Computers and Geotechnics最新文献

{"title":"Probabilistic investigation of the whole process of backward erosion piping for a two-layered levee in spatially variable soils","authors":"Wei Xiong ,&nbsp;Shui-Hua Jiang ,&nbsp;Jian-Hong Wan ,&nbsp;Chuang-Bing Zhou ,&nbsp;Liang Gao","doi":"10.1016/j.compgeo.2025.107244","DOIUrl":"10.1016/j.compgeo.2025.107244","url":null,"abstract":"<div><div>Backward erosion piping (BEP) at the base of levees is one of the main causes of levee failure. BEP typically occurs in two-layer levees systems and involves multiple stages throughout its development. While random field methods have been widely applied to model soil spatial variability, existing approaches predominantly focus on single-layer soil structures. Analyzing the impact of only single-layer spatial variability on piping development, especially during the initial uplift stage, may not adequately capture the complexities of actual conditions. To address this, this paper proposes a general framework that can be used to generate both single-layer or two-layer random field models. The Karhunen-Loève (K-L) series expansion method has been refined to generate two independent random fields, thereby facilitating the characterization of spatial variability in both the upper and lower soil layers. Monte Carlo Simulation (MCS) is employed to generate realizations of the random fields, which are then incorporated into numerical models to evaluate the effects of spatial variability on the whole process of BEP. The results show that single layer models tend to overestimate or underestimate the probability of piping initiation. The stage of backward erosion is influenced by the spatial variability of the upper and lower layered soil parameters. The single-layer random field model has a tendency to overestimate the probability of slope failure. In addition, the results of several stability analyses under the effects of extreme rainfall and upstream water level rise show that the probability of slope failure increases significantly during this process.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107244"},"PeriodicalIF":5.3,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834561","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 time-dependent microplane model for deformation and fracturing of brittle rock","authors":"Yang Yuan ,&nbsp;Tao Xu ,&nbsp;Philip G. Meredith ,&nbsp;Thomas M. Mitchell ,&nbsp;Michael J. Heap ,&nbsp;Zhen Heng","doi":"10.1016/j.compgeo.2025.107278","DOIUrl":"10.1016/j.compgeo.2025.107278","url":null,"abstract":"<div><div>A more comprehensive understanding of the progressive, time-dependent deformation and fracturing of brittle rock is crucial for assessing the long-term integrity of rock masses surrounding engineering structures. In this study, we propose a three-dimensional numerical model that integrates the microplane model and subcritical crack growth to investigate the progressive, time-dependent deformation and fracturing of brittle rock. The model incorporates subcritical crack growth and time-dependent damage evolution constitutive laws into the microplanes. By following the trend of subcritical crack growth observed in previous studies, the model accurately captures the time-dependent propagation of virtual cracks. The cooperative interaction between strain and damage evolution on the microplanes ultimately leads to localized material degeneration over extended time. Moreover, this model effectively characterizes the temporal and spatial distribution of damaged elements during time-dependent deformation and fracturing of brittle rock. The numerical simulations successfully replicate phenomena observed in laboratory experiments performed on brittle rock. Specifically, they demonstrate how different stress levels influence creep strain rate and time-to-failure. Additionally, the simulations reveal that the microscale interaction of potential cracks (microplanes) can effectively describe the complex macroscopic time-dependent behavior of brittle rock. As a result, it becomes possible to predict time-to-failure and rupture patterns using the calibrated model based on laboratory tests. The proposed numerical model holds the potential to be further extended for predicting the long-term stability of larger rock masses.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107278"},"PeriodicalIF":5.3,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143830141","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":"Microscopic insights into local scour around a vertical circular pile under steady current: Coupled LES-CGDEM simulations","authors":"Peiyun Zhang ,&nbsp;Linlong Mu ,&nbsp;Maosong Huang ,&nbsp;Xiaoqiang Gu","doi":"10.1016/j.compgeo.2025.107248","DOIUrl":"10.1016/j.compgeo.2025.107248","url":null,"abstract":"<div><div>Local scour around pile reduces its bearing capacity, jeopardizing the superstructure safety. Previous studies on this have primarily been based on continuum mechanics. Given that the scour process involves interactions between fluid-particle and particle–particle, the methods based on the continuum mechanics struggle to adequately account for collision effects between particles, while also failing to capture the migration process of soil particles. This study employs the coupled large eddy simulation (LES) and coarse-grained discrete element method (CGDEM) to conduct a detailed simulation of the local scour evolution around a vertical circular pile under unidirectional steady flow from a microscopic perspective, in which three flow intensities are considered in the simulation. It is found that as the flow intensity increases, the difference in scour depth upstream and downstream of the pile diminishes. Initially, the scour upstream of the pile is jointly controlled by scouring at the pile toe and soil erosion on the top slope surface, while it is dominated by pile toe scour in the later stage. The pile toe scour is associated with the multiple horseshoe vortices (HVs) upstream of the pile; the “NASA wall-mounted hump” downstream of the pile restricts further migration of the deposited sediment; an “unstable particles cluster” is formed on the sides of the pile, creating a preferential scour path. Particles upstream of the pile undergo a sequence of slow motion upstream, complex flow around the pile, accelerated movement downstream, and deposition, while particles on the sides of the pile experience slowly settling, accelerated motion, and deposition. The work further deepens the understanding of scour evolution mechanism.