Asphalt pavement structure performance dynamic evaluation method

Abstract

The invention discloses an asphalt pavement structure performance dynamic evaluation method, and relates to the technical field of road engineering. The method comprises the following steps: according to annual temperature field and traffic load data in historical monitoring data since traffic on the asphalt pavement, carrying out asphalt pavement strength test at multiple temperatures to inversely calculate the modulus of each structural layer, correcting a modulus main curve of each structural layer, and then collecting pavement crack and vertical permanent deformation data; calculating the current moment by using the asphalt pavement structure fatigue damage model and predicting the asphalt pavement structure damage at a certain moment in the future, correcting the transverse crack length model and the permanent deformation model in combination with pavement cracks and vertical permanent deformation data, calculating the current moment and predicting the transverse crack length and the rut depth at a certain moment in the future; and determining structural performance evaluation parameters of the asphalt pavement at the current moment and a certain moment in the future, and entering the next moment to continuously evaluate the structural performance of the asphalt pavement until the asphalt pavement finishes serving, thereby realizing accurate evaluation of the structural performance of the asphalt pavement.

Description

Technical Field

[0001] The invention relates to the technical field of road engineering, and in particular to a method for dynamically evaluating the structural performance of an asphalt pavement. Background Art

[0002] The performance of asphalt pavement on highways directly affects the driving safety, travel efficiency and maintenance investment of asphalt pavement. As the existing roads gradually enter a period dominated by maintenance, accurately grasping the performance of the pavement structure in advance is conducive to timely proposing preventive maintenance strategies. However, the pavement structure performance detection and evaluation methods currently used have certain shortcomings, such as the pavement structure performance evaluation results are inconsistent with the actual situation, the use of destructive detection methods, and low efficiency of detection data collection. The traditional pavement structure performance detection method is mainly regular manual detection, which has many limitations and requires a lot of manpower, material and financial resources. At the same time, the detection cycle is long, which is easy to affect the normal operation of traffic. At the same time, the detection results of traditional pavement structure performance detection methods often depend on the professional knowledge level, experience and on-site conditions of the detection personnel, resulting in a strong subjectivity in the detection results and it is difficult to timely detect damage to the pavement structure during the inspection interval.

[0003] In addition, at present, the performance evaluation of asphalt pavement structure is mainly carried out by analyzing the external detection information of the pavement. This method does not need to consider the internal mechanical environment of the pavement structure, but only evaluates from the external appearance of the pavement structure. It is impossible to fundamentally determine the internal cause of the pavement structure damage, and the evaluation of the pavement structure performance is mostly a post-evaluation. Only a small part of the causes of pavement damage can be determined by external observation. Most of the sources of disease are the effects of internal stress of the pavement structure, that is, the inevitable manifestation when the internal stress of the pavement exceeds the critical limit. However, the internal stress of the pavement structure cannot be directly obtained by observation. Therefore, the asphalt pavement structure performance evaluation method in the prior art cannot accurately evaluate the performance of the pavement structure. Summary of the invention

[0004] The present invention aims to solve the above-mentioned problems and provides a method for dynamically evaluating the structural performance of asphalt pavement. According to historical monitoring data and the main modulus curve of each structural layer of the corrected asphalt pavement, the structural damage of the asphalt pavement is determined in real time based on the time, axle type, and axle load interval. In combination with the real-time measured pavement cracks and vertical permanent deformation data, the structural performance of the asphalt pavement is associated with the asphalt pavement material and the service environment, thereby achieving an accurate evaluation of the structural performance of the asphalt pavement and providing a basis for the maintenance and repair of the asphalt pavement structure.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A method for dynamically evaluating asphalt pavement structural performance comprises the following steps:

[0007] Step 1, based on the annual temperature field and traffic load data in the historical monitoring data of the asphalt pavement since it was opened to traffic, obtain the hourly average temperature, traffic volume and axle load spectrum data of the asphalt pavement;

[0008] Step 2, performing strength tests on the asphalt pavement at multiple temperatures, determining the dynamic modulus of each structural layer in the asphalt pavement at different temperatures by back-calculating the structural layer modulus of the asphalt pavement, and correcting the modulus master curve of each structural layer of the asphalt pavement based on the least squares method;

