Pub Date : 2026-02-01Epub Date: 2025-12-04DOI: 10.1016/j.simpat.2025.103239
Chengpu Peng , Lin Geng , Jiaxiang Liu , Liang Tang , Xianzhang Ling
To investigate the anchorage performance of split-grouted rock bolt in fractured rock slopes, a computational model was developed that accounts for rock bolt failure modes and the nonlinear mechanical behavior of the anchorage interface. Field pullout tests were conducted on three sets of split-grouted rock bolts, with ultimate strengths of 250.73 kN, 254.45 kN, and 253.66 kN, respectively. The computational model was then used to fit the experimental data, determining a peak shear strength of the anchorage interface as 0.55 MPa with a corresponding shear displacement of 3.31 mm and a residual shear strength of 0.17 MPa. The nonlinear mechanical characteristics of the anchorage interface were incorporated into numerical simulations to examine the effectiveness of split-grouted rock bolts in slopes with varying joint spacing and grouting radius. Results demonstrated that the combined reinforcement of rock bolts and grouting effectively enhanced the integrity of fragmented rock masses, significantly improving slope stability and altering the failure mode of fractured rock slopes. These conclusions provide valuable insights and practical guidance for the engineering design of split-grouted rock bolt reinforcement systems in fractured rock slope stabilization.
{"title":"Anchorage performance of split-grouted rock bolt in fractured rock slope","authors":"Chengpu Peng , Lin Geng , Jiaxiang Liu , Liang Tang , Xianzhang Ling","doi":"10.1016/j.simpat.2025.103239","DOIUrl":"10.1016/j.simpat.2025.103239","url":null,"abstract":"<div><div>To investigate the anchorage performance of split-grouted rock bolt in fractured rock slopes, a computational model was developed that accounts for rock bolt failure modes and the nonlinear mechanical behavior of the anchorage interface. Field pullout tests were conducted on three sets of split-grouted rock bolts, with ultimate strengths of 250.73 kN, 254.45 kN, and 253.66 kN, respectively. The computational model was then used to fit the experimental data, determining a peak shear strength of the anchorage interface as 0.55 MPa with a corresponding shear displacement of 3.31 mm and a residual shear strength of 0.17 MPa. The nonlinear mechanical characteristics of the anchorage interface were incorporated into numerical simulations to examine the effectiveness of split-grouted rock bolts in slopes with varying joint spacing and grouting radius. Results demonstrated that the combined reinforcement of rock bolts and grouting effectively enhanced the integrity of fragmented rock masses, significantly improving slope stability and altering the failure mode of fractured rock slopes. These conclusions provide valuable insights and practical guidance for the engineering design of split-grouted rock bolt reinforcement systems in fractured rock slope stabilization.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"147 ","pages":"Article 103239"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145791291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The presence of soil-rock mixtures (SRM) in slopes poses significant design challenges due to their heterogeneous composition. While volumetric block proportion (VBP) and mechanical properties of soil matrix are known key factors affecting SRM slope stability, the influence of the interface between soil and rock blocks has received less attention. This study undertakes a comprehensive numerical investigation using the finite element method (FEM), combined with statistical analysis, to explore the effects of block-matrix interface parameters including cohesion, friction angle, normal stiffness and shear stiffness on SRM slope stability. Given the significant role of VBP and block geometric arrangement, the influence of interface parameters is evaluated across different VBPs and block arrangements. Results indicate that for VBPs exceeding 25%, an increase in VBP leads to substantial enhancement in factor of safety (FoS) as the failure zone is diverted into a more tortuous path. To statistically examine the importance of interface parameters, response surface methodology (RSM) and analysis of variance (ANOVA) are employed. Statistical analyses confirm that VBP is the most significant parameter controlling slope stability, and it modulates the influence of other parameters. An increase in interface cohesion and friction angle elevates the FoS, with their effects becoming more pronounced at higher VBPs. Although the normal and shear stiffness of interfaces can alter deformability and stress distribution, they do not have a significant effect on the slope stability. Furthermore, it is demonstrated that increased block density can reduce the FoS, while larger rock block sizes significantly increase heterogeneity.
