February 23rd, 2010
admin
A mat foundation having a length of 100ft. by 32ft. carries a total weight of structure plus live load of 5200 tons. The mat foundation is supported by sand underneath. Unit weight of sand is 120 pcf. The N value from the standard penetration test is equal to 18 with a correction factor Cn = 0.62. If the base of the footing is 8ft. below the ground level.
1) Compute the overburden pressure 8ft. below the ground.
2) Compute the allowable net soil pressure.
3) Compute the factor of safety against bearing capacity failure.
Solution:
Read more…
February 23rd, 2010
admin
A dam gate in the figure shown admits water to a horizontal canal. Considering the pressure distribution hydrostatic at section O, compute the discharge per meter of width when y = 1.0 m.
Solution:
Read more…
February 22nd, 2010
admin
In the figure shown Zp = 4m., length of pipe from reservoir to pump is 150m., from pump to nozzle is 1500m., f = 0.02 and diameter of pipes are 450mm and 600mm respectively. Neglecting minor losses the water maybe pumped if the atmospheric pressure is 95kPa absolute and the water temperature is 27°C. At this temperature the vapor pressure Pv = 3.5kPa absolute.
Determine:
1) Velocity of water in 450mmØ pipe.
2) The velocity of water in 600mmØ pipe.
3) The power lost due to friction.
Solution:
Read more…
February 22nd, 2010
admin
Curve wall ABC is a quarter circle having a radius of 6m. What is the vertical force acting on the gate per unit width.
Solution:
Read more…
February 22nd, 2010
admin
The 100 duct is 60mm in diameter. If the fluid has ρ = 920kg/m3 and a viscosity of μ = 0.29 Pa.s.
1) Compute the velocity of flow on the duct.
2) Compute the Reynolds Number
3) Compute the discharge.
Solution:
Read more…
February 22nd, 2010
admin
The figure shows the loading acting on one line of piles supporting a dock. The vertical load indicated includes self weight of the rigid pile cap and the piles maybe considered fixed at a depth of 20 ft. below the bottom of the cap.
1) Determine the max. axial force in pile D.
2) Determine the shear force in each pile.
3) Determine the max. bending moment in each pile.
Solution:
Read more…
February 22nd, 2010
admin
A tank 10m. is filled with 2m. of water is accelerated horizontally 2.45 m/s2. What is the minimum pressure acting at the bottom of the tank? Assume the tank is high enough to prevent spilling.
Solution:
Read more…
February 22nd, 2010
admin
A dam triangular in shape has a height of 24m. and a base of 12m. Density of masonry is 2,500 kg/cu.m. If it is supporting was at a depth of 20m. Where is the location of the resultant vertical force from the heel office dam.
Solution:
Read more…
February 22nd, 2010
admin
The weight of moist soil is 56.7 lb. The volume of the soil measured before drying is 0.5 cu.ft. After being dried out in an oven, the weight of the dry soil is 48.7 lb. If the sp.gr. of the solids is 2.69, compute the following:
1) Porosity
2) Degree of saturation
3) Density
Solution:
Read more…
February 22nd, 2010
admin
A tri-axial shear test is performed on a cohesion less soil sample. Failure occurred when the normal stress is 6300 psi and the shear is 4200 psi.
1) Compute the angle of internal friction.
2) Compute the angle of the failure plane.
3) Compute the maximum principle stress.
Solution:
Read more…
February 22nd, 2010
admin
Water flows from an upper reservoir to a lower one while passing through a turbine as shown. Neglect minor losses.
1) Find the velocity of water
2) Find the head loss due to friction
3) Find the power generated by the turbine.
Solution:
Read more…
February 22nd, 2010
admin
The jets from a garden sprinkler are one inch in diameter and are normal to the 2ft. radius The pressure at the base of the nozzles is 60 psi. Use Cv = 0.85, Cc = 1.0.
1) What is the velocity of the jet?
2) What is the force exerted by the jet?
3) What force must be applied on each sprinkler pipe 1 ft. from the center of rotation to maintain equilibrium.
Solution:
Read more…
February 22nd, 2010
admin
A solid block having the same horizontal cross-section when immersed in water leaves 20cm. height above the water level and 14cm. when immersed in oil (S = 0.85). What is the height of the solid block.
Solution:
Read more…
February 22nd, 2010
admin
A flow rate of 2.10 m3/s is to be carried in an open channel at a velocity of 1.3 m/s, Determine the required slope if the cross-section is rectangular with depth equal to one half the width. Use n = 0.02
Solution:
Read more…
February 22nd, 2010
admin
A steel pipe 8mm thick and 80cm. diameter carries water under a static head of 60cm. Find the stress in the steel.
