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Journal articles on the topic 'Rock deformation'
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1
Fan, Jinyan, Zhibiao Guo, Xiaobing Qiao, Zhigang Tao, Fengnian Wang, and Chunshun Zhang. "Constant Resistance and Yielding Support Technology for Large Deformations of Surrounding Rocks in the Minxian Tunnel." Advances in Civil Engineering 2020 (September 28, 2020): 1–13. http://dx.doi.org/10.1155/2020/8850686.
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During the excavation of the Minxian tunnel, problems of large deformations of surrounding rocks and failure of support structures appeared frequently, which caused serious influences on construction safety and costs of the tunnel. Based on laboratory analysis of mineral composition and field investigations on deformation characteristics of the surrounding rocks, the large deformation mechanism of surrounding rocks of the tunnel was considered as water-absorbing swelling molecules of carbonaceous slate and stress-induced asymmetric structural deformations of the surrounding rocks. The structural deformations of surrounding rocks mainly include bending deformation, interlayer sliding, and crushing failure of local rock blocks. Then, a new constant resistance and yielding support technology based on the constant resistance and large deformation (CRLD) anchor cable was proposed to control large deformations of surrounding rocks. The field tests and deformation monitoring were carried out. The monitoring results showed that compared with original support measure, the surrounding rock deformations, stresses of primary supports, and permanent lining using new support technology decreased greatly. Among them, the maximum deformation of surrounding rock was only 73 mm. The effects of field application and results of deformation monitoring showed that the new support technology can effectively control large deformations of the surrounding rocks in the Minxian tunnel.
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Chaturvedi, Lakshmi S., Harold M. Marsh, and Marc D. Basson. "Role of RhoA and its effectors ROCK and mDia1 in the modulation of deformation-induced FAK, ERK, p38, and MLC motogenic signals in human Caco-2 intestinal epithelial cells." American Journal of Physiology-Cell Physiology 301, no. 5 (November 2011): C1224—C1238. http://dx.doi.org/10.1152/ajpcell.00518.2010.
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Repetitive deformation enhances intestinal epithelial migration across tissue fibronectin. We evaluated the contribution of RhoA and its effectors Rho-associated kinase (ROK/ROCK) and mammalian diaphanous formins (mDia1) to deformation-induced intestinal epithelial motility across fibronectin and the responsible focal adhesion kinase (FAK), extracellular signal-regulated kinase (ERK), p38, and myosin light chain (MLC) signaling. We reduced RhoA, ROCK1, ROCK2, and mDia1 by smart-pool double-stranded short-interfering RNAs (siRNA) and pharmacologically inhibited RhoA, ROCK, and FAK in human Caco-2 intestinal epithelial monolayers on fibronectin-coated membranes subjected to 10% repetitive deformation at 10 cycles/min. Migration was measured by wound closure. Stimulation of migration by deformation was prevented by exoenzyme C3, Y27632, or selective RhoA, ROCK1, and ROCK2 or mDia1 siRNAs. RhoA, ROCK inhibition, or RhoA, ROCK1, ROCK2, mDia1, and FAK reduction by siRNA blocked deformation-induced nuclear ERK phosphorylation without preventing ERK phosphorylation in the cytoplasmic protein fraction. Furthermore, RhoA, ROCK inhibition or RhoA, ROCK1, ROCK2, and mDia1 reduction by siRNA also blocked strain-induced FAK-Tyr925, p38, and MLC phosphorylation. These results suggest that RhoA, ROCK, mDia1, FAK, ERK, p38, and MLC all mediate the stimulation of intestinal epithelial migration by repetitive deformation. This pathway may be an important target for interventions to promote mechanotransduced mucosal healing during inflammation.
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Usanov, S. V., Yu P. Konovalova, E. Yu Efremov, О. D. Kharisova, and А. V. Usanova. "Unexpected deformation processes in the rock mass in surface mining: Emergence factors and prevention capabilities." Mining Industry Journal (Gornay Promishlennost), no. 1S/2022 (March 16, 2022): 111–18. http://dx.doi.org/10.30686/1609-9192-2022-1s-111-118.
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Unexpected abnormal deformation processes in rock masses lead to disruptions in the operation of mining facilities and endanger human life and health. The studies show that physiographic conditions, physical and mechanical properties of rocks, features of structural and tectonic structure of the rock mass can influence the unexpected character of the deformation phenomena. One of the important parameters that determines the development of catastrophic deformation processes is the geodynamic activity of the rock mass, which forms its stress state. The purpose of the research is to develop methodological approaches to identification of potentially hazardous areas in the rock mass. To do this, experimental studies were carried out in a mine where unexpected abnormal deformations took place, and the role of influencing factors was analyzed. Experiments were performed using geological, geophysical and geodetic methods. As the result of the study, it was established that unexpected emergency deformation processes develop in areas where the maximum number of complicating factors is concentrated. A rating evaluation of the area of surface development has been developed based on a combination of factors affecting the stability of the rock mass. The developed approaches make it possible to diagnose the rock mass and identify areas where geomechanical processes develop according to special parameters. Area zoning can be the basis for the development of automated monitoring system of rock mass deformations to prevent unexpected emergency events.
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Wang, Ru Bin, Wei Ya Xu, and Jiu Chang Zhang. "Modeling Coupled Flow-Stress-Damage during Creep Deformation." Applied Mechanics and Materials 204-208 (October 2012): 3294–98. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.3294.
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In order to reflect the tertiary rheological characteristics of hard rocks at the high stress states, a new nonlinear visco-elastic-plastic model is proposed on the basis of linear visco-elastic-plastic model and nonlinear visco-elastic-plasticity. And then the corresponding constitutive model are deduced, which can be used for describing rocks’ long-term strength characteristics and their creep deformational behavior and time-dependent damage under interaction of coupled seepage-stress field in rock engineering. At last, considering the time effect of rock damage in the process of tertiary creep, a coupled seepage -stress creep damage model for investigating the whole creep deformation behavior, including tertiary creep failure process is established, and the related equations governing the evolution of stress, creep damage and rock permeability along with the creep deformation of rock is introduced.
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Muñiz-Menéndez, Mauro, and Ignacio Pérez-Rey. "Intact rock deformation bimodularity: an experimental study." IOP Conference Series: Earth and Environmental Science 1124, no. 1 (January 1, 2023): 012041. http://dx.doi.org/10.1088/1755-1315/1124/1/012041.
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Abstract Rock deformability under tensile stresses plays an important role in different scenarios like, e.g., in the mechanical behaviour of roofs in underground openings, hydraulic fracturing, dilatometer tests performed in massive rock masses or in tensile strength tests. Different authors have proved that the tensile deformation modulus of the intact rock can be significantly different than that obtained under compressive load, being this so-called ‘bimodularity’ often ignored. In this work, we present preliminary results from uniaxial compressive and tensile strength tests carried out in three rocks with a testing apparatus recently modified to be able to perform both types of tests. Experimental results show that the deformational behaviour of the rocks studied is dependent on the type of load applied. The present work aims at contributing to a better understanding of the deformational behaviour of rocks, in particular when subjected to uniaxial tensile loads as well as in dealing with future updates of existing test methodologies.
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Guzev, Mikhail, and Vladimir Makarov. "Investigation of Deformation of Rock Samples." Key Engineering Materials 744 (July 2017): 61–65. http://dx.doi.org/10.4028/www.scientific.net/kem.744.61.
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Deformation of rock samples compressed up to failure has been studied in laboratory. A system of trustworthy deformational precursors of the failure stage has been developed. The system includes long-term, middle-term and short-term precursors, which correspond to the threshold of dilatancy, change of the specific volume deformation, and jump of the specific volume deformation increments, respectively. Proposed methods of the complex research include deformation and mathematical methods. The mathematical model of deformation in samples of rocks at uniaxial compression is founded on hypothesis of self-equilibrium stresses. The model had been successfully used for description of oscillating deformation. Good coincidence between the experimental and theoretical results has been observed.
