The operator of a rock quarry is invited to bid on furnishing 42,000 cy of crushed aggregate for a job. The aggregate will be delivered to the job, which is 27 miles from the quarry. The aggregate will be loaded into trucks by a loader that can load at a rate of 75 cy/hr. The trucks will haul 18 cy/load at an average speed of 50 mi./hr loaded and 55 mi./hr empty. The estimated time to dump a load is 5 min. Assume a 45 min. effective hour for the loading and hauling operation.

The cost information for the job is: Royalty paid for aggregate = $1.35/cy Overhead = $0.75/cy Profit = $1.20/cy Loader = $85.00/hr Operator = $32.00/hr Trucks, each = $55.00/hr Truck driver, each = $28.00/hr Foremen = $35.00/hr

a) How many trucks are required? b) What resource dictates project duration. c) What should be the bid price per cubic yard using the economic way to conduct the project?

1- Sketch a typical atmospheric pressure steam curing cycle identifying the main steps and

requirements for each step.

2- What is meant by the characteristic strength of concrete?

3- Compressive strength specimens could be cured by standard curing method or on site

beside the concrete elements. What is meant by standard curing? Explain when each curing

4- Discuss the effect of curing, time and temperature, on compressive strength of concrete.

State the minimum moist curing period according to ACI 308.

method is used.

1. Given a magnetic azimuth in 1993 of 169° 18', and a current magnetic bearing of S 8° 26' E. If the current magnetic declination is 4° 15' W, what was the declination in 1993?

do a comparative essay between Casa Mila and Casa Batllo of the architect Antoni Gaudi. In this essay you are to look at the similarities and differences of architectural design principles applied. You are to identify at least four principles and to justify their application by the architect through the two buildings.

Based on the microstructure of wood, explain the mechanisms responsible for retention of water within the structure of wood.

1. Risk Likelihood (3 pts.)

A product improvement project involves an existing product (M), with minor complexity (C), and is dependent for schedule on an existing system (D).   (reference Risk Assessment Calculations document, Likelihood table).  

Consider that criteria are weighted as follows:

M is (0.5), C is (0.3), D is (0.2)

Calculate the Composite Likelihood Factor (CLF).

W1= 0.5, W2=0.3, W3=0.2

(CLF) = W1 * M + W2 * C + W3 * D = 0.5 * 0.1 + 0.3 * 0.3 + 0.2 * 0.3 = 0.05 + 0.09 + 0.06 = 0.20

2. Risk Impact (3 pts.)

A product test failure is expected to have a minor impact on overall technical performance and be correctable within 2 months at a cost of 10 percent. (reference Risk Assessment Calculations document, Impact table).  

Consider that criteria are weighted as follows:

TI is Moderate (0.5), CI is Minor (0.3), SI is Low (0.2)

Calculate the Composite Impact Factor (CIF).

3. Risk Consequence Rating (1 pt.)

Using the previous problems #1 Risk Likelihood (CLF) and #2 Risk Impact (CIF), calculate the Risk Consequence Rating (RCR).

(1) A simply supported steel beam is 30' long and subjected to a uniform distributed 1.3 kips per foot. What is the minimum required section modulus for this beam if we do not want its maximum stress to exceed 50 ksi?

(2) What is the minimum inertia of the beam in the previous question if we do not want it to deflect more than 1/2" ?

CONSTRUCTION PROJECT MANAGEMENT

From the late 1800s to the mid-1900s unions fought for and won improvements for labor which were later adopted by government laws and regulations for all workers. Which part of labor law and regulation was not originally won by unions:

		Mandated overtime after a 40 hour work week
		Safety regulations
		Equal opportunity and affirmative action
		Pension regulations

The results of torsion test on two shafts are shown in the figure. The top shaft shows the torsion failure in the cast iron which is a brittle material and the bottom figure is the test result in a shaft made of ductile steel. Considering the fact that brittle material are controlled by tension (fail in tension) and ductile materials are controlled by shear stress (fail in shear), explain why the brittle cast iron has a 45 degree fracture surface, while the ductile steel shaft has a flat fracture surface. Provide detailed logic based on stress transformation.

