bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the influence of various three-point bending specimen configurations on rock fracture parameters testing: an experimental study
Authors: Xie Qin , Liu Xiling , Zhong Yuchen 
Published: May 2024

Abstract
The fracture parameters of rocks, including fracture toughness and fracture energy, represent their resistance to crack propagation under external stress. These parameters play a critical role in engineering design, construction safety, geological mechanics research, and rock material assessment. This study determined the fracture parameters of granite under Mode I loading conditions using notched semicircular bend (NSCB) and single-edge notched beam (SENB) specimens. Although there was little difference between the initial and unstable fracture toughness values of the two specimen configurations, significant differences were observed in the fracture process and other fracture parameters. For example, the NSCB specimen exhibits a higher elastic modulus, and it witnessed rapid failure after reaching the peak load, whereas the SENB specimen displayed a more gradual failure process with a distinct post-peak stage. This may be one of the reasons for the higher fracture energy in the NSCB specimen than in the SENB specimen. Based on finite element analysis and the extraction of the tangential stress at the crack tip region, the application of the maximum tangential stress fracture criterion provided a robust explanation for the coherence observed in the unstable fracture toughness test results between the two specimen configurations.
Topology Optimization based Integrated Design of Structure-Foundation System
Authors: Li Xifan , Zhang Xue , Zhang Yujia 
Published: May 2024

Abstract
This study introduces a novel topology optimization method with the goal of achieving an integrated design for offshore infrastructure. A key feature of this method is its capability to eliminate artificial boundaries between the design of the above-ground support structure and underlying soil foundation, thus facilitating a more efficient and effective design solution. In contrast to traditional stress-based topology optimization methods, the proposed approach combines limit analysis with density-based topology optimization techniques. Formulated as a volume minimization task, it targets the structure’s bearing capacity, ensuring that the external force applied is precisely matches the bearing capacity of the system obtained in the design. Furthermore, it is demonstrated that the proposed method exhibits favorable convergence properties within a prescribed number of iterations, indicating a steady progression towards an optimized solution.
Numerical analysis on the behavior of suction anchor under partial drained conditions
Authors: Mu Linlong , Zhou Tao , Huang Maosong 
Published: May 2024

Abstract
The vertical bearing capacity of the suction anchors is closely related to the loading rate. The loading rate is a critical parameter. In this study, ABAQUS was used to perform a numerical analysis of the behavior of suction anchors under partially drained conditions, considering the passive suction generated by the soil, which is the main feature during the uplift process of suction anchors. The results indicated that the suction anchor gradually moved from the drained condition to the undrained condition with an increase in the normalized rate V. When 0.1<V<47, it is partially drained, and the uplift force and negative pressure inside the anchor are more sensitive to the loading rate at this stage.
Evaluation of reduced-scale railway ballast particle size effects for different test sample sizes using monotonic triaxial tests
Authors: Namwong A , Jitsangiam P , Tanchaisawat T 
Published: May 2024

Abstract
This study rigorously investigated the mechanical characteristics of railway ballast using largescale triaxial (LST) testing, focusing on shear strength, stress–strain relationships, and volumetric alterations by altering particle sizes under controlled conditions. Samples with a size ratio (D/dmax) of 4.7 are typically used in LST testing. However, the ballast used in Thailand typically features a maximum grain size of 70.00 mm, whereas LST testing requires samples with diameter exceeding 300 mm, which poses logistical and material challenges. To mitigate this issue, our test introduced a parallel grading method to decrease sample size while preserving essential ballast properties and morphological features. This test applied two grain-size distributions: normal grain-size distribution (NGD) and parallel grain-size distribution (PGD). The study aimed to ascertain whether the smaller-sized samples can still provide accurate assessments of mechanical behaviors. The outcomes demonstrated that both NGD and PGD approaches yielded similar stress–strain behaviors and cohesion values. A marginal difference in friction angle values of 4° was noted, suggesting the occurrence of minor variances in shear resistance, which did not significantly affect the overall mechanical properties. The findings validate the effectiveness of the parallel grading technique, thus offering practical implications for testing procedures in railway engineering.
Morphological analysis of ballast particles: Characterization and simplified analysis of particle morphology using imaging data
Authors: Kwunjai S , Jitsangiam P , Somsri T 
Published: May 2024

