Dynamic Response Of Asphalt Pavement Research Articles

Numerical Simulation and Experimental Measurements of Dynamic Responses of Asphalt Pavement in Dry and Saturated Conditions under Full-Scale Accelerated Loading

Asphalt pavement presents diverse dynamic responses to vehicle loading in dry and saturated conditions, which can be systematically explored by numerical simulation. Building a numerical model based on the actual conditions of asphalt pavement is necessary, and relevant field tests should be subsequently conducted to monitor dynamic responses to calibrate and validate the numerical model. On the basis of strictly controlling the paths of vehicle wheels during field tests, this study numerically analyzed the dynamic responses of asphalt pavement in dry and saturated conditions under full-scale accelerated loading. The trends of the modeling results were consistent with those of field measurements. The increase in vehicle load significantly increased the magnitudes of stress, strain, and pore water pressure, while vehicle speed showed an obvious impact on pore water pressure. The dynamic responses decreased with pavement depths. Water made the dynamic responses more complex, and pore water pressure significantly decreased with depth within the upper layer of saturated asphalt pavement. Transverse distributions of indicators presented obvious compressive states in the regions in direct contact with vehicle wheels, while tensile states were found in the range of the middle vehicle axle. The numerical results provided a basis for field measurements in future studies, especially for the exploration of factors of temperature and layer depth.

Viscoelastic Dynamic Response of Asphalt Pavement in Long Slope Sections

To deeply understand the performance of asphalt pavement in long slope sections, the object of this paper is to obtain the viscoelastic dynamic response of asphalt pavement in long slope sections considering interface bonding conditions. An asphalt pavement model is built, and then for solving the problem, the Laplace-Hankel transformation is used to transfer the partial differential equations to the ordinary differential equations. Transfer matrices are adopted to present the relationship of stress and displacement between the pavement surface and any pavement depth, and a special transfer matrix characterizes the interface bonding condition. By this method, the analytical solution of the stress and displacement at any pavement position is received. After that, an example of asphalt pavement in a long slope section is introduced considering the distribution of stress and displacement, the magnitude of the horizontal load, and the interface bonding strength. The horizontal vehicle load affects the distribution of shear stress τrz in the pavement. The interface bonding strength is more important in long slope sections than in any other normal section of asphalt pavement.

Numerical simulation of mechanical response analysis of asphalt pavement under dynamic loads with non-uniform tire-pavement contact stresses

The selection of accurate input design parameters is important for understanding the dynamic response of an asphalt pavement structure. The transverse and longitudinal shear stresses that affect the dynamic response of asphalt pavement are not considered in traditional asphalt pavement design. To this end, this study utilizes the finite element method (FEM) to analyze the mechanical response of asphalt pavement under dynamic loads with non-uniform tire-pavement contact stresses. For this purpose, firstly a three-dimensional (3D) finite element (FE) model of a rubber tire is developed. Secondly, the predicted and laboratory measured stresses are compared to develop a 3D FE model of the contact stresses. Finally, a 3D FE model of the tire–pavement contact is analyzed to investigate the influence of shear stresses on the response of the asphalt pavement and the superposition effect of the mechanical response. The results show that the distribution and magnitude of the vertical contact pressure under the free-rolling state are the same as those under the static state, and the traction and braking conditions could change the symmetry of tire-pavement interactions. In addition, the shear stress at the tire-pavement interface affects the peak response of the surface layer, indicating that shear stress plays a considerable role in controlling the development of rutting and longitudinal cracks. Considering the viscoelasticity of the asphalt material, it is observed that the superposition effect of the mechanical response is a comprehensive result of the space–time domains. In conclusion, this study analyzes the influence of tire-pavement contact on the mechanical response of asphalt pavement and proposes input design parameters for improving the design of asphalt pavement.

Influence of Axle Load and Asphalt Layer Thickness on Dynamic Response of Asphalt Pavement