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Shashenko, Oleksandr, Vladyslava Cherednyk, Natalia Khoziaikina, and Dmitro Shashenko. "PHYSICAL PREREQUISITES FOR GAS PERMEABILITY SIMULATION OF MINED ROCK MASS." JOURNAL of Donetsk Mining Institute, no. 2 (2021): 78–84. http://dx.doi.org/10.31474/1999-981x-2021-2-78-84.
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Purpose. Justification of the gas collectors formation physical model on the basis of research of conformity of permeability of rock mass to the full diagram of rock sample deformation. Methodology consists in sequential analysis of the stages of the complete deformation diagram of the rock specimen under “hard” loading, comparing them with the stages of formation of the high stress zone in front of the lava bottom and statistical analysis of laboratory test results. Results. Based on the rock’s deformation properties analysis and their comparison with the rock sample full deformation diagram, the physical model of formation of gas reservoirs during the development of gas-saturated coal seam is substantiated. Within the solved problem framework, four stages of the complete deformation process are analyzed, namely: elastic, at the limit of strength, out-of-bounds stage and equivoluminal flow zone. The gas collector boundaries, which are the characteristic points of the rock sample deformation diagram in specified deformations mode (the limit of elastic strength and the limit of final strength) are determined. It is proved that the structural and textural features of the coal mass in connection with the course of gas-dynamic processes are manifested in the change in the pores and cracks volume contained in it, which together make the filtration space. Knowledge regarding the transfer of the permeability changes established regularities and free methane accumulation zones formation to the real rock mass, if the process of its forgery is considered as a consistent change of geomechanical states of rocks, is obtained. Scientific novelty lies in the first substantiated possibility of modeling the stress state before the longwall face by equivalent stages of the rock sample destruction in the given deformations mode. Gradual comparative analysis of the internal mechanism of rock samples deformation along the complete deformation diagram allowed establishing causal relationships between geomechanical and gas-dynamic processes in coal mass, and qualitatively characterizing general trends in permeability and volumetric expansion in changes of these samples. Practical value of the work lies in the justification of the principle of construction of a digital geomechanical model for the detection of man-made gas collectors in a mined coal mass.
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Xiaoxiong, Guo, Wang Ning, Xu Xueliang, and Ye Zihui. "Analysis of Extent of Deformation Range and Failure Characteristics of Rocks Surrounding a Tunnel Crossing Fault Zone Based on FDEM." Advances in Civil Engineering 2022 (August 10, 2022): 1–12. http://dx.doi.org/10.1155/2022/9643584.
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The combined finite-discrete element method (FDEM) and laboratory test were selected to study the extent of deformation range and time-dependent deformation of surrounding rock during tunnel excavation without support in a fault-crossing tunnel project. FDEM was found to accurately reflect the deformation and failure characteristics of different surrounding rocks during stress release, including conjugate shear and extrusion. Analysis of the results showed that the disturbance range of surrounding rocks could reach 1.5 to 2.5 times the tunnel diameter when crossing the fault zone. The rock surrounding the tunnel was found to incur significant conjugate shear deformation and extrusion deformation: conjugate shear deformation was identified as dominant in the deep rock mass, whereas extrusion deformation prevailed in the rock mass near the cave wall. The conjugate shear distribution was represented as a spiral line of deformation circling around the tunnel section, with an elliptical main deformation zone with its long axis parallel to the fault plane. Compared with the findings when crossing the intact rock mass, the deformation of the surrounding rocks when crossing the fault zone was characterized by rapid development, deep expansion area, and large deformation. The study conclusions were that supporting bolts and steel arches should be implemented timely when excavating fault zones and that both lithology and optimal construction timing were essential considerations in determining the length of the supporting bolts.
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Fang, You Ling. "An Experimental Study on Destructive Nature of Seam Roof Strata with Horizontal Bedding." Applied Mechanics and Materials 448-453 (October 2013): 3869–72. http://dx.doi.org/10.4028/www.scientific.net/amm.448-453.3869.
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Subjected to external forces, the structure surface between rocks (ie, bedding planes) should be deformed under external force. If the two side walls of the rock bedding plane has perfectly flat smooth surface, after the composite layered rock subjected to force, bedding plane can be closed as surface contact manner. However, the rock bedding plane side walls generally showed local contact state in the nature, the rock layers of bedding planes will produce compressive deformation under stress. Through complete stress - strain triaxial loading experimental study on the effects of the presence of horizontal bedding on layered composite rock strength and deformation, and the elastic deformation of layered rocks are calculated using elastic mechanics, the result shows that due to the presence of irregular bedding plane, the presence of horizontal bedding formation will reduce the overall strength, and increase the overall rock deformation.
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Feng, Xiaojun, Zeng Ding, Qinjing Hu, Xue Zhao, Muhammad Ali, and Jefferson T. Banquando. "Orthogonal Numerical Analysis of Deformation and Failure Characteristics of Deep Roadway in Coal Mines: A Case Study." Minerals 12, no. 2 (January 30, 2022): 185. http://dx.doi.org/10.3390/min12020185.
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With the development of deep, underground coal mines in China, the failure mechanism of the rocks surrounding roadways is becoming increasingly complicated and the deformational control is also significantly difficult. In this study, based on the temporal and spatial deformational distribution of the deep roadway area in the 2233 working face of Fuxin Hengda Coal Mine, factors affecting the deformation and failure mechanism of deep-buried roadways, such as cohesion (c), tensile strength (σt), internal friction angle (φ), vertical ground stress (p), and the horizontal-to-vertical stress ratio (λ), were analyzed using orthogonal numerical experiments. The stress and electromagnetic radiation monitoring data were used to locate areas of highly concentrated deformation in the roadway and surrounding rocks. The results show that the order of the degree of influence of the surrounding rock and geometric parameters on the deformation of the deep-buried roadway is φ > p > σt > λ > c. The vertical stress of the roof and the horizontal stress of the two sides are negatively correlated with the tensile strength and horizontal-to-vertical stress ratio, respectively, and mainly shear failure occurs in the area. The higher the level of the surrounding rock, the more serious is the deterioration and deformation. The electromagnetic radiation reflects the distribution range of the high-stress concentration area and strength deterioration area. The test results accurately describe the deformation–deterioration-failure laws of rock surrounding deep-buried roadways influenced by different factors. The results are of great significance for analyzing the deformation and failure characteristics of rocks surrounding roadways, preventing rockburst, and supporting the parameter optimization of roadways.
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Tkachuk, Oleksandr, Daria Chepiga, Serhii Pakhomov, Serhiy Volkov, Yaroslav Liashok, Yaroslava Bachurina, Iryna Shvets, and Serhii Podkopaiev. "Evaluation of the effectiveness of secondary support of haulage drifts based on a comparative analysis of the deformation characteristics of protective structures." Eastern-European Journal of Enterprise Technologies 2, no. 1 (122) (April 28, 2023): 73–81. http://dx.doi.org/10.15587/1729-4061.2023.272454.
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The object of this study is the processes of managing the state of lateral rocks in the coal rock array with preparatory workings. The influence of deformation characteristics of the protective structures of the preparatory workings on the stability of lateral rocks in the coal rock array has been established. The stable state of the above-the-drift pillars of coal is provided within the deformation resource, which corresponds to the critical level of the specific potential energy of the deformation. The limits of the deformation resource are the range of change in the relative deformation of coal pillars 0.1≤λ≤0.25. When the critical level of the specific potential energy of deformation is passed, at λ˃0.25, there is a relative change in the volume of pillars δλ˃0,1, as a result of which their durability decreases and the state changes. Under such conditions, the residual strength of coal pillars is not enough to limit the movement of lateral rocks, which provokes their collapse. For protective structures made of crushed rock, within the established deformation resource of 0.4≤λ≤0.7, with an increase in static load and cross-sectional area, the specific potential energy of deformation decreases, simultaneously with the relative change in the volume of the embedded material. This is due to the compaction of the crushed rock and an increase in its strength. Regularities of change in the specific potential energy of deformation of protective structures have been established, which, under conditions of uniaxial compression, make it possible to assess, within the deformation resource, their stability. To ensure the stability of lateral rocks in the coal rock array and to preserve the operational condition of the preparatory workings, it is advisable to use protective structures made of crushed rock. This method will limit the movement of the roof and sole in the produced space and avoid collapses.
