Determine the natural moisture content in percent of a soil given the following properties.
Plastic limit = 27
Plasticity index = 29
Liquidity index = 0.30
Solution:
A shear center of an H-section with unequal flanges is located nearer to the bigger flange. If the smaller flange is 16mm x 100mm the larger flange is 16mm by 200mm, and the web is 9mm by 284mm. the distance of the shear center from the center of the bigger flange is:
Solution:
A propped cantilever beam (fixed at one end and simply supported at the other end) has a span L of 6m. The beam carries a concentrated moment at the simply supported end. Where is the location of maximum deflection measured from the simply supported end?
Solution:
The soil profile at the site consists of 5.0m. silty sand underlain by 13m. of clay. The ground water table is at a depth of 2.8m. below the surface. The sand has a unit weight of 19kN/m3 above the ground water table and 20kN/m3 below. The clay has a unit weight of 15.ykN/m3. The lateral effective stress at a depth of 11m. is:
Solution:
A 6m. tall cantilever wall retains soil that has the following properties. C = 0 phi = 30 degrees and soil weights 19.2kN/m3. The ground surface behind the wall is inclined at a slope of 3hor. To vertical and the wall has moved sufficiently to develop the active condition. Determine the normal force acting on the back of the wall using Rankines’ Theory.
Hint: Arc tan 1/3 = 18 degrees and Ka = 0.399
Solution:
A simply supported beam of length 7m has a concentrated couple of Mo of 10kN.m applied at one end. The maximum deflection is located at a distance of 2.95m. from the applied load. Assume E = 200000 N/mm2 and Ixx = 60 x 106mm4. The max. deflection is:
Solution:
The yield stress of the steel beam is 250N/mm2. The beam must be designed for a plastic moment capacity of 288kN.m. The required plastic section modulus is:
Solution:
Calculate the moment applied at the end of a flat steel bar 1.2m. long that will produce a midpoint deflection of 40mm. The flat bar is 75mm wide and 9mm thick. Use E = 200000MPa.
Solution:
A short deep cantilever carries a vertically downward load at its free end. Assume the shear stress is uniformly distributed over the cross-section of the beam. Use G = 25000 N/mm2. If the shear is 25 N/mm2 and the length of the beam is 0.50m., the deflection due to shear at the free end is:
Solution:
A concrete column of height 5m. has a square cross section of side 300mm. It is designed to support an axial load of 200kN. At mid-height, a recess is out in one face of the column to receive a floor beam. The cut is 300mm vertical and 75mm deep. Calculate the strain energy of the column produced by the axial load before and after the recess is cut. Use Youngs modulus = N/mm2.
Solution:
A simple beam of length “L” has a concentrated load of P at a distance “a” from the left support and “b” from the right support. The maximum moment of the beam is:
Solution:
Determine the ratio of the pressure against a wall 6.10m. high retaining a cohesion less soil (angle of internal friction phi = 34.75 degrees). The natural moisture content is 10% and sp.gr. = 2.65, when the water table is on top of the wall and when the water table is below the wall. Voids ratio is 0.50.
Solution:
An earthquake is usually measured by the magnitude M on the Richter scale. The intensity I of an earthquake and the magnitude M are related by the formula: M = log I/Io where Io is the intensity of an arbitrary chosen earthquake. The earthquake that hit Kobe, Japan, measured 5.7 on the Richter scale. The earthquake that hit Baguio, Philippines measured 7.8. How many times stronger is the earthquake that hit Baguio?
Solution:
The specific gravity of the soil is 2.65; the void ratio is 0.5; water content is 7.94% the wet density is:
Solution:
A 300mm x 75mm wooden plank is placed on top of another 600mm x 150mm wooden plank having the same material. If the superimposed beam is subjected to a total moment of 7 kN.m, determine the moment carried by the lower plank. Span of plank is 6m. E = 8,000 MPa.
Solution:
A soil sample has a void ratio of 0.76, specific gravity of 2.74 and degree of saturation of 85%. The unit weight is:
Solution:
A precast beam of length L is to be lifted at two points. The two points should be at _______ distance from the ends so the maximum moment is as small as possible.
Solution:
A reinforced concrete T-beam is to be designed for tension reinforcement only. The beam width is 250mm and the effective depth is 400mm. The flange thickness is 100mm and its effective flange width is 900mm. The applied moment is 300 kN-m. The area of tension reinforcement required is: Use fc’ = 20.7MPa and Fy = 414MPa.
Solution:
A proposed cantilever is 10m long and is required to carry a load of 100kN at mid span. If the yield stress of mild steel is 300 N/mm2, determine the plastic section modulus using a load factor failure of 1.5.
Solution:
The structural i-beam supporting a floor carries a floor load of 4.6 kN/m2. The beams span 6.0m and are simply supported at their ends. Determine the center line spacing if the allowable stress in the beam is 120MPa and the section modulus is 534 x 103 mm3.
Solution:
The properties of a given steel section is as follows. A = 6,000 mm2, Ix = 50 x 106mm4, Iy = 120 x 106mm4, Ixy = 75 x 106mm4. Compute the minimum radius of gyration.
Solution:
The specification for a job calls for a Class “b” mix a minimum compressive strength of 3,000psi at 28days. The result of 125 compressive tests are tabulated in the following table: 28-day Compressive
| Strength, psi | No. of Tests |
| 2,800 | 2 |
| 2,900 | 4 |
| 3,000 | 6 |
| 3,100 | 11 |
| 3,200 | 24 |
|
3,300 |
37 |
|
3,400 |
19 |
| 3,500 | 12 |
|
3,600 |
6 |
| 3,700 | 4 |
What is the standard deviation?
(Use the mean value 3,290 psi.)
Solution:
A flat bar 75mm wide by 9mm thick and 1.2m long is subjected to couples applied at the ends so that the midpoint deflection is 40mm. Calculate the magnitude of the couple E = 200,000MPa.
Solution:
A structural steel wide flange section has a flange section 150mm x 12mm and a web section 300mm x 9mm. It carries a max. shear of 90kN. If the average shearing stress is 33.33MPa, and INA = 108 x 106mm4, with a statistical moment of area equal to 382,050mm3, compute the max. shearing stress.
Solution:
A 1.0 cu.m. design mix was proportioned at 1:2.25:3.25. Water content was specified at 137 kg. per cu.m. maximum, and cement content is 9 bags per cu.m. (40kg. per bag of cement). The specific gravity of cement is 3.15 and that of the fine sand is 2.65 and coarse aggregates are 2.68. The requirement in kg. of fine sand per cu.m. is:
Solution:
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