Civil Engineering Technology Report: Construction Safety and Methods

This report delves into various aspects of civil engineering technology, encompassing earthmoving equipment, safety protocols for deep excavations, and temporary works required for ground stability and groundwater control. It explores pile installation techniques, complex foundation construction methods, and underground construction approaches. The report also examines appropriate construction methods, the use of falsework and formwork in reinforced concrete structures, and potential construction hazards. It further addresses the legal framework of health, safety, and welfare, including the requirements of the Construction (Design and Management) (CDM) 2007 regulations and the role of the planning supervisor. Finally, it presents solutions to civil engineering problems, incorporating modern technology, green building concepts, quality control, safety measures, renewable energy, recycling, waste minimization, and alternative materials. The report also outlines safety plans for problems arising from civil engineering activities, including roles, responsibilities, and emergency procedures.

Civil Engineering Technology 1
CIVIL ENGINEERING TECHNOLOGY
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Civil Engineering Technology 2
Table of Contents
1. Task 1: Earthmoving equipment, safety in deep excavation and temporary works.....................3
1.1. Task 1.1: Earthmoving equipment...........................................................................................3
1.1.1. Use of earthmoving equipment.............................................................................................3
1.1.2. Categories of excavation and earthmoving equipment and their uses...........................4
1.2. Task 1.2: Techniques used to ensure safety and productivity during deep excavations.......5
1.2.1. Protective systems................................................................................................................5
1.2.2. Personal protective equipment.............................................................................................6
1.2.3. Qualified personnel..............................................................................................................6
1.2.4. Underground utilities...........................................................................................................6
1.2.5. Safe access and egress.........................................................................................................6
1.2.6. Appropriate equipment........................................................................................................6
1.2.7. Environmental events...........................................................................................................6
1.2.8. Dangerous atmosphere........................................................................................................6
1.2.9. Nearby buildings..................................................................................................................7
1.2.10. Other tips.............................................................................................................................7
1.3. Task 1.3: Temporary works required in ground stability and groundwater works.............7
1.3.1. Dewatering...........................................................................................................................7
1.3.2. Ground freezing...................................................................................................................8
1.3.3. Shoring................................................................................................................................9
2. Task 2: Pile installation, complex foundation construction and underground construction
methods......................................................................................................................................................9
2.1. Task 2.1: Techniques used to install piling systems................................................................9
2.1.1. Types of piles.......................................................................................................................9
2.1.2. Techniques of pile installation.............................................................................................9
2.1.3. Soil stabilization methods..................................................................................................12
2.2. Task 2.2: Method of constructing complex foundations.......................................................12
2.2.1. Trenching methods............................................................................................................15
2.2.2. Trenchless construction methods.......................................................................................16
3. Task 3: Construction methods, and falsework and formwork.....................................................17
3.1. Task 3.1: Appropriate construction methods........................................................................17
3.1.1. Substructure.......................................................................................................................17
3.1.2. Superstructure units...........................................................................................................17
3.1.3. Lightweight cladding structures.........................................................................................18

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3.2. Task 3.2: Use of falsework and formwork in reinforced concrete structures.....................18
3.2.1. Uses of formwork and falsework.......................................................................................18
3.2.2. Types of formwork............................................................................................................19
4. Task 4: construction hazards, health and safety legal framework, and planning supervisor....19
4.1. Task 4.1: Hazards from civil engineering activities..............................................................19
4.2. Task 4.2: Legal framework of health, safety and welfare and requirements of construction
(design and management) (CDM) 2007..............................................................................................21
4.2.1. Duty holders and roles.......................................................................................................21
4.2.2. Factories and industrial undertaking ordinance (Cap 59) Hong Kong regulations.............22
4.3. Task 4.3: Role of planning supervisor in civil engineering activities...................................22
5. Task 5: Civil engineers in problem solving....................................................................................23
5.1. Task 5.1: Solutions to civil engineering..................................................................................23
5.1.1. Modern technology............................................................................................................23
5.1.2. Green building concept......................................................................................................24
5.1.3. Quality control...................................................................................................................24
5.1.4. Safety measures.................................................................................................................24
5.1.5. Renewable energy..............................................................................................................24
5.1.6. Recycling...........................................................................................................................24
5.1.7. Waste minimization...........................................................................................................24
5.1.8. Alternative materials and production methods...................................................................24
5.2. Task 5.2: Safety plans for problems arising from civil engineering activities.....................25
5.2.1. Roles and responsibilities...................................................................................................25
5.2.2. Safety procedure................................................................................................................25
5.2.3. Emergency procedure........................................................................................................26
References................................................................................................................................................26

