DNCC – 2016
Post: Assistant Engineer
Venue: BUET

1. There are nine piles in a group, each having 18 in diameter and 65 feet long, α= 0.5, unconfined compressive strength of soil is 1000 lb/ft2, cast in situ pile in a clay layer. What is the allowable skin friction of a single pile if factor of safety is 3?

2. A clay layer of 10m thickness underlying E.G.L, water table is lying 3m from E.G.L. A sand layer of 30m thickness underlying of the clay layer. Unit weight of clay over water table, under water table and saturated unit weight of sand is 16 KN/m3, 20 KN/m3 and 21 KN/m3. Find total stress, effective stress and effective pore water pressure at 20m from E.G.L

3. Compute consolidation settlement of a 2.5 m thick clay layer due to an increase of 30 KN/m2 pressure at the mid height of the layer. If vertical stress at the mid height of the layer is 40 KN/m2. Given, initial void ratio (e0) = 0.8 and compression index (Cc) = 0.28.

4. 100 cm3 sample of moist soil has a mass of 212.25 gm. Water content 16%. Specific gravity of soil is 2.68. Calculate bulk unit weight of soil, dry unit weight of soil, void ratio and porosity.

5. Calculate the angularity number for the aggregate sample from the following data relative density of the aggregate 2.8, mass of water required to fill the cylinder 2500 gm, mass of cylinder filled with compacted aggregate 5150 gm and mass of cylinder 1100 gm.

6. Find the nominal axial compression capacity of a rectangular column size is 16” x 24” and reinforced with 12-20 mm bars. Given, fy = 60 ksi and fc= 4 ksi.

7. D10 = 0.0162 mm, D30 = 0.1018 mm, D60 = 0.577. Find the coefficient of uniformity.

8. Find the maximum shear stress of section 12” x 22” subjected to a critical shear force 48 kips.

10. Land area is 62 hector and underlying bed is impermeable, so no infiltration happened. Precipitation is 2 cm/hr. what is the volume of water storage in 1 hour?

11. Show diagrammatic relationship between local roads and highway transportation system.

12. A pump discharge water from a well at a rate of 365 gpm with a static head 85 meter. If velocity and friction loss is 65m. Find the horse power of the pump. Efficiency of the pump is 70%.

AUTHOR
Engr.Abu Jobair
Assistant Engineer (Civil)