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Guo, Zhibiao, Jinyan Fan, Fengnian Wang, Hongbo Zhou, and Wei Li. "Geomechanical Model Experiment Study on Deformation and Failure Mechanism of the Mountain Tunnel in Layered Jointed Rock Mass." Advances in Civil Engineering 2021 (February 12, 2021): 1–19. http://dx.doi.org/10.1155/2021/6645124.
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The Minxian tunnel is a key engineering of the Weiyuan-Wudu expressway that is excavated in layered jointed carbonaceous slate rock mass. During the construction process, the surrounding rocks of the tunnel encountered serious large deformations and failure, which brought about great difficulties to the safety and cost of the tunnel. In order to study the deformation and failure mechanism of the surrounding rocks, a physical model test was conducted, and integrated methods including strain gauges, a digital camera, and noncontact full-field digital imaging correlation technique were used to record the response information of the surrounding rocks. The evolution process of surrounding rocks failure was simulated successfully in the model test, and the deformation characteristics were basically consistent with the actual engineering. The modelling results show that concentrated stresses in the surrounding rocks were very uneven due to developed stratified and jointed rock mass structure. The maximum and minimum concentrated stresses appeared at the vault of the tunnel and left of inverted arc area, and concentration factors were 3.11 and 1.98, respectively. The main forms of surrounding rocks deformation and failure were large area spalling of surface, severe circumferential fractures, serious bending deformations of thin rock layers, and collapse of overlying strata. The maximum displacements occurred at left sidewall and right shoulder of the tunnel and the corresponding actual displacements were 460 mm to 500 mm. Caving and failure took place firstly at several key positions with maximum concentrated stresses or displacements and subsequently gave rise to massive collapse of surrounding rocks.
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Zhang, Cheng, Amagu amagu Clement, Jun-ichi Kodama, Atsushi Sainoki, Yoshiaki Fujii, Daisuke Fukuda, and Shuren Wang. "Effect of the Connectivity of Weak Rock Zones on the Mining-Induced Deformation of Rock Slopes in an Open-Pit Mine." Sustainability 16, no. 14 (July 12, 2024): 5974. http://dx.doi.org/10.3390/su16145974.
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Geological structures significantly influence mining-induced deformations in open-pit mines, with their variations and interactions adding complexity to the excavation process and introducing uncertainties in deformation outcomes. This study utilized numerical simulations to analyze the impact of weak rock zones in a specific open-pit limestone quarry in Japan on mining-induced deformation. The simulation results were both qualitatively and quantitatively validated against field measurements, enhancing the reliability of the findings. Subsequently, four conceptual models were developed based on the characteristics of the quarry to investigate the mechanisms by which weak rock zones affect rock slope deformations. Our analyses demonstrated that slip deformation occurred exclusively when two weak rock zones were connected. This deformation was associated not only with shear failure in the upper weak rock zone but also with the contraction and bending of the lower weak rock zone. Furthermore, the simulation results were consistent with field data and supported by the conceptual models, confirming that the proposed sliding mechanisms can effectively explain the observed deformation behaviors. The insights gained from these models provide valuable references for managing similar geological challenges in other open-pit mines.
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Yao, Qiangling, Xuehua Li, Fan Pan, Teng Wang, and Guang Wang. "Deformation and Failure Mechanism of Roadway Sensitive to Stress Disturbance and Its Zonal Support Technology." Shock and Vibration 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/1812768.
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The 6163 haulage roadway in the Qidong coal mine passes through a fault zone, which causes severe deformation in the surrounding rock, requiring repeated roadway repairs. Based on geological features in the fault area, we analyze the factors affecting roadway deformation and failure and propose the concept of roadway sensitive to stress disturbance (RSSD). We investigate the deformation and failure mechanism of the surrounding rocks of RSSD using field monitoring, theoretical analysis, and numerical simulation. The deformation of the surrounding rocks involves dilatation of shallow rocks and separation of deep rocks. Horizontal and longitudinal fissures evolve to bed separation and fracture zones; alternatively, fissures can evolve into fracture zones with new fissures extending to deeper rock. The fault affects the stress field of the surrounding rock to ~27 m radius. Its maximum impact is on the vertical stress of the rib rock mass and its minimum impact is on the vertical stress of the floor rock mass. Based on our results, we propose a zonal support system for a roadway passing through a fault. Engineering practice shows that the deformation of the surrounding rocks of the roadway can be effectively controlled to ensure normal and safe production in the mine.
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Sun, Mingzhi, Gaojian Hu, Jianli Hu, Huanqing Zhang, Yu Li, Weiping Wang, and Guangbin Zhang. "Simulation Study on the Size Effect of Secant Modulus of Rocks Containing Rough Joints." Sustainability 14, no. 23 (November 24, 2022): 15640. http://dx.doi.org/10.3390/su142315640.
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The secant modulus reflects the ability of rocks to resist deformation, and it is mostly used to evaluate rock strength and deformation evolution. Due to the existence of rough joints in rocks, the secant modulus changes according to rock size. Therefore, it is very important to effectively obtain the secant modulus to evaluate rough-jointed rock deformation. In this paper, the regression analysis method is used, and 25 sets of simulation models are set up to discuss the influence of joint roughness and rock size on the rock secant modulus. The research shows that the secant modulus increases exponentially with the increase in rock size, and it increases as a power function with the increase in joint roughness. The characteristic size of the secant modulus increases exponentially with the increase in joint roughness, also as a power function. This paper gives the specific forms of these four relationships. The establishment of these relationships enables the prediction and calculation of the secant modulus and provides guidance for rock deformation analysis.
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Demin, V. F., and V. Zhurov. "Anchor bolt of rock massif in coal mines to decrease soil rock heaving of the workings." Kompleksnoe Ispolʹzovanie Mineralʹnogo syrʹâ/Complex Use of Mineral Resources/Mineraldik Shikisattardy Keshendi Paidalanu 325, no. 2 (November 28, 2022): 80–86. http://dx.doi.org/10.31643/2023/6445.21.
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During the maintenance of workings, the effects of soil rock heaving, caused by plastic deformation and extrusion into the excavation cavity under the action of the rock pressure, are usually eliminated. The identified patterns of change in the stress-strain state of coal-rock massifs (displacements, stresses, cracking zones), depending on the main mining-geological and mining-technical factors will allow to establish the optimal parameters of soil anchoring, technological schemes for decreasing soil rock heaving of mine workings to increase the stability of preparatory mine workings have been developed. The development and improvement of existing technologies of effective and safe stiffening of near-soil rocks at conducting mine workings on flat and inclined coal seams were substantiated. The modelling of the SSS shows that both side-rock and ground deformations are predominantly influenced by side anchorage which results in reduction of the effective deformations in the rocks surrounding the working and in a decrease of gas release from the coal massif. It is established that the deformations and stresses both side and in-soil rocks in the excavation are influenced by side anchors rather than near-soil ones.
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Green, Harry. "Rock Deformation Meeting." Eos, Transactions American Geophysical Union 71, no. 20 (1990): 715. http://dx.doi.org/10.1029/90eo00188.