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1. Task 1: Earthmoving equipment, safety in deep excavation and temporary works
1.1. Task 1.1: Earthmoving equipment
1.1.1. Use of earthmoving equipment
Earthmoving equipment are generally used for digging, lifting and moving earth or waste
loads generated on construction sites. Therefore earthmoving equipment comprises of equipment
used to excavate earth, lift and load it, and move it from one place to another.
1.1.2. Categories of excavation and earthmoving equipment and their uses
Below are the four main categories of excavation and earthmoving equipment and their uses:
Excavation: this category comprises of machines used for digging/excavating, trenching or
moving large objects. They are commonly known as excavators and are used in both small and
large scale construction projects. An excavator can either be wheeled or tacked. Both of them are
very versatile but tracked excavators have greater traction and floatation characteristics (Heavy
Equipment, 2017). The several uses of excavation equipment are: site preparation; digging
foundations, holes and trenches; material handling; demolition; lifting and laying pipes;
installation of underground utility; general landscaping and grading; etc. Common machines
under this category include: excavator, bulldozer, trencher and backhoe loader. In this context,
excavation equipment are construction machines that are only used for digging or excavating
earth. Below is an example of an excavation equipment.
Excavation and load: this category comprises of machines that are used to excavate rocks and
earth and load them onto another truck for dumping. These equipment excavate earth then scoop
up the excavated materials (soil, rocks, etc.) from the ground and load them onto a dump truck.
Examples of excavation and load equipment are wheel loader (also known as bucket loader, skip
loader or front loader), excavator, backhoe loader, crawl loader, skid loader, poclain/JCB,
loading shovel and bulldozer (crawler) (Suryakanta, 2014). Below is an example of an
excavation and load equipment.

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Haul and deposit: these are equipment used for moving excavated materials from the
excavation point to fill area. They can also be used for moving other items besides excavated
materials. Common examples of haul and deposit equipment are dump trucks (known as
dumpers), scrapers, tippers, poclain/JCB, trailers, tractors, cranes, bulldozers, excavators, loaders
and shovels (Rich, 2016). Scrapers are suitable for use in large construction sites with adequate
open space (Rodriguez, 2017). Below are examples of haul and deposit equipment.
Excavation, load, haul and deposit: these are equipment that can be used to excavate or dig
earth, load loose materials onto hauling machines, transport the excavated materials and deposit
them in fill areas. Examples of these equipment are: excavators, bulldozers, backhoe loaders,
crawler loaders, loading shovel, forward loader, JCB, etc. These equipment have varied
capacities for each of these operations (excavation, loading, hauling and depositing). Some of
them have greater capacity to excavate and load than haul and deposit, and vice versa.
Excavation, load, haul and deposit equipment are usually not designed to haul materials over
long distances and therefore after excavating materials, they can only move them within the site
and not to fill areas located several miles away. Below are some of the excavation, load, haul and
deposit equipment.

