 20mm and 20mm, the thickness of the middle layer is 20mm, 25mm and 25mm, and the lower layer is a whole layer. The seven layers are numbered 1-7 from top to bottom, and their respective bottom tensile stresses are shown in the table below.

[0084]

[0085]

[0086] Furthermore, by substituting the vertical compressive stress on the top surface of the asphalt layer under different axle loads and at different layers into (Formula 4), the axle load conversion coefficient based on the principle of equivalent permanent deformation of asphalt mixture layers can be obtained, as shown in the table below.

[0087]

[0088] Furthermore, such as Figure 2 As shown, by fitting the axle load conversion factors corresponding to different axle loads under different layer thicknesses on the pavement mixture using the least squares method, the axle load conversion factors for permanent deformation can be obtained:

[0089] n = 3.28 + 80e -0.04P R 2 =0.9916(Formula 11)

[0090] Among them, R 2 This represents the degree of fit, with a maximum value of 1, which is 0.9916 in this example. The higher the value, the better the fit.

[0091] Obtaining the compressive strain axial load conversion factor includes:

[0092] S221: According to the design specifications for asphalt pavement of highways, obtain the calculation model of the allowable vertical compressive strain of the top surface of the subgrade when the compressive strain of the top surface of the subgrade is used as the design index;

[0093] S222: Obtain the compressive strain of the top surface of the subgrade under different axle loads based on the ground pressure and the finite element model of the road structure, and substitute the compressive strain of the top surface of the subgrade under different axle loads into the calculation model of the allowable vertical compressive strain of the top surface of the subgrade to obtain the axle load conversion coefficient based on the equivalent principle of compressive strain of the top surface of the subgrade under different axle loads;

[0094] S223: The least squares method is used to fit the axle load conversion coefficients based on the compressive strain equivalent principle of the roadbed top surface under different axle loads to obtain the compressive strain axle load conversion coefficients.

[0095] In this embodiment, an axle load conversion method based on the equivalent compressive strain of the roadbed top surface is used; firstly, an axle load conversion model based on the equivalent compressive strain of the roadbed top surface is used.

[0096] According to the current Chinese "Specifications for Design of Asphalt Pavement" (JTG D50), when the compressive strain of the subgrade top surface is used as a design index, the allowable vertical compressive strain [ε] of the subgrade top surface is... z The calculation model for ] is:

[0097] [ε z ] = 1.25 × 10 4-0.1β (k T3 N e ) -0.21 (Formula 5);

[0098] Where: N e β is the cumulative number of equivalent design axle loads; k is the reliability index; t3 This is the temperature adjustment factor.

[0099] For the same pavement structure, parameters β and k t3 Similarly, simplifying it to the overall parameter D, equation (5) can be simplified to [ε z ] = DN e -0.21 (Formula 6);

[0100] Allowable vertical compressive strain on the top surface of the roadbed under two axle loads (P1, P2) ([ε z1 ]、[εz2 The ratio of ]) is:

[0101]

[0102] Combining (Equation 6) and (Equation 7), we can obtain the axle load conversion model based on the equivalent compressive strain of the roadbed top surface:

[0103]

[0104] Thus, the equivalent axle load conversion factor based on the compressive strain of the roadbed top surface is obtained;

[0105] The compressive strain on the top surface of the roadbed is shown in the table below.

[0106]

[0107] Substituting the compressive strain of the subgrade top surface in the table into (Formula 7), we can obtain the axle load conversion coefficients based on the equivalent principle of compressive strain of the subgrade top surface under different axle loads, as shown in the table below.

[0108]

[0109] Furthermore, such as Figure 3 As shown, by fitting the axle load conversion factors under different axle loads, the compressive strain axle load conversion factor can be obtained as follows:

[0110]

[0111] Among them, R 2 This represents the degree of fit, with a maximum value of 1, which is 0.9911 in this example. The higher the value, the better the fit.

