International Journal of Geomechanics

The axial compression behavior of reinforced helical pulldown micropiles (RHPMs) and fiber-reinforced polymer (FRP)-RHPMs is investigated through three-dimensional finite-element (FE) analysis. The model was calibrated using the results of full-scale load tests conducted by the authors. The calibrated numerical model was then used to conduct a parametric study to examine the behavior of RHPMs and FRP-RHPMs in different soil conditions. The numerical analysis provided important insights into the load-transfer mechanism, shaft resistance, and factors influencing the pile response. Based on the results of the numerical simulations coupled with experimental data, design guidelines are developed for the implementation of RHMPs and FRP-RHPMs in foundation design.

The exertion of super-long pile skin friction is an asynchronous process in deep soft soil area. The limitation of skin friction on the upper part of pile is much smaller than the lower part of pile. The softening of super-long pile skin friction is also a common phenomenon. Therefore, a new hyperbolic load transfer model is proposed in this paper, which takes into account the softening of pile skin friction and the nonlinear characteristic of pile–soil relative displacement. Meanwhile, a User-Defined Material (UMAT) subroutine is written in FORTRAN language and connected with an ABAQUS interface. The curve of pile skin friction is obtained, which is more consistent with practical engineering. It is further developed into a universally applicable function of super-long piles. The settlement and effective pile length in deep soft soil area can be calculated by a new function with the consideration of super-long pile weight. Example analysis shows that the calculation of axial force distribution of super-long pile, settlement of pile top, and effective pile length are more consistent with pile test results. In summary, the method proposed in this paper can exactly reflect the working characters of super-long pile in practical engineering, which can provide valuable reference for the design of super-long pile.

Liquefaction of unsaturated sands has been observed in laboratory tests and in the field. A comprehensive investigation of unsaturated sand deposits subjected to seismic loading, especially using validated computational tools, is still lacking. This paper presents an analysis procedure to study the response of level ground unsaturated sand deposits subjected to seismic loading. The analysis procedure is a fully coupled flow–deformation finite element code with solid skeleton displacements, pore water pressure, and pore air pressure as nodal variables. The stress–strain behavior of unsaturated sands is described by a coupled hydro-mechanical elastoplastic constitutive model that includes the hysteretic model for soil water characteristic curves and the hydro-mechanical coupling mechanisms. The finite element code is first validated by comparing simulations with centrifuge test results. Reasonable comparisons of surface accelerations, ground settlements, and lateral deformations are obtained. A parametric study is then conducted to investigate the effects of initial degree of saturation, relative density, and effective overburden pressure on the seismic response of level ground unsaturated sand deposits. The results of the parametric study show that the thickness of the liquefied layer increases with an increase in degree of saturation. The potential for liquefaction reduced with increases in relative density and effective overburden stress. The results also reveal a drastic reduction in surface accelerations following liquefaction of a sand deposit.

Quality levels for rockfill dam compaction (herein, porosity is an important index for assessing dam-material compaction quality) in any location can be estimated based on construction digitization technologies. According to the results of large-scale laboratory triaxial tests, the quantitative relationship between dam-material compaction quality and Duncan-Chang constitutive model parameters is established. In turn, the spatial estimation of model parameters of any location of a rockfill dam can be achieved. These parameters, which can reflect the actual conditions of dam-material compaction quality, can be assigned to each finite element by customizing Abaqus software. The refined three-dimensional (3D) rockfill dam model is then built for considering the influence of the actual foundation terrain on dam deformation. On this basis, the actual load process is determined from construction progress and practical dam appearances, and in turn, the refined finite-element modeling and analysis of structural behaviors (deformation and stress) occurring during rockfill dam construction is achieved. The proposed method considers spatial differences in constitutive model parameters resulting from the spatial differences in actual dam construction quality, thus representing an improvement in accuracy from the conventional method, which typically assigns the same parameters to elements of the same dam zone. A case study shows that the calculation results of the proposed method are more consistent with the measured values and can reflect structural behaviors more objectively. The method can serve as a new tool for simulating the regularity of the structural behaviors of rockfill dams.

