David Sebastian Calpa , Fabricio Fernández , Euripedes A. Vargas Jr. , Guilherme J.C. Gomes , Raquel Q. Velloso , Marcelo Miqueletto , Marcos Massao Futai
{"title":"Multi-failure numerical analysis of rainfall-triggered landslides at the basin-scale","authors":"David Sebastian Calpa , Fabricio Fernández , Euripedes A. Vargas Jr. , Guilherme J.C. Gomes , Raquel Q. Velloso , Marcelo Miqueletto , Marcos Massao Futai","doi":"10.1016/j.compgeo.2025.107622","DOIUrl":"10.1016/j.compgeo.2025.107622","url":null,"abstract":"<div><div>Climate change and rapidly growing urbanization demand advanced, physically based approaches for mapping landslide-prone regions. Yet, most existing models rely on simplified assumptions regarding subsurface water flow and slope stability analysis. This paper introduces a novel fully numerical framework (MFNA-3D) that advances basin-scale simulation of rainfall-induced slope failures through an innovative multi-failure algorithm based on Numerical Limit Analysis (NLA). The proposed method employs a one-way coupling strategy that links a three-dimensional solution of Richards equation for transient, variably saturated subsurface flow with a newly developed NLA-based stability model tailored for large-scale slope stability assessment. The NLA-based algorithm enables the efficient delineation of multiple and simultaneous failure zones with irregular geometries and the quantification of failure volumes, without requiring a priori assumptions about their shape or location. MFNA-3D improves the physical realism of basin-scale landslide simulations by capturing the effects of antecedent and extreme rainfall on pore-water pressure and stability evolution. The methodology was applied to a landslide-prone tropical basin in the state of Rio de Janeiro, Brazil, incorporating mesh refinement and parametric sensitivity analyses. Quantitative validation was conducted by comparing the Fs maps obtained from the proposed approach with those generated using the infinite slope method, against mapped landslide scars. Results confirm the model’s capability to reproduce complex landslide behavior at the basin scale. This study positions MFNA-3D as a scalable and physically grounded numerical tool for advanced landslide hazard mapping.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"189 ","pages":"Article 107622"},"PeriodicalIF":6.2,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Numerical investigation and ML-based formulation for conventional and modified suction caissons subjected to unidirectional and combined loadings","authors":"Kewen Zhu , Hang Feng , Jian Yu , Sen Li","doi":"10.1016/j.compgeo.2025.107637","DOIUrl":"10.1016/j.compgeo.2025.107637","url":null,"abstract":"<div><div>The modified suction caisson (MSC), incorporating an external short-skirted structure in addition to its inner caisson, represents an innovative variant of the conventional suction caisson (CSC) in offshore engineering. However, currently available studies lack a comprehensive comparative analysis of CSCs and MSCs and a unified prediction formulation for these foundations, which are essential for practical engineering design. To address this gap, this study systematically compares bearing capacities of CSCs and MSCs under unidirectional and combined loadings using finite element limit analysis (FELA), and proposes a unified failure envelope formulation via the evolutionary polynomial regression (EPR) machine learning technique. In particular, key influencing factors including caisson geometries, soil strength profiles, and interface adhesion are also systematically analyzed. FELA results reveal design recommendations: (i) the failure envelope of MSC and CSC is primarily influenced by the embedment ratio of the inner caisson, with minimal effects from interface adhesion or soil strength heterogeneity; (ii) a 20% increase in external skirt width results in improvements of at least 20% and 23% in vertical and lateral bearing capacities, respectively; and (iii) the lateral capacity becomes independent of the external skirt length once it exceeds 20% of the inner caisson length. Using the FELA dataset, the EPR technique can provide unified and effective bearing capacity formulations.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"189 ","pages":"Article 107637"},"PeriodicalIF":6.2,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Polar and Cartesian representations of mechanical quantities in granular materials","authors":"Chuang Zhao , Chengbo Li","doi":"10.1016/j.compgeo.2025.107632","DOIUrl":"10.1016/j.compgeo.2025.107632","url":null,"abstract":"<div><div>Characterizing mechanical quantities in granular materials is essential for understanding the relationship between macroscopic behavior and microstructural features. A key step in this process is the anisotropic decomposition of the spatial distributions of these quantities. However, studies on arbitrary-order anisotropic expansions are still scarce, and the problem remains challenging. Building on the introduction of projection operators, this study presents the expressions of irreducible tensor bases in two- and three-dimensional Cartesian coordinates and establishes the correspondence between Cartesian expansions and Fourier or spherical harmonic expansions in polar coordinates. A general theoretical framework is proposed for describing the distribution of mechanical quantities in both coordinate systems, together with the relations between the anisotropy coefficients in the two frames. Polar expansion coefficients, easy to compute, are converted into Cartesian coefficients with clearer physical meaning, allowing macroscopic properties to be explained by microscopic mechanical distributions. Finally, the theory is validated through discrete element simulations of 2D super-elliptic and 3D super-ellipsoidal systems, where stress and elastic modulus anisotropy are calculated to explain macroscopic properties. The proposed method simplifies anisotropy characterization without order limitations.