1021 Final Exam
.pdf
keyboard_arrow_up
School
University of New South Wales *
*We aren’t endorsed by this school
Course
1021
Subject
Civil Engineering
Date
Apr 3, 2024
Type
Pages
7
Uploaded by samuelharvey15
1. Briefly describe five (5) conditions that must be considered before selecting a suitable
trench support method? (10 marks)
Soil type: The type of soil whether it is extremely soft or a hard type of soil will effect what trench
support method will be used.
Depth of cut: How deep the excavation is, is a major factor in determining what trench support
systems will be used. It is a general rule that trenches that are more than 1.2 m deep require a
protective system.
Water content of soil: The water content of the soil must be considered before selecting trench
support methods, factors should be taken into place to consider if there is any dewatering
requirements and if there is going to be long-term effects on the stability and safety of the
excavation.
Other operations in the area: You will need to consult with other professionals to see if the trenc
support method you want to use will engage in the area's main electricity/ water lines. If there is
a live electrical wire nearby, nonmetal shoring may be used.
Changes due to weather or climates: If there is sudden flooding or another weather event, the
trench support method that is currently being used may need to be changed or replaced.
2. Briefly discuss the challenges associated with tunneling in urban areas and suggest
ways of addressing them. (10 marks)
There are many potential challenges that may arise
when tunneling in urban areas, such challenges include impeding on existing infrastructure in
urban areas. There are networks such as gas, water, and electricity that would cause huge
problems if these were impeded. The limited amount of space in urban environments also
magnifies the challenges of developing tunnels, as there is a higher chance of damaging
existing facilities and structures.
However, due to the advance in construction technology, there are ways of addressing these
issues. For example, there is teams of experienced individuals that will actively survey the urban
area and investigate if there is any existing underground structures before the tunneling process
begins. Furthermore, there is technology that can scan the ground ahead and alert the tunnel
machine operators that there is live electricity main for example and the process can stop before
this is damaged and would affect millions of individuals.
3. a. How does very hot weather affect the performance of concrete? (4 marks)
Extremely
hot weather can adversely affect the performance of concrete ultimately due to the increase in
evaporation; this can lead to the concrete drying out and stiffening resulting in a premature finish
of the concrete.
Through the increased evaporation of moisture from the fresh concrete, this increases the
setting time, making it harder to place the concrete effectively.
Due to the need for more water to be added to the concrete mix to maintain workability, this
increases the water to cement ratio, resulting in a decrease in strength and durability.
The increased rate of evaporation will cause a poor surface appearance of the concrete, there
may be a color difference in the concrete
b. Briefly explain any five (5) precautions that should be taken when concreting
operations have to be carried out in very hot weather in order to minimise the effect of
the hot temperature on the concrete performance. (10 marks)
Implementing set-reatrding admixtures (Type Re) in the concrete mix to slow down the setting of
the concrete, to maintain the initial moisture in the concrete mix, and to keep the concrete
workable, this avoids problems such as thermal cracking and poor surface appearance.
This is mainly used in large and extremely valuable concrete pours; injecting liquid nitrogen
directly into the concrete mixture or truck can lower the concrete temperature and keep it
workable.
When transporting and working with concrete in extremely hot temperatures, all equipment used
such as pump lines, conveyors, and chutes should be enclosed or shaded with reflective colour
to reduce the effects of the sun. This prevents the issue of thermal cracking.
Pouring concrete at night in extremely hot areas such as Dubai is extremely effective in battling
the effects of increased evaporation. This will help increase the setting time and the durability of
the concrete.
Spraying the concrete with ‘aliphatic alcohol’ after the initial finishing of the concrete will reduce
evaporation and ultimately the cracking of the concrete.
4. Mention four (4) ways of ensuring the stability of a constructed scaffold. (6 marks)
Checking if the scaffold is built on solid ground: You can ensure your scaffold is stable easily by
checking the density of the ground the scaffold has been erected on. Is the ground soft? Is the
ground muddy? If so you must check that sole boards have been used to distribute the load
properly.
Checking if the scaffold is stable: An individual can easily check if the scaffold is stable just by
looking at the scaffold to see if it is moving in the wind if it shakes when you move it yourself. If
the scaffold is shaking a lot it is not stable.
Checking if the standards are plumb: If the standards on the scaffolds are not plumb, this is an
easy indication that the constructed scaffold is unstable. However, you must always check with
the installers to see if the standards are designed to be that way.
