© 2018, Editorial Office of Chinese Journal of Geotechnical Engineering. The effects of the dilatancy, elastic strains in the plastic zone and strength theory should be comprehensively considered. The dilatancy and the elastic strains in the plastic zone affect the plastic displacement of tunnel significantly, and the influencing extent of these two factors obviously varies with different strength criteria. The inscribed Drucker-Prager criterion and the Mohr-Coulomb criterion are not encouraged. The application of the unified strength theory with parameter b=1 and the circumscribed Drucker-Prager criterion should be adopted cautiously. The effect of strength theory in elastic-plastic analysis of a circular rock tunnel is remarkable, therefore the generalized Matsuoka-Nakai criterion, the unified strength theory with parameter b=1/2, the Mogi-Coulomb criterion and the generalized Lade-Duncan criterion are recommended to be adopted. The new solutions of elastic-perfectly plastic rock can be degraded into many existing solutions and have broad applicability. It is found that the unified linear equation is concise and flexible, which is convenient to discuss the effect of strength theory. Finally, both the effect of strength theory and parametric studies about the plastic displacement of tunnel are investigated. Furthermore, the feasibility analysis of the obtained solutions is carried out. Then, with considerations of dilatancy and different elastic strains in the plastic zone, new solutions for stress and displacement of elastic-perfectly plastic rock are deduced. Under the plane strain condition, a unified linear equation is first established inductively for eight commonly used strength criteria in geotechnical engineering. and also markedly reduced the environmental implications from production blastsduring day-to-day operations.Ī reasonable strength criterion is very critical in elastic-plastic analysis of rock tunnel. The work led to huge cost benefits in explosive consumption for the company i.e. Through systemic analysis of blast-results and implementation of scientific theories combined with the usage of rock parameters and its physico-mechanical properties, it could possible to achieve around 2.0 m ³ /kg powder factor instead of 1.3-1.4 m ³ /kg maintaining stable highwall benches with 70 ⁰ or more slope angle. Good fragmentation was achieved through improved rock-explosive interactions and redefined design parameters in the trench which had restricted width and lesser initial powder factor (in m ³ /kg) due to varying rock-geologic and rock-explosive characteristics. (SECL) was the endeavour of the research team of CSIR-CIMFR in the first trench highwall mining of India. Stabilization of highwall slope by implementing presplit blasting and productivity enhancement by improving the powder factor using controlled blasting at Sharda project of South Eastern Coalfields Ltd.
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