There are a large number of non-penetrating collinear cracks in the rock slope an open-pit mine. The timeliness mass is problem that cannot be ignored terms engineering safety. Based on superposition principle and fracture mechanics, stress intensity factor crack tip with fractures under biaxial compression was calculated this study. A mechanical model propagation constant load established acco...

We report sulfur isotope anomalies with S, the deviation from a mass-dependent fractionation line for the three-isotope system (S/S vs. S/S), ranging up to 2‰ within individual Archean sedimentary sulfides from a variety of localities. Our measurements, which are made in situ by multicollector secondary ion mass spectrometry, unequivocally corroborate prior bulk measurements of mass-independent...

key factor in the successful application of a tunnel boring machine (TBM) in tunneling is the ability to develop accurate penetration rate estimates for determining project schedule and costs. Thus establishing a relationship between rock properties and TBM penetration rate can be very helpful in estimation of this vital parameter. However, this parameter cannot be simply predicted since there ...

a literature review revealed that most of the empirical equations introduced for determination of the uniaxial compressive strength (ucs) of rocks based on the schmidt hammer rebound number (n) are not sufficiently reliable mostly due to the relatively low coefficient of correlations. this is attributed to the fact that in most cases one formula is used for all types of rocks, although...