[0009] Step 3: Use a comprehensive inspection vehicle to inspect the asphalt pavement for cracks and permanent deformation, measure the pavement cracks and vertical permanent deformation data of the asphalt pavement at the current moment, and obtain the measured values ​​of the transverse crack length and rutting depth of the asphalt pavement at the current moment;

[0010] Step 4, based on the hourly average temperature, traffic volume and axle load spectrum data obtained in step 1, combined with the main modulus curve of each structural layer of the corrected asphalt pavement, the asphalt pavement structure fatigue damage model is used to calculate the asphalt pavement structure damage at the current time and predict the asphalt pavement structure damage at a specified time in the future;

[0011] Step 5, using the transverse crack length model and the permanent deformation model to calculate the calculated values ​​of the transverse crack length and the rutting depth of the asphalt pavement at the current moment, and combining the measured values ​​of the transverse crack length and the rutting depth of the asphalt pavement at the current moment, to correct the transverse crack length model and the permanent deformation model of the asphalt pavement;

[0012] Step 6: According to the main modulus curve of each structural layer of the modified asphalt pavement, the modified transverse crack length model and permanent deformation model are used to predict the transverse crack length and rutting depth of the asphalt pavement at a specified time in the future, and then the structural damage rate, transverse crack length growth rate and permanent deformation rate of the asphalt pavement at the current time and the specified time in the future are calculated and predicted in combination with the asphalt pavement structure damage, so as to complete the performance evaluation of the asphalt pavement structure at the current time;

[0013] Step 7, enter the next moment, repeat steps 1 to 6 to continue the dynamic evaluation of the asphalt pavement structure performance until the asphalt pavement ends its service, and stop the dynamic evaluation of the asphalt pavement structure performance.

[0014] Preferably, the asphalt pavement strength test is carried out using a drop weight deflectometer, and the strength of the asphalt pavement structure is tested in the high temperature domain, medium temperature domain, and low temperature domain, respectively, wherein the high temperature domain is 35℃≤50℃, the medium temperature domain is 15℃≤35℃, and the low temperature domain is 0℃≤15℃.

[0015] Preferably, the asphalt pavement structure fatigue damage model adopts a calculation method based on time, axle type and axle load range, based on the fatigue damage caused to the asphalt pavement by various axle loads in various axle load ranges at various times from the opening of the asphalt pavement to the current time, as shown in formula (1):

[0016]

[0017] in,

[0018]

[0019] Where D is the structural damage of the asphalt pavement; t is the time sequence number, T is the total duration; i is the axle type sequence number; j is the axle load interval sequence number; D ijt is the fatigue damage caused by the i-th axle type passing through the asphalt pavement within the j-level axle load range within the t-th hour; NA ijt is the total number of loads on the i-th axle type in the j-th axle load range in the t-th hour; is the fatigue life of the asphalt pavement when the i-th axle type passes through the j-th axle load range within the t-th hour; β is the target reliability; k a k is the adjustment coefficient for seasonal frozen soil areas; b is the fatigue loading mode coefficient; is the temperature adjustment factor; is the tensile strain at the bottom of the asphalt layer generated when the i-th axle type passes through the j-th axle load interval in the t-th hour; is the dynamic modulus of asphalt mixture when the i-th axle type passes through the j-th axle load interval in the t-th hour; VFA is the asphalt saturation of asphalt mixture; h a is the layer thickness of asphalt mixture.

[0020] Preferably, the transverse crack length model is:

[0021]

[0022] in,

[0023]

[0024] Where l′ is the calculated value of the transverse crack length of the asphalt pavement structure; β2 is the crack length calculation coefficient; N(·) is the standard normal distribution function; SD is the standard deviation parameter of the transverse crack depth of the asphalt pavement structure; H a is the asphalt layer thickness of the asphalt pavement structure; t is the time sequence number, T is the total time; C is the crack depth value of the asphalt pavement structure; C2 is the crack depth value of the asphalt pavement structure at the end of the second hour; C t-1 C is the crack depth of the asphalt pavement structure at the end of hour t-1; t-2Δk is the crack depth of the asphalt pavement structure at the end of hour t-2; t k is the change of stress intensity factor in the tth hour; t is the stress intensity factor at hour t; k t-1 is the stress intensity factor at hour t-1; σ t is the internal force on the crack tip in the tth hour; σ t-1 is the internal force on the crack tip within the t-1 hour; A and a are the fracture parameters of asphalt mixture; β1 is the field calibration coefficient; E * is the stiffness modulus of asphalt mixture; σ m is the indirect tensile strength of the asphalt mixture in the structural layer where the crack tip is located; m is the creep rate of the asphalt mixture in the structural layer where the crack tip is located;

