Chapter 3. Scope of work We have learnt a variety of civil engineering structure likes buildings, bridges, dams, roads etc. The consulting geotechnical engineer is concerned with how the soil behaves when it is loaded by these structures. It is the consulting geotechnical engineer’s job to make sure the load that reaches the soil is such that the soil is able to with stand the load in manner that is safe for the structure. It is the consulting geotechnical engineer, who decides the type of foundation depending upon the soil condition, type of structure and loading.

The consulting geotechnical engineer has to estimate settlement, differential settlement as well as the time; the structure will take for …show more content…
Take a representative Sample of soil received from the field and dry it in the oven.

2. Sieve it through 4.75mm IS sieve.

3. Sieve the sample retained on 4.75mm sieve through the set of course sieves by hand. While sieving should be agitated such that sample rolls in irregular motion over the sieves.

4. Determine the mass of the material retained on each sieve.
5. Similarly, sieve the dried material passing through 4.75mm sieve and retained on 75 micron sieve using set of fine sieve.

6. A minimum 10 minutes of shaking is required if a mechanical shaker is used.

7. Determined the mass of the material retained on each sieve.

8. Calculate the % of soil retained on each sieve on the basis of total mass of sample taken.

9. Determine the % passing through each sieve.

4.1.4 Observation Table: Soil Sample Taken: 1000gm
Table 1
IS Sieve Particle Size (mm) Mass Retained in gm % mass Retained Cumulative Retained % Finer
4.75 mm 4.75 38 3.8 3.8 96.2
2.36 mm 2.36 14 1.4 5.2 94.8
1.18 mm 1.18 44 4.4 9.6 90.4
600 µ 0.6 100 10 19.6 80.4
300 µ 0.3 387 38.7 58.3 41.7
212 µ 0.212 230 23 81.3 18.7
150 µ 0.15 97 9.7 91 9
90 µ 0.9 68 6.8 97.8 …show more content…
4.2 PYCNOMETER BOTTLE METHOD
4.2.1 Object: To determine specific gravity of soil solids by pycnometer bottle method.
4.2.2 Equipments:
• Pycnometer bottles 500 ml capacity.
• Weighing balance, with an accuracy of 0.001 gm.
• Glass road
• Distilled water
• I.S. sieves 2mm and 4.75mm size
• Soil sample passing 4.75mm sieve and retained on 2mm sieve.

Reference:
I.S. 2720 (part-3, section 1)-1980
4.2.3 Test Procedure:
1. Clean and dry the pycnometer. Find its mass with cap as M1.
2. Place about 200gm of oven dried soil passing through 4.75mm sieve and retained on 2mm sieve, in the pycnometer.
3. Determine mass of pycnometer with dry soil as M2.
4. Add sufficient amount of de-aired water to the soil in pycnometer. Thoroughly mix it. Vacuum, pump, may be used to de-dry the soil. Use glass road to agitate the soil-water mixture. Determine mass of pycnometer with soil and water as M3.
5. Empty the pycnometer with distilled water and find its mass as M4.
6. Now, calculate the specific gravity of soil solids as under:

Figure 2 Pycnometer bottle

4.2.4 Observation