Mechanical Calculation Method for LSAM-50 Full-depth Asphalt Pavement Considering High-temperature Temperature Field

Abstract

The present invention relates to a mechanical calculation method for LSAM-50 full-depth asphalt pavement considering high-temperature temperature field. Temperature sensors are buried in the service pavement, and an automatic weather station is established. By collecting the temperature data of the pavement structure and synchronously recording the real-time data of environmental parameters, considering the most unfavorable situation, taking the highest temperature of each layer as the characteristic temperature, a pavement temperature-pavement depth model is established. Cylindrical specimens corresponding to the indoor forming are tested for the resilient modulus values of asphalt mixtures at different temperatures, and a temperature-resilient modulus dependence model of asphalt mixtures is established. The asphalt pavement structure layer and structural sub-layer are divided. According to the pavement temperature-pavement depth model, the calculation temperature corresponding to each calculation depth is determined. According to various temperature-resilient modulus models of asphalt mixtures, the calculated resilient modulus corresponding to each calculation temperature is determined. According to the determined resilient modulus of each structural sub-layer, the elastic layered continuous system theory under the action of double circular uniform vertical loads is used to calculate the mechanical indexes of the pavement structure.

Description

Technical Field

[0001] The present invention belongs to the field of transportation civil engineering, and particularly relates to a mechanical calculation method for LSAM-50 full-depth asphalt pavement considering high-temperature temperature field. Background Art

[0002] At present, the "Code for Design of Highway Asphalt Pavements" (JTG D50-2017) in China stipulates that the elastic layered continuous system theory under the action of double circular uniformly distributed vertical loads should be adopted for calculating the mechanical indexes of pavement structures. For the structural check of full-depth asphalt pavement structures, the modulus values of structural layers should be the modulus of the asphalt surface layer under the conditions of 20°C and 10 Hz, and the modulus of asphalt base courses under the conditions of 20°C and 5 Hz. However, the existing design codes have the following deficiencies in calculating the mechanical response of LSAM-50 (Large Stone Asphalt Mixture-50) full-depth asphalt pavement:

[0003] (1) The full-depth asphalt pavement is formed by the structural combination of various asphalt mixtures. As a typical viscoelastic-plastic material, the mechanical properties and rutting resistance of asphalt mixtures are closely related to temperature. The state of asphalt mixtures undergoes three change processes of elasticity, viscoelasticity, and viscoplasticity as the temperature rises. In the elastic state, the deformation generated by the load on the asphalt mixture can be almost completely recovered; in the viscoelastic state, there is some non-recoverable permanent deformation in the load deformation; in the viscoplastic state, the rheological property is enhanced, resulting in a sharp decline in the mechanical properties of the asphalt mixture and a sharp increase in the permanent deformation. Asphalt mixtures and full-depth asphalt pavements are highly sensitive to temperature. An increase in temperature will lead to a sharp increase in the rutting deformation of the asphalt pavement. At the same time, there are also huge differences in the mechanical responses of full-depth asphalt pavements at different temperatures. When designing under the specified conditions, the high-temperature mechanical response is not considered, which may lead to early pavement diseases;

[0004] (2) During the actual service process of asphalt pavements, there is a decreasing temperature field inside them, and the temperature distributions of each structural layer change periodically with time and the environment. The mechanical properties of asphalt mixtures are highly temperature-sensitive, and their resilient modulus will change with the pavement temperature field. However, the existing design codes usually use the empirical value or representative value of the resilient modulus at one temperature to characterize the pavement materials, without considering the change of the asphalt pavement temperature field and unable to represent the stress state of the entire pavement. Summary of the Invention

[0005] Aiming at the problems existing in the above-mentioned existing design codes, the purpose of the present invention is to provide a mechanical calculation method for LSAM-50 full-depth asphalt pavement considering high-temperature temperature field. This method considers the internal temperature field distribution of LSAM-50 full-depth asphalt pavement during the actual service process, so as to calculate the mechanical response of LSAM-50 full-depth asphalt pavement more accurately.

[0006] To achieve the above tasks, the present invention adopts the following technical solutions:

[0007] A mechanical calculation method for LSAM-50 full-depth asphalt pavement considering high-temperature temperature field, characterized in that it specifically proceeds according to the following steps:

[0008] Step 1: Collect the temperature field of the in-service pavement

[0009] Select temperature sensing wires and temperature data loggers with a test temperature range of not less than -50 to 130 °C and a test accuracy of not less than 0.2 °C, and establish an automatic weather station; considering factors such as terrain, landform, and lighting, comprehensively consider the installation points of the temperature sensing wires and the automatic weather station and design the burial depth of the temperature sensing wires; bury the temperature sensing wires and connect them to the automatic weather station, check and calibrate the pavement structure temperature test equipment; collect pavement structure temperature data through temperature sensors and synchronously record real-time environmental parameter data through the automatic weather station.