Abstract
This paper introduces a novel algorithm for the rigorous characterization of three-dimensional (3D) particles, particularly for railway ballast. Degraded railway ballast must be replaced with fresh material for efficient functioning. This study examined the shape and form of degraded (used) ballast to guide future maintenance efforts. Laboratory-generated used ballast, obtained via the Los Angeles abrasion test, was compared to fresh ballast. Thirteen fundamental morphological parameters of fresh and used ballasts were investigated by utilizing the shape information obtained through 3D scanning. The algorithm efficiently processed datasets comprising multiple irregular particles and monitored the morphological characteristics of ballasts based on the shape of the particles. The trimesh library was imported for 3D processing, facilitating the mathematical calculation of diverse parameters using the developed algorithm. The algorithm also incorporated mechanisms for simultaneously storing parameters provided in various 3D configuration models. With the support of the trimesh library, a morphology analyzer was used to analyze various 3D model file formats, such as .stl, .obj, and csg. This method demonstrated its efficacy with reduced runtime and computation cost. Thus, the proposed algorithm has emerged as a valuable resource for researchers investigating the influence of ballast particle shape on the mechanical behavior of granular assemblies.
Thermo-mechanical Stability Analysis of Hollow Cellular Concrete Block Air Convection Embankments for Cold Regions
Authors: Wu H , Zhang X , Liu J 
Published: May 2024

Abstract
Crushed-rock air convection embankment (ACE), as a highly open-graded porous medium, has been used to mitigate the thaw settlement of pavement structures in permafrost regions. Previous studies have revealed that cellular concrete has significant potential as a cost-effective material for ACE to solve the problem of crushed rock shortage in interior Alaska and improved the thermal stability of pavement structures in cold climates. The design configurations of the hollow cellular concrete block ACE were further designed to maximize the performance benefits and facilitate future implementation and field construction. However, the mechanical behaviors of the proposed structures and ice-rich subgrade were still unknown. In this study, a thermo-mechanical coupling model was developed to evaluate the thermal effect on the long-term mechanical stability of the selected pavement structures and subgrade soils. The results indicated that the thermal stability of the proposed hollow cellular concrete block ACEs was superior to that of the conventional crushed-rock ACE. The maximum thaw settlement of the proposed hollow cellular concrete block ACE was only 13.4% that of the conventional crushed-rock ACE. Thermal and mechanical analyses showed that the proposed cellular concrete ACEs have a significant advantage over conventional crushed-rock ACE.
Fractional derivative modeling for dynamic response of layered viscoelastic media under moving time-harmonic loads
Authors: Ai Z Y , Gu G L , Wang X K 
Published: May 2024

Abstract
The dynamic response of layered viscoelastic media under moving time-harmonic loads is an important issue in transportation geotechnics. However, the existing research often has limitations in terms of the constant creep rate or time-independent relaxation modulus. To fill this gap, this study introduces a fractional Zener model to simulate the viscoelastic properties of media. First, the governing equations of the elastic medium are converted into ordinary differential equations using an integral transform. Subsequently, by introducing the fractional viscoelastic model and extended precise integration method, a solution to the dynamic response of layered viscoelastic media under moving time-harmonic loads is obtained. After comparing the results with those in existing literature, the reliability and accuracy of the proposed solution were verified. Finally, a parametric analysis was performed to further explore the influence of load velocity and fractional order on the dynamic response of the viscoelastic media.
Analysis of hole wall stability in saturated clay using undrained solution for cylindrical cavity contraction
Authors: Li Sheng , Lü Xilin 
Published: May 2024