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Bulat, A. F. "Rock deformation problems." International Applied Mechanics 40, no. 12 (December 2004): 1311–22. http://dx.doi.org/10.1007/s10778-005-0039-y.
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He, Hai Ying. "Mechanism and Calculation Research on Excavation Deformation of High Layered Dip Rocky Slope." Advanced Materials Research 455-456 (January 2012): 1596–600. http://dx.doi.org/10.4028/www.scientific.net/amr.455-456.1596.
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Based on rock Mechanical theory under unloading, according to the analysis of rock mechanics state of pre and post excavation of the layered dip rocky slope, it was found that excavation unloading cause deterioration of rock constitutive relation and structure plane’s mechanical parameters, deformation mechanism of high layered dip rocky slope was analyses when rock is at unloading condition in this study. Its deformation consists of the two parts which are rock mass unloading rock mass springback displacement and bedding-slip displacement along the rock mass discontinuity, and deduced the calculating formula of slope displacement. Research results with great guide significance and practical engineering value to similar engineering construction afterward.
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Shrestha, Pawan Kumar, and Krishna Kanta Panthi. "Estimating Tunnel Strain in Weak and Schistose Rock Mass under a State of in-situ Stress Anisotropy." Hydro Nepal: Journal of Water, Energy and Environment 16 (February 28, 2015): 7–13. http://dx.doi.org/10.3126/hn.v16i0.12212.
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Tunnels excavated in weak and schistose rock mass below high overburden (rock cover) are prone to instability in the form of tunnel deformation. The deformation in the tunnel takes place to such an extent that it is irreversible and of significant magnitude, which is often known as tunnel squeezing. In order to limit such plastic deformation in tunnels, it is desirable that the response of the rock mass to induced stresses is known so that requirement of rock support can be estimated. Contrary to the assumption of uniform in-situ stresses made in analytical solutions for elasto-plastic analyses, large degree of stress anisotropy condition prevails in most tunnelling conditions. The effect of such anisotropic stress condition leads to varying degrees of deformations around the tunnel contour. Therefore, stress anisotropy is also an important factor that needs to be addressed to ensure a proper support design for tunnels. This paper discusses the inter-relationship among rock mass property, in-situ stresses including horizontal to vertical stress ratio, tunnel support pressure and deformation. The study is based on the tunnel cases from the Nepal Himalaya. Three completed tunnel projects were selected, where moderate to large tunnel deformations had been recorded. Long term deformation records were analyzed to assess time independent and time dependent deformations. Results of the analyses of the tunnels in weak and schistose rock mass at stress anisotropy states show that a good correlation among tunnel strain, rock mass shear modulus, support pressure, vertical stress and stress ratio of horizontal to vertical stresses exists. Moreover, the study also shows that significant amount of time dependent deformation can occur in such weak rock mass. Such deformation was found to be high in schist and micaceous phyllite, moderate in graphitic phyllite and low in siliceous phyllite. The suggested relationships can be used as a basis for an early estimate of instantaneous and final deformations and the corresponding requirement of support pressures in tunnel walls in weak and schistose rock mass.DOI: http://dx.doi.org/10.3126/hn.v16i0.12212HYDRO Nepal Journal of Water Energy and EnvironmentIssue. 16, 2015 January Page: 7-13 Upload date: March 1, 2015
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Fu, Bo-Ye, and Li-Yun Fu. "Poro-acoustoelasticity with compliant pores for fluid-saturated rocks." GEOPHYSICS 83, no. 3 (May 1, 2018): WC1—WC14. http://dx.doi.org/10.1190/geo2017-0423.1.
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Stress-induced influences on elastic wave velocities include elastic and inelastic behaviors. In general, deformation of rocks is primarily linear elastic for small-magnitude stresses; such behavior can be predicted by the conventional poro-acoustoelasticity theory. On the contrary, large-magnitude stresses induce linear elastic deformation in stiff pores and rock grains and nonlinear elastic deformation in compliant pores. Conventional poro-acoustoelasticity combines the kinetic and strain energy functions via the Lagrange equation. This theory reveals the strain energy transformation of the stiff pores and rock grains for velocity variation. The dual-porosity model uses a semiempirical equation to express the influence of the nonlinear elastic deformation of compliant pores on velocity variations; however, this model does not include the strain energy transformation of compliant pores. We incorporate the dual-porosity model into the conventional poro-acoustoelasticity theory to account for linear and nonlinear elastic deformations through the strain energy transformation of rock grains, stiff pores, and compliant pores. We determine that the work of the loading stress is transformed into two parts: the strain energy for the linear elastic deformation of rock grains and stiff pores and the nonlinear elastic deformation of compliant pores. On applying this theory to ultrasonic measurements under different differential pressures for a saturated sandstone sample, we see that the resulting solution of stress-associated velocity variations is more precise than that obtained using the conventional poro-acoustoelasticity theory, especially in the low-effective-pressure regime.
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Tang, Bin, and Hua Cheng. "Application of Distributed Optical Fiber Sensing Technology in Surrounding Rock Deformation Control of TBM-Excavated Coal Mine Roadway." Journal of Sensors 2018 (2018): 1–10. http://dx.doi.org/10.1155/2018/8010746.
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After roadway excavation, the deformation and failure of roadway surrounding rocks typically results in roadway damage or collapse. Conventional monitoring techniques, such as extensometers, stress meters, and convergence stations, are only capable to detect the stress or strain data with the shallow layers of surrounding rocks, and they require arduous manual works. Moreover, in the abovementioned monitoring techniques, the monitoring instruments are installed behind the excavation face; therefore, the strain and deformation occurring in front of excavation face cannot be detected. In order to eliminate these shortcomings, an innovative monitoring system for surrounding rock deformation control has been developed base on Brillouin optical time domain reflectometry. Compared with conventional monitoring systems, the proposed system provides a reliable, accurate, and real-time monitoring measure for roadway surrounding rock deformation control over wide extension. The optical fiber sensors are installed in boreholes which are situated ahead of the excavation face; therefore, the sensors can be protected well and the surrounding rock deformation behaviors can be studied. The proposed system has been applied within a TBM-excavated roadway in Zhangji coal mine, China. The surrounding rock deformation behaviors have been detected accurately, and the monitoring results provided essential references for surrounding rock deformation control works.
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Cao, Wengui, Xin Tan, Chao Zhang, and Min He. "Constitutive model to simulate full deformation and failure process for rocks considering initial compression and residual strength behaviors." Canadian Geotechnical Journal 56, no. 5 (May 2019): 649–61. http://dx.doi.org/10.1139/cgj-2018-0178.
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A constitutive model with capacity to simulate the full deformation and failure process for rocks considering initial compression and residual strength behaviors is discussed in this paper. The rock was assumed to consist of the initial voids portion and the solid skeleton portion. The full deformation model of rocks can be established by the consideration of the macroscopic deformation of rocks and the microscopic deformations of the two different portions based on the statistical damage theory. Comparisons between the experimental data from triaxial compression tests and calculated results show that the proposed constitutive model provided a good prediction of the full deformation and failure process, including the effects of initial void compression, stiffness degradation, strain hardening–softening, and residual strength.
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Zhu, Yimo, Liang Chen, Heng Zhang, Zelin Zhou, and Shougen Chen. "Physical and Mechanical Characteristics of Soft Rock Tunnel and the Effect of Excavation on Supporting Structure." Applied Sciences 9, no. 8 (April 12, 2019): 1517. http://dx.doi.org/10.3390/app9081517.