[0010] Step 2: Construct a model of the high-temperature temperature field of the in-service pavement changing with the pavement depth

[0011] The rutting deformation of asphalt pavement mainly occurs during the high-temperature period in summer. Select the highest temperature from July to August each year as the representative period of high temperature for the analysis of the high-temperature temperature field of asphalt pavement. According to the high-temperature data of each layer recorded by the automatic weather station, considering the most unfavorable situation, use the highest temperature of each layer as the characteristic temperature to establish a pavement temperature - pavement depth model. The constructed model uses a quadratic polynomial:

[0012] y = Ax 2 + Bx + C, R 2 not less than 0.90;

[0013] where x represents the pavement depth, in cm; y represents the pavement temperature, in °C; A represents the pavement temperature fitting coefficient 1; B represents the pavement temperature fitting coefficient 2; C represents the fitted surface temperature;

[0014] Step 3: Test the indoor resilient modulus of asphalt mixture at different temperatures

[0015] Form cylindrical specimens corresponding to the asphalt surface layer and the LSAM-50 flexible base layer indoors, test the resilient modulus values of the asphalt mixture at different temperatures, and establish an asphalt mixture temperature - resilient modulus dependence model. The constructed asphalt mixture temperature - resilient modulus dependence model uses an exponential model, R 2 not less than 0.90.

[0016] Step 4: Divide the asphalt pavement structure layer and structural sub-layers

[0017] The LSAM-50 full-depth asphalt pavement is divided into a surface functional layer, a bonding layer, and an LSAM-50 flexible base layer. Among them, the thickness of the surface functional layer is divided into 4 cm, and the thickness of the bonding layer is divided into 6 cm; the LSAM-50 flexible base layer has a relatively large thickness, and there are significant differences in temperature and modulus within its structure. The LSAM-50 flexible base layer is divided into structural sub-layers, and the thickness of each structural sub-layer is 5 cm.

[0018] Step 5: Determine the temperature and mechanical parameters of the structural layer and structural sub-layers

[0019] According to the pavement temperature-pavement depth model constructed in Step 2, the surface functional layer uses the depth from the layer center to the road surface as the calculation depth, and each structural sub-layer of the bonding layer and the LSAM-50 flexible base layer uses the depth from the layer top to the road surface as the calculation depth. Substitute into the model in Step 2 to determine the calculated temperature corresponding to each calculation depth; according to the temperature-resilient modulus models of various asphalt mixtures constructed in Step 3, substitute each calculated temperature to determine the calculated resilient modulus corresponding to each calculated temperature.

[0020] Step 6: Perform mechanical response calculations for the LSAM-50 full-depth asphalt pavement

[0021] According to the resilient modulus of each structural sub-layer determined in Step 5, use the elastic layered continuous system theory under the action of a double circular uniformly distributed vertical load to calculate the pavement structure mechanical indexes.

[0022] For the mechanical calculation method of the LSAM-50 full-depth asphalt pavement considering the high-temperature temperature field of the present invention, due to considering the actual high-temperature temperature field of the pavement, compared with the existing design specifications, the calculation results are closer to the actual pavement mechanical response. Description of the Drawings

[0023] Figure 1 is the pavement depth-pavement temperature model;

[0024] Figure 2 is the temperature-resilient modulus dependence model of asphalt mixture. Among them, Figure (a) represents the AC-13 temperature-resilient modulus dependence model, Figure (b) represents the AC-20 temperature-resilient modulus dependence model, and Figure (c) represents the LSAM-50 temperature-resilient modulus dependence model;

[0025] Figure 3 is the double circular uniformly distributed vertical load;

[0026] Figure 4 is the high-temperature mechanical response of the pavement. Among them, Figure (a) represents the relationship between horizontal tensile stress and pavement depth, Figure (b) represents the relationship between compressive stress and pavement depth, Figure (c) represents the relationship between shear stress and pavement depth, and Figure (d) represents the relationship between vertical displacement and pavement depth;

