scholarly journals Modeling of Post-Failure Behavior of the Rock Mass and its Effect on the Stress-Deformation State in the Vicinity of a Mining Excavation

2019 ◽  
Vol 13 (2) ◽  
pp. 130-140
Author(s):  
Halina Marczak
Keyword(s):  
Rock Mass ◽  
Failure Behavior ◽  
Deformation State ◽  
Stress Deformation

scholarly journals LSSVM-Based Rock Failure Criterion and Its Application in Numerical Simulation

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Changxing Zhu ◽  
Hongbo Zhao ◽  
Zhongliang Ru
Keyword(s):  
Rock Mass ◽  
Failure Criterion ◽  
Nonlinear Problems ◽  
Failure Criteria ◽  
Rock Failure ◽  
Support Vector ◽  
Failure Behavior ◽  
Circular Tunnel ◽  
Vector Machines

A rock failure criterion is very important for the prediction of the failure of rocks or rock masses in rock mechanics and engineering. Least squares support vector machines (LSSVM) are a powerful tool for addressing complex nonlinear problems. This paper describes a LSSVM-based rock failure criterion for analyzing the deformation of a circular tunnel under differentin situstresses without assuming a function form. First, LSSVM was used to represent the nonlinear relationship between the mechanical properties of rock and the failure behavior of the rock in order to construct a rock failure criterion based on experimental data. Then, this was used in a hypothetical numerical analysis of a circular tunnel to analyze the mechanical behavior of the rock mass surrounding the tunnel. The Mohr-Coulomb and Hoek-Brown failure criteria were also used to analyze the same case, and the results were compared; these clearly indicate that LSSVM can be used to establish a rock failure criterion and to predict the failure of a rock mass during excavation of a circular tunnel.

Integrated geophysical and geotechnical monitoring for multiscale rock mass damaging investigation at the Acuto Field-Lab (Italy)

2021 ◽  
Author(s):  
Guglielmo Grechi ◽  
Danilo D'Angiò ◽  
Matteo Fiorucci ◽  
Roberto Iannucci ◽  
Luca Lenti ◽  
...  
Keyword(s):  
Rock Mass ◽  
Monitoring System ◽  
Thermal Stresses ◽  
Central Italy ◽  
Jointed Rock ◽  
Failure Behavior ◽  
Rock Masses ◽  
Geotechnical Monitoring ◽  
Strain Monitoring

<p>Rock mass damaging has become a topic of great interest in the engineering-geology research community during the last decades as it can significantly influence slopes stability. In this sense, the study of mechanics and dynamics of jointed rock masses represents a challenge because it will allow to better understand how external continuous and transient stressors can influence the short- to long-term stability controlling their pre-failure behavior. Consequently, the detection of permanent changes in physical and mechanical parameters, due to periodic or transient stressors, is an important target to mitigate the related geological risk as it can potentially lead rock masses to failure, especially when infrastructures and natural or cultural heritages are exposed elements. In this framework, the Acuto field laboratory (Central Italy) has been designed and implemented in 2016 within an abandoned quarry by employing an integrated geotechnical and geophysical monitoring system, with the aim of investigating how natural and anthropic conditioning factors could lead fractured rock masses to failure. The integrated monitoring system, which is installed on a potentially unstable 20-m<sup>3</sup> jointed rock block, is composed of several strain devices (i.e., strain gauges -SG- and jointmeters -JM-), one fully equipped weather station, one rock thermometer, eight high-sensitivity microseismic uniaxial accelerometers and optical and InfraRed Thermal cameras. The acquisition of long-term monitoring time-series, coupling multimethodological approaches, allowed to establish cause-to-effect relationships among different environmental stressors and induced strain effects, highlighting the continuous action of thermal stresses on rock mass deformations both at the daily and seasonal timescales. In fact, while the analysis of thermal and strain monitoring data allowed to characterize the cyclic contraction and relaxation response of major rock fractures and microcracks to temperature fluctuations, the microseismic monitoring array was able to detect during thermal transient (i.e., freezing conditions) the occurrence of microseismic emissions potentially related to the genesis or progressive growth of pre-existing cracks.</p><p>Starting from 2018, experimental activities at the Acuto field lab are supported by the “Dipartimento di Eccellenza” project of the Italian Ministry of Education Universities and Research funds attributed to the Department of Earth Sciences of the University of Rome “Sapienza”.  In this framework, the Acuto filed laboratory will undergo a structural upgrade that will be aimed at the investigation of two new sectors of the abandoned quarry. These new sectors will be instrumented with innovative thermal profiles probe, fiber Brag grating sensors and traditional SG and JM for detailed stress-strain monitoring, acoustic emission sensors and high-frequency and low-frequency geophones for ambient seismic noise monitoring and microseismic events detection as well as accelerometers for evaluating the rock mass response in the case of seismic shaking. The main goal of such an improvement will be both technical and methodological, and will shed light on the application of integrated geophysical and geotechnical monitoring approaches in investigating the multiscale rock mass damaging process as well as the detection of rock mass failure precursors by using non-conventional combinations and configurations of geotechnical and broad-band geophysical devices.</p>