Abstract
To investigate the stress state of soil during the instability of the hole wall (hole shrinkage) in saturated clay, the theory of cylindrical cavity contraction in an infinite medium is applied, utilizing the modified Cam-Clay (MCC) model. By employing intermediate variables, the issue of cylindrical cavity contraction is reformulated into a first-order ordinary differential equation in Lagrangian form, with three effective stress components and pore pressure as the unknowns. In MATLAB, the stress conditions at the elastoplastic boundary serve as the initial values for solving the initial value problem of the differential equation system. After determining the correlation between the stress distribution around the cavity and the diameter reduction ratio, the analysis proceeds to evaluate the internal support pressure required for stabilizing the hole wall according to various stability criteria. This pressure is then integrated into the hole wall stability coefficient formula within the soil pressure model, facilitating the evaluation of hole wall stability. The effectiveness and accuracy of the proposed semi-analytical elastic–plastic solutions were subsequently confirmed through comparison with finite element analysis results, underscoring its relevance for addressing hole wall stability challenges.
Analysis of Covered Pile on Multi-row Pile Quay
Authors: Gao J Y , Wang K F , Zhu Y 
Published: May 2024

Abstract
The multi-row pile quay wall is an innovative permanent structure comprising multiple piles, relieving slabs, flood control walls, and backfill sand. Although it additionally serves as a functional wharf, the research on multi-row pile quay walls remains insufficient. Considering the Changxing harbor Pool as a case study, this research develops a multi-row pile quay wall structure using the three-dimensional finite element software PLAXIS 3D. We investigated the effects of covered piles, pile row spacing, spacing between covered piles, and the stiffness of the front pile on the internal force and deformation of the structure. The findings indicated that the presence of the covered piles results in minimal overall displacement of the multi-row pile quay wall and reduces the bending moment in the front pile. Considering the site conditions and project costs, the sensitivity of different parameters to the retaining effect was evaluated in the order of the stiffness of the front pile > pile row spacing > spacing between the covered piles. Building on this, an optimized design scheme is proposed to reduce the bending moment in the front pile by 50% compared to the original scheme, thereby offering valuable insights for future engineering projects.
Probabilistic dislocation capacity model for mountain tunnel crossing strike–slip creeping fault
Authors: Xu Longjun , Zhu Jingzhou 
Published: May 2024

Abstract
Fault dislocations significantly affect the performances of cross–fault tunnels. However, there is a lack of rapid and accurate methods for estimating the maximum fault dislocation that tunnels can withstand (i.e., the dislocation capacity of tunnels). This study systematically investigates the dislocation capacity of circular tunnels crossing strike–slip creeping faults while considering uncertainties in the lining parameters, rock strength, and crossing angles. Through pseudostatic numerical simulations, the dislocation capacities of tunnels under various working conditions were determined, and a probabilistic dislocation capacity model was developed using a support vector machine. The proposed model can estimate the probability distribution of the dislocation capacity of a tunnel, with its median closely aligned with the numerical result. Another advantage lies in its direct correlation with the lining parameters, rock strength, and crossing angles. This facilitates a rapid assessment of the tunnel dislocation capacity based on existing parameters. The dislocation capacity and vulnerability curves of a case tunnel are estimated using our probabilistic model, which serves as a demonstration. The results demonstrate that the proposed model is convenient for engineering applications and can assist in the design and optimization of cross–fault tunnels.
A resilience optimization design model considering surcharge for large diameter shield tunnel
Authors: Zhang D M , Li H Y , Huang Z K , Gao J H , Yang G , Zhu M H 
Published: May 2024

