Republic of the Philippines

Romblon State University

COLLEGE OF ENGINEERING AND TECHNOLOGY

Name: _________________________________ Date: __________________

Situation 1: The percentages of a gravel, sand, silt, 13. Determine the maximum bulk unit weight (
and clay of a particular soil are tabulated as shown. kN/m3)
Soil Particle-size Distribution 14. Determine the minimum void ratio.
Particle Soil A Soil B Soil C 15. Determine the maximum void ratio.
Gravel 0 35 20 16. Determine the relative density.
Sand 34 15 15
Silt 40 30 25 Situation 6: The sand seabed is located 20 m below
Clay 26 20 40 the sea surface, if the thickness of the sand is more
1. Using USDA method, calculate the modified than 40 m. The sand has a specific gravity of 2.7 and
percentages of sand, silt and clay for each soil a void ratio of 0.6.
type. 17. What would be the effective stress 15 m
2. Classify each soil using USDA Textural Classification below the seabed?
Chart. 18. If the water level rises by 5 m, what would be
the new effective vertical stress 30 m below
Situation 2: The moist unit weight of a soil is 2.1 g/cc. If the the seabed?
water content is 15.5% and the specific gravity of soil is
19. If the water level drops by 10 m, what would
2.72. Determine the following:
3. Buoyant unit weight
be the new effective vertical stress 30 m
4. Weight of water in kN to be added per cu.m of soil below the seabed?
for 90% degree of saturation.
5. Weight of water in kN to be added per cu.m of soil Situation 7: A 7.5 cm diameter orifice (Cv = 0.95, Cc=
for it to reach fully saturated. 0.65) is under a head of 3.0 m of oil (s = 0.72).
Determine the pressure of the air on the oil surface so
Situation 3: In a specific gravity test, the following data that the available power in the issuing jet of oil is 6
were recorded. kW.
Mass of pycnometer jar = 520 g
Mass of pycnometer jar when full of clean water = 1600 g
Mass of pycnometer jar containing dry soil only = 950 g
Mass of pycnometer jar containing soil and topped with
water = 1870 g
6. Determine the specific gravity of soil sample.
7. If the void ratio is 0.55, what is the dry unit weight of
the soil?
8. Compute the degree of saturation when the
moisture content is 15%.
20. Determine the value of h.
9. The mass specific gravity of a saturated
21. What is the degree of consolidation at the mid
specimen of clay is 1.84 when the water content
height of the clay layer if h=2 m?
is 38%. Determine the specific gravity of solids.
Situation 4: A highway embankment needs 150000
Situation 8: A dense silt layer has a void ratio of 0.80.
m3 to be completed. DPWH requires 95%
The groundwater level is at 6 m depth. (Other soil
compaction and the contractor is to provide soil
properties: effective diameter=10𝜇m, capillary
from a borrow site.
constant= 0.20 cm2)
10. If the optimum moisture content is 18% and
22. Determine the height of capillary rise in the silt.
the maximum dry density is 18.88 kN/m3, how
23. Find the vertical effective stress (kPa) at 2 m
much borrow soil is required per cubic meter
depth, 5 m depth, 6 m depth and 8 m depth.
if the moisture content of the borrow
(Assume unit weight of solids = 26.5 kN/m3 and
material is 15% and the wet unit weight of te
that the soil above the capillary rise and
borrow is 16.06 kN/m3?
ground surface is partially saturated at 85%.)
11. How many truckloads of borrow material are
Situation 9: Undisturbed samples were collected from
needed if the soil would have a void ratio of
a 3m thick clay stratum which lies between two sand
0.70 and sp. gr. of 2.65 and the capacity of
strata. A laboratory consolidation test was
each truck is 9 m3?
performed on a 3 cm thick sample of the clay. During
12. How many liters of water are needed?
the test, water was allowed to drain out only through
Situation 5: To determine the relative density of a soil
the top of the sample. The time required for 50%
sample the following data were obtained using a
consolidation was found to be 35 minutes.
compaction mold having a mass of 5300 g and a
24. Determine the coefficient of consolidation in
volume of 950 cm3.
m2/day.
Mass of mold filled with dry soil poured in loosely =
25. Determine the time required for 50%
7000 g
settlement of the clay in days.
Mass of mold filled with dry soil dynamically
compacted = 7500 g
If the dry density of the soil in situ is 19.65 kN/m3 and
Gs=2.65

CE 3210: Hydraulics | 1