[0112] Thus, two different types of axle load conversion factors were obtained: permanent deformation axle load conversion factor (based on the equivalent axle load conversion of permanent deformation of asphalt mixture layer) and compressive strain axle load conversion factor (based on the equivalent axle load conversion of compressive strain of roadbed top surface).

[0113] After completing step S2, the complete method for obtaining the heavy-load axle load coefficient is demonstrated, thereby correcting the axle load conversion coefficient for permanent deformation of the asphalt layer and compressive strain of the top surface of the subgrade, refining the axle load conversion coefficient under different axle loads, and providing a reference for the design of heavy-load traffic pavements.

[0114] To further provide a standardized example, after obtaining the axle load conversion factor, step S3 can be performed to convert the axle load based on the axle load conversion factor to obtain the vehicle equivalent design axle load conversion factor expression, so as to express the heavy-duty axle load factor.

[0115] Since there are two types of heavy-duty axle load factors, in this embodiment, the axle load conversion factor is used to obtain the vehicle equivalent design axle load conversion factor expression, including:

[0116] A heavy-load cycle conversion coefficient model is established based on the aforementioned highway asphalt pavement design specifications.

[0117] The axle load conversion factor for permanent deformation is substituted into the preset formula for the equivalent design axle load conversion factor for a specific axle type in a specific axle load range and the axle load conversion model based on the equivalent permanent deformation of the asphalt mixture layer to obtain the equivalent design axle load conversion factor formula; the equivalent design axle load conversion factor formula is substituted into the heavy load conversion factor model to obtain the expression for the vehicle equivalent design axle load conversion factor for permanent deformation.

[0118] Alternatively, the equivalent design axle load conversion factor can be obtained by conversion based on the axle load conversion factor, including:

[0119] A heavy-load cycle conversion coefficient model is established based on the aforementioned highway asphalt pavement design specifications.

[0120] The compressive strain axle load conversion factor is substituted into the preset formula for the equivalent design axle load conversion factor of a specific axle type in a specific axle load range and the calculation model of the allowable vertical compressive strain on the top surface of the roadbed to obtain the equivalent design axle load conversion factor formula; the equivalent design axle load conversion factor formula is substituted into the heavy load cycle conversion factor model to obtain the expression for the compressive strain vehicle equivalent design axle load conversion factor.

[0121] In one specific embodiment, the vehicle equivalent design axle load conversion factor is calculated. Specifically, according to the current Chinese "Specifications for Design of Asphalt Pavement for Highways," the axle load conversion factor considering heavy loads is:

[0122]

[0123] In the formula, EALF m —Conversion factor for equivalent design axle load of Class m vehicles; NAPT mi —The average number of axes for i-type axis types; ALDF mij —Axle load distribution coefficient for axle type i in axle load range j; EALF mij —Equivalent design axle load conversion factor for axle type i in the axle load range of grade j.

[0124] In Formula 9, jk represents the axle load level of less than or equal to 100kN, and k+1-l represents the axle load level of greater than 100kN.

[0125] The formula for the equivalent design axle load conversion factor for a specific axle type in a specific axle load range, as preset in this embodiment, is as follows: Substituting into (Formula 9) yields the axle load conversion factor considering heavy traffic:

[0126]

[0127] (Formula 10); where λ = b, is used to distinguish the interval from j to k from k+1 to l. In fact, λ and b mean the same thing. When substituting, λ can be substituted as b.

[0128] Where, EALF = N e1 / N e2， Therefore, when incorporating the axle load conversion factor for permanent deformation, it is necessary to use an axle load conversion model based on the equivalent permanent deformation of the asphalt mixture layer (Formula 4). In Formula 4, 1.8n / 0.48 is the preset equivalent design axle load conversion factor formula for a specific axle type in a specific axle load range. In this equation, b and n are the axle load conversion factors for permanent deformation. When incorporating the compressive strain axle load conversion factor, the calculation model for the allowable vertical compressive strain of the roadbed top surface (Equation 8) is required. In Equation 8, n / 0.21 is b, and n is the compressive strain axle load conversion factor. Therefore, by substituting the two axle load factors into n, the value of b in Equation 10 is quantified, thus yielding the final expression for the vehicle equivalent design axle load conversion factor.