Solution:
Read more…
February 22nd, 2010
admin
What is the critical depth of a trapezoidal canal for a flow of 2300 cfs. The width at the bottom of the canal is 12ft. with a side slope of 2 horizontal to 1 vertical.
Solution:
Read more…
February 22nd, 2010
admin
For the open tank, with piezometers attached on the side, contains three immiscible liquids as shown. Find the elevations of the liquid surface in piezometer A and B.
Solution:
Read more…
February 22nd, 2010
admin
Find the total hydrostatic force acting on the gate shown.
Solution:
Read more…
February 22nd, 2010
admin
A rectangular weir having a length of one meter is constructed at one end of a tank having a square section 20×20m. and a height to 10m. If the initial head on the weir is 1m., determine the time required to discharge a volume of 72m3.
Solution:
Read more…
February 22nd, 2010
admin
Using n = 0.013 and neglecting minor losses with the pipes arranged as shown.
1) Express the head loss of pipe AB in terms of the discharge Q.
2) Find the head loss of pipe CD if the discharge is 12 cfs.
3) Find the total head loss from A to D.
Solution:
Read more…
February 22nd, 2010
admin
The pipe flow in the figure is driven by pressurized air in the tank. Assuming f = 0.014 and the flow rate is 13.60 liters/sec.
1) Find the velocity of the water in the pipe.
2) Find the head loss in the pipe neglecting minor losses.
3) Find the gage pressure needed to provide a flow rate of 13.60 liters/sec.
Solution:
Read more…
February 22nd, 2010
admin
A concrete dam 8m. high has a width of 2m. at the top and 4m.at the bottom. The depth of water on the vertical side of the dam is 6m. Coefficient between the dam and foundation is 0.48. Neglecting hydrostatic uplift. Sp.wt. of concrete = 23.5 kN/m3.
1) Compute the overturning moment of the dam.
2) Compute the factor of safety against overturning.
3) Compute the factor of safety against sliding.
Solution:
Read more…
February 22nd, 2010
admin
The fill behind the retaining wall as shown in the figure has a unit weight of 110 pcf. With an equivalent fluid pressure of 30 psf per foot Passive earth pressure maybe assumed equivalent to a fluid pressure of 300 psf per foot. The live load surcharge behind the wall is equivalent to an additional two feet of fill. Determine the following:
1) Active earth pressure acting on the wall.
2) Overturning moment about the toe.
3) Factor of safety against overturning.
Solution:
Read more…
February 22nd, 2010
admin
A retaining wall is required to retain a soil having a depth of 26ft. The dry unit weight of soil is 10 pcf with an angle of internal friction of 30°. Ground water table is located 10ft. below the level ground surface. The saturated unit weight of the soil below the water table is 120 pcf.
1) Which of the following gives the value of the Reynolds number for a flow of 0.4 ml/sec. through the needle.
2) Which of the following gives the head loss.
3) Which of the following gives the force required a flow of 0.4 ml/sec.
Solution:
Read more…
February 22nd, 2010
admin
An open channel having a slope of 0.0065 is to carry 1.0 m3/s. The channel material has a “n” value of 0.011. Find the depth of the most efficient cross section for a triangular section.
Solution:
Read more…
February 22nd, 2010
admin
For the given soil: void ratio, e = 0.50, Gs = 2.70, h1 = 1.5m., h2 = 3.0m.
1) Which of the following gives the effective unit weight of soil.
2) Which of the following gives the effective stress at A
3) Which of the following gives the hydraulic gradient for quick sand condition.
Solution:
Read more…
February 22nd, 2010
admin
In the deposit shown in the accompanying figure the ground water level was originally at the ground surface. The water table was lowered by drainage to a depth of 25 ft. where upon the degree of saturation of the sand above the lowered water table decreased to 20%.
1) Compute the vertical effective pressure at the middle of the clay layer before lowering the water table.
2) Compute the vertical effective pressure at the middle of the clay layer after lowering the water table.
3) Compute for the effective pressure at A when there’s no water on the sand layer.
Solution:
Read more…
February 22nd, 2010
admin
In the syringe as shown in the figure, the drug has 900 kg/m3 and an absolute viscosity μ = 0.002 Pa.s. Neglecting head loss in the larger cylinder.
1) Which of the following gives the value of the Reynolds number for a flow of 0.4 ml/sec. through the needle.
2) Which of the following gives the headloss.
3) Which of the following gives the force required a flow of 0.4 ml/sec.
Solution:
Read more…
