This article presents a micro-structure tensor enhanced elasto-plastic finite element (FE) method to address strength anisotropy in three-dimensional (3D) soil slope stability analysis. The gravity increase method (GIM) is employed to analyze the stability of 3D anisotropic soil slopes. The accuracy of the proposed method is first verified against the data in the literature. We then simulate the 3D soil slope with a straight slope surface and the convex and concave slope surfaces with a 90 degrees turning corner to study the 3D effect on slope stability and the failure mechanism under anisotropy conditions. Based on our numerical results, the end effect significantly impacts the failure mechanism and safety factor. Anisotropy degree notably affects the safety factor, with higher degrees leading to deeper landslides. For concave slopes, they can be approximated by straight slopes with suitable boundary conditions to assess their stability. Furthermore, a case study of the Saint-Alban test embankment A in Quebec, Canada, is provided to demonstrate the applicability of the proposed FE model. (c) 2025 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).

The study analyses the oil well blowout that took place at the Baghjan oil field in Assam, India, on 27 May 2020. This incident escalated into a massive fire on 9th June that lasted more than 5 months. The tragedy degraded the environment and inflicted substantial problems on the area's inhabitants. The present study employs the analytical case study approach and various data sources to unfold the disaster and its causes, impact, and response. It also examines the local inhabitants and environmental impact and tries to analyze the event comprehensively. The incident resulted from technical malfunctions and human errors, leading to the relocation of the adjacent settlement to refugee camps amidst the global COVID-19 epidemic. However, it is essential to mention that many households received adequate compensation for their damages. The incident has resulted in the contamination of the air, noise, soil, and water, causing significant damage to the fragile ecosystem and its rare species. The research employs the Normalized Difference Vegetation Index to quantify changes in vegetation cover resulting from the blowout, thus showing the extensive damage to the affected region. The incident shed light on legal and regulatory deficiencies alongside a lack of accountability and transparency within the Oil India Limited sector. Despite the numerous proposals for environmental restoration, it appears challenging to revert to the previous state swiftly. The present study reflects the collective and collaborative action to protect and preserve the environment.

Rockfill columns, also known as stone columns, were installed in a riverbank for slope stabilization measures. The goal of this fieldwork was to prevent slope instability of the riverbank while protecting an in-service aqueduct buried in the riverbank. At this site, rockfill columns were installed with the aid of steel casings (sleeves), which were later removed with a vibrodriver. Peak particle velocities were determined at select locations to monitor the ground vibrations during installation of rockfill columns and during extraction of the steel casings. Instrumentation and monitoring were implemented because there was uncertainty about the potential for structural damage to the nearby aqueduct due to ground vibrations during the stabilization works. In this case study, numerical modeling, calibrated versus field measurements in the ground and on the aqueduct, was used to simulate the ground vibrations due to the installation of three rockfill columns close to the aqueduct. Once calibrated, the numerical models were used to evaluate the effects of vibrations in terms of particle velocities in the ground, displacements of the aqueduct, and frequency spectra on the aqueduct walls. The numerical results showed that the highest particle velocities on the aqueduct were from the rockfill columns that had the steel casings located in the same soil layer as the aqueduct. Based solely on the response in terms of particle velocity, damage to the aqueduct is unlikely. However, the numerical results also showed that the aqueduct moves slightly, both vertically and laterally due to the vibration generated while removing the steel casings; and the frequency range of the waves in the ground are within the natural frequency of the soil, which could impose additional movement to the aqueduct if allowed to move freely with the soil. Numerical results and field data also show that even pulling the steel casings without vibration generated propagation of waves in the ground.

This research develops an elastoplastic damage constitutive model incorporating the strain softening response of common engineering soil materials in southeastern Xizang to evaluate and optimize reinforcement solutions for highway-traversing landslide accumulations. Grounded in deterioration mechanics theory, the model characterizes the progressive strength loss and failure evolution of the soils. Verified and calibrated, it is numerically implemented in FLAC3D to simulate the stability conditions of a landslide affecting planned highway infrastructure in southeastern Xizang. Safety factors of 1.25, 1.07, and 1.02 under normal operation, rainfall, and seismic excitation loads, respectively, reveal the inadequacy of intrinsic stability. Consequently, dynamic compaction and chemical grouting techniques are assessed via simulation. An optimal strategy, entailing 6-m-deep densification at the highway location with 10% silica fume enhancement of 66.3% of the landslide area and 50.8% of the soil-bedrock interface, results in safety factors of 1.70, 1.49, and 1.23 for the three scenarios. The improved area is minimized to streamline construction practicality and economics while preserving geotechnical integrity. The integrated modeling outcomes demonstrate the model's capability in capturing localized incremental damage and the efficacy of numerical simulation for stability diagnosis and targeted remediation of intricate landslides. Advancements in constitutive relations development are vital for further innovation in geohazard evaluation and infrastructure safety assurance.