http://yetl.yabesh.ir/yetl1/handle/yetl/19010 2026-04-12T07:55:55Z 2026-04-12T07:55:55Z Adolphus Lye Wasin Vechgama Mohamed Sallak Sebastien Destercke Scott Ferson Sicong Xiao http://yetl.yabesh.ir/yetl1/handle/yetl/4309998 2026-02-16T21:58:04Z 2025-01-01T00:00:00Z

Advances in the Reliability Analysis of Coherent Systems under Limited Data with Confidence Boxes Adolphus Lye; Wasin Vechgama; Mohamed Sallak; Sebastien Destercke; Scott Ferson; Sicong Xiao This paper proposes an uncertainty quantification framework that enables the analyst to compute statistically calibrated confidence bounds of the reliability of coherent systems, even in the case in which the data are limited. More specifically, we propose to use confidence boxes to do so. Such a proposal is motivated by the fact that confidence boxes offer a guarantee on statistical performances regardless of the amount of available data through repeated use, which is especially useful when considering the fact that reliability or failure data for the reliability analysis are often limited in availability. The aim of this work is to provide tools that allow the analyst to obtain the true confidence intervals over the system failure and reliability at any desired level. This paper first reviews the basics of confidence boxes and reliability analysis before providing general computation tools. From this, a mathematical formalism is presented that relates the component configurations with the corresponding Boolean logic expressions to perform a forward propagation of the confidence boxes under varying dependencies between the components. The feasibility of the proposed framework is then demonstrated through three case studies involving complex systems under varying engineering settings in the form of the (1) pressurized tank system, (2) Training, Research, Isotopes, General Atomics (TRIGA) nuclear research reactor cooling system, and (3) bridge structure system. Through case studies, the validity of our studies is empirically shown, and an evaluation of the strengths and limitations of the proposed framework is presented. Finally, this paper provides perspectives on the future research works that can be undertaken. To provide a better understanding of the proposed framework, open R source code to reproduce the results and perform other related studies is available on GitHub.

2025-01-01T00:00:00Z Faquan Wu Weixin Wan Yun Tian Ying Yang Bing Yang http://yetl.yabesh.ir/yetl1/handle/yetl/4309887 2026-02-16T21:53:49Z 2025-01-01T00:00:00Z

Analysis of Deformation Characteristics of Layered Rock Tunnel Excavation Based on Statistical Mechanics of Rock Masses Faquan Wu; Weixin Wan; Yun Tian; Ying Yang; Bing Yang Layered rock mass is prevalent in tunnel engineering, where deformation and failure of surrounding rock are primarily governed by discontinuity structural planes, leading to significant anisotropy in deformation and strength characteristics. Compared to continuous homogeneous rock masses, layered rock masses exhibit more complex engineering properties. This study utilized the constitutive theory of statistical mechanics of rock masses (SMRM) and Abaqus numerical software to analyze the influence of geometric, spatial, and mechanical characteristics of discontinuity structural planes on the stability of surrounding rock. The failure characteristics of tunnel surrounding rock with varying scales and orientations of carbonaceous slate discontinuity structural planes are examined. Additionally, the displacement distribution of surrounding rock under continuous medium conditions is compared between the SMRM constitutive theory and the Mohr–Coulomb constitutive theory. The results reveal that the SMRM constitutive theory aligns well with the Mohr–Coulomb theory under continuous medium conditions. The presence of discontinuity structural planes significantly diminishes the self-stability of the surrounding rock, with increased scale and density of structural planes amplifying their control effect. The direction of surrounding rock failure postexcavation is closely related to the formation occurrence and horizontal stress, manifesting as tangential shear sliding failure along the discontinuity structural plane and normal bending compression shear failure of the bedrock. Meanwhile, the model test results are employed to validate the feasibility of SMRM theory. This study provides an important reference for the analysis of deformation and failure mechanisms of layered rock masses with different joint surface parameters. This study on the deformation characteristics of layered rock tunnel excavation, based on SMRM, provides critical insights for tunnel engineering. It emphasizes the importance of detailed geological surveys to identify structural planes, which impact stability, and demonstrates how numerical simulations with Abaqus can predict excavation behavior, aiding in optimal design and cost-effective, safe construction. The findings highlight the need for targeted reinforcement strategies and validate the SMRM model’s alignment with established theories, offering confidence in its practical application and guiding future research to enhance geotechnical engineering practices. The research indicates that the scale and density of structural planes affect the self-stability of surrounding rock, necessitating local reinforcement and comprehensive support designs, especially in areas with prevalent structural planes. Additionally, understanding the failure direction related to formation occurrence and horizontal stress provides a basis for designing tailored support systems, enhancing tunnel durability and safety. This investigation can significantly improve tunnel design, ensuring robust and reliable structures in layered rock masses.

