Search Results (1,498)

Under the deformation potential model, the superconducting phenomenon in ABC-stacked multilayer graphene under a vertical electric field is investigated using linear combination operators and unitary transformation methods. Through the deformation potential model applied to a linear continuous medium, the effect of the external electric field is converted into the deformation potential energy of the crystal. Deformation potential phonons (LA phonons) act as propagators, generating electron–electron interactions. As the electric field increases, the ratio of the electric displacement vector to the dielectric function (D/ε) rises, leading to an increase in the electron ground-state energy, the opening of the band gap, and an enhancement of the attractive electron–electron interaction. With further increases in the external electric field, the deformation potential constant of the crystal (D_l) increases. When the phonon vibration frequency (ω) is around 8.5 THz, and the conditions are satisfied—where the wave vectors of different LA phonons are equal in magnitude and opposite in direction, and the electron spins are opposite—the attractive electron–electron interaction reaches its maximum (H_ceff), resulting in the emergence of superconductivity. Our study also provides a new perspective for understanding the unique quantum properties—such as strong correlations, superconductivity, and ferromagnetism—in different stacking configurations like AB, ABC, and ABCA. Full article

The deep foundation pit excavation of subway will cause horizontal displacement, uneven settlement and other adverse effects on the adjacent shield. The use of servo steel strut has a certain effect on deflection correction, but the current understanding of the influencing factors of deflection correction is not comprehensive. Based on structural and spatial symmetry, the influence of tunnel depth, tunnel and foundation pit clear distance and deformation control quantity of enclosure structure on deflection correction quantity was studied by symmetrically designed model test and numerical simulation, and the prediction formula of deflection correction quantity considering tunnel and foundation pit clear distance and deformation control quantity of enclosure structure was proposed. The results show that with an increase in the tunnel’s burial depth, deflection correction decreases significantly. When the tunnel is near the foundation pit bottom, there is no significant correction effect, and the control law of the tunnel ground pressure under the servo steel strut loading is consistent with the correction law. Deflection correction is negatively correlated with the tunnel and foundation pit clear distance, and positively correlated with the deformation control of the diaphragm wall. The curve of the deformation control of the enclosure structure and the deflection correction is parabolic. The deflection correction is an exponential function of the ratio of the deformation control of the enclosure structure to the clear distance between the tunnel and the foundation pit, and the servo deflection correction follows a normal distribution along the longitudinal axis of the tunnel, showing obvious symmetry characteristics in the foundation pit influence zone. Full article

Monitoring surface subsidence in mining areas is essential for geological disaster early warning and safe production. Existing geometric difference methods heavily rely on the local consistency of multi-temporal point clouds. When horizontal displacement and vertical subsidence are coupled, horizontal movements often cause local misalignments, leading to spatial deviations and discrete anomalies in vertical estimations. To address this issue, this paper proposes DL-C2C, a deep learning model for subsidence extraction from bi-temporal ground point clouds. Within a unified framework, the model introduces horizontal displacement as an auxiliary constraint into the vertical solving process, effectively improving the stability of vertical subsidence estimation through continuous cross-temporal alignment and correlation updating. For feature extraction, DL-C2C employs a PointConv multi-scale pyramid combined with a proposed scale-adaptive Transformer to enhance cross-scale information interaction under sparse and non-uniform sampling conditions. Furthermore, the network constructs dynamic local associations through iterative alignment within a recursive framework, and introduces diffusion-based residual correction at the fine-scale stage to compensate for detail errors at subsidence basin boundaries and in data-missing regions. Experiments on simulated and real-world datasets—covering aeolian sand and mountainous gully landforms—demonstrate that the method achieves mining 3D error (M3DE) of 0.16 cm and 0.22 cm in simulated scenarios. In real-world mining area validations, compared to existing methods, DL-C2C significantly reduces discrete anomalous points, yields an error distribution closer to zero, and exhibits superior performance in boundary transition continuity and non-subsidence area stability. In conclusion, this model provides reliable technical support for large-scale, high-precision intelligent monitoring of geological disasters in mining areas. Full article