{"title":"Numerical and statistical assessment of block-matrix interface parameters on the stability of soil-rock mixtures slopes","authors":"Mojtaba Bahaaddini , AmirMohammad Sheikhpourkhani , Amir Yazdani , Joung Oh , Hossein Masoumi","doi":"10.1016/j.simpat.2026.103254","DOIUrl":"10.1016/j.simpat.2026.103254","url":null,"abstract":"<div><div>The presence of soil-rock mixtures (SRM) in slopes poses significant design challenges due to their heterogeneous composition. While volumetric block proportion (VBP) and mechanical properties of soil matrix are known key factors affecting SRM slope stability, the influence of the interface between soil and rock blocks has received less attention. This study undertakes a comprehensive numerical investigation using the finite element method (FEM), combined with statistical analysis, to explore the effects of block-matrix interface parameters including cohesion, friction angle, normal stiffness and shear stiffness on SRM slope stability. Given the significant role of VBP and block geometric arrangement, the influence of interface parameters is evaluated across different VBPs and block arrangements. Results indicate that for VBPs exceeding 25%, an increase in VBP leads to substantial enhancement in factor of safety (FoS) as the failure zone is diverted into a more tortuous path. To statistically examine the importance of interface parameters, response surface methodology (RSM) and analysis of variance (ANOVA) are employed. Statistical analyses confirm that VBP is the most significant parameter controlling slope stability, and it modulates the influence of other parameters. An increase in interface cohesion and friction angle elevates the FoS, with their effects becoming more pronounced at higher VBPs. Although the normal and shear stiffness of interfaces can alter deformability and stress distribution, they do not have a significant effect on the slope stability. Furthermore, it is demonstrated that increased block density can reduce the FoS, while larger rock block sizes significantly increase heterogeneity.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"147 ","pages":"Article 103254"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-20DOI: 10.1016/j.simpat.2026.103256
{"title":"Honoring excellence in the M&S community","authors":"","doi":"10.1016/j.simpat.2026.103256","DOIUrl":"10.1016/j.simpat.2026.103256","url":null,"abstract":"","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"147 ","pages":"Article 103256"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-23DOI: 10.1016/j.simpat.2025.103247
Haoyu Han , Yihao Qu , Hongyuan Liu , Daisuke Fukuda , Xuantao Liu , Huaming An , Yingyao Cheng , Andrew Chan
An in-house combined finite-discrete element method (FDEM) is implemented to analyze the toppling failure process of anti-dip slopes. A strength reduction method integrated with kinetic energy monitoring and failure surface detection is applied to not only simulate the progressive slope failure process but also reveal complex failure mechanisms in anti-dip slopes. The FDEM is first validated through reproducing the through-going failure surface formation stage and the flexural toppling stage observed in laboratory experiments on anti-dip slope instabilities. Then, 23 numerical models are built to investigate the effects of slope geometry, thick layer position and cross-joint on the stability of anti-dip slopes. It is concluded that increasing slope angle leads to increasing failure surface depth and system kinetic energy but, decreasing factor of safety (FOS). Increasing rock layer inclination results in decreasing failure surface inclination but increasing failure surface depth. Increasing rock layer thickness, however, exerts limited effects on slope failure characteristics but enhances FOS. Furthermore, thick layer position has rather limited influence on FOS while cross-joints dominate the failure mode of anti-dip slopes. The numerical findings are expected to advance our understanding of complex failure mechanisms in anti-dip slopes and provide theoretical foundations for relevant slope stability assessment and prediction.
