Extensive study on the impact of joint inclinations on the earth pressure in rock ground

Distinct Element Code ◽

Level Of Significance ◽

The Impact

Abstract The impact of different joint inclinations on the earth pressure was extensively carried out in this study, using Universal Distinct Element Code (UDEC) which is based on discrete element method. Numerical parametric investigations, which considered varying joint inclinations and rock types, were conducted after the numerical method had been verified through a physical model test. The joint angles considered ranged from 0º to 90º in the interval of 5º and the rock types are hard, slightly and moderately weathered rocks. The results of the analyses were subjected to statistical analysis using analysis of variance (ANOVA) at 5% level of significance, and compared with empirical earth pressure envelope for sand ground. The comparisons showed that earth pressures in rock ground are substantially varied from those in sand ground. The result of ANOVA revealed that joint inclinations have statistically significant effect on magnitude of the earth pressure, and practitioners should consider this factor while designing retaining structure in rock masses.

Effect of support characteristics on the earth pressure in a jointed rock mass

Canadian Geotechnical Journal ◽

10.1139/cgj-2014-0437 ◽

2015 ◽

Vol 52 (12) ◽

pp. 1956-1967 ◽

Cited By ~ 5

Author(s):

Moorak Son ◽

Solomon Adedokun

Keyword(s):

Rock Mass ◽

Earth Pressure ◽

Numerical Approach ◽

Jointed Rock ◽

Jointed Rock Mass ◽

Physical Model Test ◽

Joint Shear Strength ◽

Rock Stratum ◽

Rock Types ◽

The Earth

This study examines the magnitude and distribution of earth pressures against a support system in a jointed rock mass according to the support characteristics (strut stiffness and spacing), different rock types, and joint conditions (joint shear strength and joint inclination angle). A series of numerical parametric analyses were performed after verifying the numerical approach through a physical model test. These analyses were based on the discrete element method, which can take into account the joint characteristics of the rock strata and the interactions between the ground and the retaining structure. The results were compared with Peck’s earth pressure for soil ground, which showed that the magnitude and distribution of earth pressure are strongly affected by the support characteristics, rock types, and joint conditions, and that the earth pressure in the rock stratum can be significantly different from that in the soil ground. The results suggest that the support characteristics, including the rock types and joint conditions, are important factors affecting the earth pressure, and should be considered for the safe and economic design and construction of retaining structures in a jointed rock mass.

Effect of Damping Mode in Laboratory and Field-Scale Universal Distinct Element Code (UDEC) Models

Rock Mechanics and Rock Engineering ◽

10.1007/s00603-021-02609-6 ◽

2021 ◽

Author(s):

Sankhaneel Sinha ◽

Rami Abousleiman ◽

Gabriel Walton

Keyword(s):

Distinct Element ◽

Field Scale ◽

Buckling Failure Mechanism of a Rock Dam Foundation Fractured by Gentle Through-Going and Steep Structural Discontinuities

Sustainability ◽

10.3390/su12135426 ◽

2020 ◽

Vol 12 (13) ◽

pp. 5426

Author(s):

Donghui Chen ◽

Huie Chen ◽

Wen Zhang ◽

Chun Tan ◽

Zhifa Ma ◽

...

Keyword(s):

Numerical Method ◽

Failure Mechanism ◽

Shear Failure ◽

Distinct Element ◽

Mechanism Analysis ◽

Rock Masses ◽

Dam Foundation ◽

Deformation Features ◽

The failure mechanism analysis of dam foundations is key for designing hydropower stations. This study analyses the rock masses in a sluice section, which is an important part of the main dam of the Datengxia Hydropower Station currently built in China. The stability of the sluice rock masses is predominantly affected by gentle through-going soft interlayers and steep structural fractures. Its foundation failure mechanism is investigated by means of a numerical method, i.e., Universal Distinct Element Code (UDEC) and the geomechanical model method. The modeling principle and process, and results for the rock dam foundation are introduced and generated by using the abovementioned two methods. The results indicate that the failure mechanism of the foundation rock masses, as characterized by gentle through-going and steep structural discontinuities, is not a conventional type of shear failure mechanism but a buckling one. This type of failure mechanism is verified by analyzing the deformation features resulting from the overloading of both methods and strength reduction of the numerical method.

