scholarly journals Drag bit/rock interface laws for the transition between two layers

2022 ◽  
Vol 150 ◽  
pp. 104980
Author(s):  
Arviandy G. Aribowo ◽  
Roeland Wildemans ◽  
Emmanuel Detournay ◽  
Nathan van de Wouw
Keyword(s):  
Rock Interface

Application of Improved Canny Edge Detection Algorithm in Coal-Rock Interface Recognition

2012 ◽  
Vol 220-223 ◽  
pp. 1279-1283 ◽  
Author(s):  
Li Hong Dong ◽  
Peng Bing Zhao
Keyword(s):  
Edge Detection ◽  
Detection Algorithm ◽  
Canny Edge Detection ◽  
Edge Detection Algorithm ◽  
Canny Edge ◽  
Rock Interface ◽  
Coal Rock ◽  
Image Edge ◽  
Canny Algorithm ◽  
Canny Edge Detection Algorithm

The coal-rock interface recognition is one of the critical automated technologies in the fully mechanized mining face. The poor working conditions underground result in the seriously polluted edge information of the coal-rock interface, which affects the positioning precision of the shearer drum. The Gaussian filter parameters and the high-low thresholds are difficult to select in the traditional Canny algorithm, which causes the information loss of gradual edge and the phenomenon of false edge. Consequently, this paper presents an improved Canny edge detection algorithm, which adopts the adaptive median filtering algorithm to calculate the thresholds of Canny algorithm according to the grayscale mean and variance mean. This algorithm can protect the image edge details better and can restrain the blurred image edge. Experimental results show that this algorithm has improved the edge extraction effect under the case of noise interference and improved the detection precision and accuracy of the coal-rock image effectively.

Creep of frozen slopes and ice-filled rock joints under temperature variation

2006 ◽  
Vol 33 (6) ◽  
pp. 719-725 ◽  
Author(s):  
Branko Ladanyi
Keyword(s):  
Creep Behavior ◽  
Large Scale ◽  
Variable Temperature ◽  
Theoretical Models ◽  
Rock Joints ◽  
Interface Problems ◽  
Frozen Ground ◽  
Rock Glaciers ◽  
Rock Interface ◽  
Creep Temperature

Owing to climate warming trends, there has been an increasing interest in recent years in the accelerating creep of rock glaciers and frozen slopes. In the field of glaciology, the creep of glaciers has been extensively studied, observed, and analyzed for more than 100 years. Many valuable and detailed theoretical models have been proposed through the years for simulating the creep behavior of glaciers. This synthesis paper has no intention of proposing another one. Its purpose is only to supply to these models a potential geotechnical background, borrowed from the connected fields of frozen ground mechanics, rock mechanics, and the mechanics of mixtures. In particular, this paper attempts to extend some known models of mechanical behavior of unfrozen soil and rock masses to masses containing ice and to apply these models to large-scale creep of ice–rock mixtures and ice–rock interface problems under variable temperature and stress conditions.Key words: ice, rock, mixture, rock joints, slope stability, creep, temperature.

scholarly journals Cutting Mechanical Study of Pick Cutting Coal Seams with Coal and Rock Interface

2021 ◽  
Author(s):  
Chenxu Luo ◽  
Junbei Qaio
Keyword(s):  
Compressive Strength ◽  
Coal Seam ◽  
Mechanical Model ◽  
Impact Load ◽  
Strength Analysis ◽  
Strength Condition ◽  
Rock Interface ◽  
Coal Rock ◽  
Rotary Cutting ◽  
Mining Coal