[0025] The modified transverse crack length model is:

[0026]

[0027] Where l is the correction value of the transverse crack length of the asphalt pavement structure; α is the calibration coefficient of the transverse crack length.

[0028] Preferably, the permanent deformation model is:

[0029]

[0030] in,

[0031]

[0032] In the formula, R a is the calculated value of the rutting depth of the asphalt pavement structure; λ is the calibration coefficient; x is the number of vehicle loads, X is the total number of vehicle loads; y is the asphalt layer number, Y is the total number of asphalt layers; t is the time number, T is the total duration; k is the rutting depth caused by the xth vehicle load acting on the yth layer of the asphalt layer in the tth hour of the current year; Ry is the comprehensive correction coefficient of the yth layer in the asphalt layer; T yt is the internal temperature of the yth layer in the asphalt layer; P yt is the vertical compressive stress at the top of the yth layer in the asphalt layer at the tth hour; N xet h is the number of standard axle load actions on the asphalt pavement structure when the xth vehicle load passes through; y is the thickness of the yth layer in the asphalt layer; h0 is the thickness of the rutting test specimen; It is the rutting depth corresponding to the yth layer of asphalt mixture in the asphalt layer at the tth hour.

[0033] Preferably, the calculation formula for the structural damage rate of the asphalt pavement is:

[0034] DR=100D (12)

[0035] Where, DR is the asphalt pavement structure damage; D is the asphalt pavement structure damage rate;

[0036] The calculation formula of the permanent deformation rate of the asphalt pavement is:

[0037]

[0038] Where, RDR is the permanent deformation rate of asphalt pavement structure; R a It is the rutting depth value of asphalt pavement structure.

[0039] The beneficial technical effects brought by the present invention are:

[0040] The present invention proposes a dynamic evaluation method for asphalt pavement structural performance. By acquiring internal temperature data and traffic load data in historical monitoring data of asphalt pavement in real time, the asphalt pavement structural damage is accurately calculated by time, axle type and axle load interval. The transverse crack length model and permanent deformation model of the asphalt pavement are corrected in combination with the real-time measured pavement cracks and vertical permanent deformation data. The asphalt pavement structural performance is combined with the asphalt pavement material and the service environment, and the structural damage rate, transverse crack length growth rate and permanent deformation rate of the asphalt pavement are accurately calculated. The problem that the internal stress of the asphalt pavement structure is difficult to obtain during the dynamic evaluation process is solved. Technical support is provided for the accurate evaluation of the asphalt pavement structural performance, which is conducive to the formulation of asphalt pavement structure maintenance and repair plans. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the pavement structure of the experimental section.

[0042] Figure 2 Schematic diagram of the corrected master curve of the dynamic modulus of the upper asphalt mixture.

[0043] Figure 3 Shown is the permanent deformation development trend of asphalt pavement.

[0044] In the figure, 1, upper layer, 2, middle layer, 3, lower layer, 4, upper base layer, 5, lower base layer, 6, bottom base layer. DETAILED DESCRIPTION

[0045] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0046] Example 1

[0047] This embodiment takes a highway in a certain area as an example, and selects an experimental section on the highway. The experimental section is an asphalt road surface with a road age of 10 years. The road surface structure of the experimental section is as follows: Figure 1 As shown, from top to bottom there are asphalt layers and base layers; the asphalt layers are arranged in order from top to bottom as an upper layer 1, a middle layer 2 and a lower layer 3, wherein the upper layer is a SMA-13 ​​layer with a thickness of 4 cm, the middle layer is an AC-20 layer with a thickness of 6 cm, and the lower layer is an AC-25 layer with a thickness of 8 cm; the base layers are arranged in order from top to bottom as an upper base layer 4, a lower base layer 5 and a bottom base layer 6, wherein the upper base layer is a LSPM25 layer with a thickness of 16 cm, the lower base layer is a cement-stabilized gravel layer with a thickness of 36 cm, and the bottom base layer is a cement-stabilized gravel layer with a thickness of 18 cm.

