98%
921
2 minutes
20
In this research, the combination of theoretical approach and numerical simulation was employed to comprehensively understand the initiation mechanism of time-delayed rockburst and analyze the time-delayed failure laws for surrounding rock after excavation unloading without prompt support. The investigations are principally at the angle of time and space, which refers to the creep property and damaged scope for surrounding rock. For the theoretical method, the analytical elastic and elastoplastic models for deep tunnel cross section and the creep model for brittle rock material from a microscopic view were combined. It was found that the time-delayed failure for surrounding rock resulted from the damage accumulation with crack development during the creep process. The surrounding rock with the elastic state was more stable than that in the plastic zone and the creep duration increased with growing distance from the center of tunnel section. Based on the theoretical creep model, the numerical simulation ulteriorly analyzed the brittle creep duration on the key positions. The surrounding rock tended to fail more in the strong excavation damage zone (SEDZ) than that in the weakly damaged zone (WEDZ), and brittle creep failure mainly occurred on the excavation border (EB) in a short space of time. In addition, the increase in the radius for tunnel cross section and the higher in situ stress distribution around the opening led to the acceleration of the creep process for surrounding rock, and the irregular cross-section shape of the tunnel caused the local damaged range extension and decreased the duration for time-delayed failure.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9102247 | PMC |
http://dx.doi.org/10.3390/ma15093035 | DOI Listing |
J Behav Health Serv Res
September 2025
Department of Health Policy and Management, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR, USA.
Telehealth is increasingly a standard and routine clinical option, indicating a changing outlook for SUD treatment from in-person to the more convenient option of telehealth. As populations across geographies increasingly prefer telehealth, more research is warranted that focuses on how where a person lives is associated with telehealth availability. The authors used the Mental Health and Addiction Treatment Tracking Repository (MATTR 2024) to identify telehealth availability among all known licensed SUD treatment facilities in the USA (N = 10,492 facilities).
View Article and Find Full Text PDFSci Total Environ
September 2025
Human Foods Program, U.S. Food and Drug Administration, College Park, MD, USA.
Cattle are a reservoir for the zoonotic human foodborne pathogen Shiga toxin-producing Escherichia coli (STEC), the causative agent of many disease outbreaks associated with contaminated fresh leafy greens. Concentrated animal feeding operations (CAFOs) housing cattle generate fugitive dust, however the potential risk of STEC movement by means of the aerosolized dust is not well known. In this investigation, we used metagenome sequencing of air samples collected in an agricultural setting to investigate airborne transfer of STEC from a large CAFO to the surrounding area.
View Article and Find Full Text PDFOncogene
September 2025
Division of Neurosurgery, Children's Hospital Los Angeles, Los Angeles, CA, USA.
It has become evident from decades of clinical trials that multimodal therapeutic approaches with focus on cell intrinsic and microenvironmental cues are needed to improve understanding and treat the rare, inoperable, and ultimately fatal diffuse intrinsic pontine glioma (DIPG), now categorized as a diffuse midline glioma. In this study we report the development and characterization of an in vitro system utilizing 3D Tumor Tissue Analogs (TTA), designed to replicate the intricate DIPG microenvironment. The innate ability of fluorescently labeled human brain endothelial cells, microglia, and patient-derived DIPG cell lines to self-assemble has been exploited to generate multicellular 3D TTAs that mimic tissue-like microstructures, enabling an in- depth exploration of the spatio-temporal dynamics between neoplastic and stromal cells.
View Article and Find Full Text PDFEcotoxicol Environ Saf
September 2025
CanmetMINING, Natural Resources Canada, Ottawa, ON, Canada. Electronic address:
Acid mine drainage (AMD) is a serious environmental problem at legacy and active mine sites around the world. Climate associated drought and rewetting events can increase the severity of AMD impacts through oxidation and release of stored metal(loid)s and acidity from contaminated sediments. The area surrounding Sudbury, Ontario, with its massive mining and smelting complexes, appears especially vulnerable to drought-driven effects.
View Article and Find Full Text PDFSci Rep
September 2025
Yunnan Provincial Transportation Planning and Design Research Institute Co., Ltd, Kunming, 650041, China.
Due to the high construction efficiency and low cost, double-arch tunnels without middle drift has been gradually promoted in engineering in recent years. However, the excavation characteristics of the left and right tunnels are easy to cause structural disturbance and deformation out of control. In particular, the surrounding rock disturbance of the front tunnel caused by the construction of the secondary tunnel often leads to lining cracking and structural instability.
View Article and Find Full Text PDF