International Journal of Rock Mechanics and Mining Sciences最新文献

{"title":"Grain size effects on hydro-seismo-mechanical responses of granite during laboratory hydraulic fracturing","authors":"Xin Zhang ,&nbsp;Guangyao Si ,&nbsp;Yinlin Ji ,&nbsp;Anye Cao ,&nbsp;Changbin Wang","doi":"10.1016/j.ijrmms.2025.106241","DOIUrl":"10.1016/j.ijrmms.2025.106241","url":null,"abstract":"<div><div>Geothermal energy in granite is becoming a significant renewable type, yet the hydrofracturing mechanisms within the coarse grains of granite remain largely unexplored. The triaxial hydraulic fracturing of granites with coarse grains has been simulated in laboratory settings to explore the influence of grain size on fracturing behaviour. Two types of granites with similar elastic properties but distinct grain sizes (&gt;2.5 mm) have been examined. Source mechanism analysis indicates that in granitic coarse grains, tensile fractures are more prevalent than non-tensile fractures. The proportion of non-tensile cracks increases over time, notably after the occurrence of rock breakdown. Comparative analysis demonstrates that coarser grains are associated with reduced breakdown pressure, prolonged fracturing durations, a greater number of seismic events, lower seismic event magnitudes, and a higher proportion of tensile cracks. Interactions between hydraulic fractures and grains, such as ‘bypass’, ‘cross’, and ‘branching’, are interpreted and conceptualized based on the cohesive zone model. Our experiments also show that the fracture complexity comes from not only the fatigue hydraulic fracturing and low viscosity injection, but also continuous injection with coarse granite grains. Larger grains introduce greater fracture complexity.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"194 ","pages":"Article 106241"},"PeriodicalIF":7.5,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144840951","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":"The novel learnable physics engines for interpretable elastoplastic models of geomaterials based on the message passing neural network","authors":"Xiao-Ping Zhou,&nbsp;Kai Feng","doi":"10.1016/j.ijrmms.2025.106244","DOIUrl":"10.1016/j.ijrmms.2025.106244","url":null,"abstract":"<div><div>Accurately predicting the path-dependent plastic behavior of geomaterials is a challenging endeavor because of the intricate evolution of microstructures. In this study, a novel learnable physics engine is proposed to infer the elastoplastic constitutive model based on graph networks. This objective is accomplished by training a neural network model that incorporates interpretable components, for instance, the stored elastic energy function and the yield function. By re - formulating the evolution fields of the physical system into a time - evolving graph network, the suggested method can infer the solutions of constitutive equations. The proposed framework leverages Sobolev training to regulate the derivatives of the elastic energy functions. Additionally, it trains the yield functions as level - set evolution. As a result, this framework is interpretable and, at the same time, shows outstanding prediction accuracy. To verify the robustness and reliability of the proposed method, numerical examples are conducted. The numerical outcomes reveal that the proposed approach can provide efficient and precise long - term forward predictions for the elastoplastic behavior of geomaterials.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"194 ","pages":"Article 106244"},"PeriodicalIF":7.5,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144840949","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":"Analytical solutions of non-circular deep tunnels incorporating thermal stresses: from analytical solutions to its application in shape optimization","authors":"Huaning Wang ,&nbsp;Ertai Wang ,&nbsp;Fei Song ,&nbsp;Wuyang Wang ,&nbsp;Alfonso Rodriguez-Dono","doi":"10.1016/j.ijrmms.2025.106232","DOIUrl":"10.1016/j.ijrmms.2025.106232","url":null,"abstract":"<div><div>The influence of the temperature field on mechanical behaviours is significant when performing stability analysis of underground structures. This article concentrates on investigating the stress and displacement of arbitrary non-circular tunnels constructed in the elastic ground, considering thermal effects. To achieve this, the complex variable function method and the conformal transformation technique are employed to derive the analytical solutions. Meanwhile, the temperature boundary and tunnel inner boundary in the physical plane are mapped into concentric annuli in the complex plane, and two potential functions are used to determine the analytical expressions of thermal stress. Additionally, the potential function forms of the boundary conditions in the complex plane are derived. Analytical solutions are then obtained to calculate the thermal stress of arbitrarily shaped, deeply buried tunnels, based on the temperature field expression in the complex plane. A good agreement is observed between analytical solutions and numerical predictions, verifying the correctness of the developed analytical theory and obtained analytical solutions.</div><div>After that, the developed analytical solutions are employed to optimize the design of tunnel shapes, taking into account the effect of the temperature field on the mechanical responses. The study found that the optimal tunnel shapes for minimizing maximum hoop stress at the hole boundary are elliptical, with or without temperature effects. Additionally, a closed-form formula for the optimal shape ratio has been proposed, considering all mechanical and physical parameters except Poisson's ratio. This approach serves as a valuable tool with significant potential for application to various engineering cases, such as optimizing the design of high-temperature tunnels and nuclear waste disposal systems.