[0048] The asphalt pavement structural performance dynamic evaluation method proposed in the present invention is used to dynamically evaluate the asphalt pavement structural performance of the experimental section, which specifically includes the following steps:

[0049] Step 1: Obtain the historical monitoring data of the asphalt pavement from the time it was opened to traffic to the current moment. According to the annual temperature field and traffic load data of the asphalt pavement in the historical monitoring data, obtain the hourly average temperature, traffic volume and axle load spectrum data of the asphalt pavement. Table 1 shows the hourly average temperature of each structural layer of the asphalt pavement within 24 hours on a certain day in the historical monitoring data.

[0050] Table 1 Hourly average temperature of each structural layer of asphalt pavement within 24 hours on a certain day

[0051]

[0052] Step 2, perform strength test on the asphalt pavement at multiple temperatures. This embodiment uses a drop weight deflectometer to perform strength test on the asphalt pavement in high temperature, medium temperature and low temperature domains, respectively, wherein 35℃≤high temperature domain<50℃, 15℃≤medium temperature domain<35℃, 0℃≤low temperature domain<15℃.

[0053] By back-calculating the modulus of the structural layer of the asphalt pavement, as shown in Table 2, the dynamic modulus of each structural layer in the asphalt pavement at different temperatures is determined, and based on the least squares method, the dynamic modulus of each structural layer of the asphalt pavement at different temperatures determined in the asphalt pavement strength test is used to correct the dynamic modulus determined by back-calculation, and the modulus master curve of each structural layer of the asphalt pavement after correction is obtained, as shown in Figure 2 shown.

[0054] Table 2 Back-calculation results of the modulus of each structural layer of asphalt pavement at different pavement temperatures

[0055]

[0056] Step 3: Use a comprehensive inspection vehicle to inspect the current asphalt pavement surface cracks and permanent deformation to obtain the current pavement crack and vertical permanent deformation data, as shown in Table 3, thereby determining the transverse crack length measurement value and rutting depth measurement value of the asphalt pavement structure at the current moment.

[0057] Table 3 Pavement cracks and vertical permanent deformation data

[0058]

[0059] Step 4: Based on the hourly average temperature, traffic volume and axle load spectrum data obtained in step 1, combined with the main modulus curve of each structural layer of the corrected asphalt pavement, the calculation method of time, axle type and axle load interval is adopted, and the asphalt pavement structure fatigue damage model is used to calculate the asphalt pavement structure damage at the current moment. At the same time, the asphalt pavement structure fatigue damage model is used to predict the asphalt pavement structure damage at a specified time in the future, as shown in Table 4.

[0060] Table 4 Asphalt pavement structural damage in the current year and subsequent years

[0061] year 10 years 11 years 12 years 13 years 14 years 15 years Asphalt pavement structure damage rate / % 0.112 0.316 0.794 1 3.162 8.916

[0062] When using the asphalt pavement structure fatigue damage model to predict the asphalt pavement structure damage at a specified time in the future, due to the lack of historical monitoring data from the current time to the specified time in the future, it is necessary to use the monitoring data preset by the staff when predicting the asphalt pavement structure damage at the specified time in the future. In this embodiment, the hourly average temperature, traffic volume and axle load spectrum data at the corresponding time in the most recent year in the historical monitoring data are used as the monitoring data for the asphalt pavement at the future time.