[0129] Therefore, the axle load conversion method based on heavy traffic in this embodiment can correct the axle load conversion coefficients for permanent deformation of asphalt layer and compressive strain of roadbed top surface, refine the axle load conversion coefficients under different axle loads, provide a reference for heavy traffic pavement design, and thus improve the service capacity of roads under heavy traffic.

[0130] like Figure 4 As shown, the present invention also provides a road axle load conversion system 100 based on heavy traffic, which implements the road axle load conversion method based on heavy traffic as described above, including:

[0131] The data storage module 110 is used to determine the tire contact area and pressure of heavy-duty vehicles to calculate the contact pressure and to establish a finite element model of the road structure.

[0132] The data conversion module 120 is used to fit the grounding pressure and the finite element model of the road structure to obtain the axle load conversion coefficient under different axle loads.

[0133] The standard conversion module 130 is used to perform conversion based on the axle load conversion factor to obtain the vehicle equivalent design axle load conversion factor expression.

[0134] The data conversion module 120 includes:

[0135] The permanent deformation coefficient calculation unit is used to establish an axle load conversion model based on the permanent deformation of the asphalt mixture layer of the pavement according to the ground pressure and the finite element model of the pavement structure, and to obtain the axle load conversion coefficient of permanent deformation under different axle loads.

[0136] The compressive strain coefficient calculation unit is used to establish an axle load conversion model based on the compressive strain of the roadbed top surface of the road surface according to the ground pressure and the finite element model of the road structure, and to obtain the compressive strain axle load conversion coefficient under different axle loads.

[0137] This allows us to obtain the axle load conversion factor for heavy-duty traffic.

[0138] The standard conversion module includes:

[0139] The permanent deformation equivalent conversion unit establishes a heavy-load cycle conversion coefficient model based on the highway asphalt pavement design specifications; it substitutes the permanent deformation axle load conversion coefficient into a preset formula for the equivalent design axle load conversion coefficient for a specific axle type in a specific axle load range and into the axle load conversion model based on the equivalent permanent deformation of the asphalt mixture layer to obtain the equivalent design axle load conversion coefficient formula; it then substitutes the equivalent design axle load conversion coefficient formula into the heavy-load cycle conversion coefficient model to obtain the expression for the vehicle equivalent design axle load conversion coefficient for permanent deformation.

[0140] The compressive strain equivalent conversion unit is used to establish a heavy-load cycle conversion coefficient model according to the highway asphalt pavement design specification; to substitute the compressive strain axle load conversion coefficient into the preset formula for the equivalent design axle load conversion coefficient of a specific axle type in a specific axle load range and the calculation model of the allowable vertical compressive strain of the roadbed top surface, so as to obtain the equivalent design axle load conversion coefficient formula; and to substitute the equivalent design axle load conversion coefficient formula into the heavy-load cycle conversion coefficient model, so as to obtain the compressive strain vehicle equivalent design axle load conversion coefficient expression.

[0141] This yields the conversion coefficient expressions for the equivalent design axle loads of the two types of vehicles.

[0142] For a more specific implementation of the road axle load conversion system based on heavy traffic, please refer to the above-described embodiment of the road axle load conversion method based on heavy traffic, which will not be repeated here.

[0143] As described above, the road axle load conversion system based on heavy traffic provided by this invention first determines the tire contact area and pressure of heavy-duty vehicles to calculate the contact pressure, and establishes a finite element model of the road structure. Then, it fits the contact pressure and the finite element model of the road structure to obtain axle load conversion coefficients for two different types of axle loads. Subsequently, it converts the axle loads of the two types of axle loads to obtain the equivalent design axle load conversion coefficient expressions for two types of vehicles. This provides a basis for the specialized design of asphalt pavements under heavy traffic and extra-heavy traffic conditions, and meets the application requirements of the increasing number of heavy-duty and overloaded vehicles on current roads.

