• AASHTO SOIL CLASSIFICATION (by AASHTO) AASHTO = American Association of scate Highway and Transport Officials Situation 2 Classification of Highway Subgrade Materials SIEVE % FINER General classification Granular materials (35 or less of total sample passing No. 200) SOIL A SOIL B SOIL C A-1 A-2 10 83 100 90 Procedure: 92 76 Group classification 40 48 A-1-a A-1-b A-3 A-2-4 A-2-5 A-2-6 A-2-7 O Group Classification • with required test data in mindl, proceed from left to right, in chart. The correct group will be found by process of elimination. The first group from the left consistent with the test data is the conect classificaton. 86 34 Sieve analysis (percentage passing) No. 10 No. 40 200 20 LL 20 70 37 50 max. 30 max. 15 max. 5 32 18 50 max. 51 min. 10 max. PI 35 max 35 max. 35 max. No. 200 Characteristics of fraction 25 max. . 35 max. Using AASHTO method: 1. Determine the group symbol and index for soil A. 2. Determine the group symbol and index for soil B. 3. Determine the group symbol and index for soil C. passing No. 40 Liquid limit Plasticity index Usual types of significant constituent materials 40 max. Il min. Silty or clayey gravel and sand 40 max. 41 min 41 min 10 max. Il min. 6 max. Stone fragments gravel, and sand NP 10 max. O Group Index Fine sand GI=(Faco-35)(00OBLL) +001(F200-15)(PI-10) if the equation hasanegative value, GI ISO. • the group index number calculated from the equation Is roundled off to the nearest whole number (note: ound off) the group index number for soil groups, namely: (A-1-a, A-1-b, A-3, A-2-4, A-2-5) is O. • when calaulating the GI for sols that belong to groups A-2-6 and A2-7, use partial GI(for PI): General subgrade rating Excellent to good Silt-clay materials (more than 35% of total sample passing No. 200) General classification A-7 A-7-5 A-7-6 Group classification A-4 A-5 A-6 Sieve analysis (percentage passing) No. 10 No. 40 36 min. 36 min. 36 min. No. 200 Characteristies of fraction passing No. 40 Liquid limit Plasticity index Usual types of significant constituent materials General subgrade rating 36 min. 41 min. 10 max 41 min. Il min. Clayey soils 40 max. 40 max 10 max. Il min. Silty soils Fair to poor GI= 0.01(F00-15XPI-10) *****

• AASHTO SOIL CLASSIFICATION (by AASHTO) AASHTO = American Association of scate Highway and Transport Officials Situation 2 Classification of Highway Subgrade Materials SIEVE % FINER General classification Granular materials (35 or less of total sample passing No. 200) SOIL A SOIL B SOIL C A-1 A-2 10 83 100 90 Procedure: 92 76 Group classification 40 48 A-1-a A-1-b A-3 A-2-4 A-2-5 A-2-6 A-2-7 O Group Classification • with required test data in mindl, proceed from left to right, in chart. The correct group will be found by process of elimination. The first group from the left consistent with the test data is the conect classificaton. 86 34 Sieve analysis (percentage passing) No. 10 No. 40 200 20 LL 20 70 37 50 max. 30 max. 15 max. 5 32 18 50 max. 51 min. 10 max. PI 35 max 35 max. 35 max. No. 200 Characteristics of fraction 25 max. . 35 max. Using AASHTO method: 1. Determine the group symbol and index for soil A. 2. Determine the group symbol and index for soil B. 3. Determine the group symbol and index for soil C. passing No. 40 Liquid limit Plasticity index Usual types of significant constituent materials 40 max. Il min. Silty or clayey gravel and sand 40 max. 41 min 41 min 10 max. Il min. 6 max. Stone fragments gravel, and sand NP 10 max. O Group Index Fine sand GI=(Faco-35)(00OBLL) +001(F200-15)(PI-10) if the equation hasanegative value, GI ISO. • the group index number calculated from the equation Is roundled off to the nearest whole number (note: ound off) the group index number for soil groups, namely: (A-1-a, A-1-b, A-3, A-2-4, A-2-5) is O. • when calaulating the GI for sols that belong to groups A-2-6 and A2-7, use partial GI(for PI): General subgrade rating Excellent to good Silt-clay materials (more than 35% of total sample passing No. 200) General classification A-7 A-7-5 A-7-6 Group classification A-4 A-5 A-6 Sieve analysis (percentage passing) No. 10 No. 40 36 min. 36 min. 36 min. No. 200 Characteristies of fraction passing No. 40 Liquid limit Plasticity index Usual types of significant constituent materials General subgrade rating 36 min. 41 min. 10 max 41 min. Il min. Clayey soils 40 max. 40 max 10 max. Il min. Silty soils Fair to poor GI= 0.01(F00-15XPI-10) *****

Principles of Geotechnical Engineering (MindTap Course List)

9th Edition

ISBN:9781305970939

Author:Braja M. Das, Khaled Sobhan

Publisher:Braja M. Das, Khaled Sobhan

Chapter2: Origin Of Soil And Grain Size

Section: Chapter Questions

Problem 2.1CTP: Three groups of students from the Geotechnical Engineering class collected soil-aggregate samples...

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