2025-01-01T00:00:00Z Petros Woldemariam Nii Attoh-Okine http://yetl.yabesh.ir/yetl1/handle/yetl/4309776 2026-02-16T21:49:07Z 2025-01-01T00:00:00Z

Multiway Analytics Applied to Railway Track Geometry and Ballast Conditions Petros Woldemariam; Nii Attoh-Okine Railroad systems generate large amounts of data, which, when effectively analyzed, can significantly enhance maintenance decisions to improve safety and system performance. Tensor decomposition, as an advanced multidimensional data analysis tool, offers unique advantages over traditional two-way matrix factorizations, such as the uniqueness of the optimal solution and component identification, even with substantial data missing. This paper introduces the basic concepts of tensor decomposition and specifically demonstrates its application in analyzing railway track geometry and subsurface conditions. By applying tensor analysis to multidimensional data sets, the study identifies critical patterns in track geometry and ballast conditions. Key findings indicate that tensor-based models can effectively predict track deformations and align maintenance schedules more accurately, thus optimizing repair operations and extending the lifespan of railway infrastructure.

2025-01-01T00:00:00Z Pedram Roshani Julio Ángel Infante Sedano Reza Rezvani Mohammad Amin Tutunchian http://yetl.yabesh.ir/yetl1/handle/yetl/4309665 2026-02-16T21:44:46Z 2025-01-01T00:00:00Z

Recalibration of LRFD Resistance Factors for Driven Steel Piles at End of Drive Conditions in Alberta, Canada Pedram Roshani; Julio Ángel Infante Sedano; Reza Rezvani; Mohammad Amin Tutunchian The geotechnical resistance factor (GRF) is an important parameter used as a part of the implementation of the load and resistance factor design (LRFD) method. This paper presents the improvement of the GRF used in the design procedure for axially loaded driven piles in Alberta, Canada. To obtain this goal, an extensive database of in situ pile load tests, including the results of 28 static load tests (SLT) and 623 pile driving analyzer (PDA) tests was collected from different locations in Alberta. Various known static analysis methods were used for the prediction of pile bearing capacity based on laboratory and in situ geotechnical tests. The GRFs for the static analysis methods were calibrated using a well-known probabilistic technique, called Monte Carlo simulation (MCS). Calibrated GRF values have been recommended for the design of pile bearing capacity based on the soil type, cohesive fine content along the pile length, different empirical methods, and geological region of Alberta. The results showed that regional calibration of GFR based on the local database resulted in higher values of resistance factors than those recommended in national codes, leading to a more accurate and cost-effective design procedure. In the recent decades, many countries have moved from the allowable strength design (ASD) method to the load and resistance factor design (LRFD) method. The LRFD method employs the geotechnical resistance factor (GRF) to design geotechnical structures such as pile foundations. As recommended by different design codes, regional recalibration of GRF based on local in situ pile tests can lead to being more reliable and removing unnecessary conservative assumptions during the pile design procedure. Using a comprehensive database, including 28 static load and 623 PDA tests carried out in Alberta, Canada, it is aimed to evaluate and calibrate the GRF of the LRFD method for the bearing capacity of driven steel piles based on site-specific geotechnical investigation reports and analytical approaches considering different static analysis methods in this study. Based on the results, the recommended GRFs in cohesive, mixed and cohesionless soils for β=2.33 are 0.58, 0.62, and 0.64, respectively. However, for β=3.00 the GRF values are 0.46, 0.49, and 0.49 for cohesive, mixed and cohesionless, respectively. The regionally recalibrated GRFs are higher than those recommended by CFEM, which may lead to reducing the number or length of piles required during the design process.

2025-01-01T00:00:00Z