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"189 ","pages":"Article 107632"},"PeriodicalIF":6.2,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A micromechanical study of shear-weakening characteristics of granular flow in a torsional shear cell","authors":"Xiaoran Sheng , Qi Zhang , Huabin Shi","doi":"10.1016/j.compgeo.2025.107591","DOIUrl":"10.1016/j.compgeo.2025.107591","url":null,"abstract":"<div><div>This study employs Discrete Element Method (DEM) simulations to investigate the micromechanical characteristics of granular materials subjected to shear in a torsional shear cell across various flow regimes, including quasi-static, transitional, and grain-inertial states. Two simulation configurations with slightly different initial volume fractions (packing densities) were compared to elucidate both force chain evolutions and macroscopic rheological responses of granular flow. The observed macroscopic stress responses, particularly shear-weakening phenomenon, were further interpreted using modified analytical constitutive laws. This approach successfully captured the trends and yielded quantitative macroscopic parameters that are sensitive to initial packing density. By further tracking the evolution of force chain properties such as length, number, curvature, anisotropy, and load distribution, we aim to establish connections between microscopic force chain characteristics and macroscopic rheological behavior like shear-weakening observed in the transitional regime. The results reveal distinct evolutionary patterns in force chain characteristics across different flow regimes and between the two simulation configurations. Notably, specific parameters such as opposing trends in force chain anisotropy and different variations in force chain numbers between two configurations can serve as microscopic indicators for identifying more noticeable macroscopic shear-weakening phenomenon. Conversely, parameters such as force chain curvature exhibited a reduced dependence on packing density and interparticle stress, indicating that they are more reflective of intrinsic structural reorganization patterns. This research enhances our understanding of the micromechanical origins of granular rheology and establishes connections between macroscopic constitutive parameters and microscopic force chain indicators.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"189 ","pages":"Article 107591"},"PeriodicalIF":6.2,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
David Santillán , Ruben Juanes , Sandro Andrés , Luis Cueto-Felgueroso
{"title":"Impact of fault permeability anisotropy on the nucleation and rupture of injection-induced earthquakes","authors":"David Santillán , Ruben Juanes , Sandro Andrés , Luis Cueto-Felgueroso","doi":"10.1016/j.compgeo.2025.107613","DOIUrl":"10.1016/j.compgeo.2025.107613","url":null,"abstract":"<div><div>This study investigates the impact of fault permeability anisotropy on the nucleation and rupture of injection-induced earthquakes. Using numerical models, we analyze the effects of varying fault permeability in both, transverse and longitudinal directions. Our research focuses on understanding how these hydraulic properties influence the onset of slip, the nucleation length, and the propagation of the rupture.</div><div>We simulate more than 400 cases with different combinations of friction parameters and hydraulic properties, verifying that the reference scaling <span><math><mrow><msub><mrow><mi>L</mi></mrow><mrow><mi>∞</mi></mrow></msub><mo>=</mo><mfrac><mrow><mi>b</mi></mrow><mrow><msup><mrow><mrow><mo>(</mo><mi>b</mi><mo>−</mo><mi>a</mi><mo>)</mo></mrow></mrow><mrow><mn>2</mn></mrow></msup></mrow></mfrac><mfrac><mrow><msup><mrow><mi>G</mi></mrow><mrow><mo>′</mo></mrow></msup><msub><mrow><mi>D</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow><mrow><mover><mrow><msubsup><mrow><mi>σ</mi></mrow><mrow><mi>n</mi></mrow><mrow><mo>′</mo></mrow></msubsup></mrow><mo>¯</mo></mover></mrow></mfrac></mrow></math></span> provides satisfactory results for scaling nucleation length. Our findings indicate that increased fault permeability delays the onset of slip and affects nucleation patterns, with high longitudinal permeability promoting larger nucleation lengths and high transverse permeability resulting in longer nucleation times.</div><div>During rupture propagation, poroelastic effects cause undrained responses in pore pressure, significantly affecting the fault strength. Permeable faults exhibit more symmetrical rupture patterns and higher seismic moments than impermeable faults. The study highlights the crucial role of hydraulic properties in the development of nucleation and rupture of induced earthquakes, emphasizing the importance of these properties for designing safer injection protocols.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"189 ","pages":"Article 107613"},"PeriodicalIF":6.2,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Trong Nghia-Nguyen , Rahmat Kurniawan , Mamoru Kikumoto