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The problem of large deformation is very prominent in deep-buried tunnel excavation in soft rock, which brings serious potential safety hazards and economic losses to projects. The knowledge of deformation law and support measures is the key to ensure the rational design and safe construction in a large deformation tunnel of soft rock. This paper describes rock physical and mechanical tests and field monitoring is employed to investigate the cause and development process of large deformation in Dongsong hydropower station in Sichuan Province, China. The results show that the free expansion rate of the rock sample is 20.0%, the average expansion stress of the rock sample is 11.0 kPa, and the expansibility of the rock is low. Large deformation of surrounding rock mainly comes from the dilatancy effect with high geostress and relaxation deformation with weak support. Shotcrete sealing exposed surrounding rock, and early strength support avoiding water immersion are useful to deal with the three main factors (weathering, water and confining pressure) that affect the strength of surrounding rocks. The second lining applied in time can effectively limit the further development of stress and deformation of initial support, and prevent the cracking and large deformation of concrete. Clearance convergence is suggested to be the main monitoring work in construction, because of its advantages of intuitive results, easy quality assurance of instrument installation and high accuracy.
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Kozyrev, Anatolii, Eduard Kasparyan, Iuliia Fedotova, and Nikolay Kuznetcov. "The specificities of deformations and failures of highly stressed hard rock massifs." E3S Web of Conferences 129 (2019): 01010. http://dx.doi.org/10.1051/e3sconf/201912901010.
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According to modern concepts, the state of highly stressed hard rock massifs is mostly caused by the effect of gravitational-tectonic stress fields. At that, a probability of brittle rock failure in a dynamic form is very high. Such failures are always accompanied by the significant energy release accumulated during the deformation process. Based on the experimental studies of deformation and failure processes in various types of rock samples from the Kola Peninsula deposits, we have proposed the criteria for classifying rocks as prone to rock bursts. The information for assessing the rock proneness to dynamic failures can be obtained by analysing the strain curve at the pre-peak section when tested on the ordinary presses and testing devices according to the standard methods. If we study the processes of rocks' deformation and energy accumulation under the triaxial loading mode, we can establish the parameters for the occurrence of dynamic failure of rocks. This, in turn, will allow identifying the conditions of such failure in the investigated rocks for a specific mining-engineering situation and, thereby, coming to a scientifically-based prediction of the rocks' proneness to dynamic rock pressure occurrences.
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Tang, Hao, Xiang Ji, Hongyi Zhang, and Tianbin Li. "Numerical Simulation of Large Compression Deformation Disaster and Supporting Behavior of Deep Buried Soft Rock Tunnel with High In Situ Stress Based on CDEM." Advances in Civil Engineering 2022 (March 3, 2022): 1–13. http://dx.doi.org/10.1155/2022/5985165.
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Large compressive deformation of tunnels is a phenomenon involving plastic deformation and failure of surrounding rocks and often refers to the weak surrounding rock self-bearing capacity loss or partial loss. This research discusses the formation and evolution of large compressive deformation and effectiveness of the combined support of high in situ stress tunnel. From the new perspective of large deformation disaster caused by the structural failure of high in situ stress surrounding rock to clarify it, this paper illustrates the mechanism of progressive cracking and large deformation of high in situ stress soft rock tunnel from the aspects of the formation of self-bearing system, deformation evolution of the surrounding rock, mechanical properties of the surrounding rock, and failure characteristics. Accordingly, the continuous and discontinuous numerical simulation methods are used. The following conclusions are drawn by comparing the simulation results of surrounding rock under combined support with no support. (1) The supporting structure constitutes the self-supporting system with the surrounding rock and plays the roles of codeformation and load-bearing. (2) The support structure has evident reinforcing effect on the rock mass in the relaxation zone, thereby leading to the phenomenon of weakened rock mass failure. Moreover, the shear area develops to the compaction zone. (3) The supporting structure improves the bearing capacity of rock mass in the relaxation zone. It also increases the surrounding rock stress and reduces the range of the compaction zone. Simulation results verify that the combined support measures have a good suppression effect on the large compressive deformation, thereby providing a reference for similar projects and research on the large compressive deformation of soft rock.
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Song, Yafen, Li Chen, Xiaotao Zhang, Qian Zhao, Linlin Yu, and Jinhua Xu. "Experimental investigation on the deformation and failure mechanism of slope with interbedding soft and hard rocks under rainfall infiltration." E3S Web of Conferences 194 (2020): 04056. http://dx.doi.org/10.1051/e3sconf/202019404056.
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Taking Peng Jiawan slope in Yiba expressway as the project background, the deformation and failure mechanism of slope with interbedding of soft and hard rocks was studied on the basis of geological analysis and similarity theory. In geomechanical model test, the water infiltration softening process is used to simulate the rainfall infiltration. The result indications showed as follows: under the condition, the deformation mode of the slope is the previous sliding-tension and upper overall creep-slip, and the failure mode is overall slip failure in the sliding zone of deep soft rock. Strictly speaking, the deformation of hard rock differs from the deformation of soft rock, hard rock deforms mainly on sliding-tension and soft rock deforms mainly on overall creep-slippage. Changes of the condition of deep soft rock affect the total stability of the interbedded slope mostly.
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Ma, Dong, Zhongsheng Tan, Linlin Bian, Baojin Zhang, and Jinpeng Zhao. "Research on Deformation and Loose Zone Characteristics of Large Cross Section Tunnel in High Geo-Stress Soft Rock." Applied Sciences 13, no. 15 (August 6, 2023): 9009. http://dx.doi.org/10.3390/app13159009.
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In constructing high-geo-stress soft rock tunnels, the major deformation disaster of the surrounding rock has always been the main problem faced during construction. The research on the deformation and loose zone characteristics of large deformation tunnels has positive significance for the safe and rapid construction of tunnels. Therefore, based on the Yuntunpu large deformation tunnel, this article first analyzes the geological and deformation characteristics of the tunnel site area in response to the problem of high-geo-stress soft rock large deformation. Subsequently, on-site testing and analysis were conducted on the loose zone characteristics of four tunnel sections. Finally, based on the comprehensive analysis of tunnel deformation and loose zone characteristics, the causes of large deformation in the tunnel are analyzed. The results indicate that the large deformation characteristics of the Yuntunpu Tunnel are mainly manifested as a large initial deformation rate of the surrounding rock, a short self-stabilization time of the surrounding rock, a large cumulative deformation amount, and a long deformation duration. The Yuntunpu Tunnel is influenced by the grade and structure of the surrounding rock, with a loosening zone ranging from 12 to 14 m, and the wave velocity variation characteristics exhibited by different grades of surrounding rock vary greatly. Adopting collaborative active control of long and short anchor rods is recommended to limit the continued development of loose zones and the deformation of surrounding rocks. The large deformation of tunnels is mainly affected by high geo-stress, formation lithology, geological structure, engineering disturbance, and groundwater. Among them, high geo-stress and formation lithology are the decisive and important factors for the occurrence of major deformation disasters in the tunnel.
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Volokhov, Evgenii, and Diana Mukminova. "Deformations assessment during subway escalator tunnels construction by the method of artificial freezing of soil for the stage of ice wall formation." Записки Горного института 252 (December 17, 2021): 826–39. http://dx.doi.org/10.31897/pmi.2021.6.5.
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The work is devoted to the study of the processes of displacement and deformation of the surface during the escalator tunnels construction of the subway by the method of artificial freezing of soils. The features of the construction and freezing technology, the rocks characteristics in which the escalator tunnels made are considered. The data of specially organized, full-scale surveying observations of deformations on the earth surface are presented. The main factors influencing deformation processes in the frozen strata of a layered inhomogeneous rock mass with inclined tunneling are determined, the complexity of the predictive task and the need to simplify the design scheme are shown. The work is focused on the assessment of the least studied geomechanical processes of soil heaving-uplifts and deformations during the periods of active and passive freezing stages. When studying the displacements processes of the earth surface and rock mass, the finite element method and analysis of the obtained data using field observations of displacements were used. A simplified calculation scheme is proposed for modeling, which allows taking into account the uneven influence of frozen rocks of an inhomogeneous layered rock mass with a large inclined tunneling. The satisfactory convergence of the data of field surveying observations on the earth surface and the results of modeling geomechanical processes for the period of active and passive freezing stages is shown. The proposed calculation scheme is recommended for the prediction of deformation at the stages of underground construction, characterized by the development of the most dangerous tensile deformations of buildings and structures on the surface.