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1.2. Task 1.2: Techniques used to ensure safety and productivity during deep
excavations
There are several safety issues that cause hazards and risks when undertaking deep
excavation activities. Some of the safety issues include: working in confined space, working at
height, collapse of excavated sides (cave-ins), flooding due to water ingress, destruction of
underground utilities causing explosion or electrocution, falling loads, falls, moving equipment,
etc. Therefore there is need to ensure that appropriate measures are put in place so as to prevent
or mitigate these hazards and risks. Some of these techniques are as follows:
1.2.1. Protective systems
Appropriate protective systems should be put in place to ensure safety of workers performing
excavation and trenching activities. These systems include sloping, benching, shoring and
shielding. Sloping entails cutting out sides of the trench at an angle from the excavation.
Benching involves cutting steps into the trench sides. Shoring involves installation of different
types of supports, such as aluminium hydraulic systems, on the sides/walls of trench or hole
excavated to prevent cave-ins or soil movements. Shielding involves use of support systems,
such as trench shields or trench boxes, to protect workers by preventing soil cave-ins
(Safety+Health, 2013).
1.2.2. Personal protective equipment
All workers must be in appropriate personal protective equipment (PPE) before entering
excavation trenches. Depending on the type, depth and conditions of excavation, some of the
PPE may include gloves, apron, safety eyewear, hearing protectors, hard hats, high-visibility
vests or reflector jackets, safety footwear (such as steel toed boots or shoes), etc. The specific
PPE to be worn may also depend on the specific type of excavation work being carried out.
Workers entering deep excavations should also have a harness attached with a lifeline (Center for
Construction Research and Training, 2017). The supervisor should ensure that PPE are inspected
regularly for signs of damage or wear and tear.
1.2.3. Qualified personnel
All excavation and trenching activities should be carried out by trained and qualified
personnel. Machine operators should be well-trained and experienced to ensure efficient and safe
operations. Competent persons should also inspect trenches daily before allowing entry of
workers to ensure that potential excavation hazards are eliminated. Inspection should also be
done throughout the deep excavation process. The company should also provide training to its
workers frequently to ensure that they have proper, adequate and updated knowledge on latest
safety measures.
1.2.4. Underground utilities
It is important to identify and mark location of all underground utilities present on site before
commencement of any excavation work. Doing so will prevent numerous dangers, damages,
losses and inconveniences. For example, if a water main is cut then the excavation may collapse
quickly causing risks to the lives of workers and losses to the company.
1.2.5. Safe access and egress
All deep excavations should have safe access and egress to enable easy entry and exit of
workers. The access and egress facilities include steps, ladders, ramps, etc. These facilities
should be provided for all excavations that are 1.22 m or deeper and must be positioned within
7.6m of all workers (Occupational Safety & Health Administration, (n.d.)).

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1.2.6. Appropriate equipment
Deep excavation should also be done using suitable types of equipment. These equipment
should be approved and used by following the manufacturer’s manual. They should be integrated
to ensure flawless excavation, loading, hauling and deposit of loose materials. The equipment
should be maintained and cleaned properly to ensure operational safety and efficiency. Most
importantly is that the equipment must be operated by qualified personnel.
1.2.7. Environmental events
It is also important to identify and assess environmental events and their related hazards.
Such events include rainstorms, which can cause instability of walls, or absorption of excess
water resulting to a slide (Meek, 2014). Other events that should be analyzed include sandstorms
and earthquakes. If any of these events occur, trenches must be inspected before allowing
workers to progress.
1.2.8. Dangerous atmosphere
Factors that can cause hazardous atmosphere include excavating near a sewer, toxic site or
landfill, or using chemicals near or inside the excavation or trench. Some of the major
contributors to dangerous atmospheres are: presence of highly flammable or toxic gases, and
oxygen deficiency. Suggested strategies to overcome their impacts include: using appropriate
PPE and installing ventilation systems to supply adequate fresh air (University of Arizona,
2017).
1.2.9. Nearby buildings
Deep excavations may affect stability of nearby structures, such as buildings. For this reason,
it is important to assess the possibility of the excavation affecting stability of nearby structures
and establishing the need to install bracing supports or other systems. These protection systems
should ensure that the excavation does not affect nearby structures adversely (WorkSafe New
Zealand, 2017).
1.2.10. Other tips
Other tips that improve safety during deep excavations and trenching include: securing work
area; managing traffic; storing excavated spoil or plant away from the excavation sides to
prevent them from falling into the excavated hole; installing barriers around the excavation (Ai
Solutions Ltd, 2017); not working under raised or suspended loads excavation or loading
equipment (Occupational Safety and Health Administration, 2015); checking & complying with
local safety and health requirements related to excavation works (Ontario Ministry of Labour,
2015); fixing safety signs at designated places; and frequently reminding workers about safety
and health regulations and tips (Northern Safety Co., Inc., 2017).
1.3. Task 1.3: Temporary works required in ground stability and groundwater
works
Controlling groundwater and ensuring ground stability during excavation are very important.
These are several temporary techniques that can be used to control groundwater and ground
stability during excavation. The following are some of this techniques:
1.3.1. Dewatering
This is one of the major methods used for controlling groundwater temporarily. There are
several dewatering methods used in construction industry. The two main methods are: exclusion
method and pumping method.

