Strengthening of fractured rock pillar by the use of small radial reinforcement pressures. Figs, Tabls, Refs.

Three investigations into the mechanical relevance of wood rays were combined for this article. The main objective was to show, that, apart from physiological functions, rays also significantly influence the radial strength and stiffness of wood. In the first approach twelve deciduous tree species with various proportions of fractions of rays were examined for their transverse tensile strength and stiffness. The second approach was based on the comparison of the radial mechanical properties of wood with a very high proportion of fraction of rays and beech wood with a normal volume. In these two investigations the mechanical relevance of rays could only be deduced indirectly. By isolating big rays of beech and carrying out tensile tests on the tissue, we found direct evidence for the mechanical relevance. The results are discussed with regard to their biomechanical relevance. The importance of a radial reinforcement for the wood is underlined. Moreover, the principle of multi-functionality in nature is emphasized in keeping with a possible transfer of biological design to technical solutions.

Download Full-text

Demonstration and Validation of a Fractured Rock Passive Flux Meter

10.21236/ada621728 ◽

2015 ◽

Author(s):

Kirk Hatfield

Keyword(s):

Fractured Rock ◽

Passive Flux Meter

Download Full-text

The Model for Calculating Elastic Modulus and Poisson's Ratio of Coal Body

The Open Fuels & Energy Science Journal ◽

10.2174/1876973x20131011004 ◽

2013 ◽

Vol 6 (1) ◽

pp. 36-43 ◽

Cited By ~ 3

Author(s):

Ai Chi ◽

Li Yuwei

Keyword(s):

Elastic Modulus ◽

Poisson’S Ratio ◽

Fractured Rock ◽

Rock Block ◽

Poisson's Ratio ◽

Linear Elastic ◽

Study Results ◽

The Face ◽

Block Face ◽

Coal Rock

Coal body is a type of fractured rock mass in which lots of cleat fractures developed. Its mechanical properties vary with the parametric variation of coal rock block, face cleat and butt cleat. Based on the linear elastic theory and displacement equivalent principle and simplifying the face cleat and butt cleat as multi-bank penetrating and intermittent cracks, the model was established to calculate the elastic modulus and Poisson's ratio of coal body combined with cleat. By analyzing the model, it also obtained the influence of the parameter variation of coal rock block, face cleat and butt cleat on the elastic modulus and Poisson's ratio of the coal body. Study results showed that the connectivity rate of butt cleat and the distance between face cleats had a weak influence on elastic modulus of coal body. When the inclination of face cleat was 90°, the elastic modulus of coal body reached the maximal value and it equaled to the elastic modulus of coal rock block. When the inclination of face cleat was 0°, the elastic modulus of coal body was exclusively dependent on the elastic modulus of coal rock block, the normal stiffness of face cleat and the distance between them. When the distance between butt cleats or the connectivity rate of butt cleat was fixed, the Poisson's ratio of the coal body initially increased and then decreased with increasing of the face cleat inclination.

Download Full-text