[0063] In this embodiment, the fatigue damage model of the asphalt pavement structure adopts a calculation method based on time, axle type, and axle load range, based on the fatigue damage caused to the asphalt pavement by various axle loads in various axle load ranges at various times from the time when the asphalt pavement was opened to traffic to the current time, as shown in formula (1):

[0064]

[0065] in,

[0066]

[0067] Where D is the structural damage of the asphalt pavement; t is the time sequence number, T is the total duration in hours; i is the axle type sequence number; j is the axle load interval sequence number; D ijt is the fatigue damage caused by the i-th axle type passing through the asphalt pavement within the j-level axle load range within the t-th hour; NA ijt is the total number of loads on the i-th axle type in the j-th axle load range in the t-th hour; is the fatigue life of the asphalt pavement when the i-th axle type passes through the j-th axle load range within the t-th hour; β is the target reliability; k a k is the adjustment coefficient for seasonal frozen soil areas; b is the fatigue loading mode coefficient; is the temperature adjustment factor; is the tensile strain at the bottom of the asphalt layer generated when the i-th axle type passes through the j-th axle load interval in the t-th hour; is the dynamic modulus of asphalt mixture when the i-th axle type passes through the j-th axle load interval in the t-th hour; VFA is the asphalt saturation of asphalt mixture; h a It is the layer thickness of asphalt mixture, in mm.

[0068] Step 5, using the transverse crack length model and the permanent deformation model to calculate the calculated values ​​of the transverse crack length and the rutting depth of the asphalt pavement at the current moment, combined with the measured values ​​of the transverse crack length and the rutting depth of the asphalt pavement at the current moment, correct the transverse crack length model and the permanent deformation model of the asphalt pavement to obtain the corrected transverse crack length model and the permanent deformation model.

[0069] In this embodiment, the transverse crack length model is:

[0070]

[0071] in,

[0072]

[0073] Where l′ is the calculated value of the transverse crack length of the asphalt pavement structure, in meters; β2 is the crack length calculation coefficient, with a value of 400; N(·) is the standard normal distribution function; SD is the standard deviation parameter of the transverse crack depth of the asphalt pavement structure, with a value of 0.769; H a is the asphalt layer thickness of the asphalt pavement structure, in m; t is the time sequence number, T is the total time; C is the crack depth value of the asphalt pavement structure, in m; C2 is the crack depth value of the asphalt pavement structure at the end of the second hour, in m; C t-1 C is the crack depth of the asphalt pavement structure at the end of the y-1 hour, in meters; t-2 is the crack depth of the asphalt pavement structure at the end of hour t-2, in meters; Δk t k is the change of stress intensity factor in the tth hour; t is the stress intensity factor at hour t; k t-1 is the stress intensity factor at hour t-1; σ t is the internal force on the crack tip in the tth hour; σ t-1is the internal force on the crack tip within the first hour t-1; A and a are the fracture parameters of asphalt mixture; β1 is the field calibration coefficient, which is 6.0; E * is the stiffness modulus of asphalt mixture, and its value is 10000; σ m is the indirect tensile strength of the asphalt mixture in the structural layer where the crack tip is located, in MPa; m is the creep rate of the asphalt mixture in the structural layer where the crack tip is located;

[0074] The modified transverse crack length model is:

[0075]

[0076] Where l is the correction value of the transverse crack length of the asphalt pavement structure; α is the calibration coefficient of the transverse crack length.

[0077] In this embodiment, the pavement cracks and vertical permanent deformation data are measured by the comprehensive inspection vehicle at the current moment, and the pavement cracks and vertical permanent deformation data are processed using the least squares method. The data are compared with the asphalt pavement transverse crack length calculated by the transverse crack length model before correction to determine the transverse crack length calibration coefficient α, thereby obtaining the corrected transverse crack length model.

[0078] The permanent deformation model is:

[0079]

[0080] in,

[0081]

[0082] In the formula, R a is the calculated value of the rutting depth of the asphalt pavement structure; λ is the calibration coefficient; x is the number of vehicle loads, X is the total number of vehicle loads; y is the asphalt layer number, Y is the total number of asphalt layers; t is the time number, T is the total duration; k is the rutting depth caused by the xth vehicle load acting on the yth layer of the asphalt layer in the tth hour of the current year; Ry is the comprehensive correction coefficient of the yth layer in the asphalt layer; T yt is the internal temperature of the yth layer in the asphalt layer, in °C; P yt is the vertical compressive stress at the top of the yth layer in the asphalt layer at the tth hour, in MPa; N xet h is the number of standard axle load actions on the asphalt pavement structure when the xth vehicle load passes through; y is the thickness of the yth layer in the asphalt layer, in mm; h0 is the thickness of the rutting test specimen, in mm; It is the rutting depth corresponding to the yth layer of asphalt mixture in the asphalt layer at the tth hour, in mm.

