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1	Soil Classification and Identification Geological Sciences 376
2	Grain Size Classification
3	Grading vs. Sorting Well Graded - Good representation of all particle sizes from largest to smallest Poorly Graded - Uniform, most particles about the same size; or skip (or gap) gradation, absence of one or more intermediate sizes. Poorly Sorted Well Sorted
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5	Soil Texture
6	1.1 Soil Texture The texture of a soil is its appearance or “feel” and it depends on the relative sizes and shapes of the particles as well as the range or distribution of those sizes.
7	1.2 Characteristics
8	Grain Size and Grain Size Distribution
9	2.1 Grain Size
10	Note:
11	2.2 Grain Size Distribution
12	2.2 Grain Size Distribution (Cont.)
13	2.2 Grain Size Distribution (Cont.)
14	2.2 Grain Size Distribution (Cont.) Describe the shape Example: well graded Criteria Question What is the C_u for a soil with only one grain size?
15	Answer Question What is the C_u for a soil with only one grain size?
16	2.2 Grain Size Distribution Engineering applications It will help us “feel” the soil texture (what the soil is) and it will also be used for the soil classification (next topic). It can be used to define the grading specification of a drainage filter (clogging). It can be a criterion for selecting fill materials of embankments and earth dams, road sub-base materials, and concrete aggregates. It can be used to estimate the results of grouting and chemical injection, and dynamic compaction. Effective Size, D₁₀, can be correlated with the hydraulic conductivity (describing the permeability of soils). (Hazen’s Equation).(Note: controlled by small particles)
17	3. Particle Shape Important for granular soils Angular soil particle ® higher friction Round soil particle ® lower friction Note that clay particles are sheet-like.
18	Soil Descriptions
19	Soil Structure
20	FIELD IDENTIFICATION PROCEDURES FOR FINE GRAINED SOILS OR FRACTIONS
21	DILATANCY (Reaction to shaking)
22	DRY STRENGTH (Crushing characteristics)
23	DRY STRENGTH (Crushing characteristics)
24	DRY STRENGTH (Crushing characteristics)
25	TOUGHNESS (Consistency near plastic limit)
26	TOUGHNESS (Consistency near plastic limit)