Based on the test data of vehicle load test on asphalt pavement, the significance of dynamic response index of different asphalt pavement to axle load change of single and double rear axle trucks is analyzed. The changes of horizontal strain at the bottom of asphalt layer, vertical compressive stress at the top of subgrade, and vertical displacement of transition layer and bottom compressive stress before and after laying of middle and upper layers are revealed. The test results show that reducing the thickness of asphalt layer or increasing the vehicle axle load can lead to the more unfavorable stress-strain distribution in asphalt pavement under driving load. The influence of the fluctuation of truck axle load or asphalt layer thickness on the stress-strain distribution in asphalt pavement varies with the type of pavement structure, pavement response index, vehicle driving speed, vehicle type, and the horizon of the measuring point. The transverse strain at the bottom of the asphalt layer is more affected by the axle load and the thickness of the asphalt layer than the longitudinal strain at the bottom of the asphalt layer. The measured value of the dynamic response index of the semirigid asphalt pavement is more affected by the axle load than that of the inverted asphalt pavement. However, the measured value of the dynamic response index of the semi-rigid asphalt pavement is less affected by the thickness of the asphalt layer when the thickness of the asphalt layer changes within a certain range. The tensile strain part of the longitudinal strain at the bottom of the asphalt layer and the compressive strain part of the transverse strain at the bottom of the asphalt layer are greatly affected by the thickness of the asphalt layer. The sensitivity of fatigue life of asphalt pavement of inverted structure to driving speed and axle load is less than that of semirigid structure. The research results can provide reference for the analysis of the asphalt pavement disease mechanism and provide guidance for asphalt pavement structural design and service life analysis.

Influence of bedrock on the dynamic deflection response and dynamic back-calculation results of asphalt pavement: Insights from the numerical simulation of falling weight deflectometer tests

The dynamic deflection response obtained by the falling weight deflectometer (FWD) test and back-calculated modulus results play an important role in road engineering. The presence of bedrock may affect the results of FWD tests on asphalt pavement. Many numerical simulation models of FWD tests have been established to obtain the dynamic response of pavement structures without considering the influence of bedrock, which prevents us from further understanding the influence of bedrock on dynamic response of asphalt pavements. Here, we consider the bedrock under asphalt pavement structures with an analysis program based on the spectral method with fixed-end boundary conditions (B-SEM). The B-SEM is employed to observe the dynamic response of a conventional asphalt pavement during the FWD test; the results are compared with those obtained by the finite element method (FEM). Semi-rigid base asphalt pavement, rigid base asphalt pavement, and flexible base asphalt pavement are simulated by the B-SEM with different bedrock depths, and the deflection results are compared and analyzed. Additionally, the bedrock’s influence on the dynamic modulus back-calculation results is investigated. The results show that compared with the FEM, the B-SEM produces results with considerable accuracy and high computational efficiency. Furthermore, shallow bedrock has an obvious influence on the dynamic deflection responses of different pavements, as well as the accuracy of the back-calculation results. The impact of bedrock on the modulus back-calculation of pavement layers is concentrated in the subbase and subgrade, with a minimal effect on the surface layer.

Theoretical and Experimental Investigation on Dynamic Response of Asphalt Pavement Under Vibration Compaction

This study aims to investigate the dynamic response regulation by combining the theoretical analysis and field test under the vibration rolling condition. Based on the viscoelastic theory of a multilayer system, the dynamic stiffness method (DSM) incorporating multidimensional Fourier transform is proposed to solve the 3-dimensional (3D) dynamic response of pavement under vibration compaction. The stiffness matrix of each pavement layer and the global stiffness matrix of the whole pavement structure are obtained. By combining vibration load with boundary conditions, the 3D exact solution is obtained and validated by the finite element method. In addition, the field test is also conducted using a series of sensors and equipment (e.g., SmartRock sensor, acceleration sensor, temperature sensors, and non-nuclear density meter) to calibrate the theoretical model to determine the wave number and dynamic modulus during the vibration rolling process. Then, considering the factors during compaction, the rules of displacement variation and pavement acceleration are investigated in terms of modulus, thickness, and density. The results show that the 3D displacement and acceleration components both vibrate with high frequencies during compaction, and peak acceleration in the vertical direction prevails. For the vertical displacement, its distribution beneath the drum of the roller is almost even except that it drops to zero abruptly around the drum edge. The relationship between thickness and acceleration follows a linear function, and the acceleration on the pavement surface rises when the thickness increases. Although the density and modulus increase with rolling times, the effect of modulus on acceleration is more obvious and prominent than that of density. In summary, the DSM presented in this article provides a robust method to calculate the dynamic response of pavement under vibratory compaction and to back-calculate the modulus of compacted pavement layers. Moreover, the regulation also sheds insight on the understanding of vibration compaction mechanism that there is a potentially strong correlation between compaction state, modulus, and vibration acceleration.