{"title":"Particle breakage limits packing density effect on pile resistance in crushable soils","authors":"Trong Nghia-Nguyen , Rahmat Kurniawan , Mamoru Kikumoto","doi":"10.1016/j.compgeo.2025.107631","DOIUrl":"10.1016/j.compgeo.2025.107631","url":null,"abstract":"<div><div>This study conducted numerical simulations of pile-bearing capacity using a finite element framework that incorporates a model for crushable soils, considering the effects of packing density. Simulations were performed for both crushable and non-crushable soils to assess how packing density affects stress–strain behavior and particle breakage during pile penetration. Results indicated that in non-crushable soils, pile resistance was significantly increased in denser soils. However, when particle breakage was included, the bearing resistance showed minimal difference between dense and loose soils. This phenomenon, consistent with experimental findings of cone penetration in pumice sand, a crushable soil. The simulations captured variation in stress–strain behavior and particle breakage around the pile tip, which are challenging to observe experimentally. In non-crushable soils, especially in dense conditions, increased dilatancy during shearing raised mobilized stresses, leading to higher shear resistance and bearing capacity. In contrast, in crushable soils, early particle breakage reduced dilatancy and mobilized stresses, minimizing the difference in bearing resistance between dense and loose soils. Additionally, particle breakage extended about 2D (D is pile diameter) below the pile tip, regardless of soil density. These findings suggest that conventional methods for calculating pile-bearing capacity can be extended to predict behavior in crushable soils by considering reduced mobilized stresses and shear resistance due to particle breakage. The study enhances the understanding of pile behavior in crushable soils and highlights the impact of soil density on pile resistance.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"189 ","pages":"Article 107631"},"PeriodicalIF":6.2,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhaogang Luo , Xuanming Ding , Joseph Mbenza , Qiang Ou , Ting Zhang , Xihong Zhang
{"title":"Macro-micro bearing analysis of shallow footings on geogrid reinforced coral sands considering varied geogrid properties","authors":"Zhaogang Luo , Xuanming Ding , Joseph Mbenza , Qiang Ou , Ting Zhang , Xihong Zhang","doi":"10.1016/j.compgeo.2025.107606","DOIUrl":"10.1016/j.compgeo.2025.107606","url":null,"abstract":"<div><div>The geogrid reinforced coral sand (GRCS) technique effectively stabilizes large-scale sites in island and coastal areas. This study develops a model test-based 3D discrete–continuous numerical model to investigate the macro–micro bearing behavior of shallow footings on reinforced coral sands, focusing on the effect of geogrid properties such as tensile strengths and node (rib) dimensions. Macroscopic bearing performance is improved with the enhanced geogrid properties, i.e., a maximum 141% increase in bearing capacity compared to the unreinforced condition. Microscopic mechanical analysis indicates enhanced geogrid properties impede stress transfer and particle movement, reducing geogrid buckling and foundation failure depth. The amount and spatial distribution of particle breakage in foundation soils depends on stress levels and particle displacements. These macro–micro bearing performances arise from stress difference and stress diffusion angle induced by geogrid properties. Given the uniform reinforcement mechanism under the influence of geogrid properties, a calculation method for the bearing capacity considering the stress difference and stress diffusion angle is proposed and validated against the numerical results. The presented study is of great significance for understanding the macro–micro bearing behavior and reinforcement mechanisms of shallow footings on geogrid reinforced coral sands.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"189 ","pages":"Article 107606"},"PeriodicalIF":6.2,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhenhao Shi , Tianyu Gan , Giuseppe Buscarnera , Xilin Lü
{"title":"Predicting brittle creep in porous rock with rate-sensitive material stability analyses","authors":"Zhenhao Shi , Tianyu Gan , Giuseppe Buscarnera , Xilin Lü","doi":"10.1016/j.compgeo.2025.107623","DOIUrl":"10.1016/j.compgeo.2025.107623","url":null,"abstract":"<div><div>Brittle creep allows porous rock to fail under stresses significantly lower than its conventional strength, making its onset critical for both natural and engineered geomechanical processes, as well as the long-term stability of underground structures. This study presents a novel theoretical framework to evaluate the conditions for the initiation of brittle creep at the constitutive level. To achieve this, we simulate the brittle creep through a viscoplastic framework equipped with bounding surface techniques proposed by the authors, which at variance with previous studies reflects explicitly the possibility of initiating delayed cracking prior to traditional rock strength (e.g., sub-critical cracking) and frames it in the concept of time-dependent stability. The stability criteria for the onset of brittle creep are derived by examining the spectral properties of the system matrix associated with the ordinary differential equation governing creep dynamics. The performance of the proposed constitutive model and stability criteria is then evaluated against