Abstract Shearer provide an effect solution for mining coal, and the cutting performance of pick largely accouts for the ability of a shearer and mining performance. We conducted pick cutting coal experiments in different seam forms on the coal and rock cutting teasted. According to the rotary cutting mechanical model of single pick cutting coal seam, combined with the strength condition of coal seam and coal-rock interface, the rotary cutting mechanical model of pick cutting coal seam with coal-rock interface is established. The stress strain and strength condition of the area in and around the interface are analyzed based on the coal-rock interface crushing theory, which provides basis for further research on the cutting mechanical model of single pick crossing the coal-rock interface. According to the analysis on the ampulitude domain, the phenomenon that force increment between the pick cutting rock and uniform coal seam linearly increases with the increase of compressive strength difference between coal seam and coal-rock interface, and the load fluctuation keep a positive correlation with the compressive strength. Analysis on the signals of the pick cutting coal seam with coal and rock interface at different conditions shows that some basic properties of the cutting load changes over times. In addition, the coal seam with coal-rock interface appears larger impact load and other time-domain characteristics.

An Analytical Model to Predict the Push-Out Capacity of Mortar from Rock Block

2011 ◽  
Vol 250-253 ◽  
pp. 2396-2406
Author(s):  
Shu Tong Yang
Keyword(s):  
Analytical Model ◽  
Interfacial Shear Stress ◽  
Tensile Load ◽  
Interfacial Shear ◽  
Rock Block ◽  
Ground Anchors ◽  
Proposed Model ◽  
Wide Range ◽  
Rock Interface ◽  
Push Out

Ground anchors have been very practical in a wide range of geotechnical structures. Good bond properties at the anchor-mortar and mortar-rock interfaces can ensure transmitting an applied tensile load to a load bearing structure efficiently. The bond performance between the mortar and rock is necessary to be studied. A push-out test of mortar from rock block can be used to analyze the interfacial properties between the two materials. In this paper, an analytical model is proposed to determine the push-out capacity of mortar from rock block. Based on the deformation compatibility at the interface, the compressive stress in the mortar and the interfacial shear stress at the mortar-rock interface are formulated at different loading stages. By modeling interfacial debonding as an interfacial shear crack, the push-out load is then expressed as a function of the interfacial crack length. In virtue of the Lagrange Multiplier Method, the maximum push-out load is determined. The validity of the proposed model is verified with the experimental results. It can be concluded that if the interfacial parameters at the mortar-rock interface are obtained, the push-out capacity of mortar from rock block can be accurately determined using the proposed model. The proposed solution in this paper would provide a good theoretical basis in evaluating the stability of ground anchors in practice.

scholarly journals Elastic Modulus Calculation Model of a Soil-Rock Mixture at Normal or Freezing Temperature Based on Micromechanics Approach

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hao Yang ◽  
Zhong Zhou ◽  
Xiangcan Wang ◽  
Qifang Zhang
Keyword(s):  
Composite Material ◽  
Elastic Modulus ◽  
Freezing Temperature ◽  
Calculation Model ◽  
Frozen Soil ◽  
Experimental Comparison ◽  
Mesoscopic Structure ◽  
Embedded Model ◽  
Single Inclusion ◽  
Rock Interface

Considering rock wrapped by soil in the mesoscopic structure of soil-rock mixture at normal temperature, a two-layer embedded model of single inclusion composite material was established to obtain the elastic modulus of soil-rock mixture. Given an interface ice interlayer attached between the soil and rock interface in the mesoscopic structure of soil-rock mixture at freezing temperature, a three-layer embedded model of double inclusion composite material and multistep multiphase micromechanics model was established to obtain the elastic modulus of a frozen soil-rock mixture. With the effect of structure pore with soil-rock mixture at normal temperature taken into consideration, its elastic modulus was calculated with the three-layer embedded model. An experimental comparison found that the predicted effect of the three-layer embedded model on the soil-rock mixture was better than that of the two-layer embedded model. The elastic modulus of soil-rock mixture gradually increased with the increase in rock content regardless of temperature. The increase rate of the elastic modulus of the soil-rock mixture increased quickly especially when the rock content is between 50% and 70%. The elastic modulus of the frozen soil-rock mixture is close to four times higher than that of the soil-rock mixture at a normal temperature.

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