Distance between standards is more than 2.5m: This is an easy way to check if the erected
scaffold is a table or not. If there is more than 2.5m distance between two standards, the
scaffold would be considered unstable.
5. In recent times, there have been increased drive for underground construction,
including tunnel construction in urban areas. Briefly discuss five (5) reasons/factors
behind this drive. (10 marks)
A desire for individuals to be able to take in the natural beauty this country has to offer such as
our incredible mountains, seaside views, and big trees has increased the drive for underground
construction to ensure that the natural flora and fauna of the land is not disrupted,
An increase in population has led to an increase in vehicles used, therefore to accommodate
the increasing traffic requirements there has been a drive for underground tunnel construction
this will also reduce traffic.
There is also been a drastic reduction in the amount of usable surface land for construction in
urban areas, therefore leading to a drive for increased underground construction.
There has been an increase in construction technologies and advancements in equipment such
as tunnel boring machines, therefore, making underground construction easier, therefore,
leading to an increased drive.
There has been an increase in people's desire for futuristic construction, and people are more
open to taking leaps for example many construction companies want the label of being the first
company to produce an underwater bridge etc,
6. a. Mention eight (8) factors affecting the selection of bridge construction methods.
(4 marks)
The scale of the bridge:
The local cost of materials
The local weather
The local labour markets
The accessibility of the site
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
Related Questions
Design a 275 ft long x 4.0 ft wide x 9.0 ft deep utility trench as a sloped excavation with no bracing following OSHA guidelines. The unconfined compressive strength of the soil is 3.2 ksf. There is not going to be vibrating equipment in the vicinity of the excavation.
What OSHA soil type is this. Justify your answer. Is benching allowed for this soil type? Explain.
arrow_forward
3. Excavation may be classified by type of material-Earth excavation
excavation, rock excavation, muck excavation, unclassified excavation. *
O a) bottom soil
O b) sub-soil
c) topsoil
O d) surface soil
arrow_forward
What are Procedures, apparatus, and calculations needed in Fall Cone/ Cone Penetration Method
arrow_forward
STATION 1+ 125
a
b.
12
10
10-m
10-m
5.30
6.20
1.5
8.80
DETERMINE THE
VALUES OF "a" AND "b"
And The volume of excavation and fill using end-area method
arrow_forward
Question number (8) Highway Engineering civil engineering
arrow_forward
The areas of the cross-section of an excavation are 3,987.23 sqm, 4,659.01 sqm,
and 3,876.30 sqm. The spacing of each cross-section from each other is 9.80m.
a) Find the volume of Excavation by End Area Method. b) Find the Loose Volume
of the soil excavated if it has a swell factor of 15.5%. c) A Dump Truck is rented
Php 20,000 per day and can make 7 trips in a day. Find the cost of hauling if 5
Dump Trucks with a capacity of 10 cu. m. per trip is used.
Your answer
arrow_forward
---DETERMINE THE VALUES OF “a” AND “b” THEN FINISH THE PROBLEM.
--- Determine the area of the cross-section
--- The volume of excavation and fill using end-area method
arrow_forward
A site consists of a 12 m thick saturated clay deposit underlain by bedrock. The clay has ?=20.0?N/?3and ??=40?N/?2 . If an excavation is to be made at a slope angle ?=25° to a depth of 10.0 m, what would be the factor of safety FSs? What type of failure circle would you expect?
(Please open the image in a new tab if need be, Thank you)
arrow_forward
Please help me answer the question in the attached photo.
arrow_forward
Q#2
During excavation processes as a civil engineer what types of precautions should be taken and what are its types .
arrow_forward
Be aware of the problems that may occur during excavation and techniques to control them
arrow_forward
List and briefly explain 3 advantages of pipe earthing as applied to earthing systems design
arrow_forward
I need right solution with clear calculations
arrow_forward
1. The height of excavation is 1.30m
2. Soil type: fairly good soil.
arrow_forward
1)A ground rod can be buried in a 2 ½ -foot-deep trench only if rock bottom is encounter, and it cannot be driven either vertically or at an angle not exceeding 45 degrees from vertical. a) True b) False
2)Soil resistivity is measured to determine the type of soil conditions, the corrosive effects in the soil, and the gest type of grounding electrode system to install. a) Trueb) False
arrow_forward
Hello! can you pls help me know this as for my understanding in our subject Geology.
a).An excavation is to be made for a footing 1.5 m x 1.5 m. However during the excavation you encountered the water table as shown the depth of excavation to be is 2m from the surface but the ground water table is 1m from the surface.How will you be able to pour the concrete mix for the footing if ground water is continuously infiltrating into your excavation and filling up the pit with water. Draw each stage of the excavation up to finishing up the footing with a short explanation for each drawing, include stage of placing formworks and rebar as well as other process to ensure that additional ground water will not mix with your newly poured concrete. How will you make the footing? (the photo attached is just 1m excavation you still have 1m more to excavate)
THANK YOU!!