Analysis of the dynamic responses of asphalt pavement based on full-scale accelerated testing and finite element simulation

This paper proposes a method of combining full-scale accelerated pavement testing (APT), indoor experiments, and finite element (FE) simulations to analyze and predict the dynamic response of a typical pavement structure with an SMA overlay. First, APT was performed under different loads from various axle weights, temperatures and speeds, and the longitudinal strain was selected as the analysis index. Indoor experiments considering the size effect were used to correct the parameters of the viscoelastic constitutive model. Then, the FE model was validated based on the consistency of the time-history curve and the proximity of the peaks of the dynamic response. Next, dynamic response analysis results indicate that the pavement structure in the influence range of the wheel track is in the strain alternating state of “compression-tension-compression”. Increased axle weight and temperature causes an increase in the longitudinal strain at the bottom of the underlayer asphalt, while the situation is reversed for the loading speed. Moreover, the longitudinal strain decreases after pavement overlaying, and the greater the axle weight loading is, the more obvious this trend. The FE analysis method further shows that the compressive stress is mainly concentrated under the wheel track, and it increases and then decreases from the center of the wheel track in the transverse distribution. The shear stress and strain increase and then decrease from the center of the wheel track. As the heavy load increases, the longitudinal strain increases nonlinearly with increasing axial loads, while the maximum shear stress increases linearly. In addition, the simulation results under a high loading speed illustrate that the effect of the loading speed change on the strain is noticeable.

Viscoelastic dynamic response of asphalt pavement with imperfect interface bonding base on transfer matrix

AbstractThe interface bonding condition between asphalt pavement layers is always imperfect because of the differing material properties of different layers and the limitation of construction techniques. Therefore, designing asphalt pavement by considering the interface to be completely continuous is not precise. The viscoelastic character of the asphalt layer contributes significantly to the performance of asphalt pavement. To explore the influence of the imperfect interface on the viscoelastic dynamic response of asphalt pavement, the Hankel–Laplace transformation was applied to convert the partial differential equations to ordinary differential equations and a transfer matrix was introduced to describe the behavior of the imperfect interface. Based on the boundary condition and integral inverse transformation technique, an analytical solution for the displacement, stress, and strain of the pavement can be obtained. By considering the variation in the interface condition and the viscoelastic characteristics of the asphalt layer, the dynamic response of the pavement was calculated based on a practical example. The results show that the interface condition between the asphalt layer and the base course has a marked influence on the viscoelastic dynamic response of the pavement and that enhancing the strength of this interface can reduce the deflection of the pavement. The series elastic component in the modified Burgers model is another significant factor that affects the calculation results of the pavement dynamic response.

Characterization of dynamic response of asphalt pavement in dry and saturated conditions using the full-scale accelerated loading test

Asphalt pavement exhibits different dynamic responses to vehicle loading in saturated conditions and in dry conditions. It is essential to directly conduct field full-scale tests to systematically investigate comprehensive influence of water on dynamic response of asphalt pavement. However, real vehicles which were often applied in field tests might result in a certain deviation in dynamic responses measured from each field loading test due to the inevitable influence of the driver’s subjective operation and the tread pattern on vehicle wheel. This study adopted the full-scale accelerated loading test system to comprehensively characterize dynamic response of asphalt pavement in both dry and saturated conditions based on the strict control of loading vehicle’s path. The results indicated that dynamic responses showed relatively larger magnitudes in saturated condition than those in dry condition. Strain and stress respectively showed slowly increasing and decreasing trends with the increase of vehicle load and speed correspondingly. Pore water pressure was apparently sensitive to vehicle speed compared with vehicle load. Pore water pressure generated by the front axle wheels showed obviously larger magnitudes than those produced by the rear axle wheels due to the change in thickness of surface runoff. The transverse distribution of pore water pressure obtained from both field tests and numerical simulation exhibited consistent variation trends. Decline degree of pore water pressure magnitudes was obtained at 86.1% for the two adjacent testing points with a distance of 100 mm under the vehicle wheel, which proved the great influence of the tread pattern of vehicle wheel on the transverse distribution of dynamic pore water pressure. A prediction model of positive pore water pressure that considered vehicle load and speed was proposed.

