overbreak

From Middle English *overbreken, from Old English oferbrecan (“to transgress, violate”), equivalent to over- +‎ break.

overbreak (third-person singular simple present overbreaks, present participle overbreaking, simple past overbroke, past participle overbroken)

1. (intransitive) To cave in near the edge of an excavation.
   • 1958, Australasian Institute of Mining and Metallurgy, Proceedings - Australasian Institute of Mining and Metallurgy: Issues 183-188:

     This proved wise as the south and west walls of the winder chamber overbroke badly and blocky ground was encountered in the area set aside for the electrical equipment.

2. (transitive, UK dialectal) To get over; recover from.

   He was never able to overbreak his rheumatism.

overbreak (plural overbreaks)

1. (civil engineering, geology) Rock or earth excavated beyond the planned extent; caving in of material near the edge of an excavation.
   • 1946, Karl Terzaghi, Rock Defects and Loads on Tunnel Supports, page 49:

     The overbreak depends on several factors. Foremost among them are the following: Spacing between the joints. Shattering effect of blasting on the rock located beyond the payline.

   • 2001, W.A. Hustrulid, Richard Bullock, Underground Mining Methods: Engineering Fundamentals and International Case Studies‎, page 248:

     The presence of faults and joint structures in stope walls within the ore body has resulted in overbreak of ore into adjacent stopes.

• underbreak

• overbrake