Dewatering must be conducted for shallow confined aquifers located below deep excavations. However, its effects on ground settlement remain unclear, due to the complicated seepage and stress condition of the strata. In this study, a coupled numerical method was adopted to study the effects of dewatering in a confined aquifer on ground settlement during excavation. A hypothetical excavation model depicting the soil layers that are typical in Shanghai was developed in a finite difference software. Excavation and dewatering in a confined aquifer were simulated. The numerical results were analyzed in association with those of an identical excavation in which the confined aquifer was removed through modification of its hydraulic conductivity. Comparative results showed that dewatering in the confined aquifer during excavation aggravates ground surface settlements, especially for the ground surface twice the maximum excavation depth (2 H_e) behind the wall, where H_e was the excavation depth. The dewatering-induced settlement beyond 2 H_e showed a similar profile as groundwater drawdown in the confined aquifer owing to the insignificant deformations of the strata above the confined aquifer. However, the settlement profile within 2 H_e was inconsistent with the drawdown profile, due to the effects of unloading inside the excavation and soil-wall interaction. At the end of excavation, the confined aquifer was significantly compressed due to dewatering. However, it was found that the aquitard above the confined aquifer expanded dramatically with its maximum expansion located near 0.5 H_e. This may be attributed to the local soil arch and insignificant consolidation in the aquitard. Additionally, postexcavation pumping resulted in significant compression of the aquitard and further aggravate the ground surface settlement.

Rock microstructure changes after hydrochemical reactions, which, in turn, leads to deterioration of mechanical properties. Thus, a quantification study on rock microstructural damage after chemical corrosion is necessary. Quantification of the microstructural damage of rocks after chemical corrosion was carried out in this study. We presented a proposal that included formulae for calculating the damage variable by analyzing the porosity changes of sandstone. The plastic deformation of sandstone specimens after soaking in chemical solution was observed. Plastic deformation can be divided into distinct stages over time. Results showed that the prepeak incremental deformation after chemical corrosion was partially due to the increase in plastic deformation before reaching the peak and to the deformation caused by pore compression. Plastic deformation is an indirect indicator of the degree of chemical corrosion of sandstone specimens. After chemical corrosion, the porosity of sandstone specimens changed consistently with the velocity of longitudinal wave. Therefore, the calculation formula of the damage variable can be used to calculate the porosity of sandstone specimens at different time periods. The chemical damage of sandstone specimens was highly consistent with the peak strain. Therefore, the damage variable based on porosity can be used to quantitatively describe the damage caused by chemical corrosion.

The ultimate bearing capacity of masonry retaining wall slope is studied by combining the upper-bound theorem, the mixed numerical discretization, and the linear programming. First, the soil mass is discretized by triangular finite elements to simulate its continuum mechanics characteristics, and the stone masonry wall is discretized by rigid finite elements (RFEMs) to simulate its noncontinuum mechanics characteristics. Meanwhile, constraint conditions for kinematically admissible velocity fields are established, and then the plastic flow conditions of interfaces between finite elements and RFEMs are established. The upper-bound linear programming model for the ultimate bearing capacity of masonry retaining wall slope is built by taking the overload coefficient as the objective function, and the dual simplex method is used to solve the linear mathematical programming problem. Last, the ultimate load (or the safety factor) of the slope and the corresponding velocity fields could be obtained directly. Two examples have proved the validity of the proposed method. The research effort in this article is an attempt to introduce the mixed numerical discretization into the limit analysis.

A shear strength reduction method based on a dual factoring strategy was considered in which cohesion and the coefficient of internal friction were each reduced by a different factor. By using a strength reduction path introduced in the present study, series of numerical tests were conducted to bring the slope into different states of critical equilibrium through which definitions of the factor of safety and the strength reduction path adopted in some preceding studies were evaluated. This strategy was found to be more conservative than the traditional shear strength reduction method. Generally, the factor of safety defined in the limit equilibrium method should be adopted, and the most probable strength reduction path under the principle of the shortest path could be an effective approach to obtain the minimum value of the factor of safety directly. To implement this strategy, a mathematical model based on limit analysis solutions is proposed to describe the shear strength components of a slope under different critical equilibrium states, and a general computational procedure is outlined.

Recent cases of damage to mountain tunnels have raised concerns about the seismic performance of underground structures. The damaged sections have been majorly observed in highly fractured and weathered geological regions. The literature suggests that the interaction of the stress waves with the discontinuous medium may considerably influence the behavior of tunnel excavations. However, most of the investigations toward the evaluation of the transverse dynamic response of tunnels idealize the geological medium as a continuum medium, failing to capture the interaction between the stress waves and joints. To overcome the limitation, the present study attempted to assess the dynamic behavior of a lined circular tunnel passing through a blocky discontinuous rock mass using the Voronoi tessellation scheme in a distinct element framework. The influence of frequency of input motion, tunnel depth, in situ stress ratio, and types of seismic waves was studied with regard to the dynamic forces that developed in the liner. Moreover, the results, presented in terms of incremental dynamic forces along the tunnel liner, were utilized to corroborate past damages reported in the literature.