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Khelalfa, Houssam, B. Aykan, and H. Boulmaali. "Monitoring of Tunnel Rock Mass Deformations During Provisional Support Stage: A Case Study." Mining Revue 28, no. 1 (March 1, 2022): 1–23. http://dx.doi.org/10.2478/minrv-2022-0001.
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Abstract The present study evaluates on site the effects of provisional support on the rate of deformation (convergence) of clay-stone of a twin-tube tunnel. The combination of shotcrete, steel lattice, steel retaining, pre-supporting iron bar and Rock bolts can act as structural support in the form of provisional support for new or existing tunnels. Applications of provisional supports as confinement mechanisms to decrease the capacity of convergence can be helpful for distressed rock mass during tunnels digging. Real-size and real-time field monitoring over a period of approximately one (01) year was carried out with a Tachometer “Leica, TS 09” and 3D Displacement Monitoring Objectives fixed on the top heading and on the invert/bench. Wherefore; a sketch of the same cross-section of the tunnel was used in order to define the deformations of the rock mass of the tunnel measured in 3D in successive periods in all directions along the weak rock mass of the fourth class (IV) after the installation of the provisional support. The study shows good results in terms of deformation of the rock mass of the tunnel and satisfactory stability in terms of confinement. Consequently; it was noticed, that there is a relation between the deformations (convergence) in the two tubes along tunnel - when the deformation of the left tube increases the deformation of the right tube decreases -, and that the deformation of the tunnel is a deformation overall of the rock mass and it is the same along the tunnel relative to its rock mass. It can be concluded that there is a reciprocal effect between the two tunnel tubes, which can be considered as a conservation principle of the rock mass.
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Wang, Lei, Yu Sheng Li, and Qing Song Huang. "Numerical Simulation Study on the Stress - Deformation Characteristics of Rock Mass of Luding Power Transmission Project in Sichuan." Applied Mechanics and Materials 368-370 (August 2013): 1688–92. http://dx.doi.org/10.4028/www.scientific.net/amm.368-370.1688.
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In this page, combination of finite element numerical simulation and discrete element numerical simulation is used to study the stress - deformation characteristics of rock mass of power transmission project site,whichclarifies the rock mass stress is mainly controlled by thegravitational field,the form of the potential deformationis dominated by compression deformation,andthere is no possibility of occurrence of the horizontal shear deformation.
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Zhang, Guoyu, Zikang Huang, Tao Zhu, Bo Wang, Xudong Xing, Yufei Liu, Guanghui Zheng, Kaiwen Liu, and Jimin Su. "Study on Rheological Properties of Coal Rock Containing Gas under Disturbance Conditions." Shock and Vibration 2022 (June 15, 2022): 1–10. http://dx.doi.org/10.1155/2022/2370301.
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In view of the dynamic phenomenon that coal and rock are susceptible to external impact disturbance in the mining process, combined with the rheological hypothesis mechanism of coal and gas outburst, the RLSS-II-type triaxial loading creep test system of gas-containing coal and rock developed by ourselves is used to carry out the conventional triaxial rheological test of gas-containing coal and rock and the rheological disturbance effect test of gas-containing coal and rock under impact disturbance. The strength limit neighborhood of gas-containing coal and rock is determined, and the gas-containing coal and rock entering the strength limit neighborhood are subjected to different impact disturbances. The experimental results show that, (1) under the confining pressure of 0 MPa, 2.5 MPa, and 5 MPa, the longitudinal deformations of gas-bearing coal and rock are 32 mm, 27 mm, and 22 mm, respectively, indicating that the deformation of coal and rock will be affected by confining pressure, and with the increase of confining pressure, the deformation will decrease. (2) In the test, the deformation of coal and rock in the late stage of uniform creep stage can be regarded as a strain threshold. Before this threshold, the strain of coal and rock is not obvious, and the deformation is only 1.1 mm. After exceeding a threshold, the deformation of coal and rock is 9 mm, and the deformation increases significantly. Then, it enters the accelerated creep stage quickly and finally damages. The vicinity of this threshold is called the strength limit neighborhood of coal and rock containing gas. (3) The gas-bearing coal and rock without entering the strength limit neighborhood and entering the strength limit neighborhood are changed by confining pressure and different impact disturbance, respectively. It is found that, whether in the strength limit neighborhood or outside the strength limit neighborhood, the confining pressure has an effect on the strain, but the influence is not large. Under different impact disturbance, the deformation of coal and rock within and outside the strength limit neighborhood is 8 mm and 0.4 mm, respectively, and the deformation changes obviously, indicating that the impact disturbance has a great influence on the deformation of coal and rock within the strength limit neighborhood, and the coal and rock with large impact disturbance are destroyed before the coal and rock with small impact disturbance, indicating that the greater the impact disturbance, the shorter the time required for destruction.
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Cao, Mengtao, and Shunde Yin. "Study on the Tri-axial Time-Dependent Deformation and Constitutive Model of Glauberite Salt Rock under the Coupled Effects of Compression and Dissolution." Energies 13, no. 7 (April 8, 2020): 1797. http://dx.doi.org/10.3390/en13071797.
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Solution mining for glauberite salt rock is a long-term process that takes several years to several decades. Therefore, deposit deformations and subsidence of ground surfaces are time-dependent deformation problems that should consider the effect of water dissolution. In order to investigate the time-dependent deformation characteristics of glauberite salt rock, tri-axial time-dependent deformation tests were conducted under the condition of 4 MPa confining pressure and 5 MPa axial pressure with infiltration pressures of 3, 2, 1, and 0 MPa, respectively, and the micro-CT scan system was used to scan the glauberite specimens before and after the experiment in order to study the fracture evolution inside the specimen, and a damage constitutive model was established to fit the time-dependent deformation curves based on the damage mechanics and effective stress principle. To simulate the solution mining process, the time-dependent deformation process of glauberite salt rock was divided into three stages: hydraulic connection stage, water-saturated stage, and drainage stage. The results demonstrate that the hydraulic connection time for glauberite salt rock decreases with increasing infiltration pressure. The time-dependent deformations of the specimens at the hydraulic connection and saturated-water stages are significantly affected by the effective stress and continual mineral dissolution. At the drainage stage, the softening degree of the solid skeleton mechanical properties, which is caused by the dissolution effect and infiltration pressure loading history, decides the deformation of glauberite salt rock. In addition, the degree of softening inside glauberite salt rock caused by dissolution becomes more severe with increasing infiltration pressure using the micro-CT scan technology. Lastly, the time-dependent damage constitutive model is able to describe the tri-axial time-dependent deformation behavior of glauberite salt rock, and the variations of time-dependent deformation parameters further indicate the damage evolution of the solid skeleton mechanical properties of glauberite caused by infiltration pressure and dissolution effect.
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PAN, PENG-ZHI, XIA-TING FENG, and HUI ZHOU. "RESEARCH ON THE EFFECT OF LOADING CONDITIONS ON THE STRENGTH AND DEFORMATION BEHAVIORS OF ROCKS." International Journal of Modern Physics B 22, no. 31n32 (December 30, 2008): 5545–50. http://dx.doi.org/10.1142/s0217979208050796.