I'll give your answer a LIKE for helping me.
arrow_forward
A shovel having a 6-cy bucket whose cost per hour, including the wages to an operator, is $85 will
excavate well-blasted rock with a swell percent of 60%, and load trucks under the stated condition
below. The maximum digging height of the machine is 30 ft. Determine the cost per bank cubic
yard. Use the average fill factor for well-blasted rock and assume the optimum height of cut for this
material is 50% of the maximum digging height.
Condition
Height of excavation (ft)
Angle of swing (degrees)
Efficiency factor (min per hr)
Edit View Insert Format Tools Table
24
75
40
Cycle Time
9 sec
6 sec
4 sec
Load
Swing loaded
Dump
Swing empty
5.sec
arrow_forward
Please explain step by step. Thank you.
-> Find the preconsolidation pressure for curve below
-> Find Compression Index, (Cc) and Swell Index (Cs) for curve with initial void ratio assumed at = 0.8
-> Find total settlement
-> Can 50% Consolidation be achieved in 6 months if total surcharge applied is 2400 psf?
CONSOLIDATION TEST - ASTM D2435
Boring / Sample No.
B-10 / R-4
Depth:
7.5' - 9'
Date
03-18-19
1.00
0.9975
0.9950
0.99
- Natural
o Submerged
0.98
0.97
0.96
0.9504
0.95
0.94
0.93
0.92
B0.91
.9089
0.90
I0.89
Silty Clay
Dry Density: 81.3 pcf
Initial Water Content: 15.1 %
Final Water Content: 24.7 %
H,O @ 400 PSF
0.88
0.87
0.86
0.8532
0.85
0.84
0.83
08341
0.82
0,8232
0.8136
0.8091
0.81
0.80
100
1000
10000
100000
Vertical Pressure (psf)
Sample Height (inches)
arrow_forward
I need a quick solution within 15 minutes With my best wishesTon.
arrow_forward
A) What are the methods used to dry the
excavation?
arrow_forward
I need the answer as soon as possible
arrow_forward
Show complete solution and answer in 4 decimal places
The areas of the cross-section of an excavation are 3,897.23 sqm, 4,596.01 sqm, and 3, 786.30 sqm.
The spacing of each cross-section from each other is 9.80m. a) Find the volume of Excavation by End
Area Method. b) Find the Loose Volume of the soil excavated if it has a swell factor of 15.5%. C) A
Dump Truck is rented Php 20,000 per day and can make 7 trips in a day. Find the cost of hauling if 5
Dump Trucks with a capacity of 10 cu. m. per trip is used.
arrow_forward
A 12” water main is being installed along the shoulder of a rural road. The excavation for the water main will be 4 feet deep and 3.5 feet wide. The soil is estimated to have a swell factor of 0.80 and an angle of repose of 31 degrees. If the stockpile will start 2 feet from the edge of the excavation, and the distance from the edge of the trench to the limits of disturbance is 20 feet, what is the estimated clear space between the far toe and of the stockpile and the limits of disturbance?
arrow_forward
A temporary excavation, with a 1 horizontal on 2 vertical slope, is to be performed in a stratum of clay 100 ft thick with an undrained shear strength of 2000 psf. The total unit weight of the clay is 125 pcf. If the safety factor must be at least 2.0, what is the maximum permissible depth of the excavation?
arrow_forward
Q14. A contractor is excavating the below trench. The contractor is supposed to dig the
trench 5ft deep and 3ft wide. The soil was tested to have an approximately swell factor of
112% and a shrinkage factor of 14%. The contractor is placing a 10" water pipe in the trench
and then backfilling with the soil that was removed. The dimensions are on center line.
Does the contractor have enough soil to backfill the trench, or will he /she have to need
more? If more soil are needed, how much does the contractor need to bring in. Answer in
LCY.