{"title":"Analysis of toppling failure mechanisms in anti-dip slopes based on FDEM simulation","authors":"Haoyu Han , Yihao Qu , Hongyuan Liu , Daisuke Fukuda , Xuantao Liu , Huaming An , Yingyao Cheng , Andrew Chan","doi":"10.1016/j.simpat.2025.103247","DOIUrl":"10.1016/j.simpat.2025.103247","url":null,"abstract":"<div><div>An in-house combined finite-discrete element method (FDEM) is implemented to analyze the toppling failure process of anti-dip slopes. A strength reduction method integrated with kinetic energy monitoring and failure surface detection is applied to not only simulate the progressive slope failure process but also reveal complex failure mechanisms in anti-dip slopes. The FDEM is first validated through reproducing the through-going failure surface formation stage and the flexural toppling stage observed in laboratory experiments on anti-dip slope instabilities. Then, 23 numerical models are built to investigate the effects of slope geometry, thick layer position and cross-joint on the stability of anti-dip slopes. It is concluded that increasing slope angle leads to increasing failure surface depth and system kinetic energy but, decreasing factor of safety (FOS). Increasing rock layer inclination results in decreasing failure surface inclination but increasing failure surface depth. Increasing rock layer thickness, however, exerts limited effects on slope failure characteristics but enhances FOS. Furthermore, thick layer position has rather limited influence on FOS while cross-joints dominate the failure mode of anti-dip slopes. The numerical findings are expected to advance our understanding of complex failure mechanisms in anti-dip slopes and provide theoretical foundations for relevant slope stability assessment and prediction.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"147 ","pages":"Article 103247"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-06DOI: 10.1016/j.simpat.2025.103242
Lianbo Deng , Jingshuang Li , Huaru Liu , Xiaoshan Zhu , Xinlei Hu
The spatiotemporal rules of passenger flow in urban rail transit (URT) hubs are complex, meaning that simulation modeling and analysis of passenger flow distributions in hubs are very important in terms of scientifically organizing passenger flow and improving travel efficiency. In this study, an analysis was conducted of passengers' travel processes and behaviors, and a simulation model combining cellular automata (CA) and agent-based modeling (ABM) was proposed. A CA grid environment was used to describe the spatial constraints and movement logic, whereas ABM was employed to construct passenger agents. This approach included a visual perception model, a behavior decision-making model that took into consideration the influence of multiple factors, a fuzzy logic-based multi-channel selection model, and a group-competition-based action execution model, in order to finely characterize the individual microscopic behaviors. Tiyu Xilu Station of Guangzhou Metro in China was taken as a case study, and the simulation results were used to verify the effectiveness of the model. The key findings were as follows: the simulation results for escalator passenger throughput were close to the design capacity, with a difference of -4.2%; the service level for the west platform of Line 3 was lower than for the east platform, with the lowest being Level E; during peak hours, for every 10% increase in the degree of bidirectional pedestrian flow, the average dwell time increased by approximately 6.8%. These research results provide decision support for optimizing passenger flow organization in URT hubs.
{"title":"Passenger flow simulation model for urban rail transit hubs based on cellular automata and multi-agent systems","authors":"Lianbo Deng , Jingshuang Li , Huaru Liu , Xiaoshan Zhu , Xinlei Hu","doi":"10.1016/j.simpat.2025.103242","DOIUrl":"10.1016/j.simpat.2025.103242","url":null,"abstract":"<div><div>The spatiotemporal rules of passenger flow in urban rail transit (URT) hubs are complex, meaning that simulation modeling and analysis of passenger flow distributions in hubs are very important in terms of scientifically organizing passenger flow and improving travel efficiency. In this study, an analysis was conducted of passengers' travel processes and behaviors, and a simulation model combining cellular automata (CA) and agent-based modeling (ABM) was proposed. A CA grid environment was used to describe the spatial constraints and movement logic, whereas ABM was employed to construct passenger agents. This approach included a visual perception model, a behavior decision-making model that took into consideration the influence of multiple factors, a fuzzy logic-based multi-channel selection model, and a group-competition-based action execution model, in order to finely characterize the individual microscopic behaviors. Tiyu Xilu Station of Guangzhou Metro in China was taken as a case study, and the simulation results were used to verify the effectiveness of the model. The key findings were as follows: the simulation results for escalator passenger throughput were close to the design capacity, with a difference of -4.2%; the service level for the west platform of Line 3 was lower than for the east platform, with the lowest being Level E; during peak hours, for every 10% increase in the degree of bidirectional pedestrian flow, the average dwell time increased by approximately 6.8%. These research results provide decision support for optimizing passenger flow organization in URT hubs.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"147 ","pages":"Article 103242"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145738580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-16DOI: 10.1016/j.simpat.2025.103246
Pasquale Legato, Massimiliano Matteucci, Rina Mary Mazza
The (re)organization of existing and planned warehouse facilities typically seeks to balance system-centric performance indicators (e.g., resource productivity) with customer-focused metrics (e.g., order response time). In pursuit of this objective, there is a growing opportunity to transition from conventional simulation models toward digital twin solutions, which offer enhanced decision-support capabilities. This manuscript focuses on the reorganization of manually executed order picking within a real-world wholesale operation. A simulation-based framework is introduced within a digital shadow environment to optimize the order picking process, following an S-shaped, person-to-goods picking strategy. At the core of the modeling approach is an enriched event graph, which captures the manual picking process at a fine-grained level by representing operational events and their real-time interdependencies. To demonstrate the framework’s effectiveness, numerical results are presented for a typical workday in a major Italian retail cooperative. These results compare alternative control policies, examining their impact on queueing dynamics and picker interference, key contributors to service blocking, resource locking, and starvation within the warehouse’s parallel picking aisles.