[0144] This invention also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the aforementioned method for converting road axle loads based on heavy traffic. The readable storage medium can be non-volatile or volatile. The readable storage medium stores a device setting self-adjustment program, which, when executed by a processor, implements:

[0145] Determine the tire contact area and pressure of heavy-duty vehicles to calculate the contact pressure, and establish a finite element model of the road structure;

[0146] The axle load conversion coefficient under different axle loads is obtained by fitting the ground pressure and the finite element model of the road structure.

[0147] The axle load conversion factor is used to obtain the vehicle equivalent design axle load conversion factor expression.

[0148] Specifically, the specific implementation method of the computer program when executed by the processor can be referred to the description of the relevant steps in the embodiment of the method for converting road axle load based on heavy traffic, which will not be repeated here.

[0149] In the several embodiments provided by this invention, it should be understood that the disclosed methods, systems, and readable storage media can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and other division methods may be used in actual implementation.

[0150] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0151] The method, system, and computer-readable storage medium for calculating road axle loads based on heavy traffic, according to the present invention, have been described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various modifications can be made to the method, system, and computer-readable storage medium for calculating road axle loads based on heavy traffic proposed in this invention without departing from the scope of the invention. Therefore, the scope of protection of this invention should be determined by the appended claims.

Claims

1. A method for converting road axle loads based on heavy traffic, characterized in that, include: Determine the tire contact area and pressure of heavy-duty vehicles to calculate the contact pressure, and establish a finite element model of the road structure; The axle load conversion coefficient under different axle loads is obtained by fitting the ground pressure and the finite element model of the road structure. The axle load conversion factor is used to obtain the vehicle equivalent design axle load conversion factor expression.

2. The method for converting road axle loads based on heavy traffic as described in claim 1, characterized in that, Based on the grounding pressure and the finite element model of the road structure, fitting is performed to obtain the axle load conversion coefficients under different axle loads, including: Based on the grounding pressure and the finite element model of the pavement structure, axle load conversion models are established based on the permanent deformation of the asphalt mixture layer and the compressive strain of the top surface of the subgrade, respectively, to obtain the axle load conversion coefficients for permanent deformation and compressive strain under different axle loads.

3. The method for converting road axle loads based on heavy traffic as described in claim 2, obtaining the axle load conversion factor for permanent deformation, includes: According to the design specifications for asphalt pavement, the permanent deformation of each layer of the pavement is obtained when the permanent deformation of the asphalt mixture layer is used as the design index. Based on the permanent deformation of each layer of the road surface, an axle load conversion model equivalent to the permanent deformation of the asphalt mixture layer is obtained. Based on the grounding pressure and the finite element model of the road structure, the tensile stress at the bottom of the layer corresponding to different axle loads under different layer thicknesses on the road mixture layer is obtained, and the tensile stress at the bottom of the layer is substituted into the axle load conversion model to obtain the axle load conversion coefficients corresponding to different axle loads under different layer thicknesses on the road mixture layer. The least squares method was used to fit the axle load conversion coefficients corresponding to different axle loads under different layer thicknesses on the pavement mixture layer to obtain the axle load conversion coefficient for permanent deformation.

4. The method for converting road axle loads based on heavy traffic as described in claim 2, characterized in that, Obtaining the compressive strain axial load conversion factor includes: According to the design specifications for asphalt pavement of highways, a calculation model for the allowable vertical compressive strain of the top surface of the subgrade when the compressive strain of the top surface of the subgrade is used as the design index is obtained. The roadbed top surface compressive strain under different axle loads is obtained based on the ground pressure and the finite element model of the road structure. The roadbed top surface compressive strain under different axle loads is then substituted into the calculation model of the allowable vertical compressive strain of the roadbed top surface to obtain the axle load conversion coefficient based on the equivalent principle of roadbed top surface compressive strain under different axle loads. The least squares method was used to fit the axle load conversion coefficients based on the compressive strain equivalent principle of the roadbed top surface under different axle loads to obtain the compressive strain axle load conversion coefficients.