Soil consolidation causes pore compression and ground subsidence. Accordingly, void ratio, compressibility, and permeability change, thereby affecting the consolidation process. Thus, the consolidation generates a nonlinear coupling interaction with pore compression. Considering the effect of pore evolution on consolidation is important for accurate analysis of the consolidation process. In this article, a one-dimensional (1D) nonlinear consolidation equation is reformulated based on the property relationships related to pore evolution, and a consolidation coefficient is provided as an independent variable. The nonmonotonic change in the consolidation coefficient with an increase in the effective stress is described. In addition, an asymptotic solution for the present consolidation equation is obtained by adopting the Galerkin–iterative method. In this solution, the pore-water pressure is decoupled into two physical quantities: pore-water pressures of Terzaghi’s consolidation theory and pore evolution effect; the latter characterizes the effect of pore evolution on the dissipation of pore-water pressure. On the basis of the present consolidation equation and its asymptotic solution, some complex consolidation characteristics reported in the literature are clarified. The predicted results of the asymptotic solution and the corresponding experimental results have a better consistency compared with the results calculated by Terzaghi’s solution.

In this research, a series of centrifuge modelings, including those with two different superstructures supported by a nonconnected piled raft foundation system (NPRS) in a dry sand bed, was conducted. The superstructures were simulated by 2 one-degree-of-freedom systems under two different natural frequencies. Using a shaker positioned on a centrifuge base, the sinusoidal waves with two amplitudes (0.14 and 0.4 g) and two different motion frequencies (1 Hz and 2 Hz), as the main shaking events, were imposed to each model. A cushion layer consisting of crushed grained sand between the raft and the dry sand bed, provided secure resistance against the horizontal movement of the raft and superstructures during the shaking. The results of the modeling indicated that the internal forces, including axial forces and the bending moment, along the piles were small in the NPRS, and the effects of superstructure frequencies on these internal forces were minimal. The responses of each system at both levels of input acceleration were similar and independent of excitation frequency.

The representation of the Hoek-Brown criterion is an irregular curved hexagonal pyramid in the principal stress space, which leads to the occurrence of numerical singularities on the edges of the pyramid. With the aim of achieving a physical approximation to the pyramid, this study used both the C1 and C2 smoothing artifices on its sharp edges, and it was found that they were able to successfully eliminate the singularity and ensure the convexity of the yield surface. Meanwhile, to reflect the characteristic of the poor tensile strength of a rock mass, a tension cutoff surface was employed to form the whole modified combined yield surface. To facilitate comprehension and programming, the initial Hoek-Brown criterion and the smoothing and tension cutoff yield functions were all expressed in terms of stress invariants. The fully implicit backward Euler integral regression algorithm was employed to form the consistent stiffness matrix to ensure the high accuracy and fast convergence of numerical computations. In accordance with the failure zone in which a trial stress may fall, it may be pulled back to the initial Hoek–Brown yield surface, the transitional rounding yield surface, the tension cutoff yield surface, or the vertices that are the intersections of the former two with the latter. Furthermore, to facilitate the application of this modified Hoek-Brown criterion, a three-dimensional (3D) user-defined material behavior subroutine was developed in a finite-element program, and its reliability and applicability were verified through the numerical simulations of the triaxial compression and uniaxial tension tests of a rock and the excavation of a rock tunnel.

In this study, we analyzed the influence of the excavation size and the sequence of excavation on the convergence evolution in drifts excavated in Callovo-Oxfordian claystone. The drifts, which are part of the Underground Research Laboratory of the French National Radioactive Waste Management Agency (ANDRA), had diameters ranging between 0.7 m and 6.3 m. The measurements showed an anisotropic convergence with the maximum and minimum values in horizontal and vertical directions. Using a semi-empirical law, convergence evolution was fitted independently for each drift. The results show that the values for the parameters describing the time-dependent properties of the system rock-support depended upon the time elapsed for the support installation and the rate of excavation. For drifts following the same sequence of excavation, these parameters did not depend upon the size of the excavation. Finally, the analysis of a drift cross section enlargement showed that the convergence evolution was more isotropic and that the values for the parameters describing the time-dependent properties were lower, suggesting that overexcavation could limit the delayed response of the ground.