experimental data on porous sandstone. The theoretical framework is subsequently used to investigate the influence of stress conditions on creep response, identifying four distinct stress regions based on creep stability behavior. Finally, we apply the stability criterion to explore the deterioration of long-term strength of porous rock due to brittle creep and examine the relationship between this strength degradation and confining pressures. The findings of this study provide theoretical support for understanding the similarities between the failure mechanisms underlying brittle failure caused by varying and sustained loads (i.e., creep). They also offer insights into the connection between the bifurcation of accelerated creep, which can lead to either uncontrolled failure or regained stability, as influenced by volume changes in the rock.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"189 ","pages":"Article 107623"},"PeriodicalIF":6.2,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Pore scale polymer migration in BPC-GCLs influenced by PSD, bentonite swelling, and polymer location","authors":"Juan Hou , Chenxi Chu","doi":"10.1016/j.compgeo.2025.107626","DOIUrl":"10.1016/j.compgeo.2025.107626","url":null,"abstract":"<div><div>The study investigates the hydraulic behavior of bentonite-polymer composite geosynthetic clay liners (BPC-GCLs), focusing on the effects of particle size distribution (PSD), polymer location near the inlet and outlet, swelling-induced pore structure evolution, mobile porosity, and polymer migration using COMSOL Multiphysics. The results indicate that the spatial distribution and migration behavior of the polymer have a significant influence on fluid transition patterns. When located near the inlet, the polymer undergoes a three-stage migration process involving progressive deformation, entrapment, and eventual immobilization in narrow pores, resulting in a significant and irreversible reduction in porosity from 0.099 to 0.007 and a decrease by four orders of magnitude in hydraulic conductivity. In contrast, polymers near the outlet initially undergo clogging, followed by hydraulically driven elution, resulting in a more gradual and more minor reduction in porosity, from 0.101 to 0.071, and a one-order-of-magnitude decrease in hydraulic conductivity. The pressure distribution within the domain reflects the evolving hydraulic response to polymer migration, where localized pressure buildup corresponds to pore clogging. In contrast, subsequent pressure equalization signifies the progressive elution of polymer and the restoration of flow paths. These findings demonstrate the critical role of pore-scale heterogeneity and spatial polymer location in dictating the sealing performance of BPC-GCLs. This multiphysics framework provides a robust foundation for designing and optimizing polymer-enhanced barrier systems in environmental and geotechnical engineering.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"189 ","pages":"Article 107626"},"PeriodicalIF":6.2,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiang Ping-wei , Zhang Zhi-hong , Huang Jin-kun , Zheng Hong , Wan Tao
{"title":"Three-Dimensional Stress-Free Assumption 3-DOF FE-LEM for Tunnel Face Stability","authors":"Jiang Ping-wei , Zhang Zhi-hong , Huang Jin-kun , Zheng Hong , Wan Tao","doi":"10.1016/j.compgeo.2025.107607","DOIUrl":"10.1016/j.compgeo.2025.107607","url":null,"abstract":"<div><div>Currently, existing three-dimensional limit equilibrium methods (LEM) for calculating the limit support pressure of the tunnel face discard the drawbacks of the inter-slice force assumptions in the traditional LEM. They assume that the potential failure body in front of the tunnel face is a wedge, thereby transforming the problem from a statically indeterminate to a statically determinate one, with only one degree of freedom for optimization. This approach fails to accurately reflect the true failure pattern of the tunnel face and the ultimate support pressure, leading to less precise results. In this paper, no assumptions are made regarding the normal stress on the slip surface. Instead, <em>σ</em> is treated as the primary variable, and finite element method (FEM) interpolation is used for approximation. A 5th-order parameter vector <strong><em>a</em></strong> is employed to construct <em>σ</em>, ensuring that it satisfies the limit equilibrium condition of the entire slip mass. A new FE-LEM calculation method is thus proposed. At the same time, the failure mode of the tunnel face is modeled as a quarter-ellipsoid, and the degree of freedom for optimization is increased from 1 to 3, making the failure shape more consistent with the actual sliding body. The accuracy of the proposed calculation method was verified through typical examples of homogeneous stratigraphy, composite layered stratigraphy, and numerical calculation results. Finally, the calculation model was extended to account for the spatial variability and anisotropy of geotechnical properties. By comparing the optimization results from random field calculations with model test results, it was found that the optimized ellipsoid radius parameters can effectively cover the collapse area in front of the tunnel face. Additionally, the mean value of the limit support pressure (<em>T</em>) obtained is largely consistent with the model test results.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"189 ","pages":"Article 107607"},"PeriodicalIF":6.2,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}