{"title":"Towards a digital twin solution for manual order-picking operations in a wholesale distribution center","authors":"Pasquale Legato, Massimiliano Matteucci, Rina Mary Mazza","doi":"10.1016/j.simpat.2025.103246","DOIUrl":"10.1016/j.simpat.2025.103246","url":null,"abstract":"<div><div>The (re)organization of existing and planned warehouse facilities typically seeks to balance system-centric performance indicators (e.g., resource productivity) with customer-focused metrics (e.g., order response time). In pursuit of this objective, there is a growing opportunity to transition from conventional simulation models toward digital twin solutions, which offer enhanced decision-support capabilities. This manuscript focuses on the reorganization of manually executed order picking within a real-world wholesale operation. A simulation-based framework is introduced within a digital shadow environment to optimize the order picking process, following an S-shaped, person-to-goods picking strategy. At the core of the modeling approach is an enriched event graph, which captures the manual picking process at a fine-grained level by representing operational events and their real-time interdependencies. To demonstrate the framework’s effectiveness, numerical results are presented for a typical workday in a major Italian retail cooperative. These results compare alternative control policies, examining their impact on queueing dynamics and picker interference, key contributors to service blocking, resource locking, and starvation within the warehouse’s parallel picking aisles.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"147 ","pages":"Article 103246"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145791294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-23DOI: 10.1016/j.simpat.2025.103248
Elif Ravza Özaras , Mahmut Tutam , Nadide Çağlayan Özaydın , Sinan Öztaş
As online buyers desire a wider variety of products in smaller quantities with faster delivery times, warehouse technology is evolving to meet their needs. The Robotic Compact Storage and Retrieval System (RCS/RS) provides a solution by offering improved flexibility, continuous operation, and efficient use of available space. This study focuses on a single-robot RCS/RS configuration, in which one robot moves horizontally across a grid-based storage area and accesses vertical stacks while performing storage and retrieval tasks. To access a specific bin, the robot first removes any blocking bins above it and temporarily repositions them to neighboring stacks before delivering the requested bin to the port. To support improved system design, this study implements a large-scale, full-factorial experimental framework to evaluate key factors, including total bin capacity, stack height, arrival rate, and robot velocity. A refined simulation model, incorporating detailed retrieval and storage operations, is developed using ARENA 16.0 under an academic license. ANOVA-based analysis using IBM SPSS Statistics 28.0 is applied to the simulation results to evaluate the effects of system factors and their interactions on performance. Results indicate that robot velocity is the dominant factor, followed by total bin capacity and arrival rate, while stack height has a comparatively minor effect. The analysis also shows that several factor interactions play a significant role, highlighting the importance of considering combined effects when designing RCS/RS systems.