Motion blur degrades single-frame imaging when relative motion occurs during sensor exposure; yet, quantitative validation is difficult because ground-truth motion parameters are rarely available in real images. This paper presents an interpretable, measure-first framework for detecting, localizing, and quantifying motion blur in single-frame grayscale images under a validated operating condition of one-dimensional horizontal uniform motion. The method analyzes each image row as a one-dimensional spatial signal, where Movement Artifact denotes the scanline-level imprint of motion blur retained in the legacy algorithm names MAPE and MAQ. The pipeline combines three stages: Movement Artifact Position Estimation (MAPE) using scanline self-similarity, Reference Origin Point Estimation (ROPE) using robust structural trends, and Movement Artifact Quantification (MAQ), which summarizes blur magnitude as an average horizontal spatial displacement after adaptive filtering. The pipeline is evaluated on a controlled empirical dataset of 110 images of a high-contrast marker acquired at known tangential velocities from 0.0 to 1.0 m/s in 0.1 m/s increments (10 images per level). MAPE achieves 70–90% detection rates across velocities, and ROPE localizes reference origins with 97–99% detection. An empirical polynomial mapping from MAQ to velocity attains R² = 0.9900 with RMSE 0.0229 m/s and MAE 0.0221 m/s over 0.0–0.7 m/s, enabling calibrated velocity estimates from blur measurements within the validated regime. An extended additive-noise robustness analysis further shows that severe perturbation can preserve candidate self-similarity responses while progressively destabilizing reference-origin localization and MAQ pairing, thereby clarifying the empirical boundary of the current controlled single-marker regime. The approach is not claimed to generalize to uncontrolled scenes, non-uniform blur, or multi-dimensional and non-rigid motion. Full article

During the installation of prefabricated vertical drains (PVDs) in soft soil foundations, the smear effect induced by mandrel shoe penetration can severely damage the soil structure and reduce permeability, thereby becoming a key factor restricting foundation consolidation efficiency. Previous studies have generally neglected the smear disturbance caused by the geometry of the mandrel shoe. Although existing studies have conducted numerical and theoretical analyses on the smear effect induced by PVD installation, most of them are still based on equivalent circular simplifications and are therefore unable to characterize the anisotropic disturbance induced by a triangular mandrel shoe. To address this limitation, a three-dimensional CEL penetration model considering the real triangular geometry was established, and the traditional cavity expansion theory was directionally modified. The effects of penetration rate, geometric angular structure, and soil type of the triangular mandrel shoe on the smear zone were systematically investigated. The results show that, with increasing penetration rate, the near-field peak stress and far-field displacement increase simultaneously; from slow penetration to fast penetration, the near-field peak stress increases by approximately 42%. By quantitatively defining the critical threshold corresponding to a sharp 50% attenuation in radial displacement as the boundary of the strong smear zone, it was found that increasing the size of the mandrel shoe significantly amplifies the geometric corner effect, and the near-field disturbance range increases by about 21% compared with that of the small-sized case. The larger the size, the more pronounced the anisotropic disturbance characteristics become: the stress concentration effect and displacement splitting in the vertex direction are further enhanced, causing the disturbance range in that direction to far exceed that in the side direction. Soil properties are the key medium parameters controlling the smear zone. Owing to its relatively high stiffness index and skeleton strength, Clayey Silt shows the largest displacement range, whereas Common Clay exhibits the smallest smear zone because of its stronger structural constraint. The modified theoretical model agrees well with the CEL numerical simulation results, verifying its effectiveness under conditions that consider the geometric characteristics of the mandrel shoe. This study provides a theoretical basis and numerical support for the structural design of mandrel shoes in soft-ground PVD construction. Full article

Microbially induced desaturation and precipitation (MIDP) is a promising eco-friendly technique for liquefaction mitigation. However, existing studies have primarily focused on silica sands under element-scale cyclic loading, and the dynamic response of MIDP-treated marine sand under seismic excitation remains poorly understood. In this study, the denitrifying bacterium Pseudomonas stutzeri was used to generate nitrogen gas in situ within typical liquefiable marine sand from the Haikou Jiangdong New Area, producing treated specimens with degrees of saturation ranging from approximately 99% to 80%. Shaking table tests were performed under Wenchuan earthquake motions with peak ground accelerations of 0.10–0.20 g. The results show that reducing the degree of saturation by approximately 18.9% decreases surface settlement by 77.6%, while the peak pore water pressure and lateral displacement are reduced by 21% and 15%, respectively. The acceleration response of the treated specimens also exhibits a notable attenuation effect. These findings provide preliminary comparative experimental evidence for the application of MIDP in the eco-friendly liquefaction mitigation of coastal marine sand foundations. Full article