To investigate the influence of the geometry of a fracture and grouting on failure behaviors and mechanical properties of rock masses, uniaxial compressive tests were conducted on rock-like specimens containing single unfilled and grout-infilled flaws having different geometries. The compressive strength, deformation behaviors, and failure modes were studied and compared among the said specimens. Grouting improves the strength of grouted specimens through the following two mechanisms: (1) by increasing the shear-strength parameter values of the interface between the grout and model material and (2) by reducing the stress concentration at the flaw tips. Seven and eight crack types identified based on the crack geometry and crack-propagation mechanisms were used to analyze the failure modes of the specimens with the unfilled flaws and the grout-infilled flaws, respectively. An equivalent strength theory is introduced to predict the strength and the range of the flaw inclination angle of the grouted specimens for which the damage occurs along the interface between the grout and model material.

Because of the nonlinearity nature of contacts, real contact information in discontinuous computation is unknown before analysis. In standard three-dimensional (3D) discontinuous deformation analysis (3D DDA), the indeterminacies of the contacts arise from two aspects: the singular block boundaries and the nonsmooth frictional behavior. Because the contact occurs only at the first entrance position, the first entrance theory is the general physical law of block contacts. Therefore, the first entrance approach is proposed in this study to select the first entrance plane and to evaluate the related first entrance points, along which the contact forces would be applied. Furthermore, the procedure and criteria of the open-close iteration (OCI) for the 3D frictional contact problem is presented to determine the most suitable status and force of each contact. With this rigorous method, the information of each contact can be determined, such that the two kinds of the contact indeterminacies are resolved. The effectiveness of the proposed method is verified by three numerical tests, suggesting that the proposed method works at a practical level in accuracy and robustness.

Offshore pipelines are commonly laid directly on the seabed, which is dominantly soft clayey deposits in deep-water areas. This article presents a numerical finite-element study of the undrained bearing capacity of a pipeline partially embedded in clay soil and subjected to combined vertical (V) and horizontal (H) loading. The effect of tensile capacity between the pipe and soil is considered. Expressions for bearing-capacity envelopes explicitly written in the V–H space and covering a practical range of embedment ratios and uplift tensile capacities are presented. This allows offshore engineers to estimate pipeline behavior under combined loading with consideration of the tension between pipe and soil.

Pumping artesian water is mandatory in deep excavation above a shallow confined aquifer with a high piezometric head. In this study, a comprehensive monitoring program is performed to investigate the responses of far-field ground and groundwater to the pumping of artesian water in deep excavations. The artesian water level was monitored by observation wells, and the pore pressures along the depth were monitored by a cluster of vibrating wire piezometers. The ground surface settlement and subsurface settlement were surveyed by level instruments and multiple position extensometers, respectively. These measured data are analyzed comprehensively and thoroughly. Moreover, a simplified prediction method of far-field groundwater drawdown and ground surface settlements induced by dewatering is proposed. Results indicate that the response of artesian water levels is closely related to the discharge and recharge flow. Because of the vertical drainage, the pore pressures in the lower portion of the aquitard above the confined aquifer decrease slightly during the dewatering process. However, the pore pressures in poorly conductive soils barely increase during the short dated recharge. The developments of the ground surface settlements are consistent with the artesian water level. The ground surface beyond 4H_e settled significantly after dewatering, and the influence zone of dewatering on ground surface settlements extended to 10H_e, where H_e represents the final excavation depth. The measured data reveal that dewatering in the confined aquifer resulted in the compression of all soil layers. The comparison between predicted results and the monitoring data confirms the practicability of the proposed method.

This study focuses on the evaluation of the load transfer mechanism and the determination of the shape of the load distribution transmitted to the geosynthetic layer when a cavity appears under granular and cohesive backfills. Trapdoor experimental technique with high-speed acquisition of digital images and continuous monitoring of load and displacements were used for this purpose. Testing different soil types, it has been demonstrated that an approximate parabolic or inverted triangular load distribution seems acceptable for granular soil layer, whereas for cohesive backfill the load distribution could be approximately represented by two concentrated forces near the edges of the cavity. In both cases, an important overload on the soil surface could change the shape of the load acting on the geosynthetic sheet. Experimental results are then approached by Terzaghi’s formulation with an appropriate shape of load distribution and a convenient value of the earth pressure coefficient. Finally, recommendations are proposed to promote a better design of such reinforcement structures.

