Discuss the feasibility, difficulties, and merits of building an offshore wind farm in Hong Kong.
In: Civil Engineering
Identify five product, structure or system designs you think can be improved. For your initial post, pick one of the five and write a preliminary problem statement for the engineering design process.
In: Civil Engineering
1) Describe how you can use measurements of stream height (stage) to estimate discharge and what pieces you need to do so. (I’m looking for you to describe both the curve and one method for making discharge measurements)
2) If a flood occurs and erodes the channel where we are measuring stage, can we still use the same relationship between stage and discharge? Why or why not?
In: Civil Engineering
In the year 2015, leaders from 193 countries of the world gathered and moderated by the United Nation and finally summarized that there are 17 goals for the world to be achieved in 2030 named as UNDP Sustainable Development Goals (SDG) towards 2030.
THIS IS THE LINK FOR 17 GOAL.
https://www.undp.org/content/dam/undp/library/corporate/brochure/SDGs_Booklet_Web_En.pdf
In: Civil Engineering
Pick two of the five assumptions that are required to apply the unit hydrograph to a watershed. For each assumption, state what it is, describe it, and give an example of how that assumption might be violated in the real world.
In: Civil Engineering
A) what is the difference between BOD vs COD and sBOD vs sCOD ?
B) Explain the application of using TBOD, sBOD, sCOD and TCOD.
C) which measurement should be used to evaluate or make sure that the process is working properly: i) Primary treatment ii) Secondary treatment with clarifier iii) secondary treatment with membrance
In: Civil Engineering
A Sample of coarse grained soil tested in the
laboratory. The gradation analysis results are as shown
in the table below.
Sieve Size
(mm)
Mass retained on
each sieve (g)
4.75 0
2.00 40
0.850 60
0.425 89
0.250 140
0.180 122
0.150 210
0.075 56
Pan 12
Classify the soil according to Unified Soil Classification System
(USCS)
In: Civil Engineering
The City of Columbus recently issued an NPDES permit to a beer brewery discharging wastewater at a flowrate of 0.15 m3/sec into Buckeye Creek (flowrate = 0.25 m3/sec), such that BOD5 of immediately after discharge must not exceed 2.5 mg/L. Upstream of the discharge, BOD5 in Buckeye Creek was measured at 1.5 mg/L. BOD decay rate constants were measured separately for the upstream creek (k = 2 d-1), the wastewater effluent (k = 0.2 d-1), and the downstream creek after mixing (k = 0.5 d-1).
In: Civil Engineering
finite element problem
Tapered bar subjected to variable axial distributed load A Titanium tapered bar of 25 in. length has a variable cross-sectional area that decreases linearly from 20 in2 to 10 in2 . It is fixed at one end and subjected to an axial concentrated force F = 100 kip at the free end, as shown in the following figure. It’s also subjected to a linearly axial distributed load of variable intensity ?(?) = 0.1 (1 − ? ? ) kip/in. The problem is considered as one dimensional, and the aim of this project is to find, using Finite Element Method, the displacement ?(?) at any position on the x-axis.
The differential equation governing this elastic bars problem is given by: − ? ?? (??(?) ?? ??) − ?(?) = 0 ; 0 < ? < ? Where ? is the Titanium’s Young Modulus of 16. 106 ???; ?(?) is the variable cross-sectional area; and ?(?) is the intensity of the axial distributed load.