{"title":"Simulation-based performance analysis of a Robotic Compact Storage and Retrieval System under single-robot operation","authors":"Elif Ravza Özaras , Mahmut Tutam , Nadide Çağlayan Özaydın , Sinan Öztaş","doi":"10.1016/j.simpat.2025.103248","DOIUrl":"10.1016/j.simpat.2025.103248","url":null,"abstract":"<div><div>As online buyers desire a wider variety of products in smaller quantities with faster delivery times, warehouse technology is evolving to meet their needs. The Robotic Compact Storage and Retrieval System (RCS/RS) provides a solution by offering improved flexibility, continuous operation, and efficient use of available space. This study focuses on a single-robot RCS/RS configuration, in which one robot moves horizontally across a grid-based storage area and accesses vertical stacks while performing storage and retrieval tasks. To access a specific bin, the robot first removes any blocking bins above it and temporarily repositions them to neighboring stacks before delivering the requested bin to the port. To support improved system design, this study implements a large-scale, full-factorial experimental framework to evaluate key factors, including total bin capacity, stack height, arrival rate, and robot velocity. A refined simulation model, incorporating detailed retrieval and storage operations, is developed using ARENA 16.0 under an academic license. ANOVA-based analysis using IBM SPSS Statistics 28.0 is applied to the simulation results to evaluate the effects of system factors and their interactions on performance. Results indicate that robot velocity is the dominant factor, followed by total bin capacity and arrival rate, while stack height has a comparatively minor effect. The analysis also shows that several factor interactions play a significant role, highlighting the importance of considering combined effects when designing RCS/RS systems.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"147 ","pages":"Article 103248"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-05DOI: 10.1016/j.simpat.2025.103241
G. Xiroudakis , G. Saratsis , G.E. Exadaktylos , E. Machairas , E.A. Varouchakis , S. Mavrigiannakis
The room-and-pillar mining method is an ancient technique used in the extraction of underground deposits. Even today, it remains one of the most widespread and productive methods of underground mining, where the abandoned pillars ensure the stability of the opening. The mechanical behavior of the pillar plays an important role in its sizing and the estimation of ore recovery. In this paper, the rock material from a historical ancient underground quarry in Gortyna, Crete, Greece, was numerically investigated. This material, composed of limestone, that exhibits pronounced layering and is very soft, allowed the ancient Romans to excavate underground tunnels with a total length of >2.5 km. A high-resolution 3D X Phase Pro S2 360 camera, was used to capture panoramic photos in both horizontal and vertical planes. These photos were used to estimate the dimensions of the chambers and the central pillar of the accessible underground area of the site (the large underground quarry has been closed). The effect of micro-cracking of the rock on the behavior of the room and pillar excavation method was investigated using Linear Elastic Fracture Mechanics (LEFM) theory. For this purpose, a numerical model was created using the FLAC2D software to estimate the effective elastic parameters of the material based on its density and the arrangement of cracks within it. This analysis revealed that the presence of microcracks introduces an anisotropy similar to that of a transversely isotropic material. The observed anisotropy results in larger deformations in the main chamber crown than those obtained using average elastic properties from experimental, literature, and field investigations of limestone rock.