Abstract
Large-diameter shield tunnels face challenges owing to the complex strata and surcharges. The robustness of ground disturbance during excavation and resilience during operation in the design model must be considered. This involves establishing a damage evolution law for existing shield tunnels after surcharging and proposing a resilience design method for the entire cycle. In this study, the design process was initiated by utilizing existing borehole survey information and incorporating stratum uncertainty. Subsequently, a ground surcharge was applied to evaluate the changes in the force and deformation at different design points after surcharging. A resilience assessment was conducted in accordance with the specified criteria, and the results indicated that a majority of the design points exhibited robustness within acceptable limits after the surcharge. The original excavation design demonstrated satisfactory initial performance in terms of robustness. However, the resilience after surcharging was suboptimal, exhibiting a value of only 0.65. To enhance the resilience, the design must modify the reinforcing rate to achieve a higher resilience state of 0.8. By considering both the robustness of the design and its resilience after surcharging, modifications can be made to align the design with real operational conditions, which may help improve the overall resilience.
Study on the evolution patterns of concrete lining’s physical and mechanical properties under sulfuric acid corrosion conditions
Authors: Xu Q , Wang H , Huang X 
Published: May 2024

Abstract
During operation, deep water storage and drainage tunnels may face sulfuric acid corrosion resulting from microbiologically induced chemical reactions. In this study, sulfuric acid corrosion experiments were performed on C60 concrete specimens with steel fiber volume ratios of 0% (plain) and 1% using a sulfuric acid solution with an initial pH of 1. For one-face corrosion, five faces of cubic concrete samples were coated with exposed resin, leaving only one face exposed to sulfuric acid. For all-face corrosion, all faces were exposed to sulfuric acid. Concrete corrosion under different loading conditions was compared by adding weights on top of the concrete. Rate of mass change variations and uniaxial compressive strength at various corrosion time points were monitored. The results indicated that after sulfuric acid corrosion, there was an increase in the mass but an overall decrease in the strength of the specimens. Compared with all-face corrosion, one-face corrosion led to a smaller increase in the mass of the concrete specimens and a more substantial decrease in strength, primarily because of the slower corrosion rate and reduced gypsum formation. Compared to plain concrete, steel fiber-reinforced concrete experienced a lower increase in the mass of the concrete specimens because the steel fibers obstructed sulfuric acid infiltration. However, there was significant corrosion of the steel fibers and surrounding concrete owing to accumulation of sulfuric acid around the former, resulting in a more substantial decrease in the uniaxial compressive strength of the steel fiber-reinforced concrete. With increasing load, the rate of change in the concrete mass initially decreased and then increased; this could be because increased loads densify the concrete, hindering sulfuric acid infiltration and promoting the development of microcracks within the concrete, thereby enhancing the effects of sulfuric acid corrosion.
Mechanical characterization of lining under three-dimensional complex load during shield posture adjustment
Authors: Yudong Wu , Wenqi Ding , Xiaoqing Chen 
Published: May 2024

Abstract
The shield tunneling method is widely used in urban underpass construction. However, research on the mechanical characteristics of segments during construction is insufficient. Throughout the shield tunneling construction process, segments undergo a diverse range of loads, and their modes become complex. During the adjustment of the posture of the shield machine along a curved path, segments must withstand three-dimensional uneven loads from the shield tail brush and extrusion of the shield shell, in addition to conventional loads. Thus, this study delves into the mechanical characterization of the lining during shield posture adjustment. First, three-dimensional refined models of the longitudinal and circumferential joints were established to investigate their bending and shear mechanical properties. Using the joint and shield tail brush stiffness models, a nonlinear spring-connector-shell model was developed for the mechanical analysis of segments during posture adjustment. Subsequently, a three-dimensional segment load model was formulated for the construction period. The segment response under the influence of different posture adjustments was examined using a numerical model of a tunnel subjected to a complex three-dimensional load. Furthermore, a multistage model of the segment response under various posture adjustments was established. This model serves as a valuable reference for engineering applications.
Framework for determining the safety distance of karst caves adjacent to tunnels
Authors: Ding M , Lin P 
Published: May 2024

