Download presentation

1
**Unified Soil Classification System Training**

Part B - USCS using Laboratory Data

2
**Comparison of Particle Size Definitions**

USDA cobbles sand clay gravel 3” 2 m .05 mm # 4 silt USCS cobbles sand fines gravel .074 mm # 4 3” # 200

3
**ASTM Standards Lab Data Classification is by ASTM D2487**

Classification of Peat Samples, see ASTM D 4427 Field Classification is by D2488

4
**Comparison of Particle Size Definitions**

5
**Activity 2 - Particle Size Comparisons**

6
**USCS Flow Chart - Activity 3**

7
**Flow Chart Overview Two Broad Categories**

Fine-Grained - 50% or more finer than the # 200 sieve Coarse-Grained - Less than 50% finer than the # 200 sieve

8
USCS Overview

9
**Flow Chart Overview Fine-Grained Soils Organic ( LL ratio < 0.75 )**

Inorganic (no odor and LL ratio not < 0.75) Classify by LL, PI Modifiers are H or L for LL value, C or M for plasticity and O for organic

10
USCS Overview

11
**Activity 4 - Organic Soil**

Solve 4 samples

12
**Abbreviations Fine-Grained**

H - High LL ( > 50 ) L - Low LL ( < 50 ) C - Plastic Fines M - Nonplastic or slightly plastic fines O - Organic Pt - Peat

13
**Activity 5 - Plasticity Chart**

14
**Activity 5 - Plasticity Chart**

Solve 4 samples

15
**Activity 7 - Classify Fine-Grained Samples**

Assume 6 samples are not organic and classify by USCS

16
**Flow Chart Overview Coarse-Grained Soils - 3 Groups**

Clean - Less than 5 % Fines Dirty - More than 12 % Fines Dual - From 5% to 12% Fines, inclusive

17
Coarse-grained Soils

18
**Abbreviations Sands and Gravels**

G - Gravel S - Sand P - Poorly Graded W - Well Graded

19
**Sieve Analyses % gravel = % finer 3”minus % finer # 4**

% sand = % finer # 4 minus % finer # 200 % fines = % finer than # 200 sieve

20
**Percent Particle Categories**

To compute % Gravel subtract % finer than # 4 from % finer than 3” To compute % Sand subtract % finer than # 200 from % finer than # 4 Percent Fines is % finer than # 200

21
**For 7 samples, fill out Activity**

22
**Additional Definitions**

To Classify Clean Coarse-Grained Soils, you must first plot grain-size curve and determine three parameters D10, D30, D60

23
**Determining D10, D30, and D60 60 % finer D60, millimeters 30 10**

24
**Coefficient of Uniformity**

Computing CU and CC Coefficient of Uniformity High Values Indicate Well-Graded Soil Coefficient of Curvature Values Between 1-3 Indicate Well-Graded Soil

25
**Plot Curve from Data, compute CU Value**

Activity 9 Plot Curve from Data, compute CU Value

26
**Plot Curve from Data, compute CC Value**

Activity 10 Plot Curve from Data, compute CC Value

27
**Characterizing Clean Sands and Gravels**

Clean Well Graded Sands and Gravels have less than 5 % fines and a wide range of particle sizes that are equally distributed Well graded % Finer Particle Size

28
**Poorly Graded Sands and Gravels**

% Finer Particle Size Either Mostly One-Size Particle Gap graded Particle Size % Finer Or Gap- Graded

29
**Clean, Well/Poorly Graded Definitions**

Sands less than 5 % fines CU > 6 CC = 1-3 Gravels less than 5 % fines CU > 4 CC = 1-3

30
**Activity 11 - Problems 1. Verify % Fines - Coarse-Grained/Clean**

2. Compute % Gravel and % Sand 3. Note which predominates 4. Using provided CU and CC, Determine whether poorly or well graded 5. Determine Correct USCS classification

31
Activity 12 Review Example Soil

32
**Use Flow Chart, Classify Soil**

Activity 13 Use Flow Chart, Classify Soil

33
**Activity 14 Summary of Classifications of Coarse-Grained Soils**

Clean Sands and Gravels (< 5% fines) Clean Poorly Graded Gravels GP Clean Well Graded Gravels GW Clean Poorly Graded Sands SP Clean Well Graded Sands SW

34
**Dirty Coarse-Grained Soils**

If a sample has less than 50 % Fines And it has more than 12 % Fines, it is a Dirty Coarse-Grained Soil To Classify, follow the flow chart and the following steps

35
**Dirty Coarse-Grained Soil**

Determine whether there is a greater % of Sand or Gravel % G = % finer 3” minus # 4 % S = % finer # 4 minus # 200 Determine where minus # 40 fines plot on plasticity chart

36
**Dirty Sands and Gravels**

SC - Fines Plot Above A-Line SM - Fines Plot Below A-Line SC-SM - Fines Plot in Hatched Zone GC - Fines Plot Above A-Line GM - Fines Plot Below A-Line GC-GM - Fines Plot in Hatched Zone Gravels

37
Activity 16 - Problems

38
**Activity 17 - Example of Classifying Dual-Classification Coarse-Grained Soil**

39
Activity 18 - Problem

40
**Activity 20 - Review Questions**

41
**Activity 21 - Comprehensive Problems**

Similar presentations

Presentation is loading. Please wait....

OK

Soil Classification.

Soil Classification.

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on petroleum industry in india download Ppt on council of ministers bulgaria Ppt on health care system in india Ppt on indian english literature Ppt on google self driving car Ppt on noise in frequency modulation Ppt on global warming for class 9 download Ppt on water softening techniques for managing Best ppt on earth day by alex Ppt on indian army weapons and equipment