Seismic dynamic analysis of gravity dams of five different heights in the time domain was performed based on the fluid–structure coupling model (FSCM). Compared with the results from the FSCM, the maximum hydrodynamic pressures on dams were found to be overestimated by the classical Westergaard formula. The position of the maximum hydrodynamic pressure from the FSCM was found to be obviously raised along the upstream surface of the dam, not at the heel of the dam as in the solution of Westergaard formula. Thus, the Westergaard formula was revised with consideration to the influence of the height of dam, the elasticity of dam, and the absorption characteristic of the reservoir bottom on the hydrodynamic pressure. The solutions of the Westergaard correction formula are quite consistent with the hydrodynamic pressures noted in previous reports.

Stone column use has gained popularity around the globe as an effective ground improvement technique to improve the load-bearing capacity of soft soils. End-bearing stone columns are commonly used, but occasionally floating stone columns are adopted since they have been proven to achieve the necessary load-carrying capacity and serviceability requirements. However, stone column parameters are often estimated without much basis for simulation and design purposes due to a lack of practical research and real-life case studies in this area. Hence, in order to develop a fundamental understanding of the load-settlement responses of floating stone columns in soft clays, detailed back-analysis was performed in this study. Throughout the back-analysis, all the numerical models were validated by comparing the analysis results with field measurements. This study highlights the existence of some critical interpreted parameters, namely soil cohesion c′, friction angle ϕ′, and dilation angle ψ′, as well as the soil–structure interaction mechanism that influences the load-settlement responses of the floating stone columns. The successful characterization of the stone column materials and the modeling technique of stone columns in finite element analyses show great potential in assessing the real-life performance of floating stone columns in soft clays.

It has been accepted that, in geo-materials, almost all the cracks forming at final failure in the tension test and those occurring at the crack initiation (CI) and crack propagation stages in the compression test are tensile cracks. Because of this, tensile strength is attracting more attention. Compared with the experiment for obtaining tensile strength, the results obtained from a CI stress experiment are inaccurate for the subjective judgments of the user, and the results obtained from the fracture toughness test show a rather large variation of 30–50%. A review was conducted to determine the relationships among CI stress, Mode I fracture toughness, and tensile strength from the view of the failure mechanism and the data gathered from the available literature. It was found that CI stress has a linear relationship with Brazilian tensile strength with the linear coefficient of 0.075, and the linear coefficient between Mode I fracture toughness and tensile strength is in the range of 0.1–0.15, although both correlation coefficients are at a low level. The relationships can be the basis for preliminary design purposes and for rock classification and characterization. It is suggested that the shape of the sample for testing should be consistent and the methods for obtaining each property should be standardized, and more data are needed for further study.

The fundamental solution for saturated multilayered soils with anisotropic permeability and elastic superstrata is deduced by gathering the analytical layer elements of single-phase soil layers and saturated soil layers. According to the displacement coordination along the plate-soil contact surface, the fundamental solution is substituted into the boundary element method (BEM) formula of the elastic thin plate. Some theoretical and experimental results are presented to certify the correctness of the method in this study, and the influences of the elastic superstratum, time factor, plate-soil relative stiffness, and stratification characteristic on the time behavior of elastic thin plates are explored.

The segregation of rubber sand mixtures, when they form heaps, as observed by the method of digital image processing (DIP), is presented. Through segmenting the digital images into a binary picture, the DIP method enables material ingredients identification and three-dimensional mapping of mixture segregation. This helps reach a better understanding of mixture heterogeneity when incorporating artificial material into conventional geotechnical materials. To gain an insight into the mixture heterogeneity, the DIP results were used to validate a discrete element model, and the model was then used to examine the influence of particle properties on the segregation. The discrete element simulations showed that the particle density is critical in material segregation, and the segregation becomes more noticeable when the materials density ratio increases. This trend is restricted by increasing the interparticle surface roughness.

In this paper, a computational algorithm based on the eXtended Finite Element Method (X-FEM) is developed to study the fluid-lag zone involved in hydraulic fracturing treatments. The fluid-lag zone, caused due to the high pressure gradient in the vicinity of the hydrofracture tip, is primarily treated by the imposition of the vapor pressure. The capillary action at the flow front is captured by inclusion of the surface tension effects. The overlap of the hydrofracture faces, particularly within the fluid-lag region, is prevented using an X-FEM penalty algorithm. The governing equations of the hydrofracture inflow and the surrounding domain are solved in a sequential order called the staggered Newton strategy. Finally, the performance and the accuracy of the proposed numerical approach are explored by means of numerical simulation.