Question:

1. Why do engineers prefer to use to ‘constant failure rates’ for reliability calculations? Consider also the ‘convolution functions’ .
2. What conclusions do you draw from the article for preventative maintenance? From your analysis and understanding of the course, how would you modify reliability analysis to comply with the article or would you accept the limitations?

A six lane urban freeway (three lanes in each direction) in mountainous terrain has 10-ft lanes and obstructions 5 ft from the right edge. For every mile of freeway, there is one interchange. The traffic stream consists of mostly commuters with a peak hour factor of 0.84, peak hour volume of 2500 vehicles, and 4% recreational vehicles. What is the LOS? Assume base free flow speed of 70 mph

Problem 3 A column supports a roof and a second floor. The loads that act on the column are shown below. Using the ASCE 7 load combinations determine the factored design load in the column just above the second floor and the factored design load in the column just above the foundation. Show all load combination calculations and identify the controlling load combination and resulting load values at each design location. ( “ - “ load : indicates it is going away from the diaphragm surface)

Service Loads:

Roof Live Load 5.5 kip

Snow Load 6 kip

Roof Vertical Wind Load - 2.5 kip

Roof Horizontal Wind Load 9.2 kip

Roof Vertical Earthquake Load ±1.5 kip

Roof Horizontal Earthquake Load 9 kip

Roof Dead Load Maximum 3.5 kip

Roof Dead Load Minimum 2.75 kip

Live Load 9 kip

2 nd Floor Vertical Earthquake Load ±3.5 kip

2 nd Floor Horizontal Earthquake Load 20 kip

2 nd Floor Horizontal Wind Load 8 kip

2 nd Floor Dead Load Maximum 7 kip

2 nd Floor Dead Load Minimum 7 kip

Problem 2: A simple roof beam with a span 30 ft has a tributary width of 5 ft. The nominal loads that act on the roof system are shown below. Using the ASCE 7 Strength Design load combinations determine the factored design load in the beam (plf). Show all load combination calculations and identify the controlling load combination and resulting design values for positive and negative moment (±Mu) and shear (Vu).

Nominal Loads

Roof Live Load 20 psf

Snow Load 26 psf

Roof Vertical Wind Load -16psf

+5 psf

Roof Rain Load 12 psf

Roof Vertical Earthquake Load ±8 psf

Roof Dead Load Maximum 25 psf

Roof Dead Load Minimum 18 psf

Which of the following are stormwater management principles?

Select one:

a. Maintain water cycle balance

b. Disconnect. Decentralize. Distribute.

c. Integrate early into site design process

d. Protect/utilize natural systems

e. All of the other answers are correct.

3. Consider the following situation and answer the subsequent questions to the best of your engineering ability and judgment. a. There are two Schultz Creek watersheds, East and West. The East drains into unincorporated communities east of Flagstaff, and the West drains into the City of Flagstaff itself. The key point about ‘unincorporated’ is that this means these residents did not live in a city or town, and for some infrastructure aspects like storm drainage, there were no requirements or regulations. Prior to 2010 both of these watersheds were heavily forested and due to almost a hundred years of fire suppression instead of fire management, both watersheds had accumulated thick, water-absorbing masses of pine needles and decomposed pine needles on the forest floor. This prevented the watersheds from ‘delivering’ runoff to its streams in normal years because all of the precipitation was stored in the pine needle layers, sometimes referred to as ‘duff’. Only in heavy snow and rain years, about once every 5-7 years, would the streams flow, instead of every one or two years. i. The East Schultz Creek Watershed is approximately 14 square miles in area. The West is about 6 square miles in area. Assume that the following hydrologic soil group percentages hold for both watersheds prior to 2010: 5% HSG D, 8% HSG C, 15% HSG B, and the rest is HSG A, due to the extensive duff in the watershed.