房柱采矿法是一种用于开采地下矿床的古老技术。即使在今天,它仍然是最广泛和最有效的地下采矿方法之一,其中废弃的支柱确保了开口的稳定性。矿柱的力学行为对矿柱的尺寸确定和回采率的估计起着重要的作用。本文对希腊克里特岛Gortyna一个历史悠久的地下采石场的岩石材料进行了数值研究。这种由石灰石组成的材料,具有明显的分层性,非常柔软,古罗马人因此得以挖掘总长2.5公里的地下隧道。高分辨率3D X Phase Pro S2 360相机,用于捕捉水平和垂直平面的全景照片。这些照片被用来估计墓室的尺寸和可到达的地下区域的中央柱子(大型地下采石场已经关闭)。采用线弹性断裂力学(LEFM)理论,研究了岩石微裂纹对硐室和矿柱开挖行为的影响。为此,利用FLAC2D软件建立数值模型,根据材料的密度和材料内部裂纹的排列来估计材料的有效弹性参数。这一分析表明,微裂纹的存在引入了类似于横向各向同性材料的各向异性。观察到的各向异性导致主室顶部的变形比通过实验、文献和现场调查石灰石的平均弹性特性获得的变形更大。
{"title":"The effect of microstructure on the behavior of an underground excavation","authors":"G. Xiroudakis , G. Saratsis , G.E. Exadaktylos , E. Machairas , E.A. Varouchakis , S. Mavrigiannakis","doi":"10.1016/j.simpat.2025.103241","DOIUrl":"10.1016/j.simpat.2025.103241","url":null,"abstract":"<div><div>The room-and-pillar mining method is an ancient technique used in the extraction of underground deposits. Even today, it remains one of the most widespread and productive methods of underground mining, where the abandoned pillars ensure the stability of the opening. The mechanical behavior of the pillar plays an important role in its sizing and the estimation of ore recovery. In this paper, the rock material from a historical ancient underground quarry in Gortyna, Crete, Greece, was numerically investigated. This material, composed of limestone, that exhibits pronounced layering and is very soft, allowed the ancient Romans to excavate underground tunnels with a total length of >2.5 km. A high-resolution 3D X Phase Pro S2 360 camera, was used to capture panoramic photos in both horizontal and vertical planes. These photos were used to estimate the dimensions of the chambers and the central pillar of the accessible underground area of the site (the large underground quarry has been closed). The effect of micro-cracking of the rock on the behavior of the room and pillar excavation method was investigated using Linear Elastic Fracture Mechanics (LEFM) theory. For this purpose, a numerical model was created using the FLAC2D software to estimate the effective elastic parameters of the material based on its density and the arrangement of cracks within it. This analysis revealed that the presence of microcracks introduces an anisotropy similar to that of a transversely isotropic material. The observed anisotropy results in larger deformations in the main chamber crown than those obtained using average elastic properties from experimental, literature, and field investigations of limestone rock.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"147 ","pages":"Article 103241"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145738584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-03DOI: 10.1016/j.simpat.2025.103238
Jixin Shi , Maoyu Li , Nan Jiang , Hanchen Yu , Hongyun Yang , Xiaodong Zhou , Lizhong Yang
Efficient evacuation in complex building environments remains a fundamental challenge in simulation modeling and public safety. Traditional models based on static path-finding or rule-based decision-making often result in unbalanced exit utilization and congestion, limiting their ability to represent adaptive human behavior in emergencies. To address these shortcomings, this study proposes a Collaborative Decision-Making Framework based on Multi-Agent Deep Reinforcement Learning (CDF-MADRL). The framework introduces a dynamic multi-objective reward mechanism that adaptively balances individual evacuation time and collective efficiency, and a localized observation strategy that significantly reduces computational burden in large-scale multi-agent environments. Implemented using the MAPPO algorithm, the model was validated in a complex asymmetric multi-exit scenario with varying population sizes. Results show that CDF-MADRL improves training stability by over 70% and reduces average evacuation time by 2–11% compared with baseline models. Beyond improving evacuation efficiency, this research contributes methodologically by demonstrating how reinforcement learning can be systematically embedded into simulation modeling practice, offering a scalable and intelligent framework for evacuation analysis. These findings highlight the potential of integrating artificial intelligence with simulation modeling to enhance resilience in complex built environments.
