نتایج جستجو برای: rock blasting

تعداد نتایج: 40275  

Journal: :int. journal of mining & geo-engineering 2014
najaf ali ghavidel hosein memarian soheil mohamadi mohammad heydarizadeh

considering the fact that rocks fail faster under tensile stress, rock tensile strength is of greatimportance in applications such as blasting, rock fragmentation, slope stability, hydraulic fracturing,caprock integrity, and geothermal energy extraction. there are two direct and indirect methods tomeasure tensile strength. since direct methods always encompass difficulties in test setup, indire...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تهران - دانشکده علوم 1387

چکیده ندارد.

2010
Selcuk Gumus Burak Aricak Korhan Enez H. Hulusi Acar

Nacrtak Forest roads provide access for people to study, enjoy or contemplate natural ecosystems. Therefore, roads are one of the most important tools needed in forestry. Forest roads are built by excavation of soil and rock. Rockfall occurs during construction works, caused by excavated rock pieces on embankment slopes and by blasting of block rock masses. This study analyzes rockfall damage t...

Journal: :JCP 2011
Yongmou Zhang Feihong Xie

In order to understand the stress changes of various points in sandy frozen soil, tension-compression conversion, fissure development on the surface, the rupture process, the expansion speed and scope of frozen soil duing blasting, the dynamic characteristics of thin-layered sandy frozen soil were analyzed in this paper. The blasting process of frozen soil is regarded as a dynamic pressure oper...

2012
Sung-Uk Kuh Young-Sung Kim Hong-June Choi Kyung-Hyun Kim Jeong-Yoon Park Hyun-Yong Jeong Dong-Kyu Chin Keun-Su Kim Young-Sul Yoon Yoon-Chul Lee Yong-Eun Cho

OBJECTIVE Polyaxial pedicle screws are a safe, useful adjunct to transpedicular fixation. However, the large screw head size can cause soft tissue irritation, high rod positioning, and facet joint injury. However, the mechanical resistance provided by small and low profile pedicle screws is very limited. We therefore developed a novel, low profile pedicle screw using grooving and blasting treat...

Rapid development of engineering activities expands through a variety of rock engineering processes such as drilling, blasting, mining and mineral processing. These activities require rock dynamic fracture mechanics method to characterize the rock behavior. Dynamic fracture toughness is an important parameter for the analysis of engineering structures under dynamic loading. Several experimental...

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