The fluid flow of Jijicao block in Beishan, one of the main candidate sites for a Chinese high-level radioactive waste (HLW) repository, was studied by a simulation on the basis of the discrete fracture network (DFN) model that was optimized by measured information with a coupled stochastic-deterministic approach. The spatial distribution of the fracture network within a certain domain matches that in reality based on the deterministic information obtained from field investigation. The presentation started with the generation of stochastic DFN models, and then the geometric properties (location, density, etc.) of fracture inside the models are modified to reflect the reality as objectively as possible. Further, the inherent hierarchy and the intersection relationship of fracture networks were adjusted in a locally coupled manner to make the model further optimized. Finally, to obtain the directional permeability of Jijicao block the calculation of fluid flow was performed within two-dimensional (2D) planes [three orthogonal planes in three-dimensional (3D) space] based on the optimized model. Results show that the size of the representative elementary volume (REV) ranges from 8 to 12 m in 2D, and for K₁-K′₁, K₂-K′₂, and K₃-K′₃ planes they are about 8, 8–10, and 10–12 m, respectively. In addition, the directional permeabilities are all of −13 orders of magnitude. Specifically, the convergence values of permeability in the K₁-K′₁ plane are 5.33 × 10⁻¹³ m² (k_x) and 6.41 × 10⁻¹³ m² (k_y), in the K₂-K′₂ plane the values are 2.57 × 10⁻¹³ m² (k_y) and 4.38 × 10⁻¹³ m² (k_z), and in the K₃-K′₃ plane the values are 5.77 × 10⁻¹³ m² (k_z) and 4.25 × 10⁻¹³ m² (k_x), respectively. The fluid flow simulations in the HLW repository provide an effective way to evaluate the long-term impact on the environment induced by radionuclide migration associated with regional fluid flow.

This paper presents an analytical solution to predict the radial bulging displacement and vertical settlement behaviors of geosynthetic-encased stone columns (GESCs) considering the nonlinear-elastic and elastoplastic models of stone-column materials. This method was verified via comparison with elastic model and testing data in the literature. Parametric studies were conducted to investigate the influences of geosynthetic encasement stiffness, area replacement ratio, and soil parameters on the vertical settlement and radial bulging displacement behaviors of GESCs.

Many engineering problems, such as soil stabilization, nuclear waste storage, and oil and gas extraction, require understanding and modeling of the coupled chemomechanical behavior of soils. Based on the framework of the Barcelona basic model (BBM), a constitutive model (BBM-C) for addressing chemomechanical coupling behavior of saturated soil is proposed. By replacing matric suction with osmotic suction, the analogous yield function, hardening law, and flow rule are introduced for the BBM-C. This study also presents a parameter calibration method for the proposed constitutive model. To validate the BBM-C, three oedometer tests, in which the specimen was subjected to mechanical loading with constant osmotic suction, were used to calibrate the model parameters. Two other oedometer tests, including (1) mechanical loading at constant osmotic suction and (2) alternative chemical and mechanical loading, were used as blind tests to verify the proposed BBM-C with the calibrated model parameters. A comparison between experimental data and predicted results demonstrated that the BBM-C was able to capture the main features of the chemomechanical coupling behavior of saturated soil.

The reconstruction of microstructural models is the prerequisite step for the micromechanical simulation of asphalt concrete. Computer-generated microstructural models have been developed because the traditional X-ray image-based models are costly and time-consuming. One concern for the computer-generated model is the accuracy in aggregate morphology and internal structure compared with the X-ray image-based models. Therefore, it is desirable to generate microstructural models with aggregate morphology and internal structures close to the real asphalt concrete samples. Although aggregate morphology and internal structures for real samples have been previously studied, these parameters for computer-generated models are rarely reported. This study aims to propose an approach to analyze and quantify the aggregate morphology and internal structures of computer-generated microstructural models of asphalt concrete. Sphere clumps were used to represent aggregate particles and air voids. Then the aggregate skeleton and air voids were generated based on which both discrete element (DE) models and finite-element models on the microscale can be reconstructed. The aggregate sphericity and angularity, air void distribution, aggregate orientation, aggregate contact points, and aggregate distribution were analyzed based on the DE model. Some novel approaches were proposed to quantify these parameters. The results showed that all these parameters can be successfully obtained and quantified. The outcomes of this study can serve as a prestep of the ultimate goal of reconstructing microstructural models that display aggregate morphology and an internal structure comparable to real asphalt concrete samples.