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"194 ","pages":"Article 106232"},"PeriodicalIF":7.5,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144830730","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":"SPH-based modelling of the entire rock caving process: insights into failure mechanisms","authors":"Vinh T. Le ,&nbsp;Tien V. Nguyen ,&nbsp;Murat Karakus ,&nbsp;Giang D. Nguyen ,&nbsp;Ha H. Bui","doi":"10.1016/j.ijrmms.2025.106228","DOIUrl":"10.1016/j.ijrmms.2025.106228","url":null,"abstract":"<div><div>Cave mining is a cost-effective method for extracting large, low-grade orebodies, but its success depends on the cavability of a rock mass, governed by complex interactions between fracturing, fragmentation, and material flow. Despite extensive research, two competing failure mechanisms dominate the literature: (1) a continuous damage profile ahead of the cave back, as interpreted in the Duplancic conceptual model, and (2) discrete parallel fracture banding observed in experimental and field studies. However, no continuum-based model has fully reproduced and explained these failure mechanisms. This study presents the first continuum-based numerical framework that captures the entire caving process and replicates experimentally observed failure mechanisms, both qualitatively and quantitatively. Using Smoothed Particle Hydrodynamics (SPH) coupled with an advanced damage-plasticity model, which accounts for rock failure under different loading conditions, ranging from compression-shear to tensile-shear failures and material flow, parallel fracture banding observed in physical experiments is successfully reproduced, challenging the assumption of a continuous damage profile. The simulation results indicate that parallel fracture banding arises due to the consistent undercutting span and the transition from compression-shear failure to tensile-shear failure during cave propagation. Additionally, based on our current simulation results, the dilation angle tends to play a decisive role in cave stability: a high dilation angle promotes stable arching, supporting the Duplancic model, whereas a low dilation angle facilitates progressive failure through discrete fracture bands. Further analysis reveals that tensile fracture energy, material randomness, and horizontal stress significantly influence fracture propagation and caving efficiency. Strong agreement between simulations and centrifuge test data validates the proposed framework as a robust tool for studying rock caving processes and provides critical insights into the underlying failure mechanisms.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"194 ","pages":"Article 106228"},"PeriodicalIF":7.5,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144828610","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":"Automated bidirectional search for key blocks on complex high-steep slopes using spatial loops formed by intersections of discontinuities","authors":"Shengyuan Song ,&nbsp;Han Xiao ,&nbsp;Baotian Li ,&nbsp;Mingyu Zhao ,&nbsp;Yaoyao Jiang ,&nbsp;Jilin Li","doi":"10.1016/j.ijrmms.2025.106224","DOIUrl":"10.1016/j.ijrmms.2025.106224","url":null,"abstract":"<div><div>High-steep rock slopes develop numerous random discontinuities, and the unstable blocks formed by their intersection pose a serious threat to traffic engineering construction. Current methods for identifying these blocks are limited by the complex morphology of the slope surface and often overlook the impact of line-type discontinuities, leading to slow and inaccurate identification processes. To address this, this study presents an innovative method for identifying 3D unstable rock blocks by integrating UAV multi-angle nap-of-the-object photogrammetry with a spatial loop bidirectional search algorithm. The method comprises four steps: 1) Collaborative extraction of line-type and face-type discontinuities from a high-precision 3D model; 2) Rapid determination of discontinuity intersections using an R-tree data structure; 3) Retrieval of closed polygons via a bidirectional search algorithm; 4) Screening of finite blocks using geometric topological constraints. Engineering verification shows that this method successfully identified 120 closed cycles on the slope of the Eastern Himalayan Syntaxis, resulting in 74 finite blocks and 22 unstable blocks. This study introduces a novel point-line-face multi-level progressive search architecture. By coupling the analysis of line-type discontinuities with block spatial combinations, this method addresses a limitation of traditional approaches that inadequately consider the role of line-type discontinuities in block formation. Applicable to any complex structure of high-steep slopes, this method enhances both the accuracy and efficiency of identifying unstable blocks in complex geological settings. Furthermore, by integrating subsequent modules for geometric characterization and mechanical analysis, this method provides a theoretically sound and broadly applicable technical solution for preventing and controlling rockfall disasters on high-steep slopes.