[0027] Figure 5For the high-temperature mechanical responses of pavements with different LSAM-50 flexible base course thicknesses, where Figure (a) shows the relationship between the maximum tensile stress at the bottom of the layer and the LSAM-50 flexible base course thickness, Figure (b) shows the relationship between the maximum shear stress and the LSAM-50 flexible base course thickness, and Figure (c) shows the relationship between the maximum vertical displacement and the LSAM-50 flexible base course thickness;

[0028] Figure 6 For the high-temperature mechanical responses of pavements with different soil subgrade resilient moduli, where Figure (a) shows the relationship between the maximum tensile stress at the bottom of the layer and the soil subgrade resilient modulus, Figure (b) shows the relationship between the maximum shear stress and the soil subgrade resilient modulus, and Figure (c) shows the relationship between the maximum vertical displacement and the soil subgrade resilient modulus.

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

[0030] In this embodiment, a test section of an asphalt pavement with an extra-large-sized LSAM-50 flexible base course is paved relying on the newly built G347 project, and a mechanical calculation method for the LSAM-50 full-depth asphalt pavement considering the high-temperature temperature field is given. The specific steps are as follows:

[0031] Step 1: Collect the temperature field of the in-service pavement

[0032] To study the temperature field distribution of the LSAM-50 full-depth asphalt pavement of the newly built G347 project, a temperature sensing line and a temperature data collector with a test temperature range of -50 to 130 °C and a test accuracy of 0.1 °C are selected, and an automatic weather station is established; according to factors such as terrain, landform, and lighting, the setting points of the temperature sensing line and the automatic weather station are comprehensively considered, and it is planned to bury temperature sensors at the road shoulders with depths from the road surface of 2 cm, 7 cm, 12 cm, 17 cm, 22 cm, 27 cm, 32 cm, 37 cm, 44 cm, and 51 cm respectively; the buried temperature sensors are connected to the automatic weather station through data lines, and the road surface structure temperature test equipment is inspected and calibrated; the road surface structure temperature data is collected through the temperature sensors, and the real-time data of environmental parameters are synchronously recorded through the automatic weather station.

[0033] Step 2: Construct a model of the high-temperature temperature field of the in-service pavement varying with the pavement depth

[0034] The rutting deformation of asphalt pavements mainly occurs during the high-temperature period in summer. In this embodiment, August 2021 of the G347 test section is selected as the representative high-temperature period for the analysis of the high-temperature temperature field of the asphalt pavement. According to the high-temperature data of each layer recorded by the automatic weather station, considering the most unfavorable situation, the highest temperature of each layer is used as the characteristic temperature to establish a pavement temperature - pavement depth model ( Figure 1 ), and the constructed pavement temperature - pavement depth model uses a quadratic polynomial:

[0035] y = Ax 2 + Bx + C, R 2 is 0.98, where x represents the pavement depth in cm; y represents the pavement temperature in °C; A represents the pavement temperature fitting coefficient 1; B represents the pavement temperature fitting coefficient 2; C represents the fitted surface temperature of the road surface.

[0036] The relationship between pavement temperature and pavement depth is shown in Figure 1 . In the figure, y = 0.0066x 2 - 0.707x + 58.721, R 2 = 0.9792.

[0037] Step 3: Test the indoor resilient modulus of asphalt mixture at different temperatures

[0038] For the newly built G347 project, the surface functional layer of the LSAM-50 full-depth asphalt pavement uses AC-13 asphalt mixture, the bonding layer uses AC-20 asphalt mixture, and the base layer uses LSAM-50 asphalt mixture. Cylindrical specimens of AC-13, AC-20, and LSAM-50 are formed indoors to test the resilient modulus values of the three types of asphalt mixtures at different temperatures, and a temperature-resilient modulus dependence model of asphalt mixture is established. The established model uses an exponential model, and the Rs 2 are 0.94, 0.97, and 0.99 respectively. The temperature-resilient modulus dependence models of AC-13, AC-20, and LSAM-50 asphalt mixtures are shown in Figure 2 . In the figure, figure (a) represents the temperature-resilient modulus dependence model of AC-13, figure (b) represents the temperature-resilient modulus dependence model of AC-20, and figure (c) represents the temperature-resilient modulus dependence model of LSAM-50.

