Foundation Engineering Practical Portion

Experiment No. 1 Classification of Soil according to USC and AASHTO Classification System. 2Foundation Engineering ENGR. FAIZAN TAHIR

Designation AASHTO M (2000) ASTM D Foundation Engineering ENGR. FAIZAN TAHIR

Scope Tests Required for the Classification  Sieve Analysis  Atterberg Limit test 1. Liquid Limit Test 2. Plastic Limit Test 4Foundation Engineering ENGR. FAIZAN TAHIR

Sieve Analysis Column -1Column -2 Standard Designation (mm) Alternate Designation (in) (75)3 in. (37.5)1 ½ in. (19)¾ in. (9.5)3/8 in. (4.75)No. 4 (2.00)No. 10 (0.840)No. 20 (0.420)No. 40 (0.250)No. 60 (0.15)No. 100 (0.075)No. 200 The sieves normally required are as follows 5Foundation Engineering ENGR. FAIZAN TAHIR

Procedure Take a sample about 500-g. of soil, when soil contain larger particles (gravels), bigger soil sample will be required. Carefully check all the sieves and remove any particles sticking to the sieve mesh. Sieves are arranged in the descending order of their sizes with a pan at bottom. The sieving operation shall be conducted by lateral and vertical motion of the sieves so as to keep the sample moving continuously over the sieve surface. The soil particles shall not be turned or manipulated through the sieves by hand. Sieving shall be continued until not more than 1-percent by mass of the residue passes any sieve during 60-seconds. Remove the sieves from the sieve shaker and carefully weigh the soil retained on each sieve. Remove the particles sticking to the sieve mesh and should be included to the weight retained. Tabulate the data and calculate the percentage passing as shown in the following table. 6Foundation Engineering ENGR. FAIZAN TAHIR

Sieve Size (mm)Weight retained (gm) Weight passed (gm) (75) (37.5) (19) (9.5) (4.75) (2.00) (0.840) (0.420) (0.250) (0.15) (0.075) pan Percentage passing Foundation Engineering7ENGR. FAIZAN TAHIR

Liquid Limit Test APPARATUS: 1. Knife, 2. Grooving tool, 3. Balance, 4. Liquid limit apparatus, 5. Drying oven, 6. Containers for moisture content determination Cassagrande Apparatus Grooving tools 8Foundation Engineering ENGR. FAIZAN TAHIR

Steps: 1. Sample as taken from the field 2. Sample after passing sieve No. 40 (About 100-g sample passing #40 Sieve) 9Foundation Engineering ENGR. FAIZAN TAHIR

12.7mm 3.. Making the paste 4. Paste in the Cassagrande cup 5. Groove in the paste 6. Groove closed for a length of 12.7-mm. Foundation Engineering10ENGR. FAIZAN TAHIR

Test data Test repetitions Row -1 Weight of can (gm) Row -2 Weight of wet soil + can (gm) Row -3 Weight of dry soil + can (gm) Row -4 Weight of dry soil (gm) (Row.3 – Row.1) Row -5 Weight of moisture (gm) (Row.2 – Row.3) Row -6 Moisture content, m% (Row.5 / Row.4 x 100) Row -7 No. of blows N Calculations: 11Foundation EngineeringENGR. FAIZAN TAHIR

Graph: 12Foundation Engineering ENGR. FAIZAN TAHIR

Plastic Limit Test Steps: 1. Take abut 20-g of sample passing # 40 sieve, make a paste 2. Take 8-g of sample and deform it into ellipsoidal shaped mass. 3. Now roll the mass into a thread of uniform diameter throughout its length Ellipsoidal shape sample Thread rolling 13Foundation Engineering ENGR. FAIZAN TAHIR

4. When the diameter of the thread becomes less than 3-mm. break the thread, and repeat last step again. 5. Continue performing step-3 until thread crumbles without reaching the Diameter of 3-mm. 6. Plasticity Index = Liquid Limit – Plastic Limit 14Foundation Engineering ENGR. FAIZAN TAHIR

Calculations: Column-1 Column-2Column-3Column-4Column-5Column-6 Weight of can (gm) Weight of wet soil thread + can (gm) Weight of dry soil thread + can (gm) Weight of dry soil (col.3 – col.1) (gm) Weight of moisture (col.2 – col.3) (gm) Moisture content, m% (col.5/col.4) 15Foundation Engineering ENGR. FAIZAN TAHIR

AASHTO SOIL CLASSIFICATION TABLE Table 16Foundation Engineering ENGR. FAIZAN TAHIR

UNIFIED SOIL CLASSIFICATION TABLE Table 17Foundation Engineering ENGR. FAIZAN TAHIR