Part A: a) Give the expression of the differential equation governing this problem as a function of ?;
b) Give the approximate functions for a quadtratic element;
c) Give the elementary stifness matrix for a quadtratic element;
d) Give the elementary load vector for a quadtratic element;
Part B: We’ll calculate the displacement using a Finite Element Model of one quadratic element.
a) Give the elementary stiffness matrix of the element representing the whole bar
b) Give the elementary load vector of the element representing the whole bar;
c) Give the global matrix form of the Finite Element Model;
d) Give the boundary conditions on the nodal variables (primary as well as secondary variables)
e) Give the condensed equations of the Finite Element Model;
f) Calculate the displacements at ? = ? and ? = ? /2
g) Using the approximation functions, calculate the displacements at ? = ?/ 4 and ? = 3?/ 4
Part C: We’ll calculate the displacement using a Finite Element Model of two quadratic elements.
a) Give the elementary stiffness matrix of each element;
b) Give the elementary load vector of each element;
c) Give the global Matrix Form of the Finite Element Model;
d) Give the boundary conditions on the nodal variables (primary as well as secondary variables);
e) Give the condensed equations of the Finite Element Model;
f) Calculate the displacement at ? = ? /4 ; ? = ? /2 ; ? = 3? /4 and ? = ?..
In: Civil Engineering
Design an aeration tank for activated sludge wastewater treatment designed to meet an effluent standard of 10 mg/L BOD5. The flow from the primary effluent is 10 m3/min with a primary effluent BOD5 of 250 mg/L. The design calls for the suspended solids to equal 3500 mg/L for an SRT of 5 days. The decay rate constant is 0.03 day-1 and the yield is 0.75 mg/mg. Determine:
In: Civil Engineering
A 300 kN point load is applied to a soil profile that consists of 7 meters of sand (γt = 19 kN/m3) above 4 meters of clay (γt = 17.5kN/m3) with the groundwater table at a depth of 5 meters. The clay has an OCR = 1.6, an initial void ratio of 0.86, a Cc=0.64 and a Cr=0.12. The sand has a Cc = 0.35 and an initial void ratio of 0.68. Calculate the overall settlement of the profile due to the application of the point load.
In: Civil Engineering
Sketch example stress strain curves for the following material properties (2 curves on each graph):
Graph 1: Brittle and Ductile
Graph 2: strong and weak (relative)
Graph 3: Non-linear and linear material
In: Civil Engineering
problem 4.8 a five meter retaining wall has to retain backfill of sandy soil having a unit weight 18.2 kn/m3 and angle of internal friction 32 degree,the surface of the backfill in inclined at an angle of 10 degree to the horizontal determine:the magnitude and point of application of the active thrust on the wall,draw a diagram of given situation ,and determine total active earth pressure acting with vertical or with horizontal.
please provide neat and clean solution ..
In: Civil Engineering
Discuss the theories behind the following methods of structural analysis. Use appropriate diagrams.
In: Civil Engineering
(a)
At a reclamation site, a 6-m thick sand layer overlies a 5.8-m
thick clay layer, which is underlain by impermeable rock stratum.
The water level is initially 2.5 m above the ground surface. The
saturated unit weights of sand and clay are 19 kN/m3 and 17 kN/m3,
respectively. A 5-m thick layer of fill will be placed on the
original ground surface, and the unit weights of fill are 19 kN/m3
and 20 kN/m3 above and below water table, respectively. Determine
the water pressures and effective vertical stresses at the middle
of clay layer (i) immediately after the fill is placed, and (ii)
many years after the fill is placed.
(b)
Following part (a), the clay has an initial void ratio of 1.02,
with compression index (Cc) of 0.34 and recompression/expansion
index (Ce) of 0.073. It is also found to be overconsolidated, with
OCR of 1.23 throughout the entire layer.
i. Making use of results from part (a) and considering stresses at
the middle of clay layer, determine the final consolidation
settlements of the clay.
ii. Assuming instantaneous loading (no need to correct for
construction time), estimate the consolidation settlements after 12
months and 36 months, if the coefficient of consolidation (cv)
equals 1.5 m2/year.
iii. Now consider the necessary correction for a construction
period of 10 months. Counting from start of fill placement, how
long does it take for 65% consolidation to complete?
iv. For the corresponding stress range, what will be the equivalent
value of coefficient of volume compressibility (mv) in m2/MN?
In: Civil Engineering