STUPIDSID
1(a)
Critically define the terms void ratio, porosity and water content with phase diagram.
4 M
1(b)
Derive the relation \( \gamma _{d}=\dfrac{G.\gamma w}{1+e} \) with usual notations.
6 M
1(c)
In an earthen embankment under construction, the bulk unit weight is 16.5kN/m3 at water content 11%. If the water content has to be increased to 50%, compute the quantity of water to be added per cubic meter of soil. Assume no change in void ratio. Also determine 'e' at this water content taking G = 2.65.
10 M
2(a)
Define relative density of sand and list its importance in geotechnical engineering.
4 M
2(b)
Describe consistency of soil. List and define consistency limits.
6 M
2(c)
The following results are obtained by conducting liquid limit test on clayey soil in the laboratory:
Plot flow curve. Determine Liquid limit, Toughness index. Assume plastic limit = 20%.
| No. of blows (N) : | 34 | 23 | 18 | 12 |
| Water content (W%): | 44.6 | 49.4 | 51.4 | 55.6 |
Plot flow curve. Determine Liquid limit, Toughness index. Assume plastic limit = 20%.
10 M
3(a)
Explain with the help of typical particle size distribution curve, well graded, poorly graded and gap gtaded soil.
4 M
3(b)
With the neat sketch, explain structure of clay minerals.
6 M
3(c)
Following results are obtained from the laboratory tests conducted on two soil samples :
Show the positions of these soils on plasticity chart and classify as per I.S. system.
| Soil sample | A | B |
| Liquid limit | 85% | 45% |
| Plastic limit | 50% | 12% |
Show the positions of these soils on plasticity chart and classify as per I.S. system.
10 M
4(a)
Derive the relation between co-efficient of permeability and percolation with usual notations.
7 M
4(b)
Explain Quick - sand phenomena and list its importance during construction.
5 M
4(c)
A falling head permeater accommodates a soil sample of 6cm length and 500cm2 in area. The permeability of sample is expected to be 1 × 10-4 cm/sec. Head of water in the standpipe falls from 30cm to 10cm in 40 minutes. Determine the size of the stand pipe which should be used.
8 M
5(a)
Explain sensitivity and thixotropy of clayey soil.
4 M
5(b)
List the factors affecting shear strength of soil.
4 M
5(c)
A direct shear test results are obtained as follows :
Determine shear parameters graphically. Also draw Mohr's circle corresponding to second test result and report major and minor principal stresses.
| Normal stress (kN/m2) : | 100 | 200 | 300 |
| Shear stress (kN/m2) : | 130 | 185 | 240 |
Determine shear parameters graphically. Also draw Mohr's circle corresponding to second test result and report major and minor principal stresses.
12 M
6(a)
List the factors affecting compaction of soil and explain any 2 in detail.
5 M
6(b)
List and explain various types of field compaction equipments.
5 M
6(c)
The results of standard compaction test conducted in the laboratory are tabulated as follows:
Find MDD and OMC with usual notaions by plotting comoaction curve. Also draw ZAVD -line assuming G = 2.65.
| Water content% : | 5.00 | 10.00 | 14.00 | 20.00 | 25.00 |
| Bulk density kN/m3 | 17.70 | 19.80 | 21.00 | 21.80 | 21.60 |
Find MDD and OMC with usual notaions by plotting comoaction curve. Also draw ZAVD -line assuming G = 2.65.
10 M
7(a)
State the assumptions of one - dimensional Terzaghi's theory of consolidation. Also write standard / general differential one - dimensional consolidation equation with usual notation.
8 M
7(b)
Explain with neat sketch, determination of co-efficient of consolidation by square - root of time fitting method.
6 M
7(c)
A layer of soft clay is 6m thick and lies under newly constructed building. The weight of sand overlying the clayey layer produces a pressure of 260 kN/m2 and this new construction increases the pressure by 100kN/m2. If the compression index is 0.5, compute settlement of soil layer given water content 40% and G = 2.65.
6 M
8(a)
Critically discuss limitations of direct shear test.
4 M
8(b)
Explain Vane shear test with neat sketch along with relations.
6 M
8(c)
A vane apparatus test. A torque of 45N-m was applied at which failure took place. Subsequently, vane instrument rotated rapidly, so as to get reolded soil sample. This remolded soil was sheared at a torque of 18 N-m. Then calculate sensitivity of clayey soil.
10 M
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