scholarly journals Estimation of Size Effects in Rock Strength Based on Specific Energy

2004 ◽  
Vol 120 (10,11) ◽  
pp. 555-559 ◽  
Author(s):  
Katsunori FUKUI ◽  
Seisuke OKUBO
Keyword(s):  
Specific Energy ◽  
Size Effects ◽  
Rock Strength ◽  
Strength Based

Investigation on jointed rock strength based on fractal theory

2017 ◽  
Vol 24 (7) ◽  
pp. 1619-1626 ◽  
Author(s):  
Lan-lan Yang ◽  
Wei-ya Xu ◽  
Qing-xiang Meng ◽  
Ru-bin Wang
Keyword(s):  
Rock Strength ◽  
Fractal Theory ◽  
Jointed Rock ◽  
Strength Based

scholarly journals Investigating the Effects of Mechanical Properties of Rocks on Specific Energy and Penetration Rate of Borehole Drilling

2020 ◽  
Author(s):  
Peter Kolapo
Keyword(s):  
Mechanical Properties ◽  
Specific Energy ◽  
Rock Strength ◽  
Penetration Rate ◽  
Testing Machine ◽  
Correlation Coefficients ◽  
Point Load ◽  
Drilling Process ◽  
Load Testing ◽  
Linear Relationships

Abstract This paper deals with the analysis of effects of mechanical properties of rock on penetration rate and specific energy. Five specimens were collected from the four locations in Federal capital territory, Abuja. These samples were subjected to laboratory point load strength index using point load testing machine. Results of the point load tests were used to estimate the uniaxial compressive strength of the rocks. The penetration rate and specific energy were determined using empirical equations. The results from the investigation showed that the rate of penetration decreases with increase in rock strength and the specific energy increases with increase in rock strength. Based on the investigation, a number of linear relationships that described the effects of mechanical properties on penetration rate in the drilling process were obtained with strong correlation coefficients.

Studies on Rock-Breaking of Positive Disc Cutter and Edge Disc Cutter

2014 ◽  
Vol 508 ◽  
pp. 159-164 ◽  
Author(s):  
Kai Yang ◽  
Yi Min Xia ◽  
Yuan Wu
Keyword(s):  
Energy Consumption ◽  
Simulation Model ◽  
Specific Energy ◽  
Inflection Point ◽  
Rock Strength ◽  
Specific Energy Consumption ◽  
Rock Breaking ◽  
Disc Cutter ◽  
Installation Angle ◽  
Optimal Values

Based on TBM disc cutter layout, a rock-breaking model of positive disc cutter and edge disc cutter is built. Sequential rock-breaking of the two cutters under different parameters is simulated; rock fragmentation, three-axis force and energy consumption are studied; optimal rock-breaking condition with different parameters is determined; feasibility of the simulation model is finally verified by experiment. The results show that three-axis force of positive disc cutter and edge disc cutter both increase with the increase of rock strength. Also, the increase of installation angle leads to larger three-axis force of edge disc cutter. Compared with positive disc cutter, edge disc cutter suffers larger squeezing strength from rocks, which results in larger three-axis force in edge disc cutter. Specific energy consumption variation has an inflection point. To meet optimal rock-breaking condition, the optimal values of installation angle in breaking siltstone, granite and marble are respectively 6°, 7° and 7°.

Strength-Based Attachment Model of Latina/o College Students' Psychological Adjustment

2008 ◽  
Author(s):  
Patton O. Garriott ◽  
Keisha M. Love ◽  
Kenneth M. Tyler ◽  
Deneia M. Thomas ◽  
Carrie L. Brown
Keyword(s):  
College Students ◽  
Psychological Adjustment ◽  
Strength Based ◽  
Attachment Model
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