Mechanical characters of rock
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This document summarizes the key mechanical properties of rocks, including density, specific gravity, strength, strain, stress, porosity, and permeability. It defines each property, provides examples for common rock types, and notes that mechanics refers to how materials respond to applied loads. The conclusion restates that the document covered the mechanical characteristics of rocks according to these seven properties.
Mechanical characters of rock
- 2. contents Introduction Mechanical characters of rocks Density specific gravity strength strain stress porosity permeability Conclusion reference
- 3. INTRODUCTION The material can be divided as rocks,soil,&fluid. Rocks are the important building materials and they provide foundation to many engineering structure. Mechanicsm refers to the response of materials to applied load. This seminar deal with mechanical characters of rocks
- 4. DENSITY Density is the term for how heavy an object is for its size. Density is usually expressed in units like grams per cubic centimeter (g/cc or g/cm3 ), kilograms per cubic meter, pounds per cubic inch. Rocks considerably in high density, so the density of a rock is often a good identification tool and useful for distinguishing limestone (2.6 g/cm3 or less), quartzite (2.7 g/cm3 ), and granite (2.7-2.8 g/cm3 ) are all common low-density rocks. The basalt one of the most common kinds of volcanic rocks, its can be as high density as 3.0 g/cm3 .
- 5. SPECIFIC GRAVITY . Specific gravity is the ratio of the mass (weight) of a rock to the mass of the same volume of water. Water has a density of 1.0 g/cm3 , so the numeric value of specific gravity for a rock is the same as that for density. Because specific gravity is a ratio, it has no unit. Specific gravity is easier to measure than density.
- 6. STRENGTH The strength of a material defined as the lode under which the material cracked and disintegrated. The experimental definition of strength is determined by increasing the lode observing at the point at which the first crack appeared. It is obvious that such criteria can’t applied to a piece of rocks which is completely surrounded by other rock at the depth in the earth’s crust.
- 7. STRAIN Strain is the deformation caused by the strees,strain may be dilation which is a change in volioum or distortion which change in the form or both. The application of stress to a material causes it to deform. The amount of deformation is called strain. axial strain:- deformation along the direction of loading. lateral strain:- the lateral extension perpendicular to the direction of loading. Poisson's ratio = (lateral strain)/(axial strain).
- 10. STRESS Stress is force per unit area acting on a plane at any point within a material. There are three types of stresses: compressive stress:- equal forces that act towards a point from opposite directions tensile stress:- equal forces that pull away from each other. shear stress:- equal forces that operate in opposite directions across the body.
- 12. POROSITY Porosity is an index of the amount of the groundwater that can be stored in the saturated formation. Porosity Is the ratio between the total voids or pores of particular rocks to the total volume of the same rocks. It is usually expressed in percentage of the bulk volume of the rocks. There are two type of porosity Primary porosity (before the formation) Secondary porosity (after the formation)
- 13. Primary & secondary porosity
- 14. PERMEABILITY Is the capacity of porous medium to transmit water or liquid .ie,a relative easy to flow of a liquid under unequal pressure. It a factor how a rock will act as a source of water for a well A rock permeable when the rock has got many connected pore space
- 15. conclusion Mechanicsm refers to the response of materials to applied loads. specific gravity: the ratio between the mass and that of equal volume of water. porosity n: measurement of the relative amount of void space . permeability: measurement of the rate at which fluids will flow through a saturated materials. Stress is force per unit area acting on a plane at any point within a material.
- 16. Cont.…… The application of stress to a material causes it to deform. The amount of deformation is called strain. According to above mention features density, specific gravity,strenght,strain,stress,porosity,and permeability, are the mechanical characters of rocks.
- 17. REFERENCE Books L.U de Sitter STRUCTURAL GEOLOGY (1956)McGraw- HILL publishing company limited new york landon p18-p30 Marland P Billings STRUCTURAL GEOLOGY(1984) third edition prenticve hall of India privet limited new Delhi, p11-p34 NW Gokhale THE THEORY OF STRUCTURAL GEOLOGY (1996) CBS Publication & Distribution, p5-p19 Internet file:///F:/Mass,%20Weight,% 20Density%20or%20Specific%20Gravity%20of%20Bulk%20Materials.htm www.google.com