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The paper aims at a numerical study of strength and deformation behaviors of rocks under different loading conditions in uniaxial compression with an elasto-plastic cellular automaton (EPCA2D) code. Two loading conditions, i.e. with and without considering frictions between loading platens and rock specimen's ends, are used in the failure processes of heterogeneous rocks. Rock specimens are assumed to be the same heterogeneity, i.e. the specimens with different sizes have the same probability of containing flaws. Under this condition, it is concluded that the strength and deformation behaviors of rocks are influenced by the heterogeneity a little. The mismatch of elastic properties of the platen and the rock in influencing the stress distribution at the ends of the specimen is the dominant cause for the so-called strength and deformation size effects, which in turn affects the final failure patterns of rocks.
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Shi, Da Kun, and Yang Song Zhang. "A Study on Stability of Expressway Tunnel Surrounding Rock Containing Weak Intercalated Rock." Advanced Materials Research 168-170 (December 2010): 2543–47. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.2543.
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Weak intercalated rock plays an important role in the stability of engineering rock mass. It controls the mechanism of deformation and breakage of rocks. Systematic numerical tests have been carried out to study the stability of surrounding rock mass with different distributions of weak intercalated rock has been analyzed by the FEM software ABAQUS. All of the numerical modelings are plain-strain type with elasto-plastic constitutive law and Drucker-Prager failure criterion. Some quantificational results about the influence of weak intercalated rock are summarized, especially the influence on the deformation, stress of surrounding rocks and plastic zone. Because of weak intercalated rock, the stress of surrounding rock appears the character of discontinuity. In addition, the distribution of plastic zone is also affected. When weak intercalated rocks exist in vault, spandrel and bottom, the situation of surrounding rock is comparatively unfavorable. These results have a certain role in guiding significance to the site selection and layout, the majorization of supporting system and the construction of tunnel of the same kind.
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Zhao, Chongbin, and Qibo Liu. "Investigating Effects of Structural Deformation Regimes on Mineralization Distributions in Fluid-Saturated Rocks: Computational Simulation Approach through Generic Models." Minerals 13, no. 5 (May 12, 2023): 664. http://dx.doi.org/10.3390/min13050664.
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Structural deformation regimes in the upper crust of the Earth can have significant effects on the distributions of pore-fluid flow in existing fissured and fractured zones, which are surrounded by fluid-saturated porous rocks. Based on the modern mineralization theory, mineralization distributions in ore-forming systems depend strongly on the distributions of pore-fluid flow velocity. Therefore, different structural deformation regimes associated with mineralization systems can remarkably affect mineralization distributions in existing fissured and fractured zones. This article utilizes a computational simulation approach, which is rigorously developed on the basis of fundamental scientific laws and principles, to solve coupled rock deformation, porosity–permeability evolution and pore-fluid flow problems, which are deeply involved in rock deformation driven mineralization systems. In particular, the porosity and permeability variations, which are caused by rock deformation, and often neglected in the previous studies of solving mineralization problems, are explicitly considered in the computational simulation approach of this study. The proposed approach is verified through a benchmark problem and, moreover, it was employed to examine how different structural deformation regimes can affect the mineralization distributions in existing fissured and fractured zones within the surrounding fluid-saturated porous rocks through using a generic model, which can be viewed as a representation of a generalized and simplified geological model. Main results obtained from this study have demonstrated the following conclusions: (1) consideration of porosity–permeability variations can have significant impacts on the computational simulation solutions of coupled rock deformation, porosity–permeability evolution and pore-fluid flow problems in fluid-saturated porous rocks; (2) different structural deformation regimes can have a significant effect on the mineralization enrichment distributions in ore-forming systems consisting of fluid-saturated porous rocks; (3) there are two favorable mineralization enrichment environments associated with compressional and extensional deformation regimes in ore-forming systems involving permeable fractured zones or faults.
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Liu, Gang, Dongwei Wang, Yonglong Zan, Shengxuan Wang, and Qiqi Zhang. "Feasibility Study of Material Deformation and Similarity of Spatial Characteristics of Standard Coal Rocks." Processes 12, no. 3 (February 23, 2024): 454. http://dx.doi.org/10.3390/pr12030454.
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The comparison between similar materials and original coal rock is the basis for similar simulation experiments in coal mines. The differences in mechanical properties, acoustic characteristics, and damage laws between similar materials and the original coal rock are of great significance for similar simulation research, to reveal objective laws. First, materials similar to coal rock with similar theoretical ratios were taken as the object of research, and the sand–cement ratio, the carbon paste ratio, and the water content were determined by multivariate linear regression to accurately match the ratios. Second, by using acoustic emission and digital scattering technology to explore the acoustic law, deformation characteristics, and spatial feature similarities of the materials similar to coal rock, the acoustic emission evolution law of the original rock was found to be the same as that of the similar materials. Digital scattering was able to describe the localization of strain in the similar materials, and the correlation between the overall deformation and the local deformation was explored. This indicates that materials similar to coal rock can effectively simulate the deformation of actual coal rocks. Lastly, these materials were found to allow effectively simulating the deformation characteristics and spatial properties of actual coal rock, which provides an important experimental means and method for similar research in the field of coal rock engineering.
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Zhang, Lei, Xufeng Wang, Zhijun Niu, and Jianbo Dai. "Simulation Analysis of the Influence of Amplitude on Deformation and Fracture Characteristics of Hard Rock under Ultrasonic Vibration Load." Processes 12, no. 1 (December 28, 2023): 74. http://dx.doi.org/10.3390/pr12010074.
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The utilization of auxiliary tools employing ultrasonic high-frequency vibration to enhance rock breaking efficiency holds significant potential for application in underground hard rock excavation engineering. To investigate the failure mechanism of rocks under high frequency ultrasonic vibration load, this study employs particle flow software PFC2D for numerical simulation. By incorporating boundary conditions from actual ultrasonic vibration rock breaking experiments and utilizing a parallel bond model to construct the rock, we analyze the deformation, damage, fracture, and energy evolution process of hard rocks subjected to vibrational loads. The results demonstrate that the maximum displacement in hard rocks increases nearly linearly with vibrations until reaching 5.0199 × 10−3 m, after which it plateaus. Additionally, macroscopic fissures formed during rock failure exhibit an X-shaped pattern. Furthermore, based on our model, we examine the impact of amplitude variation on hard rocks with an equal number of cycles (5,000,000 cycles). Under ultrasonic vibration loads, amplitude influences the total input energy within the rock system. While increasing amplitude does not alter maximum deformation in rocks, it enhances fragmentation degree, fracture degree and energy dissipation coefficient—thereby improving rock breaking efficiency.
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Wang, Fengnian, Shizhuang Chen, Pan Gao, Zhibiao Guo, and Zhigang Tao. "Research on Deformation Mechanisms of a High Geostress Soft Rock Roadway and Double-Shell Grouting Technology." Geofluids 2021 (October 31, 2021): 1–13. http://dx.doi.org/10.1155/2021/6215959.
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In this study, the deformation characteristics and mechanical properties of coal and rock mass in the S2N5 working face of the Xiaokang coal mine are analyzed to address the problem of large deformation of soft rocks with high in situ stress surrounding roadways. Through a newly developed grouting pipe, a double-shell grouting technology, consisting of low-pressure grouting and high-pressure split grouting, is proposed for the Xiaokang coal mine. In addition, the effect of grouting is evaluated by borehole peeping and deformation monitoring. The results show that the double-shell grouting technology can effectively improve the overall mechanical properties of the surrounding coal and rock mass, preventing the large deformation and failure of the roadway. This technology can be useful when analyzing and preventing large deformation of soft rock roadways.
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Grocholski, B. "Rock deformation goes magnetic." Science 353, no. 6307 (September 29, 2016): 1509–10. http://dx.doi.org/10.1126/science.353.6307.1509-f.
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Roberts, J. L. "Principles of Rock Deformation." Journal of Structural Geology 9, no. 8 (January 1987): 1055–56. http://dx.doi.org/10.1016/0191-8141(87)90016-2.