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"194 ","pages":"Article 106224"},"PeriodicalIF":7.5,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144830728","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":"Micro-mechanism of mechanical hysteresis of crystalline rock: Insights from time-integrated X-ray computed tomography and digital volume correlation","authors":"Qinxin Hu ,&nbsp;Alice Macente ,&nbsp;Shangtong Yang ,&nbsp;Zoe K. Shipton ,&nbsp;Katherine J. Dobson ,&nbsp;Xun Xi ,&nbsp;Huachuan Wang ,&nbsp;James Minto ,&nbsp;Matthew Divers ,&nbsp;Junlong Shang","doi":"10.1016/j.ijrmms.2025.106230","DOIUrl":"10.1016/j.ijrmms.2025.106230","url":null,"abstract":"<div><div>Under repeated loading and unloading, the mechanical response of crystalline rock exhibits hysteresis. To elucidate the linkage between macroscale hysteresis, microscale deformation, and microstructural evolution in crystalline rock, we perform in-situ time-integrated X-ray Computed Tomography (X-CT) test to image the microstructural evolution along a complete loading-unloading hysteresis loop followed by reloading until failure of Blue Hone granite. The microstructural evolution is quantified by the development of geometries and orientations of segmented voids. The evolved accumulative strain fields are calculated by Digital Volume Correlation (DVC) to characterize distribution of micro-scale deformation and reveal the interaction between strain localization and microstructural evolution and build relationship across length scales. The orientation distribution of first principal strain is analysed to characterize the influence of microstructural evolution on overall deformation. The results show that the macroscale hysteresis comes from the microscale hysteresis in dilation zones, which are highly correlated with high shear strain zones. Crack-like voids (perpendicular, inclined and parallel to axial load) in dilation volumes exhibit prominent hysteresis compared to those in contraction volumes, resulting in the delayed strain releasing of dilation volumes. The evolution of inclined crack-like voids confirms that the hysteresis mainly results from the newly developed inclined crack-like voids (shear cracking). After reloading to the same stress at the onset of unload, a further evolution of damage and strain localization is observed, while the sample deforms in a higher efficiency way to accommodate applied stress. This observation is discussed with the insight of rock fatigue.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"194 ","pages":"Article 106230"},"PeriodicalIF":7.5,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144830729","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":"Assessing the contribution of mineral composition to meso-macro progressive failure in granite under thermo-hydro-mechanical (THM) conditions: Inspiration for hydraulic fracturing in Enhanced Geothermal Systems (EGS)","authors":"Mengyi Li ,&nbsp;Mengli Li ,&nbsp;Fengshou Zhang ,&nbsp;Zhijun Wu ,&nbsp;Yuan Zhou ,&nbsp;Xiufeng Zhang","doi":"10.1016/j.ijrmms.2025.106238","DOIUrl":"10.1016/j.ijrmms.2025.106238","url":null,"abstract":"<div><div>The Enhanced Geothermal System (EGS) is a breakthrough technology for harnessing geothermal energy, and a comprehensive evaluation for the mechanical performance of reservoir rocks under complex geological conditions is crucial for ensuring effective hydraulic fracturing and the safe operation of geothermal system. In this study, a refined THM simulation algorithm was operated to simulate the meso mechanical behaviors of different mineral grain interfaces. Nine numerical granite models with distinct mineralogical compositions were subjected to 20 THM scenarios under EGS design environments, and the progressive failure mechanisms governed by mineralogical topology spanning meso-interactions (cohesion degradation, interface damage, shear slip) to macro fracture mechanics were evaluated. Results demonstrated that temperature and pore pressure synergistically govern fluid flow pathways in granite, with pore aperture evolution, micro-defect connectivity, and interfacial crack propagation emerging as critical factors affecting seepage behavior. With the increased temperature and pore pressure, two mechanisms affecting rock failure process exist, including the competitive mechanism between thermal behaviors of quartz-related interfaces and biotite-related interface breakage on rock structure, as well as the inducement of thermal-on pore pressure-induced micro-cracks at quartz/feldspar-related crystal boundaries. Finally, a quantified analysis framework was developed to integrate mineralogical heterogeneity, temperature and pore pressure interactions with the meso-macro mechanical properties of granite. It revealed that the effect of quartz on the mechanical strength of granite is the most significant under high temperature and low pore pressure conditions, while its effect on the elastic modulus is obvious under high temperature and high pore pressure. Feldspar has the greatest impact on the elastic modulus of granite under high temperature and low pore pressure, with a relatively stable effect on the mechanical strength of granite under THM conditions. The proposed framework synergistically integrates elastic modulus-based brittleness indices with strength parameters, offering novel insights for evaluating the hydraulic fracability of granite and optimizing site selection in EGS applications.