JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Pre-Requisites

NIL

Course Objectives

To understand the rock mechanics, rock cutting technology, rock cutting tools and

rock excavating machine

Course Outcomes

The students will have knowledge about mechanism of rock excavation process,

influences of rock properties in excavation, rock cutting technology and types of excavating machines.

UNIT - I

Introduction: Concepts, historical developments in rock excavation systems, factors affecting the rock fragmentation, mechanism of rock breakage and fracture; their application to rock fragmentation methods– explosive action, cutting, ripping and impacts.

UNIT - II

Rock Properties: Rock properties related to excavation process; application of compressive, tensile and tri- axial strengths, index tests and abrasivity, anisotropy, elasticity, porosity, laminations, bedding and jointing in rock fragmentation process.

UNIT - III

Rock Cutting Technology: Mechanism of drilling – rotary, percussive, rotary percussive, mechanics of rock cutting, theory of single tool rock cutting, crack initiation and propagation, breakage pattern, rock excavation by cutting action – picks, discs, roller cutters, water jet cutting, methods of evaluation of drillability and cuttability index of rocks.

UNIT - IV

Rock Cutting Tools: Rock cutting tool materials, different types, relative applications and their choice, tool shape and size, specific energy consumption, tool wear, effect of operational parameters on tool performance, maintenance and replacement of cutting tools of excavating machines.

UNIT - V

Rock Excavating Machines: Excavating machines, principles, operation, applicability and technical indices of road headers, TBM’S coalface machines and bucket wheel excavators.

TEXT BOOKS:

• 1. Hartman, H.L., Introductory Mining Engineering, John Wiley and Sons, New York, 1987.
• 2. Clark, G.B., Principles of Rock Fragmentation, John Wiley and Sons, New York, 1987.

REFERENCE BOOKS:

• 1. Hartman, H. L. (Editor), SME Mining Engineering Handbook, 3rd edition, Vol I & II, Society of Mining Engineers, New York, 2011.
• 2. Chugh, C.P., Diamond Drilling, Oxford-IBH, 1984.