This study aims to determine the current seismic resistance of two masonry minarets that were severely damaged during the 6 February 2023 Kahramanmaraş earthquakes, while also evaluating whether a model-updating approach based on experimental dynamic characteristics can reliably capture the actual seismic behavior and collapse mechanism of such structures under real earthquake conditions. The dynamic characteristics of the minarets were identified using Operational Modal Analysis (OMA) based on previous in-situ vibration measurements. These characteristics were used to calibrate finite element models through a model-updating process employing Multi-Criteria Decision-Making (MCDM) methods. The initial modal analyses revealed discrepancies of up to 13.7% in natural frequencies and 9.7% in mode shapes. After applying MCDM methods to a wide set of model variants, these differences were reduced to 2.0% and 9.2%, respectively, improving the agreement between numerical and experimental results. Once the most representative models were obtained, nonlinear seismic analyses were performed using actual ground motion records from the earthquake. The results included evaluations of peak displacements, base shear forces, and principal stresses. The concentration of principal stresses near the transition zone showed good qualitative agreement with the observed collapse locations, indicating a reasonable consistency between numerical results and observed damage patterns. These findings demonstrate the value of integrating OMA-based model updating with MCDM methods and support a data-driven framework for assessing the seismic performance of historical masonry structures. Full article

To address the challenge of surrounding rock instability in deep-buried tunnels crossing fractured fault zones, this study focuses on the Xigu Tunnel of the Lanzhou–Hezuo Railway. A combination of laboratory triaxial tests, an optimized multi-source advanced geological prediction workflow, and a site-specific parameter-weakened Mohr–Coulomb numerical simulation is employed to systematically reveal the physical–mechanical properties, spatial distribution, and deformation response of fractured rock masses under excavation-induced disturbance. The triaxial test results show that the average peak strength of the surrounding rock reaches 149.04 MPa; however, significant variability is observed among samples, and the failure mode exhibits a typical brittle–shear composite feature. The measured cohesion and internal friction angle are 20.57 MPa and 49.91°, respectively, indicating high intrinsic strength of individual rock blocks. Nevertheless, due to the presence of densely developed joints and crushed structures, the overall mass is loose and highly sensitive to dynamic disturbances such as blasting and excavation, revealing a unique mechanical paradox of high-strength rock blocks with low overall rock mass stability in deep-buried fractured zones. Joint TSP (Tunnel Seismic Prediction Ahead) and ground-penetrating radar (GPR) prediction reveals decreased P-wave velocity, increased Poisson’s ratio, and intensive seismic reflection interfaces; a quantitative index system for identifying the boundaries of narrow deep-buried fractured zones is proposed based on these geophysical characteristics. Combined with geological face mapping, these results confirm the existence of a highly fractured zone approximately 130 m in width, characterized by well-developed joints, heterogeneous mechanical properties, and localized risks of blockfall and groundwater ingress. The developed numerical model, with parameters weakened based on triaxial test and geological prediction data, effectively reproduces the deformation law of the fractured zone, and the simulation results agree well with field monitoring data, with peak displacement concentrated at section DK4 + 595, thus accurately identifying the center of the fractured belt as a key engineering validation result of the integrated technical framework. During construction, based on the identified spatial characteristics of the fractured zone and the proposed targeted support insight, enhanced dynamic monitoring and targeted support measures at the fractured zone center are required to ensure structural safety and long-term stability of the tunnel. This study develops an integrated engineering-oriented technical framework for deep-buried tunnels crossing narrow fractured zones, and provides novel mechanical insights and quantitative identification indices for such complex geological engineering scenarios. Full article

The Tuzla Submarine Landslide represents one of the most significant mass-wasting features associated with the active North Anatolian Fault Zone (NAFZ). The failure surface geometry and sediment stratigraphy indicate the presence of a mechanically weak, saturated layer that may become unstable under strong seismic loading. This study presents a comprehensive geotechnical evaluation of the Tuzla Submarine Landslide. Based on regional sediment properties, the landslide was characterized and modeled with an estimated volume of 0.015 km³ and an average slope angle of 14°. The submarine landslide potential was investigated through re-analysis of seismic, geotechnical, and bathymetric datasets. Finite Element Method (FEM) simulations were conducted to model the seismic slope failure. Based on these analyses, the seismic slope displacements, stress distributions, and equivalent plastic strains were identified. The estimated landslide displacements under varying seismic acceleration scenarios corresponding to three major earthquakes ranged between 2.38 m and 4.12 m, depending on the triggering ground motion and slope stability conditions. These findings highlight that reactivation of the Tuzla submarine landslide, potentially triggered by a future large earthquake along the NAFZ, could pose a moderate landslide hazard to the coastal settlements bordering the Marmara Sea. Full article