{"title":"A multi-agent deep reinforcement learning model for crowd coordinated evacuation simulation in complex environments","authors":"Jixin Shi , Maoyu Li , Nan Jiang , Hanchen Yu , Hongyun Yang , Xiaodong Zhou , Lizhong Yang","doi":"10.1016/j.simpat.2025.103238","DOIUrl":"10.1016/j.simpat.2025.103238","url":null,"abstract":"<div><div>Efficient evacuation in complex building environments remains a fundamental challenge in simulation modeling and public safety. Traditional models based on static path-finding or rule-based decision-making often result in unbalanced exit utilization and congestion, limiting their ability to represent adaptive human behavior in emergencies. To address these shortcomings, this study proposes a Collaborative Decision-Making Framework based on Multi-Agent Deep Reinforcement Learning (CDF-MADRL). The framework introduces a dynamic multi-objective reward mechanism that adaptively balances individual evacuation time and collective efficiency, and a localized observation strategy that significantly reduces computational burden in large-scale multi-agent environments. Implemented using the MAPPO algorithm, the model was validated in a complex asymmetric multi-exit scenario with varying population sizes. Results show that CDF-MADRL improves training stability by over 70% and reduces average evacuation time by 2–11% compared with baseline models. Beyond improving evacuation efficiency, this research contributes methodologically by demonstrating how reinforcement learning can be systematically embedded into simulation modeling practice, offering a scalable and intelligent framework for evacuation analysis. These findings highlight the potential of integrating artificial intelligence with simulation modeling to enhance resilience in complex built environments.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"147 ","pages":"Article 103238"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145738582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-14DOI: 10.1016/j.simpat.2026.103252
Ying-Chuan Ni, Anastasios Kouvelas, Michail A. Makridis
Dynamic traffic models that reproduce the pattern of congestion propagation in urban road networks are essential for the evaluation of traffic management strategies and prediction of traffic states. Many approaches developed in the past simplified the movement of vehicles and the propagation of traffic waves. The overlooked problems can be particularly influential for the simulation of interrupted flow with traffic signal control due to the frequent accumulation and dissipation of the waiting queue on a road link. This study first reviews state-of-the-art macroscopic and mesoscopic link-level urban traffic flow models and provides a comparative discussion of their similarities, differences, and gaps. We then put forward an event-based mesoscopic model to simulate link-level interrupted flow traffic dynamics (LIFT). The model (i) simulates the transmission of vehicles between links based on the demand and supply of exit and entry events, (ii) monitors queue spillback through the consideration of backward traveling spaces, and (iii) adheres to first-in-first-out at intersections for congested situations. Taking the outcomes generated from microscopic simulation as ground-truth, the case studies show that LIFT outperforms the other models by accurately capturing the evolution of link densities and mean path speeds in congested conditions. It is reliable even in complex scenarios with diverge blocking phenomena and desired speed heterogeneity. Without having to simulate the interaction between individual vehicles, the model also becomes much more computationally efficient than microscopic simulation. It can be applied in simulation-based optimization or control problems which require the consideration of finer-level details that macroscopic models are unable to offer.
{"title":"Simulating link-level interrupted flow traffic dynamics and the comparison between different models for urban road networks","authors":"Ying-Chuan Ni, Anastasios Kouvelas, Michail A. Makridis","doi":"10.1016/j.simpat.2026.103252","DOIUrl":"10.1016/j.simpat.2026.103252","url":null,"abstract":"<div><div>Dynamic traffic models that reproduce the pattern of congestion propagation in urban road networks are essential for the evaluation of traffic management strategies and prediction of traffic states. Many approaches developed in the past simplified the movement of vehicles and the propagation of traffic waves. The overlooked problems can be particularly influential for the simulation of interrupted flow with traffic signal control due to the frequent accumulation and dissipation of the waiting queue on a road link. This study first reviews state-of-the-art macroscopic and mesoscopic link-level urban traffic flow models and provides a comparative discussion of their similarities, differences, and gaps. We then put forward an event-based mesoscopic model to simulate link-level interrupted flow traffic dynamics (LIFT). The model (i) simulates the transmission of vehicles between links based on the demand and supply of exit and entry events, (ii) monitors queue spillback through the consideration of backward traveling spaces, and (iii) adheres to first-in-first-out at intersections for congested situations. Taking the outcomes generated from microscopic simulation as ground-truth, the case studies show that LIFT outperforms the other models by accurately capturing the evolution of link densities and mean path speeds in congested conditions. It is reliable even in complex scenarios with diverge blocking phenomena and desired speed heterogeneity. Without having to simulate the interaction between individual vehicles, the model also becomes much more computationally efficient than microscopic simulation. It can be applied in simulation-based optimization or control problems which require the consideration of finer-level details that macroscopic models are unable to offer.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"147 ","pages":"Article 103252"},"PeriodicalIF":3.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}