[0083] In this embodiment, the rutting depth measurement value of the asphalt pavement structure at the current moment is obtained based on the pavement cracks and vertical permanent deformation data measured by the comprehensive detection vehicle at the current moment, and the calibration coefficient λ is determined by combining the rutting depth of the asphalt pavement structure calculated by the permanent deformation model before correction, so as to correct the permanent deformation model and obtain the corrected permanent deformation model.

[0084] Step 6: According to the main modulus curve of each structural layer of the modified asphalt pavement, the modified transverse crack length model and permanent deformation model are used to calculate the transverse crack length and rutting depth of the asphalt pavement at the current moment, and then the modified transverse crack length model and permanent deformation model are used to predict the transverse crack length and rutting depth of the asphalt pavement at a specified time in the future, as shown in Table 5.

[0085] Table 5 Transverse joint length and permanent deformation of asphalt pavement in the current year and subsequent years

[0086] year 10 years 11 years 12 years 13 years 14 years 15 years Length of transverse seam / (m / km) 70.56 73.45 85.16 96.49 119.1 136.53 Rutting depth / mm 11.55947 12.11097 12.63739 13.14184 13.62682 14.0944

[0087] Figure 3 The permanent deformation development trend diagram of the asphalt pavement is shown. According to the asphalt pavement structural damage calculated at the current moment in step 5, the structural damage rate of the asphalt pavement at the current moment is calculated, and then according to the measured values ​​of the transverse crack length and rutting depth of the asphalt pavement at the current moment, the transverse crack length growth rate and permanent deformation rate of the asphalt pavement at the current moment are calculated. The structural performance of the asphalt pavement is evaluated based on the structural damage rate, transverse crack length growth rate and permanent deformation rate of the asphalt pavement. At the same time, according to the asphalt pavement structural damage predicted at the specified future moment in step 5, the structural damage rate of the asphalt pavement at the specified future moment is predicted using the structural damage rate calculation formula of the asphalt pavement, and the transverse crack length and rutting depth of the asphalt pavement at the specified future moment are predicted based on the modified transverse crack length model and permanent deformation model, and the transverse crack length growth rate and permanent deformation rate of the asphalt pavement at the specified future moment are predicted, and the structural performance of the asphalt pavement at the specified future moment is evaluated based on the structural damage rate, transverse crack length growth rate and permanent deformation rate of the asphalt pavement at the specified future moment.

[0088] In this embodiment, the structural damage rate calculation formula of the asphalt pavement is:

[0089] DR=100D (12)

[0090] Where DR is the asphalt pavement structure damage; D is the asphalt pavement structure damage rate.

[0091] The calculation formula of the permanent deformation rate of the asphalt pavement is:

[0092]

[0093] Where, RDR is the permanent deformation rate of asphalt pavement structure; R a is the rutting depth value of the asphalt pavement structure, specifically the calculated value or measured value of the rutting depth; when calculating the permanent deformation rate of the asphalt pavement structure at the current moment, R a is the measured value of the rutting depth at the current moment, which is determined based on the pavement cracks and vertical permanent deformation data measured at the current moment; when calculating the permanent deformation rate of the asphalt pavement structure at a specified time in the future, R a is the calculated value of rutting depth, determined using the modified permanent deformation model.

[0094] In this embodiment, the current year for the dynamic evaluation of the structural performance of the asphalt pavement is 10 years. Further calculation shows that the structural damage rate of the asphalt pavement in the current year is 1.2%, the transverse joint length growth rate is 4%, and the permanent deformation rate is 4%. That is, the structural strength and performance of the asphalt pavement in the current year remain in good condition in the current year. At this stage, only corresponding functional maintenance of the asphalt pavement is required.

[0095] At the same time, after completing the dynamic evaluation of the asphalt pavement structural performance at the current moment, the dynamic evaluation of the asphalt pavement structural performance will continue at the next moment, and steps 1 to 6 will be repeated until the asphalt pavement ends its service and the dynamic evaluation of the asphalt pavement structural performance will be stopped.

