Non-blasting Excavation
As the restriction of the surrounding conditions, non-blasting method of rock excavation have to be use. Different kinds of non-blasting methods for rock excavation are introduced in this chapter.
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Non-blasting Excavation
Non-blasting methods for rock excavation may be required in some situations: • The excavation site is very close to the public area; any flyrock which may be caused by blasting is a major concern even if protective measures are adopted; • There are some very sensitive receivers to ground vibration induced by blasting, like some important buildings or facilities, some monuments or some precise instrument, in the adjacent area of the excavation site; • Nearby slopes or natural terrain where blasting may affect the stability or cause rockfalls which may threaten the safety of people or structures; • Small quantity of rock excavation, so no need to apply for a blasting permit from the local authority, which may consume time and effort.
7.1 7.1.1
Manual Splitting and Hydraulic Rock Breaker Manual Splitting
Manual splitting is usually used for small-scale rock excavation. Holes are first drilled along a line on the rock at a certain spacing. The distance depends upon the drillhole diameter and rock characters. Small holes (40–50 mm) with small spacing are used for small splitting tools and large holes (76–89 mm) with larger spacing are used for larger splitting tools. The tools which are used to split the rock consist of one to three pieces, and one or two of them have a wedge shape (see Fig. 7.1). The wedge splitter is pushed into the drillhole by hand hammer (8 or 12 lbs) for small hole splitting, or hydraulic hammer for large holes.
© Metallurgical Industry Press and Springer Science+Business Media Singapore 2017 D. Zou, Theory and Technology of Rock Excavation for Civil Engineering, DOI 10.1007/978-981-10-1989-0_7
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7 Non-blasting Excavation
Fig. 7.1 Spliters for manual splitting
7.1.2
Hydraulic Hammer Breaker
Hydraulic hammer breaker is a common method used for non-blasting excavation of rock. The main working components of a hydraulic hammer breaker include cylinder, piston, control valve, and chisel (breaking tool) (see Fig. 7.2). The impact energy has a wide range, from
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