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107248"},"PeriodicalIF":5.3,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143825707","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":"Relationship between internal void ratio and morphological parameters of carbonate sand","authors":"Yan Qian ,&nbsp;Yuedong Wu ,&nbsp;Yuzhe Ren ,&nbsp;Yi Pik Cheng ,&nbsp;Abraham C.F. Chiu ,&nbsp;Jian Liu ,&nbsp;Tiange Ge","doi":"10.1016/j.compgeo.2025.107266","DOIUrl":"10.1016/j.compgeo.2025.107266","url":null,"abstract":"<div><div>With the advancement of marine geotechnical engineering, increasing attention has been focused on the influence of the particle morphology and internal voids of carbonate sand (CS) on its engineering properties. The purpose of this study was to explore the relationship between the internal void ratio and particle morphological parameters using X-ray computed tomography (CT) scanning and three-dimensional (3D) reconstruction of CS particles with a particle size of 0.5–1 mm. A unique particle-tray mould was designed using 3D printing to avoid over segmentation of images of the watershed segmentation algorithm during 3D reconstruction and to guarantee scanning accuracy. The mould was made of an acrylonitrile butadiene styrene (ABS) resin with a density that differed significantly from that of the CS, which also facilitated threshold segmentation in 3D reconstruction. In addition, an ambient occlusion algorithm was adopted to compute the surface-connected voids and surface recesses of the CS. Based on the internal void characteristics, CS particles were classified into three types: solid, distributed, and spiral. A random selection of 100 particles from each type was analysed to determine the internal void ratio and morphological parameters. The results indicated that spiral-type CS particles exhibited the highest internal void ratio, followed by distributed-type CS particles, whereas solid-type CS particles had the lowest internal void ratio. Distributed-type CS particles appeared in plate-like or flattened forms, spiral-type CS particles were elongated, and solid-type CS particles displayed significant variability in their shape distribution. Furthermore, no significant correlation was observed between the internal void ratio and particle morphological parameters such as elongation, flatness, or aspect ratio. However, a strong correlation was observed between the internal void ratio and sphericity, convexity, and <em>3D</em> shape angularity group indicator (<em>SAGI</em>). Both the sphericity and convexity decreased with increasing internal void ratio, whereas <em>3D-SAGI</em> increased as the internal void ratio increased. Notably, the internal void ratio, sphericity, convexity, and <em>3D-SAGI</em> of distributed-type CS particles were significantly influenced by the extent of particle surface smoothing, whereas solid- and spiral-type CS particles were not significantly affected. This study can provide the ranges of CS particle morphology parameters for discrete element method modelling and offer convenience for the calibration of void ratios in the future.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107266"},"PeriodicalIF":5.3,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823260","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":"Study on the influence of 3D pre-existing joint on rockfall fragmentation during impact based on discrete element method","authors":"Yongjie Zhao ,&nbsp;Yong Wu ,&nbsp;Yingpeng Wang ,&nbsp;Siming He ,&nbsp;Xinpo Li ,&nbsp;Lei Zhu ,&nbsp;Zhangqing Wang","doi":"10.1016/j.compgeo.2025.107270","DOIUrl":"10.1016/j.compgeo.2025.107270","url":null,"abstract":"<div><div>Rockfalls pose significant threats to human society as one of the three major geological hazards. Numerous joints developed internally during their geological formation, leading to their fragmentation in motion and affecting trajectory and accumulation range, thereby increasing the hazard uncertainty. There are few studies on the fragmentation of jointed rockfalls, and only some focus on the influence of terrain, impact angle, and material properties on rockfall failure with continuous mechanics and extended finite element methods. However, very few analyses of the fragmentation mechanism of 3D jointed rockfall are from the perspective of discontinuous medium mechanics. Based on the indoor experiments to acquire the calculation parameters and consider the fracture character, we use the Discrete Element Method (DEM) to establish an impact model of rockfall with pre-existing joints to address these. We conduct numerical impact tests on samples containing joints of varying lengths, inclinations, thicknesses, and positions. By proposing the volume fragmentation ratio and number of main fragments and calculating them, monitoring changes in crack propagation events, acoustic emission events, impact force, and energy, the study investigates the specific effects of joints on the impact