One of the most crucial factors involved in the optimum design and cost estimation of rock sawing process is the rock abrasivity that could result in a significant cost increase. Various methods including direct and indirect tests have been introduced in order to measure rock abrasivity. The Schimazek’s F-abrasiveness factor ( ) is one of the most common indices to assess rock abrasivity.  is t...

Introduction: A bullet type sampler is sometimes used to obtain a sample from an asteroid on samplereturn missions [1]. On the other hand, in-situ analysis is demanded for the investigation of more amount of rock samples. Many drilling or coring devices have been developed [2-5]. Slicing the rock sample is preferable to observe its interior rather than shaving [6]. Because coolant cannot use in...

A new theoretical/empirical model has been developed for performance prediction of hard rock TBMs. The model uses information on the rock properties and cutting geometry to calculate TBM rate of penetration. The model can also be used for TBM butterhead design optimization to achieve maximum performance in a given geology.

This paper describes part of the construction of a second theater in the underground museum complex, below the Gateway Arch in St Louis. Given the needs for relatively quiet, non-intrusive rock removal, and yet precise cutting within the museum complex a method of using low pressure (35 MPa) abrasive laden waterjets was developed for cutting the vertical walls of the theater down to a depth of ...

Mechanical methods of tunnel excavation are widely used because their high output, and the selection appropriate technology depends on ground composition project-related features. Compared with boring machines (TBMs) roadheaders, mechanical pre-cutting in widening have proven to be reliable capacity expansion. other machines, characteristics not systematically analyzed rare use. In this study, ...

With its portable, simple and affordable attributes, the Schmidt hammer (SH) is an ideal index apparatus, which underlies its increasing popularity and expanding range of applications. The SH rebound hardness value (R) is perhaps the most frequently used index in rock mechanics practice for estimating the uniaxial compressive strength (UCS) and the modulus of elasticity (E) of intact rock both ...