scholarly journals Permeability Characteristic and Failure Behavior of Filled Cracked Rock in the Triaxial Seepage Experiment

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Xinyu Liu ◽  
Zhende Zhu ◽  
Aihua Liu
Keyword(s):  
Growth Rate ◽  
Rock Mass ◽  
Failure Modes ◽  
Peak Stress ◽  
Confining Pressure ◽  
Strength Characteristics ◽  
Failure Behavior ◽  
Compression Tests ◽  
Secondary Cracks ◽  
Safety And Stability

Filling is commonly found in natural cracked rock mass. As the weakest part of the rock, the filling properties directly affect the rock deformation and strength, permeability, and so on and affect the safety and stability of the rock mass engineering. In this study, a single slit has been preset in sandstones and filled with different physical properties materials. Based on the laboratory triaxial seepage test, the permeability and strength characteristics of filled cracked sandstones are analyzed, and the failure modes are obtained. The main findings of this study are as follows: (1) The permeability coefficient peak value of the filled cracked rock appears before the stress peak. (2) At the same confining pressure growth rate, the peak stress growth rate of the filled cracked rock is generally higher than that of the intact rock and the strength growth rate of the cracked rock increases with the length of the fracture. The strength characteristics of the filling in the uniaxial compression tests and triaxial seepage tests are significantly affected by the hydraulic properties. (3) The strength and permeability coefficients of cracked rock filled with cement mortar are more sensitive to the change of confining pressure, while under the same condition, the ones of cracked rock filled with gypsum mortar are stable. (4) According to the failure mechanism, under the seepage stress, the secondary cracks can be divided into 3 types and the failure modes can be divided into 2 types.

The stress-deformation state of the roof rocks during working of a steeply dipping or inclined seam

1973 ◽  
Vol 9 (1) ◽  
pp. 25-29 ◽  
Author(s):  
A. K. Kovrizhin ◽  
B. A. Apen'kin ◽  
V. M. Musalimov ◽  
P. N. Kurtukov
Keyword(s):  
Deformation State ◽  
Stress Deformation ◽  
Roof Rocks

Stress-Deformation State in the Rock Massif (Illustrated with the Example of Macedonia)

2015 ◽  
Vol 725-726 ◽  
pp. 214-219 ◽  
Author(s):  
Zlatko Zafirovski ◽  
Nikolay Vatin
Keyword(s):  
Geotechnical Properties ◽  
Rock Massif ◽  
Numerical Analyses ◽  
Water Tank ◽  
Surge Tank ◽  
Secondary Stress ◽  
Stability Analyses ◽  
Deformation State ◽  
Stress Deformation ◽  
The Stability

Main goal of this article is to introduce an used methodology of analyses for excavation of surge tank enlargement of HEC MATKA1. The way of combining of the methods for analyses of discontinual and continual media are explained. The main information’s about existing geological and geotechnical properties are also given, as a basis for analytical and numerical analyses. Some of the results from the stability analyses of structural controlled instabilities during excavation of water tank are presented. The newly secondary stress – deformation state as a result from enlargement (excavation) is analysed with program Z-SOIL.

The stress-deformation state of an elastic half-space with a spheroidal thermal inclusion

1992 ◽  
Vol 28 (7) ◽  
pp. 426-434
Author(s):  
V. S. Kolesov ◽  
N. M. Vlasov ◽  
L. O. Tisovskii ◽  
I. P. Shatskii
Keyword(s):  
Half Space ◽  
Elastic Half Space ◽  
Deformation State ◽  
Stress Deformation ◽  
Thermal Inclusion
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