Abstract
Karst caves pose safety issues for tunnels in karst areas. Karst caves at a certain distance from the tunnel must be treated fully to mitigate risks. A threshold of 3 m is typically adopted; caves within this threshold are fully treated, while those beyond are left untreated, regardless of the geological environment, cave features, tunnel design, operating conditions, etc. This poses risks to tunnel safety during construction and operation. This paper proposes a novel framework based on the aforementioned aspects to determine the treatment distance for caves from the perspective of uncertainty and risk. Geological conditions include the soil and rock type, weathering degree, underground water system, and pH. Karst caves primarily include the size, shape, distance, spatial distribution, density, and filling condition; the tunnel aspect refers to the tunnel diameter, construction method, design life, importance, lining, and tolerable criterion; and operation conditions refer to the vehicle speed, operation time, vehicle load, and maintenance. Herein, the parameters/indices for these aspects and methods to quantify their values are described. A decision-making process is illustrated to revive the mindset of risks in tunnel engineering. The proposed framework is effective for optimizing decision-making in karst cave treatment for tunnels in karst areas.
Research on construction and environmental impacts of a large-diameter pipe jacked along curve underwater
Authors: Zhen L , Wang J , Wang J , Hou S 
Published: May 2024

Abstract
The pipe jacking method is widely used in water supply and drainage, power tunnels, vehicle tunnel construction, and other fields. The main challenges include friction resistance, axis deviation, and environmental disturbance, especially when large-diameter pipes are jacked along the curve underwater. Based on a large-diameter pipe jacking project under Jinshan Lake, this paper records the settlement of surrounding structures, the jacking force, and the deviation in the axis and elevation during the jacking process. Furthermore, the factors affecting the monitoring data under different working conditions are studied, and the key points are concluded. The outcomes of the study will provide a reference and serve as a guidance for future related projects.
Multifidelity operator learning for predicting displacement fields of tunnel linings under external loads
Authors: Xu C , Liu Z , Cao B T , Meschke G , Liu X 
Published: May 2024

Abstract
In practical tunnel projects, the deformation of tunnel linings affects the service performance and structural reliability of tunnels. However, currently, several monitoring points must be installed to represent the specific deformation patterns of tunnel linings accurately, incurring high labor and financial costs. In recent years, the rapid development of artificial intelligence has provided potential solutions to this issue. To solve the aforementioned problem, this study proposed a multifidelity DeepONet framework, which comprised two neural networks. The first low-fidelity network was trained with data provided by a macro-level numerical model validated by experimental campaigns to learn the physical deformation patterns of tunnel linings. The second network was trained with limited high-fidelity monitoring data to learn the correlations between observations and numerical models. Even with very limited monitoring data, the proposed framework could still predict the mechanical behavior of tunnel linings under different loading scenarios. In this study, data collected from noncircular tunnel projects were used as case studies. The results demonstrated that the final output conformed to the deformation pattern obtained with the numerical simulations and was consistent with the actual measurements, achieving seamless fusion of the experimental campaigns and numerical models.
A tentative study on the effect of tunnel width on the maximum temperature under the ceiling in tunnel fires
Authors: Wang A M , Yan Z G 
Published: May 2024

Abstract
Maximum gas temperature under the ceiling in tunnel fires has been studied experimentally and numerically. Full scale burning test in tunnel with length 100 is carried out. Three different pool fires with approximate maximum heat release rate of 0.6, 1.0 and 5MW were set up. The smoke temperature is collected by the Fiber-optic Bragg grating system. CFD simulations were carried out to study the effect of tunnel width on the maximum temperature. By analyzing the experimental and numerical simulation results, a critical point of ratio B/H and two stages concerning the varying of B/H are proposed to clarify the influence of tunnel width, meanwhile we conclude that it is interdependent between the ratio of H/B and the ventilation velocity when discussing the maximum gas temperature in tunnel fires.