A rock mass is a system of various scale blocks embodied into one another. Inter-block layers are usually composed of weaker and fissured rocks. On the action of dynamic-static loads, it can induce slip instability between blocks. In this paper, the slip instability laws of block rock masses are studied. Based on theory and calculation analysis finding that the friction force between rock blocks varies with block vibration and the friction between rock blocks can drop sharply, resulting in slip instability. The critical thrust and occurrence time of block rock masses slip instability are proposed. The factors affecting block slipping instability are analyzed. This study has significance to the rock burst mechanism induced by slip instability of rock masses.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10264412 | PMC |
http://dx.doi.org/10.1038/s41598-023-36771-4 | DOI Listing |
Polymers (Basel)
January 2025
Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland.
The deformation behavior and instabilities occurring during the drawing of high-density polyethylene (HDPE) were investigated using wide- and small-angle X-ray scattering (WAXS and SAXS) and scanning electron microscopy (SEM) in plain HDPE and paraffin wax- and/or chloroform-modified samples. In contrast to neat HDPE, the modified materials demonstrated strongly suppressed cavitation. However, regardless of cavitation, the tensile deformation of all samples was found to be governed by crystallographic mechanisms active in the crystalline lamellae, supported by shear in the amorphous layers, i.
View Article and Find Full Text PDFMedicina (Kaunas)
January 2025
Department of Orthopaedic Surgery, Chosun University Hospital, 365 Pilmundae-ro, Dong-gu, Gwangju 61453, Republic of Korea.
Managing periprosthetic femoral fractures is challenging, particularly in osteoporotic patients with fragile bones. Revision with a long stem is commonly considered but may fail to provide adequate fixation and stability in fragile bones. A novel approach using sandwiched strut allografts and controlled bone crushing with robust cable fixation can offer mechanical support and provide secondary stability to the loosened femoral stem and can be considered a treatment option for low-demand patients.
View Article and Find Full Text PDFOrthop Surg
January 2025
Department of Orthopedics, The First People's Hospital of Yangquan, Yangquan, China.
Objective: High-grade dysplastic spondylolisthesis (HGDS) is a relatively rare condition mainly involving the L5/S1 segment of the spine and occurring in children and adolescents. Whether surgical fixation should be L5-S1 monosegmental or extended up to L4 remains controversial. This study aimed to compare clinical outcomes and the risk of adjacent segment spondylolisthesis between L5-S1 monosegmental fixation and L4-S1 double-segmental fixation for pediatric HGDS.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Institut Langevin, École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, Université Paris Sciences & Lettres, CNRS, Paris 7587, France.
Understanding the dynamic response of granular shear zones under cyclic loading is fundamental to elucidating the mechanisms triggering earthquake-induced landslides, with implications for broader fields such as seismology and granular physics. Existing prediction methods struggle to accurately predict many experimental and in situ landslide observations due to inadequate consideration of the underlying physical mechanisms. The mechanisms that influence landslide dynamic triggering, a transition from static (or extremely slow creeping) to rapid runout, remain elusive.
View Article and Find Full Text PDFLangmuir
January 2025
Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819, China.
The stick-slip phenomenon as a prevalent friction instability poses significant challenges to industry, including frictional vibration, reduced precision, and noise generation. The interfacial interactions between asperities on the surface of materials are critical in influencing stick-slip behavior. This study focused on modifying the asperities on the surface of zinc-coated steel through temper rolling as a new approach to suppress friction-induced stick-slip vibration and noise.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!