5. The method for converting road axle loads based on heavy traffic as described in claim 3, characterized in that, The axle load conversion factor is used to obtain the vehicle equivalent design axle load conversion factor expression, including: A heavy-load cycle conversion coefficient model is established based on the aforementioned highway asphalt pavement design specifications. The axle load conversion factor for permanent deformation is substituted into the preset formula for the equivalent design axle load conversion factor for a specific axle type in a specific axle load range and the axle load conversion model based on the equivalent permanent deformation of the asphalt mixture layer to obtain the equivalent design axle load conversion factor formula; the equivalent design axle load conversion factor formula is substituted into the heavy load conversion factor model to obtain the expression for the vehicle equivalent design axle load conversion factor for permanent deformation.

6. The method for converting road axle loads based on heavy traffic as described in claim 5, characterized in that, The axle load conversion factor is used to obtain the vehicle equivalent design axle load conversion factor expression, including: A heavy-load cycle conversion coefficient model is established based on the aforementioned highway asphalt pavement design specifications. The compressive strain axle load conversion factor is substituted into the preset formula for the equivalent design axle load conversion factor of a specific axle type in a specific axle load range and the calculation model of the allowable vertical compressive strain on the top surface of the roadbed to obtain the equivalent design axle load conversion factor formula; the equivalent design axle load conversion factor formula is substituted into the heavy load cycle conversion factor model to obtain the expression for the compressive strain vehicle equivalent design axle load conversion factor.

7. A road axle load conversion system based on heavy traffic, characterized in that, Implementing the road axle load conversion method based on heavy traffic as described in any one of claims 1-6, comprising: The data storage module is used to determine the tire contact area and pressure of heavy-duty vehicles to calculate the ground pressure and to establish a finite element model of the road structure. The data conversion module is used to fit the grounding pressure and the finite element model of the road structure to obtain the axle load conversion coefficient under different axle loads. The standard conversion module is used to convert the axle load according to the axle load conversion factor to obtain the vehicle equivalent design axle load conversion factor expression.

8. The road axle load conversion system based on heavy traffic as described in claim 7, characterized in that, The data conversion module includes: The permanent deformation coefficient calculation unit is used to establish an axle load conversion model based on the permanent deformation of the asphalt mixture layer of the pavement according to the ground pressure and the finite element model of the pavement structure, and to obtain the axle load conversion coefficient of permanent deformation under different axle loads. The compressive strain coefficient calculation unit is used to establish an axle load conversion model based on the compressive strain of the roadbed top surface of the road surface according to the ground pressure and the finite element model of the road structure, and to obtain the compressive strain axle load conversion coefficient under different axle loads.

9. The road axle load conversion system based on heavy traffic as described in claim 8, characterized in that, The standard conversion module includes: The permanent deformation equivalent conversion unit establishes a heavy-load cycle conversion coefficient model based on the highway asphalt pavement design specifications; it substitutes the permanent deformation axle load conversion coefficient into a preset formula for the equivalent design axle load conversion coefficient for a specific axle type in a specific axle load range and into the axle load conversion model based on the equivalent permanent deformation of the asphalt mixture layer to obtain the equivalent design axle load conversion coefficient formula; it then substitutes the equivalent design axle load conversion coefficient formula into the heavy-load cycle conversion coefficient model to obtain the expression for the vehicle equivalent design axle load conversion coefficient for permanent deformation. The compressive strain equivalent conversion unit is used to establish a heavy-load cycle conversion coefficient model according to the highway asphalt pavement design specification; to substitute the compressive strain axle load conversion coefficient into the preset formula for the equivalent design axle load conversion coefficient of a specific axle type in a specific axle load range and the calculation model of the allowable vertical compressive strain of the roadbed top surface, so as to obtain the equivalent design axle load conversion coefficient formula; and to substitute the equivalent design axle load conversion coefficient formula into the heavy-load cycle conversion coefficient model, so as to obtain the compressive strain vehicle equivalent design axle load conversion coefficient expression.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for converting road axle loads based on heavy traffic as described in any one of claims 1 to 6.

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