Wave Propagation Approach for Elastic Transient Responses of Transversely Isotropic Asphalt Pavement under an Impact Load: A Semianalytical Solution

The conventional transfer matrix method, adopted formerly in a semianalytical solution for layered elastic or viscoelastic asphalt pavement structures, has inherent deficiencies, such as ill-condition matrix, numerical overflow, and error accumulation, due to exponential items. This phenomenon is more evident in multilayered dynamic analysis with imperfect interfaces. Moreover, several studies revealed that pavement materials exhibit transverse isotropy in service. Consequently, a novel semianalytical solution methodology, wave propagation approach, was proposed herein to calculate the dynamic responses of asphalt pavement under an impact load considering the transversely isotropic material model and the imperfect interfaces. First, the transfer matrix was established based on matrix theory and wave propagation approach, while the relation between the state vector and wave vector in the transformed domain was constructed simultaneously. Then, combined with the boundary conditions and interface contact conditions, the solution of the wave vector in the transformed domain was derived. Finally, based on Laplace–Hankel inverse transform, the state vector in the time domain was obtained, followed by numerical computation with programming. The accuracy and efficiency of the proposed semianalytical solution, together with the influence regularities of several variables, were discussed. Results showed that due to the absence of positive exponential functions and a large-dimensional matrix, accuracy and efficiency requirements were satisfied during calculation. Moreover, the variation induced by the transversely isotropic properties and interface conditions, presented in the dynamic responses, reiterated that these factors should be considered during the design and analysis of asphalt pavement structures.

Dynamic response of asphalt pavement under vibration rolling load: Theory and calibration

Vibrating compaction is a critical procedure to guarantee the quality of asphalt pavement, and the dynamic response of asphalt pavement is a complicate problem in the process of vibration rolling. This paper aims to theoretically investigate the dynamic response regulation and influencing factors of pavement under the moving vibration load. Firstly, based on the viscoelastic theory of multi-layer system, the dynamic response governing equation of asphalt pavement is established under the vibration load, the governing equation was then simplified by the two-dimensional Fourier transform method. Further, the stiffness matrices of the single-layer and multi-layer pavement structures are obtained by using the dynamic stiffness method. Consequently, the exact solution is obtained for the plane strain problem by programming and validated with the finite element results, which is proved to be more efficient in the calculation. Moreover, the model is calibrated by the field test to determine the wave number and dynamic modulus during the vibration rolling process. Subsequently, the effects of material and load frequency are investigated on the dynamic response in terms of acceleration and displacement. The results show that both of the acceleration and displacement of pavement surface vibrate periodically with the vibrating load, and the changing regulations of the acceleration and displacement with loading time can be divided into three stages corresponding to the engineering practice such as rapid decline, slow decline and stable stages. Finally, the influencing factors are analyzed in terms of the modulus of materials (i.e., surface course and base course) and the frequency of load. It shows that the peak values of acceleration and displacement of the pavement surface change significantly and nonlinearly with the material modulus in the form of power function. Meanwhile, the influence of vibrating frequency is also significant and a quadratic relationship between the acceleration/displacement and frequency. This paper provides an insight into understanding the dynamic response of pavement under vibration rolling condition to some extent, and potentially provides theoretical and technical support for accurately determining and modifying some indexes that characterize the compaction degree of asphalt pavement.

Dynamic Response Analysis of Airport Asphalt Pavement Subjected to High-Temperature Jet Wake Based on Finite Element Simulation

Abstract With the dramatic increase of air traffic volume and the rapid development of civil aviation airport construction in China, asphalt layers overlaying original concrete pavement in civil aviation airports has become the primary rehabilitation scheme. However, asphalt airport pavement is prone to excessive deformation when subjected to the repeated and heavy aircraft loading, especially when coupled with high-temperature field. However, the impact of high-temperature jet wake is rarely considered in the existing structural design and analysis of airport asphalt pavement. In order to investigate the impact of high-temperature jet wake on the dynamic response of asphalt pavement, the coupling of finite element (FE) simulation of the temperature field and aircraft loading based on sequential decoupling methodology was implemented herein. Firstly, the temperature field distribution induced by the high-temperature jet wake on the asphalt pavement was simulated and analyzed by FE simulation on the ABAQUS CFD platform. Then, the temperature field distribution was integrated within the asphalt pavement structure by combining the temperature field distribution produced by jet wake and thermal conduction between ambient radiation and pavement. Secondly, the viscoelastic parameters of each asphalt layer under the obtained temperature field distribution were calculated to represent more real material properties. Finally, FE simulation of airport asphalt pavement subjected to the coupling of aircraft loading and integrated temperature field was conducted. The results show that the amplitudes of transverse strain, vertical strain, and longitudinal strain of the asphalt pavement considering jet wake together with ambient radiation are basically higher than those without consideration. Consequently, the dynamic responses of airport asphalt pavement produced by jet wake and ambient radiation should be fully considered in the design and analysis of airport asphalt pavement.