[0039] Step 4: Divide the asphalt pavement structural layer and structural sub-layers

[0040] For the newly built G347 project, the structural layer of the LSAM-50 full-depth asphalt pavement is divided into a surface functional layer, a bonding layer, and an LSAM-50 flexible base layer. Among them, the surface functional layer is 4 cm of AC-13 asphalt mixture, the bonding layer is 6 cm of AC-20 asphalt mixture. The thickness of the LSAM-50 asphalt mixture flexible base layer is relatively large, and there are large differences in internal temperature and modulus. The LSAM-50 flexible base layer is divided into structural sub-layers, and the thickness of each structural sub-layer is 5 cm. The pavement structural layer positions and the layering results of the calculation model are shown in Table 1 below.

[0041] Table 1: Pavement structural layer positions and calculation model layering

[0042]

[0043]

[0044] Step 5: Determine the temperature and mechanical parameters of the structural layer and structural sub - layer

[0045] According to the pavement temperature - pavement depth model constructed in Step 2, for the surface functional layer, the calculation depth is the depth from the middle of the layer to the road surface; for the bonding layer and each structural sub - layer of LSAM - 50, the calculation depth is the depth from the top of the layer to the road surface. When the thickness of the LSAM - 50 flexible base course is 40 cm, the calculation depths, calculation temperatures and calculation resilient moduli are shown in Table 2 below.

[0046] Table 2: Temperature and mechanical parameters of pavement structural layer and structural sub - layer

[0047] Calculation depth / cm Calculation temperature / °C Calculation resilient modulus / MPa 2 57.3 376.58 4 56.0 391.85 10 52.3 619.10 15 49.6 680.69 20 47.2 739.82 25 45.2 794.86 30 43.5 844.18 35 42.1 886.26 40 41.0 919.76 45 40.3 943.56

[0048] Step 6: Conduct mechanical response calculation of the full - thickness LSAM - 50 asphalt pavement

[0049] According to the resilient moduli of each structural sub - layer determined in Step 5, the elastic layered continuous system theory under the action of a double - circle uniformly distributed vertical load is used to calculate the pavement structural mechanical indexes.

[0050] The "Code for Design of Highway Asphalt Pavements" (JTG D50 - 2017) stipulates that the elastic layered continuous system theory under the action of a double - circle uniformly distributed vertical load should be used to calculate the pavement structural mechanical indexes. The schematic diagram of the double - circle uniformly distributed vertical load is shown in Figure 3 , and the x - axis is the driving direction. The distance between the centers of the two wheels is fixed at 319.5 mm. The coordinates of points A, B, C, D, and E under the action of the standard axle load BZZ - 100 are shown in Table 3 below. The radius of the load circle is 106.5 mm, and the unit of the calculation point coordinates is m.

[0051] Table 3: Coordinates of each calculation point under the action of BZZ - 100 load

[0052] Calculation parameters Coordinates of point A Coordinates of point B Coordinates of point C Coordinates of point D Coordinates of point E Parameter value (0,0) (-0.0266,0) (-0.0533,0) (-0.1598,0) (-0.2663,0)

[0053] The stress indexes selected for pavement structural mechanical index calculation are shear stress, vertical stress and tensile stress. The main reason for rutting in the pavement structure is that the shear stress in the pavement structure is greater than the shear strength of the asphalt mixture. Therefore, the shear stress of the asphalt surface layer is selected as the index to evaluate the rut - resistance ability of the pavement structure; the vertical deformation of the pavement structure under the action of load at high temperature is used as the index to evaluate the rut - resistance ability of the pavement; due to the repeated action of tensile stress in the pavement structure, when it exceeds the fatigue strength, the material undergoes fatigue cracking. Therefore, the tensile stress is selected as the index to evaluate the fatigue - resistance ability of the pavement structure.

[0054] In this embodiment, the mechanical response calculation of the full - thickness LSAM - 50 asphalt pavement is carried out from the following three aspects:

[0055] ① The variation law of stress (or displacement) with depth at different calculation points;

[0056] ② Influence of the thickness of the LSAM-50 flexible base course on the mechanical response of the pavement structure under high-temperature conditions;

[0057] ③ Influence of the resilient modulus of the subgrade on the mechanical response of the pavement structure under high-temperature conditions.

