Bench stability in open pit mines : a methodology for jointed rock masses
The methods used to determine the overall gradients of the slopes in open pit workings aim to sufficiently eliminate all risk of failure on a scale comparable wich the pit walls. For this the slopes musc be made shallow gradual and reinforcing measures must generally be applied. Most often these consist of ensuring the drainage of the slopes and in limiting the effects of blasting (reinforcement is generally too costly in the case of very high slopes and deep planes of failure).
Risk and risk analysis in rock engineering
Abstract Risk analysis and decision-making procedures are being applied to large engineering projects with increasing frequency. Risk analysis is a versatile tool in decision-making, whether the decisions are in the form of an engineering design, selecting particular construction procedures, or more general decisions made by private or public entities. An overview of the basic aspects of risk analysis and decision-making are followed by a detailed discussion of three typical rock engineering applications: (1) slope design, (2) flow through fractured media, and (3) tunnelling. The paper includes examples from current tunnel projects (e.g., the Gotthard base tunnel, the Adler tunnel and the Lotschberg base tunnel).
Pasteurella haemolytica serotype 1 colonization of the nasal passages of virus-infected calves.
Nasal passages of calves with a virus-induced respiratory tract disease became colonized by Pasteurella haemolytica serotype 1 after they were inoculated intranasally with P haemolytica. Inoculation with infectious bovine rhinotracheitis virus caused a more severe clinical illness and resulted in a greater degree of colonization with P haemolytica than developed after inoculation with parainfluenza-3 virus. Nasal passages of parainfluenza-3 virus-inoculated calves were colonized to a greater degree with P haemolytica than were those of healthy, nonstressed calves. Calves were susceptible to P haemolytica colonization during or shortly after virus-induced illness, even though they had been previously exposed to P haemolytica and had serum antibody and nasal secretion antibody to P haemolytica.