Experimental investigation on dynamic response of asphalt pavement using SmartRock sensor under vibrating compaction loading

Although compaction is one of the most critical steps during the construction of asphalt pavements, effective real-time technologies to detect the compactness of the asphalt mixture non-destructively are still rare. Currently, most methodologies in practice are experience-based, and few studies have provided insight into the particle interaction characteristics and quantitative response during the vibration compaction of asphalt pavements. Accordingly, both field and laboratory tests are conducted in this study to investigate the response of an asphalt mixture quantitatively under a vibrating compaction load at the meso-scale. First, a field test program is designed, and sensors (e.g., SmartRock and acceleration sensors) are used to measure the dynamic response of an asphalt pavement and the vibrating drum during vibrating compaction. The quantitative analysis reveals that the first three rolling impacts exert a significant and dominant compact effect on the asphalt mixture. Subsequently, a linear relationship between the acceleration of the vibrating drum and the vertical stress in the asphalt pavement is demonstrated. Furthermore, the SmartRock sensor is also employed in the laboratory test to detect the internal dynamic response under gyratory compaction, and the relationship between the compaction degree and the vertical stress in the asphalt mixture is established. Finally, three assessment methods for asphalt mixture compactness are proposed as characterization of the compactness by the acceleration of a vibrating drum, intermediate variables such as the stress of the mixture under a gyratory compaction, or acceleration and stress of the pavement. Comparison of the results illustrates that the dynamic response inside the mixture during the compaction can directly reflect the compaction degree of the asphalt mixture, and the compaction degree and the peak acceleration of the vibrating drum exhibit a strong linear correlation during the vibration rolling process.

A Study on the Friction Dynamic Response of Asphalt Pavement Considering the Unevenness

In order to quantitatively analyse the influence of pavement unevenness on the stress of asphalt pavement, a tire-road coupling model with stable rolling was established. Sinusoidal wave is used to describe the pavement unevenness, and based on the established tire-road coupling model, different conditions of axle load and base elastic modulus are used to analyse the influence of unevenness on the dynamic response of asphalt pavement. The results show that the influence of unevenness on vertical stress of asphalt pavement increases with the increase of axial load. As the elastic modulus of base increases, the vertical stress of asphalt layer will decrease, while the vertical stress of base layer increases. But the influence of unevenness on dynamic response of asphalt pavement cannot be eliminated. Therefore, the unevenness should be taken into account in the simulation of real road surface.

Dynamic simulation analysis of the tire-pavement system considering temperature fields

In order to analyze tire footprints in different conditions and calculate dynamic responses of asphalt pavement with vehicle braking, a tire-pavement coupling simulation system, which can use a viscoelastic constitutive model of asphalt concrete considering temperature dependence, is established. The user subroutine of the material model was programmed by the FORTRAN language, and viscoelastic parameters of the material model were recognized based on dynamic strain data of dynamic impact tests, whose validity was verified by using test data in the literature. The tire-pavement coupling simulation system was established to analyze tire footprints in static and dynamic conditions at different temperatures of asphalt concrete layer, whose calculation accuracy of the numerical simulation was verified. Based on measured temperature data at different depths of an actual pavement structure and the corresponding simulation model, thermal parameters of each layer in the pavement structure were recognized. Field distributions of the viscoelastic parameters in the asphalt concrete layer of the coupling simulation system were obtained by using the heat transfer analysis and the user subroutine. Average braking decelerations of trucks at a chosen intersection were calculated according to the investigation data. Based on the tire-pavement coupling simulation system, peak values of dynamic shear strain in the asphalt concrete layer at the intersection were calculated, which considered the coupling effect between axle loads and temperature fields.

Application of Dynamic Analysis in Semi-Analytical Finite Element Method.

Analyses of dynamic responses are significantly important for the design, maintenance and rehabilitation of asphalt pavement. In order to evaluate the dynamic responses of asphalt pavement under moving loads, a specific computational program, SAFEM, was developed based on a semi-analytical finite element method. This method is three-dimensional and only requires a two-dimensional FE discretization by incorporating Fourier series in the third dimension. In this paper, the algorithm to apply the dynamic analysis to SAFEM was introduced in detail. Asphalt pavement models under moving loads were built in the SAFEM and commercial finite element software ABAQUS to verify the accuracy and efficiency of the SAFEM. The verification shows that the computational accuracy of SAFEM is high enough and its computational time is much shorter than ABAQUS. Moreover, experimental verification was carried out and the prediction derived from SAFEM is consistent with the measurement. Therefore, the SAFEM is feasible to reliably predict the dynamic response of asphalt pavement under moving loads, thus proving beneficial to road administration in assessing the pavement’s state.