Structural evaluation of railway tracks in operation requires the integration of field measurements and numerical models capable of adequately representing the mechanical behavior of permanent railway pavement components. In this context, this study presents the structural analysis of a railway segment based on the combination of field instrumentation, laboratory testing, and numerical simulations grounded in the Finite Element Method, adopting linear elastic and resilient material behavior for all track components, using SysTrain software (v.1.88).The objective of this work is to assess the application of a back-analysis methodology based on field instrumentation and numerical modeling, as well as to verify the structural conditions of an in-service railway pavement. The back-analysis was conducted using the SysTrain software, with a focus on calibrating the ballast resilient modulus (RM) and analyzing its effects on the propagation of stresses, internal forces, and displacements throughout the track structure. To this end, field-measured deflections obtained from LVDT sensors installed at the sleeper ends were used, together with the geotechnical, resilient, and permanent deformation (PD) characterization of the underlying soil layers obtained in the laboratory. The results indicated that the calibration of the numerical model requires a ballast resilient modulus in the order of 1500 MPa, suggesting a condition of high layer stiffness. The simulations showed vertical stress levels below 100 kPa in the lower layers, while laboratory tests revealed the high susceptibility of the soils to PD, particularly under moisture variations. It is concluded that the applied methodology enables a consistent assessment of the structural conditions of the track and contributes to a more robust understanding of the ballast response under repeated loading, providing support for railway design, maintenance, and management criteria. Full article

This paper presents a nonlinear time-history reassessment of an existing reinforced concrete frame building originally designed in 2007 according to the Romanian seismic code P100-1/2006 and re-evaluated under current seismic demand. Two three-dimensional solid finite-element models were developed in ANSYS Workbench 2025 R2: a bare reinforced concrete frame and an infilled frame with masonry panels. A distinctive feature of the modelling strategy is the explicit representation of longitudinal and transverse reinforcement embedded in the concrete solids, which allows direct tracking of steel stress demand and post-cracking load transfer. The models were subjected to bidirectional ground motions from the Vrancea 1977 and 1990 earthquakes and the Türkiye 2023 earthquake, scaled to the P100-1/2013 target spectrum for the investigated site. The results show that masonry infills markedly increase global stiffness and reduce displacement-related demand, with substantially lower roof displacements and interstorey drift measures in the infilled configuration. The bidirectional response remains predominantly translational, while the local stress and inelasticity fields indicate qualitative concentration zones in the frame, masonry panels, and staircase region. Overall, the study shows that masonry infills can strongly modify the actual seismic response of existing reinforced concrete frame buildings and should be considered explicitly in performance assessment. Full article

Potash is a strategically critical mineral resource essential for ensuring national food security, thereby necessitating the exploration of new deposits to sustain long-term supply. This study systematically evaluates the risk of ground subsidence associated with a “brine extraction–replenishment equilibrium” mining scheme through an integrated framework combining three-dimensional geological modeling and numerical simulation. The research focuses on deep potassium-rich brine resources in the Sanshui Basin, Guangdong Province, China. Geological data from 95 boreholes were processed to construct a high-resolution three-dimensional geological model (61.40 km × 35.20 km × 3.50 km) using Petrel software. Numerical simulations based on poroelastic theory were conducted under multiple extraction scenarios, and the predicted subsidence was assessed against relevant engineering standards for highways and building foundations. The results indicate that: (1) brine extraction from consolidated sandstone represents a fluid displacement process, where the equilibrium scheme induces only minor effective stress redistribution without forming dissolution cavities; (2) global subsidence investigations suggests consolidation primarily affects Quaternary unconsolidated strata, making consolidated sandstone extraction associated with extremely low risk; (3) the maximum subsidence is 5.55 mm and 6.82 mm in the primary and secondary exploration areas, with corresponding surface inclinations of 0.00047‰ and 0.00040‰; (4) unlike solution mining that creates large cavities, deep brine extraction generates no significant inter-stratal pressure differentials. These findings demonstrate that under the extraction–replenishment equilibrium scheme, ground subsidence remains well below the regulatory limits, posing no risk to surface infrastructure. This research provides a scientific foundation for safe development of similar deep brine resources globally. Full article

