1) reasons why unsaturated soil mechanics is needed in the analysis of seepage and shear strength of unsaturated soil, and 2) how to evaluate the seepage and shear strength of unsaturated soil

A curve needs a widening of 4 feet to the inside due to off-tracking. Calculate the taper length for 35mph. Calculate the taper length for 55mph.

Widely recognised as one of the best airports in the world, Changi Airport provides excellent connectivity to the Asia Pacific region, making Singapore a vibrant aviation hub of choice. Changi Airport is served by many leading airlines and is an important hub for airline alliances such as Star Alliance and Oneworld, providing an important connection from ASEAN cities to ones in Europe and the United States.

There are currently 4 terminals in operations at Changi Airport and with the addition of the fifth terminal that is scheduled to be operational in 2030, Changi Airport will be able to cater to more than 135 million passengers per year.

As an intern at the airport, you have been provided with a set of aircraft traffic data (from January 1991 to December 2019) that shows the number of aircraft arrival and departure for each month and are required to analyse and do a projection of the aircraft traffic up to December 2021. This information will help the authority to decide if the pace of constructing Terminal 5 needs to be accelerated for completion ahead of 2030.

(a) Discuss which time period of the record should be used for this forecasting. Recommend an appropriate time series model to forecast the monthly aircraft traffic up to December 2021 with justifications.

(b) From Question 3(a)’s conclusion, determine the monthly forecast for aircraft traffic up to December 2021. Show the steps in calculating the forecast.

Long question

Discuss the design mixture and construction techniques of bituminous stabilization.

You, a car accident investigation expert, are assigned a case where the insurance company suspects that the car company did not properly account for the fatigue failure when designing the axle of their car. You are given a sample of a broken front-right axle to determine if the axle failure was a fatigue failure. You were told that the axle broke when the car traveling at 45 mph hit a pothole in the road. How will you most efficiently determine if the failure caused was a fatigue failure or the pothole effect? You are only given the broken axle.

A 450 mm × 650 mm column supports factored axial load of 2500 kN centered in single footing. After assuming the depth and density of soil above footing, assume the required depth of footing [10 marks].

a) Check depth due to two-way shear

b) Check depth due to one-way shear action

c) Calculate the bending moment and steel reinforcement

e) Determine development length of dowels

d) Check bearing stress

e) Determine development length of dowels

(Is a 14 or 4.88 ? ) A dual wheel having a load per tire of 9,000 lb, 120 psi pressure, and a 14-inch center to center wheel spacing is placed on an infinite space layer with a modulus of elasticity of 20,000 psi. Calculate the pavement displacement at a depth of 15 inches at the following radial distances from the centerline of one tire between the two tires: r = 0, 3, 6, 9, and 12 inches. Assume Poisson Ratio 0.5

Problem .

Determine the number of people who can be sustainably supported by a watershed under the following conditions: (a) watershed area = 207.2 km2 ; (b) annual rainfall rate = 114.3 cm/year; (c) annual evaporation rate = 50.8 cm/year; (d) water resource development = 75%; (e) raw water reservoir volume to store 50% net annual yield or provide half of a year’s water supply, whichever is higher = 49.205 BL; and (f) water consumption rate = 568 Lpcd.

Phase Diagram:

A sample of moist soil was found to have the following characteristics:

Volume: 0.60 Ft³ (as sampled)

Mass: 60 Lb (as sampled)

Mass: 50 Lb (after oven drying)

Specific Gravity: 2.65

First Question:

Find a-h? (show your work)

1. Ratio
2. Porosity
3. Degree of Saturation
4. Wet density (total density)
5. Dry density
6. Volume of Solid
7. Volume of Void
8. Weight of air

1).         A plug-flow reactor has a flow pattern of uniform velocity and concentration in the axial (longitudinal) direction.

