Experimental Investigation on the Energy Properties and Failure Process of Thermal Shock Treated Sandstone Subjected to Coupled Dynamic and Static Loads

Thermal shock (TS) is known as the process where fractures are generated when rocks go through sudden temperature changes. In the field of deep rock engineering, the rock mass can be subjected to the TS process in various circumstances. To study the influence of TS on the mechanical behaviors of rock, sandstone specimens are heated at different high temperatures and three cooling methods (stove cooling, air cooling, and freezer cooling) are adopted to provide different cooling rates. The coupled dynamic and static loading tests are performed on the heated sandstone through a modified split Hopkinson pressure bar (SHPB) system. The influence of heating level and cooling rate on the dynamic compressive strength, energy dissipations, and fracturing characteristics is investigated based on the experimental data. The development of the microcracks of the sandstone specimens after the experiment is analyzed utilizing a scanning electron microscope (SEM). The extent of the development of the microcracks serves to explain the variation pattern of the mechanical responses and energy dissipations of the specimens obtained from the loading test. The findings of this study are valuable for practices in rock engineering involving high temperature and fast cooling.

New application of open source data and Rock Engineering System for debris flow susceptibility analysis

This research describes a quantitative, rapid, and low-cost methodology for debris flow susceptibility evaluation at the basin scale using open-access data and geodatabases. The proposed approach can aid decision makers in land management and territorial planning, by first screening for areas with a higher debris flow susceptibility. Five environmental predisposing factors, namely, bedrock lithology, fracture network, quaternary deposits, slope inclination, and hydrographic network, were selected as independent parameters and their mutual interactions were described and quantified using the Rock Engineering System (RES) methodology. For each parameter, specific indexes were proposed, aiming to provide a final synthetic and representative index of debris flow susceptibility at the basin scale. The methodology was tested in four basins located in the Upper Susa Valley (NW Italian Alps) where debris flow events are the predominant natural hazard. The proposed matrix can represent a useful standardized tool, universally applicable, since it is independent of type and characteristic of the basin.

Geotechnics: Welcome to A New Open Access Journal for A Growing Multidisciplinary Community

On behalf of the editorial board and MDPI Publishing, may we extend a very warm welcome to this first editorial of Geotechnics—a new and international, open access, scholarly journal aimed at showcasing and nurturing high-quality research and developmental activities in soil and rock engineering and geo-environmental engineering, worldwide [...]

Korelasi Point Load Index dan Uniaxial Compressive Strength pada Satuan Batupasir dan Batulempung Formasi Latih untuk Penentuan Koefisien Kekuatan Batuan di Pit X Tambang Batubara PT Berau Coal, Kalimantan Timur

Physical and mechanical properties of rock for engineering purposes are indispensable for any civil/construction, mining and other engineering requirment. The results of the uniaxial compressive strength (UCS) test are very much needed in various geotechnical analyzes or engineering, in particular in the mining industry in relation to the calculation of the pit slope design and other mining infrastructure. Rock samples used in this study were obtained from the results of geotechnical drilling (full core drilling). The rock engineering properties test to obtain UCS and PLI values was carried out in the laboratory. Testing the rock hardness index using the point load index (PLI) can be done more quickly, cheaply, practically and can use rock samples with a variety of sample shapes. The focus and object of the research are mudstone and sandstone units as part of the Lati Formation. These two types of layers are the most dominant rock types as a constituent of the pit slopes in the research area. To ensure that the correlation results are in accordance with the rules of scientific research, the distribution of UCS and PLI data from laboratory test results is verified using a statistical approach / testing. Correlation and analysis between the two rock engineering properties test results are very useful for geotechnical analysis data input. The coefficient or constant values obtained can be used to determine the rock strength values used in various geotechnical analyzes so that the analysis can be carried out more efficiently, effectively and quickly and can support geotechnical engineering work.