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This study proposes a novel instantaneous total energy method to perform an activity analysis of ground fissures deformation, which is calculated by integrating the extreme-point symmetric mode decomposition (ESMD) method and kinetic energy based on the time-series displacement acquired by shape acceleration array (SAA) sensors. The proposed method is tested on the Xiwang Road fissure in Beijing, China. First, to fully monitor the hanging wall and footwall of the monitored ground fissure, a 4 m-long SAA in the vertical direction and an 8 m-long SAA in the horizontal direction were embedded in a ground fissure to obtain an accurate time-series displacement with an accuracy of ±1.5 mm/32 m and a displacement acquisition frequency of once an hour. Second, to improve the accuracy of the activity analysis, the ESMD method and Spearman's rho are applied to perform signal denoising of the original time-series displacement obtained by the SAA sensors. Finally, the instantaneous total energy is obtained to analyze the activity of the monitored ground fissure. The results demonstrate that the proposed method is more reliable to reflect the activity of a monitored ground fissure compared to the time-series displacement.
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http://dx.doi.org/10.3390/s19112607 | DOI Listing |
Materials (Basel)
August 2025
Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao 266590, China.
The increasing depth of coal mine construction has led to complex geological conditions involving high ground stress and elevated groundwater levels, presenting new challenges for water-sealing technologies in rock microfissure grouting. This study investigates ultrafine cement grouting in microfissures through systematic analysis of slurry properties and grouting simulations. Through systematic analysis of ultrafine cement grout performance across water-cement (W/C) ratios, this study establishes optimal injectable mix proportions.
View Article and Find Full Text PDFJ ISAKOS
August 2025
Division of Sports Shoulder & Elbow Surgery, Department of Orthopaedic Surgery, National University Hospital, 1E Kent Ridge Road, Singapore 119228, Singapore. Electronic address:
Introduction/objectives: Bouldering, a dynamic climbing discipline performed without ropes, is associated with high-energy ground falls. While most existing climbing injury literature has focused on the upper extremities, our data indicated an increasing number of complex knee injuries related to bouldering. This review was conducted to characterize the injury patterns sustained from bouldering ground falls, and to compare the relative burden of these injuries with those sustained in other high-participation sports.
View Article and Find Full Text PDFQuant Imaging Med Surg
August 2025
Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Background: Pulmonary ground-glass nodules (GGNs) are increasingly being detected as manifestations of early lung cancer. However, conventional computed tomography (CT) images may fail to clearly show small lesion details, particularly in the case of small, low-density GGNs, which are often difficult to observe. Limited evidence suggests that dual-layer spectral detector CT (SDCT) electron density imaging (EDI) improves the visualization of ground-glass opacities (GGOs) and increases the detection rate of mixed GGNs (mGGNs).
View Article and Find Full Text PDFSci Rep
July 2025
China Energy Shendong Coal Group Co., Ltd., Shenmu, 719315, Shaanxi, China.
During high-intensity mining of shallow coal seams, severe overburden movement and surface subsidence can lead to geological hazards like ground fissures. This study investigates these phenomena at a representative working face in the Shendong mining area. Numerical simulations were conducted to analyze overburden displacement, stress distribution, fracture evolution, breakage characteristics, and surface subsidence under varying mining advance distances.
View Article and Find Full Text PDFSci Rep
May 2025
School of Civil Engineering, Inner Mongolia University of Science and Technology, Baotou, 014010, China.
To make efficient use of land resources and minimize the seismic destruction of structures in the ground fissures zone, the shaking table tests and 3-dimensional numerical calculation of the soil were completed, based on the ground fissures site in Xi'an (Class II, with the shear wave velocity Vs ranging from 250 m/s to 500 m/s). Influence laws of ground motion characteristics and geological structure characteristics on seismic response spectra were revealed. Based on the statistics and analysis of seismic waves of the ground fissures site, standardized design response spectra and mathematical formula of the ground fissures site were determined.
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