Structural Flashcards
The orientation in space of a line or plane.
Attitude
By convention, the attitude of a __________ is expressed as its strike and dip
Plane
The attitude of a __________ is expressed as trend and plunge
Line
The horizontal angle between a line a specified coordinate direction, usually true north or south
Bearing
The compass direction or azimuth
Bearing
The bearing of a horizontal line contain within an inclined plane
Strike
A line of equal elevation on a plane
Strike
There are an __________ number of parallel strike lines for any inclined plane
infinite
Vertical angle between an incline plane
Dip
A horizontal line perpendicular to its strike
Dip
The direction of ___________ can be thought of as the direction water would run down the plane
Dip
The bearing of a line
Trend
Non - horizontal lines trend in the down plunge direction
Trend
The vertical angle between a line and the horizontal
Plunge
Angle measured within an inclined plane between a horizontal line and the line in question.
Pitch
Also called Rake
Pitch
Vertical angle between an inclined plane and a horizontal line that is not perpendicular to the strike of the plane
Apparent Dip
For any inclined plane except a vertical one, the true dip is always ____________ than any apparent dip
greater
Two ways of expressing the strikes of planes and trends of lines
- Azimuth Method
- Quadrant Method
Method based on a 360 clockwise circle
Azimuth
Method based on four 90 quadrants
Quadrant Method
4 Major techniques for solving Apparent Dip Problems
- Orthographic Projection
- Trigonometry
- Alignment Diagrams (nomograms)
- Stereographic Projection
This method is particularly suitable when very small dip angles are involved
Trigonometric Solution
A method that is more time consuming but it helps you to develop the ability to visualize in three dimensions and to draw precisely
Orthographic Projection