Formation, breaching and flood consequences of a landslide dam near Bujumbura, Burundi

Natural Hazards and Earth System Science ◽

10.5194/nhess-18-1867-2018 ◽

2018 ◽

Vol 18 (7) ◽

pp. 1867-1890 ◽

Cited By ~ 7

Author(s):

Léonidas Nibigira ◽

Hans-Balder Havenith ◽

Pierre Archambeau ◽

Benjamin Dewals

Keyword(s):

Distinct Element ◽

Mass Movement ◽

Geophysical Methods ◽

Landslide Dam ◽

Propagation Time ◽

Landslide Process ◽

Distinct Element Code ◽

Set Up ◽

Flood Intensity

Abstract. This paper investigates the possible formation of a landslide dam on the Kanyosha River near Bujumbura, the capital of Burundi, as well as the interplay between the breaching of this landslide dam and the flooding along the river. We present an end-to-end analysis, ranging from the origin of the landslide up to the computation of flood waves induced by the dam breaching. The study includes three main steps. First, the mass movement site was investigated with various geophysical methods that allowed us to build a general 3-D model and detailed 2-D sections of the landslide. Second, this model was used for dynamic landslide process modelling with the Universal Distinct Element Code. The results showed that a 15 m high landslide dam may form on the river. Finally, a 2-D hydraulic model was set up to find out the consequences of the breaching of the landslide dam on flooding along the river, especially in an urban area located downstream. Based on 2-D maps of maximum water depth, flow velocity and wave propagation time, the results highlight that neglecting the influence of such landslide dams leads to substantial underestimation of flood intensity in the downstream area.

Research on Mining Technological Parameters of 7# Thin Coal Seam in Liuquan Mine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.629.937 ◽

2012 ◽

Vol 629 ◽

pp. 937-942

Author(s):

Dong Sheng Zhang ◽

Xu Feng Wang ◽

Yang Zhang ◽

Jin Liang Wang

Keyword(s):

Coal Seam ◽

Distinct Element ◽

Horizontal Displacement ◽

Simulation Software ◽

Surrounding Rock ◽

Technological Parameters ◽

Thin Coal Seam ◽

Geological Conditions ◽

Aimed at the specific geological conditions of 7# thin coal seam in Liuquan Mine, this paper used the methods of numerical calculation and theoretical analysis to determine the reasonable technological parameters of high-grade conventional mining face. The numerical simulation software of UDEC (Universal Distinct Element Code) was used to contrast and analyse the characteristics of surrounding rock stress distribution and overlying rock horizontal displacement under the condition of different length of coalface, then it was indicated that the surrounding rock deformation was less when length of coalface was 110 m which was advantageous for roof control; according to the conditions of roof and floor, the roof support strength was being calculated systematically to determine the row space of props being 700×1200 mm; the main equipments of coalface was assorted, and reasonable work manner in coalface and gob processing measure was put forward, which provided guidance for efficient mining in thin coal seam.

Formation, breaching and flood consequences of a landslide dam near Bujumbura, Burundi

10.5194/nhess-2017-372 ◽

2017 ◽

Author(s):

Léonidas Nibigira ◽

Hans-Balder Havenith ◽

Pierre Archambeau ◽

Benjamin Dewals

Keyword(s):

Flood Hazard ◽

Distinct Element ◽

Mass Movement ◽

Geophysical Methods ◽

Landslide Dam ◽

Propagation Time ◽

Landslide Process ◽

Maximum Water ◽

Abstract. This paper investigated the possible formation of a landslide dam on the Kanyosha River near Bujumbura, the capital of Burundi, as well as the interplay between the breaching of this landslide dam and the flooding along the river. We present an end-to-end analysis, ranging from the origin of the landslide up to the computation of flood waves induced by the dam breaching. The study includes three main steps. First, the mass movement site was investigated with various geophysical methods that allowed us to build a general 3D model and detailed 2D sections of the landslide. Second, this model was used for dynamic landslide process modelling with the Universal Distinct Element Code. The results showed that a fifteen-meter-high landslide dam may form on the river. Finally, a 2D hydraulic model was setup to find out the consequences of the breaching of the landslide dam on flooding along the river, especially in an urban area located downstream. Based on 2D maps of maximum water depth, flow velocity and wave propagation time, the results highlight that neglecting the influence of such landslide dams leads to substantial underestimation of flood hazard in the downstream area.

Preliminary Study on the Progressive Failure of a Layered Rock Slope under Explosions

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.306-308.1461 ◽

2006 ◽

Vol 306-308 ◽

pp. 1461-1466 ◽

Cited By ~ 1

Author(s):

Y.Q. Liu ◽

Hai Bo Li ◽

H.C. Dai ◽

Jun Ru Li ◽

Qing Chun Zhou

Keyword(s):

Critical Point ◽

Rock Slope ◽

Progressive Failure ◽

Distinct Element ◽

Failure Process ◽

Two Dimensional ◽

Layered Rock ◽

Preliminary Study ◽

The progressive failure process of a layer rock slope under explosions is simulated using two-dimensional Universal Distinct Element Code (UDEC). It is shown that the failure process of the slope can be divided into three phases, the formation and growth of local failure area as well as coalescence of sliding plane. In addition, the displacement components of a critical point of the slope are also suggested to be a progressive process.

