1. Structural Mechanics and Materials

One way vs Two way slab

Determinate Beam formula/Degrees of freedom

R (DofF) < 3 n

Determinate Truss/ Degrees of Freedom

M + R (DofF) < 2 J

Stress-Strain Curve

Poisons Ratio

Deflection/ flexibility/ stiffness

See notebook :)

Shear displacement

Delta = Gamma (rad) x L

Average Strain

Max Shear stress of a rectangle and a circle

Shear Flow formula meaning

q = (# Bolts x Bolt capacity) / Spacing

beams subject to eccentric loads

beams subject to axial loads and moments

Formula for Specific gravity

Unit weight of soil/ Unit weight of water

AASHTO GI

Group Index = Indicator of the suitability for the soil to be used as subgrade, the lower the better

Permeability tests

Falling and Constant head test

Total Vertical stresses formulas

When the water table increases, what happens to the effective stress?

Decreases

Latera Soil Pressure, formula, types, and section

Section 3.1

At rest, no movement = Ko

Active pressure, Soil pushes = Ka

Passive, Soil is being pushed = Kp

Lateral Pressure vs Lateral Strain (Movement) relationship

Lateral strain to mobilize passive soil > Lateral strain to mobilize active soil

Rankine Theory Assumptions

-No friction

-Resultant force is parallel to the backfill soil

-Soil/Wall interface is vertical

Colum Theory Assumptions

-There is Friction

-Lateral Pressure is not limited to vertical walls

-Resultant force is not necesarily parallel

Factor of Safety: Overturning

• Vertical Weights

• Lateral Active Forces

Factor of Safety: Sliding

• Horizontal Friction forces

• Lateral Active Forces

Lateral Stresses for groundwater

Surcharge Load Formula

= K*q*H

Settlement and Consolidation

Initial Settlement: Expulsion or air, elastic deformation of the soil

Primary Consolidation: Volume change from expulsion of water, Occurs fast for sandy soils and slow for Clayey soils

Secondary Consolidation: Restructure of soil Particles

Sandy Soils Settlement

• Immediate

Clayey Soils Settlement

• Long Term

Over Consolidation Ratio

Normally consolidated = OCR = 1

Under consolidated = OCR < 1

Over consolidated = OCR > 1

Types of Cement

Cement Chemical Add Mixtures

What is Steel Made out of?

Iron + Small Amount of Carbon

• More Carbon = Cast Iron

• Less Carbon = Wrought Iron

• Carbon, +Strength -Ductility -Weldability

Heat Treater Steel

More Strength

Less Strain

Toughness Definition

• Ability to absorb Impact

• Area under the stress/Strain curve

• Tested using the Charpy Test (V-Notch)

3 Common Steel ASTM

ASTM A36:

• Fy = 36 kips Fu = 58 Kips

• Standard for plates and shapes

ASTM A992:

• Fy = 50 kips Fu = 65 kips

• Hass alloy elements

• Common for I beams

ASTM A325

• Fu = 105 kips

• Heat Treated

• Used for Bolts

Fatigue and Fatigue Stress

• Reduction of strength over time due to repetitive loads

• Max stress from fatigue loading

Endurance limit

Stress level at which material can endure infinite number of load cycles