[0096] When entering the next moment to carry out dynamic evaluation of asphalt pavement structural performance, the temperature data and traffic load data monitored at the previous moment are automatically stored in the historical monitoring data, and each time entering the next moment, the modulus master curve, transverse crack length model and permanent deformation model of each structural layer of the asphalt pavement are re-corrected in combination with the real-time collected pavement cracks and vertical permanent deformation data. The calculation method of time, axle type and axle load interval is adopted to dynamically evaluate the damage rate, transverse crack length growth rate and permanent deformation rate of the asphalt pavement structure at the current moment, thereby realizing the cumulative application of monitoring data during the service of the asphalt pavement. By using the accumulated monitoring data from the opening of the road to the evaluation moment, the modulus master curve, transverse crack length model and permanent deformation model of each structural layer of the asphalt pavement are corrected in each dynamic evaluation of the structural performance of the asphalt pavement, instead of setting the modulus of each structural layer of the asphalt pavement to a fixed value, the calculation accuracy of the transverse crack length and rutting depth is greatly improved with the successive correction of the transverse crack length model and the permanent deformation model, and the accuracy of the evaluation of the structural performance of the asphalt pavement is further improved.

[0097] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for dynamic evaluation of asphalt pavement structural performance, characterized in that: The following steps are involved: Step 1, based on the annual temperature field and traffic load data in the historical monitoring data of the asphalt pavement since it was opened to traffic, obtain the hourly average temperature, traffic volume and axle load spectrum data of the asphalt pavement; Step 2, performing strength tests on the asphalt pavement at multiple temperatures, determining the dynamic modulus of each structural layer in the asphalt pavement at different temperatures by back-calculating the structural layer modulus of the asphalt pavement, and correcting the modulus master curve of each structural layer of the asphalt pavement based on the least squares method; Step 3: Use a comprehensive inspection vehicle to inspect the asphalt pavement for cracks and permanent deformation, measure the pavement cracks and vertical permanent deformation data of the asphalt pavement at the current moment, and obtain the measured values ​​of the transverse crack length and rutting depth of the asphalt pavement at the current moment; Step 4, based on the hourly average temperature, traffic volume and axle load spectrum data obtained in step 1, combined with the main modulus curve of each structural layer of the corrected asphalt pavement, the asphalt pavement structure fatigue damage model is used to calculate the asphalt pavement structure damage at the current time and predict the asphalt pavement structure damage at a specified time in the future; Step 5, using the transverse crack length model and the permanent deformation model to calculate the calculated values ​​of the transverse crack length and the rutting depth of the asphalt pavement at the current moment, and combining the measured values ​​of the transverse crack length and the rutting depth of the asphalt pavement at the current moment, to correct the transverse crack length model and the permanent deformation model of the asphalt pavement; Step 6: According to the main modulus curve of each structural layer of the modified asphalt pavement, the modified transverse crack length model and permanent deformation model are used to predict the transverse crack length and rutting depth of the asphalt pavement at a specified time in the future, and then the structural damage rate, transverse crack length growth rate and permanent deformation rate of the asphalt pavement at the current time and the specified time in the future are calculated and predicted in combination with the asphalt pavement structure damage, so as to complete the performance evaluation of the asphalt pavement structure at the current time; Step 7, enter the next moment, repeat steps 1 to 6 to continue the dynamic evaluation of the asphalt pavement structure performance until the asphalt pavement ends its service, and stop the dynamic evaluation of the asphalt pavement structure performance.

2. The method for dynamic evaluation of asphalt pavement structure performance according to claim 1, characterized in that: The asphalt pavement strength test is carried out using a drop-hammer deflectometer, and the strength of the asphalt pavement structure is tested in high temperature, medium temperature and low temperature domains, wherein the high temperature domain is 35°C ≤ <50°C, the medium temperature domain is 15°C ≤ <35°C, and the low temperature domain is 0°C ≤ <15°C.

