Eighty five percent of the bits used in deep rock marble drilling endure rock resistance and 95% survive after the exposure to drilling. 80% can be pressure treated to go for one shift or more of drilling and only 10% of those which are not can be used for one shift or more. a) Draw the reliability chart of these drill bits b) What is the likelihood that a bit would last one or more lap?
In: Civil Engineering
Answer the following questions from Civil Engineering Licensure Examination
a. CE Board May 2007
A 300 mm concrete wall supports a dead load of 300 KN/m and a live
load 0f 220 KN. The allowable
bearing pressure is 240 KN/m2 and the level of the footing is 1.2 m
below the ground surface. Assume
concrete weighs 24 KN/m3 and that of soil is 16 KN/m3, fc’ = 28
Mpa, fy =248 Mpa. Use 28 mmθ
reinforcing bars. Thickness of footing = 600 mm, steel covering 100
mm. Determine the spacing of bars
at critical section.
b. CE Board May 2012
A 450 mm square interior column carries a dead load of 825 KN and a
live load of 668 KN. A
rectangular footing is required to carry the column loads such that
the length of the long side must be
equal to twice the width of the short side. Assume base of footing
is 1.5 m below the ground surface.
Allowable bearing pressure of soil is 15.74 KN/m3 and that of
concrete is 23.5 KN/m3. Use normal
weight concrete. Thickness of footing is 0.60 m. Determine the
steel requirements in the short and
long direction
In: Civil Engineering
Identify any one busy street on your community with large volumes of surface traffic comprised of vehicles, cyclists, and pedestrians. Then answer the following questions
i). establish the goals and objectives;
ii). the criteria to assess the desirability, efficiency, or effectiveness of each design alternative; and
iii)choose the best of the conceptual design alternatives.
In: Civil Engineering
Write a detailed note on effects of atmospheric hazards on human life. Note: Plagiarism of assignment must be under 12%.
In: Civil Engineering
In: Civil Engineering
Discuss the smart concrete materials by self-sensing materials as a breakthrough resulting form use of nanotechnology
In: Civil Engineering
In: Civil Engineering
In: Civil Engineering
How would the hydraulic performance of the culvert change if instead a pipe you use a box culvert of dimensions 39 mm x 39 mm? Would it change the type of control (i.e., inlet/outlet controls)?
give full answers with calculation
In: Civil Engineering
In: Civil Engineering
You are renovating a 900 ft2, 1-story house and decide to invest in adding more insulation to make it more energy efficient. As part of the renovation, you add cellulose to the wall cavities and improve the R-value of the walls from R12 to R30. In doing so, you reduce the air exchange rate from 1 h-1 to 0.5 h-1. Assume that the house is built on a square foundation, the height from the floor to the ceiling is 10 feet, and the wall thickness is 1 foot. For the sake of simplicity, ignore losses through the floor and ceiling and losses due to air infiltration. HINT: the heat loss through bldg skin equation [Heat loss through bldg. skin = (1/R) x (area) x (time)] provides the total heat loss over a given time period per degree delta T. R-value units are [(ft2·ºF·hr)/Btu].
(1 kWh = 3412.14 Btu)
In: Civil Engineering
Wastewater plant discharges effluent in river from the center. Characteristics of River and wastewater is given in Table below.
Velocity of River V= 10 cm/s,
After intial mix, Dissolved-oxygen concentration C0 = 9.5 mg/L,
Saturation Dissolved-oxygen concentration at 15 C Cs= 11 mg/L,
Deoxgenation rate at 20 C k1,20 = 0.55 per day,
Reoxgenation rate at 20 C k2,200= 0.85 per day
Temperature of River Tr=12 C
BOD load L0=25 mg/L
How long (in days) it takes to reach DO concentration fully saturation level (11 mg/L)
In: Civil Engineering
In: Civil Engineering
Sedimentation reduces the reservoir capacities and can affect reservoir operation and effectiveness.
1) Describe the factors that contributes to reservoir sedimentation, and hence discuss some methods on how this issue can be solved or mitigated.
In: Civil Engineering
Problems 3, 4 and 5 refer to the following alternatives on the table below
Consider the following alternatives that have a ten-year useful life. The MARR is 10%
A | B | C | |
---|---|---|---|
Initial Cost | 800 | 300 | 150 |
Uniform Annual Benefit (s) | 142 | 60 | 33.5 |
3. Based on Benefit-Cost ratio analysis, the alternative to be selected is
(A) Alternative A
(B) Alternative B
(C) Alternative C
(D) No Alternative
4. Based on Payback Period, the alternative to select is
(A) Alternative A
(B) Alternative B
(C) Alternative C
No Alternative
5. Based on Future Worth, the alternative to select is
(A) Alternative A
(B) Alternative B
(C) Alternative C
(D) No Alternative
In: Civil Engineering