Random Dynamic Response Analysis of Asphalt Pavement Based on the Vehicle-Pavement Interaction

In order to analyze the dynamic response of asphalt pavement under vehicle load, the random characteristic of pavement roughness was considered and the vehicle was simplified into 1/2 model with four freedom degrees when establishing the dynamic load model. Then the sequence of the random dynamic load coefficient was obtained by developing a MATLAB program based on the incremental Newmark-β method. Based on the plane strain assumption, a two-dimensional layered finite element model of asphalt pavement was established by ABAQUS software. Then the dynamic load coefficient was used to modify tire pressure that would be applied on the ABAQUS model. Then dynamic response rule of the model and how it was effected by vehicle speed were studied under random load. The results show that under the condition of random load, dynamic response of the pavement structure exhibiting a fluctuation trend as vehicle speed increases and the dynamic response characteristics of each point is different.

Measured Dynamic Response of Asphalt Pavement under FWD Load

To study the real dynamic response regularity of asphalt pavement structure under dynamic load, a road test was conducted for three types of typical asphalt pavement. Dynamic and static deflection basins were established. The characteristics of the dynamic deflection basin were studied. The set-in dynamic strain sensors at the bottom of the surface layer collected the dynamic strain response under falling weight deflectometer (FWD) load. Results show that the static deflection basin is deeper than the dynamic deflection basin, but the range of the latter is larger than that of the former. The characteristics of the two deflection basins differ. The change trends of dynamic response with an increase in FWD load reflect nonlinear characteristics. The dynamic strain of three typical asphalt pavements at the bottom of the surface layer does not induce fatigue failure in the pavement structure. The longitudinal strain is larger than the lateral strain. Different prediction models on dynamic strain on the basis of dynamic deflection basin parameters are established.

Dynamic model and criteria indices of semi-rigid base asphalt pavement

This paper presents a dynamic model of asphalt pavement by considering the characteristics of moving tyre load, visco-elastic performance of material and layered system of pavement. The pavement is defined as an infinite layered system with the tyre load moving at a constant speed, and asphalt concrete (AC) is characterised as a kind of visco-elastic material. Using the spectrum analysis method, a complex tyre load is decomposed into a series of harmonic loads. Based on the frequency characteristics of a linear system, a universal formulation pattern for differential visco-elastic constitutive relations is provided. And then, a model is set up to analyse the dynamic response of asphalt pavement under moving harmonic load, and then to extend to the arbitrary moving load according to the superposition principle of a linear system. The dynamic responses of seven typical semi-rigid base asphalt pavements are analysed using the model. Analysis results indicate that the tensional strain at the bottom of the AC layer and the vertical compression strain at the top of the roadbed are not suitable for key indices of the semi-rigid base asphalt pavement. The shearing strain at the bottom of the AC layer can be taken as a key index to evaluate the fatigue performance, and the vertical compression strain at the top of the pavement surface can be taken as a key index to evaluate pavement rutting, and the vertical shearing strain at the top of pavement surface can be taken as a key index to evaluate top–down crack.

Dynamic Response of Asphalt Pavement on Semi-Rigid Base due to Heavy Load

The purpose of this paper is to study dynamic-characteristics of asphalt-pavement on semi-rigid base loaded with moving, heavy-load. Based on transient-dynamics theory, three-dimensional finite-element (FE) model was developed for structural dynamic-responses analysis using ANSYS software. The heavy-duty axle-load model was established according to Belgium-Design Code, and the dynamic-load was simplified as sinusoidal-wave load. For the pavement mechanics indexes (road-surface deflection, the vertical and lateral stress, the shear stress and the strain), the time-history curves and distribution conditions in the structure were presented. Expect tensile-strain at surface-layer, the relationship between axle-load weight and mechanic-indexes are almost linearly proportional. The calculation shows that under moving heavy-load, the surface-layer suffers from rather high vertical compressive-stress and shear-stress, the base and subbase are loaded with high tensile-stress and the subgrade top undergoes large vertical-strain . For asphalt-pavement on semi-rigid loaded with moving, heavy-load, besides the conventional indexes (including road-surface deflection and tensile-stress at the bottom of base or subbase), the design indexes should also include the shear-stress on road surface, the vertical-strain on the top of subgrade and the vertical compressive-stress on road surface.