overbreak

overbreak

[′ō·vər‚brāk]
(civil engineering)
Rock excavated in excess of the neat lines of a tunnel or cutting. Also known as backbreak.

overbreak

Any excavation beyond the limits set by the neat line.
References in periodicals archive ?
Unplanned dilution consists of waste, which is mined due to overbreak, which may result from poor drilling or blasting or as any waste incorporated during mucking.
If continuously forced toward the same side of the wall, overbreak occurs and the bit naturally wanders in that direction.
In [18, 19], artificial neural networks were combined with multiregression in order to optimize overbreak prediction.
ABSTRACT: Discontinuities are an integral part of the rock masses and pose special problems in blasting operations in mining and civil industries resulting in high excavation cost due to underbreak and overbreak problems.
Our aim has been to reduce the risk of people working beneath unsupported ground during heading development, as well as to cut the amount of heavy manual handling that face crews need to do when installing supports such as steel arches." The MR341 can be equipped for PLC control, which then allows cutting profile control to be included--an important feature where arch support is being used, since both under- and overbreak must be minimized.
Occurrence mode Comprehensive mode Related indexes Affects the limit support stress ratio (B1) Basic indexes Change of strata (B2) (no.) Overbreak of the affected strata (B3) Shield-excavating equipment design (D1) Design indexes Shield-pushing equipment design (D2) (no.) Strata adaptability of the shield (D3) Level of the construction technology (C1) Construction Construction period (C2) indexes (no.) Construction environment (C3) Control measures (C4) The limit support stress ratio is the ratio of the value of limit support stress to original lateral geostress, where the limit support stress refers to the minimum stress that can support face stability.
Any dilution from overbreak also contains lower grade mineralisation that has been quantified by estimation against the Resource model
Zip-It bags from Overbreak LLC, Sun Valley, Calif., come in a variety of sizes and, since they start out so small, you can bring more than one on road trips.
Possible applications, amongst others, include milling of trenches down to a width of 700 mm -- true to profile and without unnecessary overbreak, tunnelling, demolition and asphalt cutting.
The overbreak of the blast influences slope stability, slope steepness, pit safety and scaling costs.
It automatically scans overbreak and underbreak to save valuable time during the drilling cycle, helping customers develop more meters every month.
LineChaserz, from Overbreak LLC, Sun Valley, Calif., are among the hottest new vehicles to race onto the market in years.