[0058] First, calculate the mechanical response of the pavement structure with a 40-cm-thick LSAM-50 flexible base course and a 60-MPa resilient modulus of the subgrade under a high-temperature temperature field. The variation law of the stress (or displacement) at different calculation points with depth is shown in Figure 4 . From Figure 4 (a), it can be seen that when the pavement depth ≤ 30 cm, the pavement is horizontally compressed under the load, and the maximum stress (<0.6 MPa) is at the road surface; as the depth increases, the stress values at each calculation point tend to be the same and the stress experiences a change from compression to tension. The bottom of the asphalt layer is the point with the largest tensile stress, but the tensile stress is relatively small (≤0.2 MPa). From Figure 4 (b), it can be seen that the compressive stress at points A and B shows a parabolic variation trend with depth and reaches the maximum value near the bottom of the surface layer. Since points A and B are not directly under the wheel load, the compressive stress at the road surface is small. As the depth increases, the wheel load pressure spreads to the area below points A and B, resulting in an increase in compressive stress; points C, D, and E are located under the wheel load, and the compressive stress continuously decreases with the increase in depth. Among them, the compressive stress at point D is the largest (0.7 MPa). From Figure 4 (c), it can be seen that the maximum shear stress of the pavement occurs in the bonding layer, which is directly related to the phenomenon that traditional rutting damage occurs in the bonding layer. The shear stress reaches 0.22 MPa at 5 cm below point D. The relatively large shear stress is an important reason for the shear deformation of the pavement. From Figure 4 (d), it can be seen that the vertical displacement at each point shows a variation law of decreasing with the increase in depth. Point D is located at the center of the wheel load and has the largest vertical deformation. The maximum horizontal tensile stress is at the bottom of the flexible base course at point A, the maximum compressive stress is at the top of the pavement at point D, the maximum shear stress is at 0 - 10 cm (surface functional layer and bonding layer) at point D, and the maximum vertical displacement is at the top of the pavement at point D.

[0059] Second, to explore the influence of the thickness of the LSAM-50 flexible base course on the mechanical response of the pavement structure under high-temperature conditions, it is planned to use LSAM-50 flexible base courses with thicknesses of 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, and 50 cm. The pavement mechanical response is shown in Figure 5 . From Figure 5(a) It can be seen that the maximum tensile stress at the bottom of the asphalt layer of the pavement decreases with the increase of the thickness of the LSAM-50 flexible base layer. It shows higher sensitivity when the thickness of the LSAM-50 flexible base layer is small. When the thickness of the LSAM-50 flexible base layer increases from 10cm to 20cm, the maximum tensile stress at the bottom of the asphalt layer decreases from 0.53MPa to 0.37MPa, a decrease of more than 30%; when the thickness of the LSAM-50 flexible base layer increases from 40cm to 50cm, the maximum tensile stress at the bottom of the asphalt layer decreases from 0.19MPa to 0.14MPa. Figure 5 (b) It can be seen that the increase in the thickness of the LSAM-50 flexible base will increase the shear stress of the bonding layer, but the increase is small. When the thickness of the LSAM-50 flexible base increases from 10cm to 50cm, the maximum shear stress of the bonding layer increases from 0.17MPa to 0.22MPa, which is only an increase of 0.05MPa. Figure 5 (c) It can be seen that the vertical deformation of the pavement decreases with the increase of the thickness of the LSAM-50 flexible base. Increasing the thickness of the LSAM-50 flexible base has a mitigating effect on the vertical deformation. The vertical deformation of a 50cm thick base is only half of that of a 10cm thick base. Increasing the thickness of the LSAM-50 flexible base has a negative impact on the pavement shear stress, but the impact is small. It has a positive impact on the tensile stress and vertical deformation. When designing the pavement, it is necessary to comprehensively consider the mechanical response and design the pavement thickness.

[0060] Third, in order to explore the influence of soil base rebound modulus on the mechanical response of pavement structure under high temperature conditions, it is proposed to use soil base rebound modulus of 10MPa, 20MPa, 30MPa, 40MPa, 50MPa, 60MPa, 70MPa and 80MPa, and the pavement mechanical response is shown in Figure 6 .Depend on Figure 6 (a) It can be seen that the maximum tensile stress at the bottom of the asphalt layer of the pavement decreases with the increase of the soil base rebound modulus. It shows higher sensitivity when the soil base rebound modulus is small. When the soil base rebound modulus increases from 10MPa to 20MPa, the maximum tensile stress at the bottom of the asphalt layer decreases from 0.31MPa to 0.27MPa; when the soil base rebound modulus increases from 70MPa to 80MPa, the maximum tensile stress at the bottom of the asphalt layer decreases from 0.18MPa to 0.17MPa. Figure 6 (b) It can be seen that the increase in the soil base rebound modulus will increase the shear stress of the bonding layer, but the increase is small. When the soil base rebound modulus increases from 10MPa to 80MPa, the maximum shear stress at the bottom of the bonding layer increases from 0.20MPa to 0.22MPa, which is only an increase of 0.02MPa. Figure 6 (c) It can be seen that the vertical deformation of the pavement decreases with the increase of the soil base rebound modulus. Increasing the soil base rebound modulus has a mitigating effect on the vertical deformation. Increasing the soil base rebound modulus has a negative impact on the pavement shear stress, but the impact is small. It has a positive impact on the tensile stress and vertical deformation. When designing the pavement, it is necessary to comprehensively consider the mechanical response to determine the soil base rebound modulus.

