نتایج جستجو برای: soft rock
تعداد نتایج: 163433 فیلتر نتایج به سال:
Considering the structure effect of tunnel stability in western mining of China, three typical kinds of numerical model were respectively built as follows based on the strain softening constitutive model and linear elastic-perfectly plastic model for soft rock and interface: R-M, R-C(s)-M and R-C(w)-M. Calculation results revealed that the stress-strain relation and failure characteristics of t...
The indexes of argillaceous soft rocks in Western China, such as rock strength and softening coefficient, are much smaller than those commonly seen other areas. Such susceptible to a more serious creep phenomenon if encountering water. Accordingly, the study theoretically constructed constitutive model considering weakening coefficient damage surrounding rocks. Next, viability this was verified...
The secondary lining failure of deep buried soft rock tunnel often occurs, which is obviously related to the time factor. formation mechanism this phenomenon studied in paper. Therefore, combination situ stress measurement and neural network inversion used analyze distribution characteristics stress. At same time, creep surrounding are tested laboratory, key parameters obtained. Combined with r...
This study investigates the hypothesis that shallow edge lifting force in high-level rock climbers is more strongly related to fingertip soft tissue anatomy than to absolute strength or strength to body mass ratio. Fifteen experienced climbers performed repeated maximal single hand lifting exercises on rectangular sandstone edges of depth 2.8, 4.3, 5.8, 7.3, and 12.5 mm while standing on a forc...
Recent studies show that a broad category of materials share "nonclassical" nonlinear elastic behavior much different from "classical" (Landau-type) nonlinearity. Manifestations of "nonclassical" nonlinearity include stress-strain hysteresis and discrete memory in quasistatic experiments, and specific dependencies of the harmonic amplitudes with respect to the drive amplitude in dynamic wave ex...
We studied the elastic moduli, ductile creep behavior, and brittle strength of shale-gas reservoir rocks from Barnett, Haynesville, Eagle Ford, and Fort St. John shale in a series of triaxial laboratory experiments. We found a strong correlation between the shale compositions, in particular, the volume of clay plus kerogen and intact rock strength, frictional strength, and viscoplastic creep. V...
The accurate understanding of the influence confining pressure on mechanical characteristics soft rock and how to comprehensively consider this in elastoplastic analysis tunnels are fundamental premises for effective evaluation deformation control stability tunnels. Therefore, paper firstly investigates effect strength phyllite slate, using triaxial experiment results proposed variable models p...
Rocks and fossils do not come with labels informing us of their age. They must be understood in light of their geologic context, and interpreted within a worldview. Unfortunately, my evolutionary colleagues are often so dominated by uniformitarian brainwashing they can't objectively understand young-Earth evidence. Nevertheless, some of the evidence is clear and open for all to see. One such cl...
Gypsiferous Aridisols are of great importance and extent in arid and semi-arid environments. There is a close relationship between soil genesis and landscape positions. This study aimed to determine the genesis and classification of gypsiferous soils and to investigate the relationship between micro-and macro-morphology of gypsum crystals and geomorphic positions in Rafsanjan area. The study ar...
According to the geological characteristics of Xinjiang Ili mine in western area of China, a physical model of interstratified strata composed of soft rock and hard coal seam was established. Selecting the tunnel position, deformation modulus, and strength parameters of each layer as influencing factors, the sensitivity coefficient of roadway deformation to each parameter was firstly analyzed b...
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