Mechanics of Materials: Principal Stresses

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Why can rocks undergo significant deformation below the transition point?

Because the strain rates applied are extremely fast

Because the strain rates applied are extremely slow (correct)

Because the rocks are extremely cool

Because the rocks are extremely hot

What is the characteristic of the upper crust?

It is cool

It is mainly ductile

It is hot

It is mainly brittle (correct)

What is the area of maximum curvature in a fold?

Limb

Hinge (correct)

Syncline

Anticline

What is the term for fracture or failure surfaces in rock masses?

Joints Signup and view all the answers

What is the term for rocks that contain neither joints nor hair cracks?

Intact Rock Signup and view all the answers

What is the term for the classification of discontinuities in rock masses?

Terzaghi's Classification Signup and view all the answers

What is the primary purpose of a geological map?

To show the aerial extent of different types of bedrock and/or superficial deposits Signup and view all the answers

What is the term for the angle the plane makes with the horizontal?

Dip Signup and view all the answers

What is the term for a layer of sedimentary rock that is distinctly different from overlying and underlying layers?

Beds Signup and view all the answers

What is the term for the point where the rock is exposed at the surface?

Outcrop Signup and view all the answers

What is the subsidence hazard in case (a) due to?

The presence of soluble rock underlying the site Signup and view all the answers

What is the term for a break in the geological record, where older rocks are overlain by younger rocks?

Unconformity Signup and view all the answers

What type of fault occurs when there is horizontal compression with slip parallel to the dip of the fault surface?

Reverse fault Signup and view all the answers

What is the result of horizontal layers being subjected to compressive forces?

Folds Signup and view all the answers

What is the characteristic of a fault with a dip of less than 450?

Thrust fault Signup and view all the answers

What is the term for the process by which rocks undergo a transition from brittle behavior to ductile behavior?

Transition under pressure Signup and view all the answers

What type of fault occurs when there is horizontal shear with slip parallel to the strike of the fault surface?

Strike-slip fault Signup and view all the answers

What is the definition of a fault?

Any fracture with a significant displacement Signup and view all the answers

What is the unit of pressure?

Force per unit area Signup and view all the answers

What is the relationship between stress and pressure?

Stress is pressure per unit area Signup and view all the answers

What is the unit weight of the shale unit in the example problem?

27.5 kN/m3 Signup and view all the answers

What is the formula for calculating the vertical stress?

σv = γa ha + γb hb Signup and view all the answers

What is the porosity of the shale at a depth of 600 ft?

33.5 % Signup and view all the answers

What is the unit of γdry?

kN/m3 Signup and view all the answers

What is a potential consequence of blasting on the rock?

Spalls may drop off the roof several hours or days after blasting Signup and view all the answers

What is one of the index properties of rock that can be determined through visual description?

Color Signup and view all the answers

What is the purpose of a triaxial compression test?

To determine the deformability of rock Signup and view all the answers

What is one of the methods used to determine the mineralogical composition of rock?

Optical microscopy Signup and view all the answers

What is one of the mechanical properties of rock that can be determined through a direct tension test?

Tensile strength Signup and view all the answers

What is one of the index properties of rock that can be determined through a permeability test?

Permeability coefficient Signup and view all the answers