The construction of suspension bridges in mountainous expressways often involves tunnel-type anchorages in close proximity to shallow-buried bifurcated tunnels, particularly in soft rock strata with dense overlying structures. This proximity poses significant challenges to construction safety and stability. This study aims to investigate the influence of tunnel-type anchorage construction on the ground surface, surrounding rock, and adjacent bifurcated tunnels under such complex conditions. It was hypothesized that the anchorage load transfer and deformation mechanisms would significantly affect the adjacent tunnel, with potential cumulative effects due to the twin-anchor configuration. To address this, a combined approach of in situ scaled model testing (1:10 scale) and three-dimensional numerical simulation was employed. The model test incorporated monitoring of deformation and stress at key locations (anchor plug, rock mass, and anchor–rock interface) under incremental cable loads. Quantitative results from the model test indicate that at the design load (1P, equivalent to 2016.84 kN per anchor), deformations were minimal (e.g., maximum anchor displacement 0.35 mm). The anchor–rock interface exhibited limited slip (max 0.06 mm at 1P), and contact stresses were highest in the rear part of the anchor plug, indicating a non-uniform load transfer. Under overload conditions, the system reached yield at 7P and peak strength at 10.5P, with measured ground surface cracks up to 5 mm. Numerical simulations, calibrated against the experimental data, revealed that under increasing load (up to 10P), the plastic zones around the two anchors progressively expanded and eventually coalesced, leading to a characteristic “inverted trapezoid” failure pattern propagating to the surface, accompanied by shear failure along the 14° bedding plane. The combined results quantify the progressive interaction between the twin anchorages and the surrounding rock, highlighting the critical role of the anchor–rock interface and the cumulative effect of twin anchors on ground deformation and potential failure mechanisms. This research provides a scientific basis for the design and construction of tunnel-type anchorages in similar challenging geological and spatial settings. Full article

This article examines how algorithmic mediation reshapes social trust and solidarity in the post-secular age. Historically grounded in shared moral horizons shaped by religion, tradition, and communal practices, trust has increasingly been displaced by technocratic governance, market rationality, and algorithmic systems that mediate work, cognition, communication, and political life. Through a critical analysis of contemporary developments—including algorithmic labour management, neurotechnology, large language models, digital public spheres, technological sovereignty, and global AI governance—the article argues that algorithmic mediation intensifies the fragility of trust by instrumentalizing human agency, fragmenting public reason, and concentrating power within opaque technological infrastructures. Against technological determinism and purely procedural approaches to ethics, the article advances a normative framework rooted in solidarity and the common good. Drawing on post-secular perspectives, a retrieval of natural law normativity, and the resources of Catholic Social Teaching, it contends that trust cannot be sustained through efficiency, prediction, or regulation alone. Instead, social trust depends upon relational goods—dignity, responsibility, participation, and truth—that resist reduction to data-driven optimization. Reclaiming solidarity therefore requires re-embedding AI within moral horizons capable of guiding technological development toward integral human flourishing. In this sense, the governance of AI emerges not merely as a technical challenge but as a decisive moral and political task for post-secular societies. Full article

To address the progressive collapse of mountainous stilted RC frames induced by debris flows, this study establishes a three-dimensional refined solid model using ABAQUS. The alternate path method (element removal method) is employed to simulate the failure of ground-floor columns under impact, revealing the underlying damage evolution mechanism. The results indicate that the loss of an edge column compromises structural stability significantly more than that of a corner column. Sequential multi-column failure leads to a nonlinear accumulation of damage; specifically, the simultaneous failure of a ‘corner column and its adjacent edge column’ completely severs the outer load-transfer paths, triggering a drastic inward load redistribution. Furthermore, under extreme scenarios, the maximum structural displacement and nodal stress surge to 66.67 mm and 40 MPa, respectively, while the axial force of the core central column jumps by nearly 150% (reaching 2.67 × 10⁶ N). The crushing of internal central columns due to overloading is identified as the critical mechanism triggering global collapse. Based on these findings, design recommendations are proposed, emphasizing the reinforcement of upstream edge columns and the construction of a ‘component-joint-global’ hierarchical defense system. Full article