Correction of Earth Pressure and Analysis of Deformation for Double-Row Piles in Foundation Excavation in Changchun of China

Advances in Materials Science and Engineering ◽

10.1155/2016/9818160 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Yijun Zhou ◽

Aijun Yao ◽

Haobo Li ◽

Xuan Zheng

Keyword(s):

Physical Model ◽

Model Test ◽

Large Scale ◽

Similarity Theory ◽

Earth Pressure ◽

Physical Model Test ◽

Deep Foundation ◽

Foundation Pit ◽

Double Row ◽

The Earth

In order to study the earth pressure and the deformation behavior of the double-row piles in foundation excavation, a large-scale physical model test was introduced to simulate deformation of double-row piles in foundation excavation based on the principle of similarity theory in this paper. Represented by the deep foundation pit engineering of Changchun, the strain and the displacement of the double-row piles and the earth pressure are calculated by the above-mentioned physical model test. Then a numerical simulation has been carried out to validate practicability of the physical model test. The results show that the strain and the displacement of the front-row piles are larger than the back-row piles. The earth pressure of the front-row piles appears to be “right convex,” correcting the specification of the earth pressure and putting forward the coefficient of β. The results in this paper may provide constructive reference for practical engineering.

Physical and numerical tests of the excavation walls in jointed rock masses

Canadian Geotechnical Journal ◽

10.1139/cgj-2013-0081 ◽

2014 ◽

Vol 51 (5) ◽

pp. 554-569 ◽

Cited By ~ 12

Author(s):

Moorak Son ◽

Jaehyun Park

Keyword(s):

Physical Model ◽

Model Test ◽

Earth Pressure ◽

Jointed Rock ◽

Physical Model Test ◽

Rock Masses ◽

Jointed Rock Masses ◽

Rock Types ◽

Joint Characteristics ◽

Parametric Studies

This paper examines the magnitude and distribution of earth pressure on the support systems of open cuts in jointed rock masses. A physical model test was carried out using concrete blocks with man-made joints to represent a jointed rock mass. The model test was simulated numerically to provide a justifiable basis for extended numerical parametric studies. This study focused on the overall procedures of the physical model test, its numerical simulation, and extended numerical parametric studies. A comparison of the results from both the physical model test and numerical simulation confirmed that the applied numerical approach and methodology were suitable for further extended numerical parametric studies. The controlled parameters were the different rock types and joint characteristics including joint shear condition, joint spacing, and joint inclination angle. Results of the earth pressures from the numerical parametric tests in jointed rock masses were compared with Peck’s empirical earth pressure for soil ground. The comparison showed that the earth pressure in jointed rock masses can be very different from that in the soil ground. Accordingly, the effect of the rock types and joint characteristics needs to be considered when designing excavation support systems in jointed rock masses.

Numerical Investigation into Evolution of Crack and Stress in Residual Coal Pillars under the Influence of Longwall Mining of the Adjacent Underlying Coal Seam

Shock and Vibration ◽

10.1155/2019/2094378 ◽

2019 ◽

Vol 2019 ◽

pp. 1-18

Author(s):

Xin Wang ◽

Yuechao Wu ◽

Xuehua Li ◽

Shun Liang

Keyword(s):

Coal Seam ◽

Longwall Mining ◽

Distinct Element ◽

Movement Characteristics ◽

Voronoi Method ◽

Mining Safety ◽

Distinct Element Code ◽

Coal Pillars ◽

Residual Coal

Longwall mining of the adjacent coal seam with the presence of residual coal pillars overlying the seam can result in abnormal strata pressure and severe overburden failure, which poses a significant threat to mining safety. The threat is mainly manifested in the form of intense coal or rock burst and hazardous interconnection between gobs. This study employed the universal distinct element code (UDEC) to investigate the microscopic failure mechanism of the overlying residual coal pillars under the influence of longwall mining of an adjacent underlying coal seam in Yuanbaowan coal mine, China. Using the Voronoi method, we innovatively visualized the evolution of cracks in residual pillars, revealed the mechanism behind the failure of pillars, and explored the evolution and distribution of abutment stress. Also, strata movement characteristics during underlying panel extraction have been surveyed. Based on the modeling results, effective measures are proposed to ensure safe mining under residual coal pillars. This study might provide a certain reference for safe extraction of multiple seams in Datong Coalfield, China, and also in the central and western Appalachian Basin, United States, where many mining activities are carried out under residual pillars.