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"194 ","pages":"Article 106238"},"PeriodicalIF":7.5,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144826872","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 shear strength criterion for rock discontinuities considering roughness degradation and loading rate effect","authors":"Shengwen Qi ,&nbsp;Bowen Zheng ,&nbsp;Songfeng Guo ,&nbsp;Guangming Luo","doi":"10.1016/j.ijrmms.2025.106231","DOIUrl":"10.1016/j.ijrmms.2025.106231","url":null,"abstract":"<div><div>The degradation of surface roughness of rock discontinuities under cycling loading weakens shear strength with the accumulating shear displacement. This effect enlightens us to propose a new shear strength criterion for rock discontinuities based on the law of <em>JRC</em> (joint roughness coefficient) degradation and Barton's shear strength equation, which would be critical for determining the permanent displacement and thus the stability of rock slope under seismic loading. The effect of loading rate on roughness degradation has been included in our model of <em>JRC</em> degradation. The comparison with previous analytical models on predicting the degradation of <em>JRC</em> after cycling loading suggests a good accuracy of our model. In compensation to previous direct shear experiments concerning cyclic loading, we carried out cyclic shearing experiments on granite rock discontinuities to put constraints on the coefficient of degradation rate used in our model. Opposite to previous considerations, we suggest more factors would control the degradation rate, including the normal stress, the joint wall strength, the initial roughness, the loading rate and the cycling amplitude, and their effects have been discussed based on experimental data.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"194 ","pages":"Article 106231"},"PeriodicalIF":7.5,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144809665","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":"An explicit 3D numerical manifold method with potential-based contact force for rock mass system","authors":"Junfeng Li ,&nbsp;Yongtao Yang ,&nbsp;Shuilin Wang","doi":"10.1016/j.ijrmms.2025.106236","DOIUrl":"10.1016/j.ijrmms.2025.106236","url":null,"abstract":"<div><div>To address the movement and failure of discrete rock mass system in rock engineering, a 3D contact-potential based numerical manifold method (3DCPNMM) using explicit time integration scheme is presented. In this method, tetrahedral finite element grids are utilized to construct the mathematical cover system, enabling flexible discretization of both continuous and discontinuous rock mass systems. Additionally, two types of contact potential, namely, the volume potential and distance potential are introduced to calculate the contact force between the adjacent manifold elements. Note that the potential based contact force can be directly calculated from the overlapping volume of the manifold elements, thereby eliminating the need to differentiate between complex contact types. Several benchmark problems related to rock mass movement are examined using the proposed 3DCPNMM to verify its correctness. The numerical results obtained align well with the analytical solutions, demonstrating the reliability and accuracy of the proposed method. In addition, the distance potential offers higher accuracy than the volume potential for the proposed 3DCPNMM. Finally, the 3DCPNMM is applied to complex engineering cases involving the movement and failure of complex rock mass, which will be helpful for rock mechanics research and engineering design in the future.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"194 ","pages":"Article 106236"},"PeriodicalIF":7.5,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144809663","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":"Mohr-Coulomb strength and FDEM parameter determination of weathered granite via optimized neural network and deep learning","authors":"Tong Ye ,&nbsp;Chunshun Zhang ,&nbsp;Zhuang Chen ,&nbsp;Congying Li","doi":"10.1016/j.ijrmms.2025.106233","DOIUrl":"10.1016/j.ijrmms.2025.106233","url":null,"abstract":"<div><div>The traditional finite discrete element method (FDEM) is less applied in practical engineering-scale modeling due to its complex input parameter calibration process, poor prediction ability of calibration techniques, and insufficient description of material plastic damage. This study proposed a novel FDEM model enriched with the Mohr-Coulomb (MC) model and applied the neural network method to standardize the input parameters. The method enables rapid calibration of input parameters for various rock materials and accurately predicts their plastic development and failure modes, thereby enhancing the adaptability of FDEM in complex engineering scenarios. First, the Newton-Raphson-Based Optimizer (NRBO)-Back Propagation Neural Network (BPNN) method is employed to establish the correspondence between input parameters and Unconfined Compressive Strength (UCS) and Brazilian Tensile Strength (BTS) results. Subsequently, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) is used to manage and assign numerical parameters to match the target rock strength. Notably, by introducing failure mode parameters, the method refines the FDEM's description of different failure modes in weathered granites. Finally, the consistency between experimental and numerical results demonstrates the effectiveness of the proposed approach. This work successfully addresses the rapid calibration of FDEM input parameters using machine learning and overcomes the limitations of traditional models in describing the plastic development of rock materials.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"194 ","pages":"Article 106233"},"PeriodicalIF":7.5,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144809664","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}