3. The method for dynamic evaluation of asphalt pavement structure performance according to claim 1, characterized in that: The fatigue damage model of asphalt pavement structure adopts a calculation method based on time, axle type and axle load range, based on the fatigue damage caused to the asphalt pavement by various axle loads in various axle load ranges at various times from the opening of the asphalt pavement to the current time, as shown in formula (1): in, Where D is the structural damage of the asphalt pavement; t is the time sequence number, T is the total duration; i is the axle type sequence number; j is the axle load interval sequence number; D ijt is the fatigue damage caused by the i-th axle type passing through the asphalt pavement within the j-level axle load range within the t-th hour; NA ijt is the total number of loads on the i-th axle type in the j-th axle load range in the t-th hour; is the fatigue life of the asphalt pavement when the i-th axle type passes through the j-th axle load range within the t-th hour; β is the target reliability; k a k is the adjustment coefficient for seasonal frozen soil areas; b is the fatigue loading mode coefficient; is the temperature adjustment factor; is the tensile strain at the bottom of the asphalt layer generated when the i-th axle type passes through the j-th axle load interval in the t-th hour; is the dynamic modulus of asphalt mixture when the i-th axle type passes through the j-th axle load interval in the t-th hour; VFA is the asphalt saturation of asphalt mixture; h a is the layer thickness of asphalt mixture.

4. The method for dynamic evaluation of asphalt pavement structure performance according to claim 1, characterized in that: The transverse crack length model is: in, In the formula, l ′ is the calculated value of the transverse crack length of the asphalt pavement structure; β2 is the crack length calculation coefficient; N(·) is the standard normal distribution function; SD is the standard deviation parameter of the transverse crack depth of the asphalt pavement structure; H a is the asphalt layer thickness of the asphalt pavement structure; t is the time sequence number, T is the total time; C is the crack depth value of the asphalt pavement structure; C2 is the crack depth value of the asphalt pavement structure at the end of the second hour; C r-1 C is the crack depth of the asphalt pavement structure at the end of hour t-1; t-2 Δk is the crack depth of the asphalt pavement structure at the end of hour t-2; t k is the change of stress intensity factor in the tth hour; t is the stress intensity factor at hour t; k t-1 is the stress intensity factor at hour t-1; σ t is the internal force on the crack tip in the tth hour; σ t-1 is the internal force on the crack tip within the t-1 hour; A and a are the fracture parameters of asphalt mixture; β1 is the field calibration coefficient; E * is the stiffness modulus of asphalt mixture; σ m is the indirect tensile strength of the asphalt mixture in the structural layer where the crack tip is located; m is the creep rate of the asphalt mixture in the structural layer where the crack tip is located; The modified transverse crack length model is: Where l is the correction value of the transverse crack length of the asphalt pavement structure; α is the calibration coefficient of the transverse crack length.

5. The method for dynamic evaluation of asphalt pavement structure performance according to claim 1, characterized in that: The permanent deformation model is: in, In the formula, R a is the calculated value of the rutting depth of the asphalt pavement structure; λ is the calibration coefficient; x is the number of vehicle loads, X is the total number of vehicle loads; y is the asphalt layer number, Y is the total number of asphalt layers; t is the time number, T is the total duration; k is the rutting depth caused by the xth vehicle load acting on the yth layer of the asphalt layer in the tth hour of the current year; Ry is the comprehensive correction coefficient of the yth layer in the asphalt layer; T yt is the internal temperature of the yth layer in the asphalt layer; P yt is the vertical compressive stress at the top of the yth layer in the asphalt layer at the tth hour; N xet h is the number of standard axle load actions on the asphalt pavement structure when the xth vehicle load passes through; y is the thickness of the yth layer in the asphalt layer; h0 is the thickness of the rutting test specimen; It is the rutting depth corresponding to the yth layer of asphalt mixture in the asphalt layer at the tth hour.

6. The method for dynamic evaluation of asphalt pavement structure performance according to claim 1, characterized in that: The calculation formula for the structural damage rate of the asphalt pavement is: DR=100D (12) Where, DR is the asphalt pavement structure damage; D is the asphalt pavement structure damage rate; The calculation formula of the permanent deformation rate of the asphalt pavement is: Where, RDR is the permanent deformation rate of asphalt pavement structure; R a It is the rutting depth value of asphalt pavement structure.

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