fragmentation of samples. The results indicate that the Discrete Element Method with parameters corrected by fracture tests can realistically simulate the three-dimensional fragmentation of jointed rockfall under actual conditions, solving the problem of stress concentration at the crack tip in Finite Element analyses. The geometric parameters and spatial position of the pre-existing joint largely determine the fragmentation of rockfall and the shape of blocks after disintegration, significantly impacting the impact force and the kinetic energy of the bouncing stone. Among them, joint inclination and length greatly influence the overall fragmentation of rockfall. In contrast, the position of a side or centered joint notably influences the micro-cracks and local damage on the contact area of rockfall, and joint thickness close to the maximum radium of calculation particle affects fragmentation significantly.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107270"},"PeriodicalIF":5.3,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823257","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 new algorithm for accurate contact point calculation between convex polyhedral particles in DEM","authors":"Yuval Keissar ,&nbsp;Michael Gardner ,&nbsp;Nicholas Sitar","doi":"10.1016/j.compgeo.2025.107240","DOIUrl":"10.1016/j.compgeo.2025.107240","url":null,"abstract":"<div><div>Contact detection and contact geometry are among the most important steps in Discrete Element Method (DEM) simulations. Accurately representing the contact between two particles is crucial, and when modeling fractured rock using polyhedral particles, the accuracy of the contact point calculation is essential for obtaining realistic and reliable simulation results. The point of contact is where contact forces are applied to particles in a DEM simulation and, thus, an inaccurate representation of that point leads to artificial torque acting on particles, resulting in non-physical rotation and particle interactions.</div><div>Herein we present a new algorithm for accurately calculating the contact point between two colliding polyhedral particles. The algorithm uses the topology of the particles to assert their interaction with the plane of contact and not directly with each other. The new algorithm provides improved performance in terms of global stability of DEM models by mitigating numerically induced instability associated with errors and sporadic movement in the contact point calculation. The performance of the new algorithm is showcased in several examples that illustrate how accurately representing the contact point is a requirement for generating reliable numerical simulations.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107240"},"PeriodicalIF":5.3,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823203","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":"Time-dependent system reliability analysis of anchor-reinforced slopes based on surrogate models","authors":"Xuegang Pan,&nbsp;Jinqing Jia","doi":"10.1016/j.compgeo.2025.107257","DOIUrl":"10.1016/j.compgeo.2025.107257","url":null,"abstract":"<div><div>This study proposes a time-variant reliability calculation method for anchor-reinforced slope systems (ARSS) based on a surrogate model. By incorporating composite failure modes, the variability of geotechnical materials, and the effects of corrosion as uncertainty factors, the proposed method overcomes the limitations of traditional system reliability analysis approaches. The probability of system failure is defined as the sum of the product of the combined probabilities of local anchor failures and the conditional probabilities of slope failure under corresponding conditions. The time-variant system reliability of the anchor-reinforced capacity, which degrades over time due to corrosion effects, is also calculated. The results indicate that ARSS possesses a certain level of redundancy. However, owing to the stress redistribution effect, local anchor failures significantly increase the probability that the remaining anchors and the slope fail. The failure of adjacent anchors and those in the middle to lower portions of the slope has a more significant impact. While the probability of system failure is dominated primarily by non-anchor failure events, neglecting local anchor failures can lead to nonconservative results. Anchors initially exhibit strong corrosion resistance. However, over time, the corrosion effect significantly reduces their load-bearing capacity, resulting in a nearly fourfold increase in the probability of slope failure. This study highlights the importance of accounting for local anchor failures, geotechnical material variability, and corrosion effects in long-term reliability assessments of ARSS. Such considerations contribute to enhancing the safety and sustainability of geotechnical engineering practices.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107257"},"PeriodicalIF":5.3,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823204","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":"Simulation of Sand-Filled Nodular Pile (SFNP) installation process using DEM","authors":"Enze Yi ,&nbsp;Juntao Wu ,&nbsp;M.Hesham El Naggar ,&nbsp;Kuihua Wang ,&nbsp;Pengcheng Fu","doi":"10.1016/j.compgeo.2025.107249","DOIUrl":"10.1016/j.compgeo.2025.107249","url":null,"abstract":"<div><div>The sand-filled nodular pile (SFNP) is an emerging foundation system that features improved bearing capacity in reclamation sites and accelerates consolidation settlement. This study investigates the filling morphology of the gravel introduced by SFNP installation to further elucidate its formation mechanism and explore its effect on the pile behaviors. The discrete element method (DEM) is