[0061] The above content is a further detailed description of the present invention in combination with specific embodiments. It cannot be determined that the specific embodiments of the present invention are limited thereto. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, and all should be regarded as falling within the protection scope defined by the claims of the present invention.

Claims

1. A mechanical calculation method for LSAM-50 full-depth asphalt pavement considering high-temperature temperature field, characterized in that, it specifically proceeds according to the following steps: Step 1: Collect the temperature field of the in-service pavement Select temperature sensing lines and temperature data loggers with a test temperature range of not less than -50 to 130 °C and a test accuracy of not less than 0.2 °C, and establish an automatic weather station; according to terrain, landform, and lighting factors, comprehensively consider the installation locations of temperature sensing lines and automatic weather stations and design the burial depth of temperature sensing lines; bury temperature sensing lines and connect them to the automatic weather station, check and calibrate the pavement structure temperature test equipment; collect pavement structure temperature data through temperature sensors and synchronously record real-time environmental parameter data through the automatic weather station; Step 2: Construct a model of the change of high-temperature temperature field of the in-service pavement with pavement depth Select the highest temperature from July to August each year as the representative period of high temperature for analyzing the high-temperature temperature field of the asphalt pavement. According to the high-temperature data of each layer recorded by the automatic weather station, considering the worst-case scenario, use the highest temperature of each layer as the characteristic temperature to establish a pavement temperature - pavement depth model. This pavement temperature - pavement depth model uses a quadratic polynomial: y =A x 2 +B x +C, R 2 not less than 0.90; Among them, x represents the pavement depth, with the unit of cm; y represents the pavement temperature, with the unit of °C; A represents the pavement temperature fitting coefficient 1; B represents the pavement temperature fitting coefficient 2; C represents the fitted road surface temperature; Step 3: Test the indoor resilient modulus of asphalt mixture at different temperatures Cylindrical specimens corresponding to the indoor forming, asphalt surface layer and LSAM-50 flexible base course are made to test the resilient modulus values of asphalt mixtures at different temperatures, and a temperature-resilient modulus dependence model for various asphalt mixtures is established. The temperature-resilient modulus dependence model of this asphalt mixture adopts an exponential model. R 2 Not less than 0.90; Step 4: Divide the structural layers and structural sub-layers of the asphalt pavement The structural layers of LSAM-50 full-depth asphalt pavement are divided into a surface functional layer, a bonding layer, and an LSAM-50 flexible base layer. Among them, the thickness of the surface functional layer is divided into 4 cm, and the thickness of the bonding layer is divided into 6 cm; the thickness of the LSAM-50 flexible base layer is relatively large, and there are significant differences in internal temperature and modulus within its structure. Divide the LSAM-50 flexible base layer into structural sub-layers, and the thickness of each structural sub-layer is 5 cm; Step 5: Determine the temperature and mechanical parameters of the structural layers and structural sub-layers According to the pavement temperature - pavement depth model constructed in Step 2, the surface functional layer uses the depth from the surface to the middle of the layer as the calculation depth, and each structural sub-layer of the bonding layer and LSAM-50 flexible base layer uses the depth from the surface to the top of the layer as the calculation depth. Substitute into the model in Step 2 to determine the calculated temperature corresponding to each calculation depth; according to the temperature - resilient modulus dependence model of various asphalt mixtures constructed in Step 3, substitute each calculated temperature to determine the calculated resilient modulus corresponding to each calculated temperature; Step 6: Perform mechanical response calculation of LSAM-50 full-depth asphalt pavement According to the resilient modulus of each structural sub-layer determined in Step 5, use the elastic layer continuous system theory under the action of a double circular uniform vertical load to calculate the pavement structure mechanical indexes.

2. The method according to claim 1, characterized in that, the surface functional layer uses AC-13 asphalt mixture, and the bonding layer uses AC-20 asphalt mixture.

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