(T), (F)

2).         For natural water (pH around 6−8), alkalinity is equal to the concentration of HCO₃^-. (T), (F)

3).         Unit operation means a treatment unit in which “treatment” is accomplished through chemical/biological means.  (T), (F)

4).        Based on the law of mass action, the reaction rate is proportional to the remaining concentration of the products

(T), (F)

5).        Strict household use from public water supply systems is about 105 gpd for each person served.  (T), (F)

6).        It is generally reported that about 60%−80% of the total water supplied to a community becomes wastewater. (T), (F)

7).        For n-CSTRs in series, when n  , the response of these n-CSTRs for a tracer input is the same as a plug-flow reactor. (T), (F) (Note: if you don’t know this, study my notes a bit and then do it)

8).        In flocculation tank design, the GT value of the floculation tank should be around 50000-100000. (T), (F)

9).        Zeta potential is the magnitude of the charge at the surface of shear. (T), (F)

10).       To design a flocculation tank with 4 compartments, the G value in each compartment should be reduced from about 70 to 10 s^-1. (T), (F)

11).       The performance of a plug-flow reactor is as like as a batch reactor that have a reaction time to be exactly the same as the hydraulic retention time of the plug-flow reactor.  (T), (F)

12).       Hardness in water is caused by the ions of calcium, magnesium, HCO₃^-, and CO₃^2-. (T), (F)

13).       After excess-lime treatment, the water is scale forming and must be neutralized to remove caustic alkalinity.  The chemical process to accomplish this task is called recarbonation.  (T), (F)

14).       According to minimum national standards for secondary treatment, the average 30-day concentrations of BOD₅ and SS should be less than 30 mg/L.  (T), (F)

15).       The design year is the year when the facilities reach their full designed capacity.  (T), (F)

16).       The design flow rate is usually assumed to be the average daily flow rate at the beginning of the design period.  (T), (F)

17).       For type I sedimentation, if the Re number is < 2000, the flow is a laminar flow. (T), (F)

18).       In U.S drinking water regulations, the second type of regulation specifies treatment technology in lieu of MCLs when it is infeasible to determine the level of a contaminant in drinking water.  (T), (F)

19).       Three types of sewer systems are used for the removal of wastewater and stormwater: sanitary sewer system, storm sewer systems, and combined sewer systems.  (T), (F)

20).       To design a sand filter, the two most important parameters about the filter media are P₁₀, and P₅₀. (T), (F)

1. explain the differences between reinforcing and prestressing and the relative advantages and disadvantages of each
2. under what circumstances would you use pretensioning, and under what circumstance would you use posttensioning?

In the lecture videos you have seen different techniques to visualize flow field and
gather qualitative and quantitative information flow characteristics. Obtain information
about new laser based techniques for measuring velocity fields. Give some information /
examples of case studies on their usage on following topics at differe nt disciplines using
scientific literature: building aerodynamics, a utomotive a erodynamics , river flow,
offshore structures.
Notes:
This part should not exceed 2 paragraphs . You can use library website to reach
scientific databases and online resources . Cite your references at the end.

With the aid of annotated digram, critically explain the application of various
construction materials for Civil & Infrastructural projects as well as comparing the
physical characteristics of construction materials
1. Low rise building
2. High rise building
3. Pavement project

- Should be .DOC
- The length of essay should be between 1500 - 2000 words.
- The report shall be typeset
- Formal report format is required
- Photos are appreciated in the report
- Reference should be provided

1. Construction Management, Inc. (CMI) has a safety awareness program, but it does not seem to be working. CMI’s president and his two vice presidents developed the program themselves and implemented it company wide six months ago. Unfortunately, they have seen no decrease in the number of accidents and incidents. What possible problems do you see with CMI’s safety awareness program? What changes or improvements would you recommend?

2. Employees of Bearden Construction Company have begun to complain regularly about Josh Randall. They say that his behavior has become unpredictable and that he blows up at the slightest provocation. One employee even said, “This guy is going to hurt somebody.” To each complaint, the supervisor’s response is the same: “Be patient. Josh is a good man. He’s just dealing with some personal problems right now. He’ll get over it.” What do you think of the supervisor’s response to employee concerns? How do you think this situation should be handled?

What is the information to be furnished during the planning and design stages of report on the work- activities in an engineering project?