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Kozyrev, A. A., V. I. Panin, V. A. Mal'tsev, M. V. Akkuratov, and V. V. Zakharov. "Laws of rock deformation." Journal of Mining Science 32, no. 1 (January 1996): 18–25. http://dx.doi.org/10.1007/bf02046573.
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Roeloffs, Evelyn. "Radon and rock deformation." Nature 399, no. 6732 (May 1999): 104–5. http://dx.doi.org/10.1038/20072.
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White, J. M. "Principles of rock deformation." Earth-Science Reviews 24, no. 4 (October 1987): 293–94. http://dx.doi.org/10.1016/0012-8252(87)90074-2.
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SINITSA, I. V., E. A. ERMOLOVICH, and S. D. YATSYNYAK. "PREDICTING THE STOPINGINFLUENCE ON THE STRESS-STRAINSTATE OF THE MASSIF IN THE DOWNCAST SHAFT AREA." News of the Tula state university. Sciences of Earth 2, no. 1 (2023): 418–31. http://dx.doi.org/10.46689/2218-5194-2023-2-1-418-431.
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This article gives an assessment of the stress-strain state of the rock massif in the area of the downcast shaft located in rocks. The development of geomechanical processes in the rock massif in the downcast shaft area is considered. The problem of continuum mechanics is applied in a flat setting, taking into account the influence of camera phased development. Deformation processes in rocks are realized by introducing into the numerical model an elastic-plastic model of rock deformation. This approach makes it possible to increase the reliability of the stress-strain state of the massif prediction in the downcast shaft area.
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Zhao, Changzheng, Shenggen Cao, Shuyu Du, Chiyuan Che, and Xingyao Wang. "Failure Characteristics and Deformation Control Methods of the Bottom Drum of Roadways during Repeated Mining of Multiple Coal Seams." Geofluids 2022 (May 23, 2022): 1–14. http://dx.doi.org/10.1155/2022/3903370.
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As the problems of serious bottom drum and roadway broken surrounding rock are influenced by repeated mining in multiple coal seams, the factors affecting the surrounding rock deformation of a +980 m roadway in Faer coal mine by analyzing the rock composition and obtaining borehole video data are investigated. The mechanism of the overburden caving affected by repeated mining of multiple coal seams is analyzed theoretically, and the numerical simulation is conducted to evaluate the deformation mechanism of roadway bottom drum. A combined support technology is proposed consisting of bolts, anchor cables, grouting, and pressure relief grooves. The measurements obtained during a 50 d monitoring period indicate that the deformations of the roof, floor, and both sides of roadway in the repaired and reinforced section are only 26, 56, and 26 mm, respectively. The fissures filled with slurry in the rock surrounding roadway can prevent further deformation of the rock mass.
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Chepiga, Daria, Serhii Pakhomov, Vitalii Hnatyuk, Maksym Hryhorets, Yaroslav Liashok, and Serhii Podkopaiev. "Determining the deformation properties of crushed rock under compressive compression conditions." Eastern-European Journal of Enterprise Technologies 4, no. 1 (124) (August 31, 2023): 85–95. http://dx.doi.org/10.15587/1729-4061.2023.284386.
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The object of this study is the process that forms fill materials from crushed rock under load for managing the condition of side rocks in a coal-bearing massif with preparatory workings. Deformation properties of crushed rock under laboratory conditions were evaluated on the basis of a study of compressive compression of the fill material. It was registered that there is a quadratic functional dependence between the change in the bulk density of crushed rock of different granulometric composition and the specific potential energy of deformation. It was experimentally established that the specific potential energy of deformation reaches the limit values at the maximum compression of crushed rock when the fill material consists of parts of different sizes. For experimental samples with different thickness of the rock layer h0 (m), there was a linear relationship between their longitudinal deformation Dh (m) and the external load F (kN), which determined the behavior of the deforming body at critical levels. Under such conditions, with a relative change in the volume of the fill material dV=0.36, that is, with the same relative deformation at any values of the parameter h0 (m) and the compaction coefficient of the crushed rock kcon=1.57, the maximum stiffness of the rock supports was ensured. With a limited amount of external static load on the experimental samples, in the process of their deformation when the parameter h0 was reduced by 2 times before their compression, the compaction coefficient of the crushed rock increased from kcon=1.33 to kcon=1.57. At the same time, the specific potential energy of deformation increased by 40 %, which made it possible to ensure the maximum rigidity of the fill material at the minimum value of the longitudinal deformation Dh (m) of the experimental samples
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Fedotoval, Iuliia, Nikolay Kuznetcov, and Eduard Kasparyan. "Estimating the rockburst hazard of hard rocks based on laboratory test results." E3S Web of Conferences 129 (2019): 01008. http://dx.doi.org/10.1051/e3sconf/201912901008.
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The results of laboratory tests of samples are used to estimate rock proneness to dynamic fractures, in particular, by brittleness index. A common drawback of the approaches in use is that they do not expressly consider the main condition of dynamic rock fracture – rock mass ability to accumulate energy when loaded. The article discusses the results of studies of the nature of elastic energy accumulation during loading and deformation of samples of various rocks under uniaxial compression in order to assess the degree of their explosion. The approach is original as it studies the deformation curve of rocks at the pre-peak stage that may be obtained with any standard equipment without the use of special-purpose test (“rigid”) devices. Results of the studies conducted on standard test devices have allowed us to identify two different deformation patterns for the rock type tested with further establishment of criteria of rock classification by the degree of proneness to dynamic fractures. This approach is of practical value as it specifies the geomechanics zoning method of the rock mass and improves the assessment of rockburst hazard degree of specific areas at deposits being developed.
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Xu, Jiahui, Guichen Li, Ruiyang Bi, Haoyu Rong, and Changlun Sun. "Explanation on the Abnormal Behavior during the Nanoindentation Holding Stages by Amplifying Oscillation." Advances in Civil Engineering 2022 (January 18, 2022): 1–11. http://dx.doi.org/10.1155/2022/8886965.
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Recently, the holding states of nanoindentation experiments have been widely used to analyze the time-dependent deformations of various rocks, and the dynamic mechanical analysis (DMA) method seems to be more applicable than the quasi-static mechanical analysis (QMA) method when the influence of creep deformation on mechanical properties of rocks was analyzed. However, the former method causes an abnormal behavior during the creep holding stages that was not clearly interpreted.2 Consequently, in this study, by amplifying the oscillation of the DMA method, the mechanical mechanism of this phenomenon was explained. Experimental results confirm that the rheological deformation of rocks consists of the creep deformation (depth increasing) and the elastic aftereffect deformation (depth decreasing) during the creep time with small oscillation; once the elastic aftereffect deformation exceeds the creep deformation, the abnormal behavior can be observed. Besides, some other abnormal behaviors might be found for other rock materials when the DMA method with different oscillations is used, which illustrates the complexity and limitation of applying this method. Thus, the QMA method was recommended to investigate the above questions in future studies.
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Ping, Yang, and Shu Chen Li. "Triaxial Compression Experimental Study on Post-Peak Deformation Characteristics of Rock Masses with Persistent Joints." Advanced Materials Research 1030-1032 (September 2014): 1074–77. http://dx.doi.org/10.4028/www.scientific.net/amr.1030-1032.1074.
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Controlling the stability of surrounding rocks in underground excavations during in-depth resource development must be confronted with post-peak deformation and failure problems of jointed rock masses. This paper describes routine triaxial compression testing on standard cylinder specimen with persistent joints in different inclinations and under different confining pressures, and analyzes deformation characteristics of rock masses with persistent joints in different inclinations and under different confining pressures. Test results show that the peak strength, residual strength, and peak strain of the jointed specimen basically increase with increasing confining pressures but decrease with increasing joint inclinations. Test results well reflect that it is incorrect to evaluate deformation characteristics of jointed rock masses with continuum mechanics and research results provide a reference for the research on the stability of surrounding rocks in underground excavations.