40ft
3ft
16ft
40ft
20ft
24ft
60ft
arrow_forward
SEE MORE QUESTIONS
Recommended textbooks for you
Structural Analysis (10th Edition)
Civil Engineering
ISBN:9780134610672
Author:Russell C. Hibbeler
Publisher:PEARSON
Principles of Foundation Engineering (MindTap Cou...
Civil Engineering
ISBN:9781337705028
Author:Braja M. Das, Nagaratnam Sivakugan
Publisher:Cengage Learning
Fundamentals of Structural Analysis
Civil Engineering
ISBN:9780073398006
Author:Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel Lanning
Publisher:McGraw-Hill Education
Traffic and Highway Engineering
Civil Engineering
ISBN:9781305156241
Author:Garber, Nicholas J.
Publisher:Cengage Learning
Related Questions
- Design a 275 ft long x 4.0 ft wide x 9.0 ft deep utility trench as a sloped excavation with no bracing following OSHA guidelines. The unconfined compressive strength of the soil is 3.2 ksf. There is not going to be vibrating equipment in the vicinity of the excavation. What OSHA soil type is this. Justify your answer. Is benching allowed for this soil type? Explain.arrow_forward3. Excavation may be classified by type of material-Earth excavation excavation, rock excavation, muck excavation, unclassified excavation. * O a) bottom soil O b) sub-soil c) topsoil O d) surface soilarrow_forwardWhat are Procedures, apparatus, and calculations needed in Fall Cone/ Cone Penetration Methodarrow_forward
- STATION 1+ 125 a b. 12 10 10-m 10-m 5.30 6.20 1.5 8.80 DETERMINE THE VALUES OF "a" AND "b" And The volume of excavation and fill using end-area methodarrow_forwardQuestion number (8) Highway Engineering civil engineeringarrow_forwardThe areas of the cross-section of an excavation are 3,987.23 sqm, 4,659.01 sqm, and 3,876.30 sqm. The spacing of each cross-section from each other is 9.80m. a) Find the volume of Excavation by End Area Method. b) Find the Loose Volume of the soil excavated if it has a swell factor of 15.5%. c) A Dump Truck is rented Php 20,000 per day and can make 7 trips in a day. Find the cost of hauling if 5 Dump Trucks with a capacity of 10 cu. m. per trip is used. Your answerarrow_forward
- ---DETERMINE THE VALUES OF “a” AND “b” THEN FINISH THE PROBLEM. --- Determine the area of the cross-section --- The volume of excavation and fill using end-area methodarrow_forwardA site consists of a 12 m thick saturated clay deposit underlain by bedrock. The clay has ?=20.0?N/?3and ??=40?N/?2 . If an excavation is to be made at a slope angle ?=25° to a depth of 10.0 m, what would be the factor of safety FSs? What type of failure circle would you expect? (Please open the image in a new tab if need be, Thank you)arrow_forwardPlease help me answer the question in the attached photo.arrow_forward
- Q#2 During excavation processes as a civil engineer what types of precautions should be taken and what are its types .arrow_forwardBe aware of the problems that may occur during excavation and techniques to control themarrow_forwardList and briefly explain 3 advantages of pipe earthing as applied to earthing systems designarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Structural Analysis (10th Edition)Civil EngineeringISBN:9780134610672Author:Russell C. HibbelerPublisher:PEARSONPrinciples of Foundation Engineering (MindTap Cou...Civil EngineeringISBN:9781337705028Author:Braja M. Das, Nagaratnam SivakuganPublisher:Cengage Learning
- Fundamentals of Structural AnalysisCivil EngineeringISBN:9780073398006Author:Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel LanningPublisher:McGraw-Hill EducationTraffic and Highway EngineeringCivil EngineeringISBN:9781305156241Author:Garber, Nicholas J.Publisher:Cengage Learning
Structural Analysis (10th Edition)
Civil Engineering
ISBN:9780134610672
Author:Russell C. Hibbeler
Publisher:PEARSON
Principles of Foundation Engineering (MindTap Cou...
Civil Engineering
ISBN:9781337705028
Author:Braja M. Das, Nagaratnam Sivakugan
Publisher:Cengage Learning
Fundamentals of Structural Analysis
Civil Engineering
ISBN:9780073398006
Author:Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel Lanning
Publisher:McGraw-Hill Education
Traffic and Highway Engineering
Civil Engineering
ISBN:9781305156241
Author:Garber, Nicholas J.
Publisher:Cengage Learning