employed, incorporating the superposition of gaussian distributions (SGDs) method to achieve continuous gradation and fit the actual particle size distribution (PSD) curve. The numerical model is used to investigate the effect of nodular width, nodular spacing and gravel size on the filling effect of the SFNP foundation. According to the observed gravel filling pattern, the filling gravel can be divided into two zones: source zone and filling zone. The gravel between adjacent nodular segments is invaded by the pile-surrounding soil, making the filling morphology close to an inverted cone shape. The results indicate that increasing the nodular segment width and/or reducing the nodular spacing can effectively expand the filling zone and reduce the invasion of soil around the pile. This may be accompanied by soil squeezing effect, which may increase the driving resistance but can eventually improve the soil around the pile. Although increasing the gravel size can effectively increase the filling zone, it is not effective in preventing the invasion of pile-surrounding soil. These findings can provide practical guidance for the application of the SFNP foundation in engineering practice.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107249"},"PeriodicalIF":5.3,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823258","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 strain work constitutive model for structured soils","authors":"Ling Xu ,&nbsp;Xinqi Guan ,&nbsp;Hongjian Liao ,&nbsp;Yingpeng Fu","doi":"10.1016/j.compgeo.2025.107243","DOIUrl":"10.1016/j.compgeo.2025.107243","url":null,"abstract":"<div><div>The mechanical behavior of structured soils is influenced by both inter-particle bonding and fabric arrangements. Existing constitutive models primarily account for soil structure through fabric arrangements. In this study, we first present experimental investigations on intact loess samples, including isotropic compression (IC), conventional consolidation undrained (CU), and consolidation drained (CD) triaxial tests, which reveal the complex structural properties of the soil. Next, we employ the work done by strain energy to comprehensively account for soil structure, incorporating both inter-particle bonding and fabric arrangements. Subsequently, a new strain work constitutive model for structured soils is presented within the critical state framework. Specifically, a linear decreasing function between strain power and mean effective stress is introduced to capture structural degradation, and a new hardening rule is derived from the relationship between strain work and mean effective stress. Compared to traditional structured soil models, the proposed model offers clear physical meaning, and its parameters are easily obtainable. The model’s simulation results are validated against experimental data, demonstrating its ability to capture key mechanical and deformation characteristics, such as strain softening under CU conditions and strain hardening under CD conditions. Finally, we compare our model with the structured cam clay (SCC) model, and the results show that our model provides a better fit to the experimental data, further confirming its accuracy and effectiveness.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107243"},"PeriodicalIF":5.3,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823205","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":"Multiscale investigation of shear mechanical behaviour in cemented soil–rock mixtures (CSRMs) regulated by matrix–block welding states","authors":"Minghui Ren ,&nbsp;Hai Pu ,&nbsp;Guangsi Zhao ,&nbsp;Ruilin Li ,&nbsp;Lulu Liu ,&nbsp;Runhua Zhang","doi":"10.1016/j.compgeo.2025.107254","DOIUrl":"10.1016/j.compgeo.2025.107254","url":null,"abstract":"<div><div>Soil–rock mixtures (SRMs) are characterized by heterogeneous structural features that lead to multiscale mechanical evolution under varying cementation conditions. However, the shear failure mechanisms of cemented SRMs (CSRMs) remain insufficiently explored in existing studies. In this work, a heterogeneous three-dimensional (3D) discrete element model (DEM) was developed for CSRMs, with parameters meticulously calibrated to examine the role of matrix–block interfaces under different volumetric block proportions (VBPs). At the macroscopic scale, significant influences of the interface state on the peak strength of CSRMs were observed, whereas the residual strength was found to be largely insensitive to the interface cementation properties. Pronounced dilatancy behaviour was identified in the postpeak and residual phases, with a positive correlation with both interface cementation and VBP. Quantitative particle-scale analyses revealed substantial heterogeneity and anisotropy in the contact force network of CSRMs across different components. A highly welded interface was shown to reduce the number of interface cracks at the peak strength state while increasing the proportion of tensile cracks within the interface zone. Furthermore, the welding degree of the interface was found to govern the formation and morphology of shear cracking surfaces at the peak strength state. Nevertheless, a reconstruction method for the shear slip surface was proposed to demonstrate that, at the same VBP, the primary roughness of the slip surfaces remained consistent and was independent of the interface properties. Based on the extended simulations, the peak strength of the weakly welded CSRMs progressively decreased with increasing VBP, whereas further exploration of the enhanced residual strength is needed.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107254"},"PeriodicalIF":5.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817713","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}