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Exclusion method: this method involves installing an impermeable structure (known as cut-
off wall) to prevent groundwater from the excavation. The cut-off wall stops flow of
groundwater to the excavation. Cut-off walls can be created using various geotechnical methods
including: slurry trenches and walls, steel sheet piles, compressed air, freeze walls, secant pile
walls, diaphragm walls, grout curtains, etc. If properly installed, cut-off walls eliminate or reduce
the need for pumping groundwater (Groundwater Engineering, 2014). Some of the methods used
to construct or install cut-off walls are: underground excavation and caissons. Underground
excavation is used when it is not desirable or possible to lower the level of groundwater or where
the soil is extremely pervious. Caisson is where a caisson structure is constructed and during
excavation, the structure is sunk by imposed loads or self-weight. Instead of installing a cut-off
wall, the excavation can also be protected against groundwater by diverting the water.
Pumping method: this method entails pumping groundwater from several sumps or wells so
as to lower groundwater levels temporarily and allow excavation works to be undertaken under
stable and dry conditions. Figure 1 below is a schematic diagram of a groundwater pumping
system.
Figure 1: Schematic diagram of groundwater pumping system (Preene, 2014)
There are 5 common pumping techniques used for groundwater dewatering: sump
pumping system, well point system, deep well system, ejector or eductor system and siphon
draining system. Sump pumping system is where groundwater is allowed to flow into the
excavation and collected in sumps from where the water is pumped out (WJ Groundwater, 2017).
Well point system is where rings or lines of closely well points (shallow wells) are set up around
the excavation and connected to a header pipe. Well point pumps are then used to pump water
from these shallow wells on the principle of suction. Deep well system is where electric
submersible pumps are used to pump groundwater from a bored well. The wells are bored round
the excavation perimeter. Ejector well system is most suitable regulating pore water pressures
found in materials that are less permeable. The system’s operation is based on venturi principle.
Here, a vacuum is created as high pressure water circulates in the ejector wells. This vacuum
facilitates drainage in strata with low permeability. Siphon draining is where water is pumped
from installed wells by gravity through siphon pipes. The wells have to be installed above the
excavation’s unstable zone so that the pumping can be enabled by gravity (Moving Water
Industries Corp., 2016).

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1.3.2. Ground freezing
This is the method where groundwater is converted into a solid and impermeable wall of ice.
The groundwater is frozen by placing vertical freeze pipes in the soil then removing heat energy
through these pipes, as shown in Figure 2 below (Nemati, 2007). When earth temperature
reaches 0 °C, groundwater present in the soil turns to ice. The ice continues to solidify with
further cooling. Common ground freezing techniques include brine circulation and liquid
nitrogen process.
Figure 2: Freeze pipes (Nemati, 2007)
1.3.3. Shoring
This is a method that ensures ground stability protection of excavation against groundwater
effects. The technique simply involves installing or constructing protective support systems
around the excavation. Common excavation support and protective systems used are: soil nailing
systems, soldier beam & lagging systems, excavation bracing and tieback systems, among others
(Kamran, 2007).
2. Task 2: Pile installation, complex foundation construction and underground
construction methods
2.1. Task 2.1: Techniques used to install piling systems
Piling is one of the most common and effective methods used to strengthen and support
foundations. Piles are used to provide the required support to various engineering structures,
including bridges, buildings, dams, industrial structures, etc. (Groundforce, 2017).
2.1.1. Types of piles
Piles can be classified based on the following:
Composition or type of material – piles under this category include: concrete piles, timber
piles, steel piles and composite piles (AboutCivil, 2014).
Installation method – piles under this category include: bored piles, driven piles and
driven & cast in-site piles.
Function – this is where piles are classified based on their use. They include: end bearing
piles, tension piles, friction piles, anchor piles, compaction piles and dolphins and fender piles
(Khan, (n.d.)).

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2.1.2. Techniques of pile installation
Pile installation in Hong Kong can be done using several techniques. The technique used is
selected depending on: soil conditions, equipment available, load bearing requirements, local
practice, etc. (Adejumo, 2013) Some of these techniques include:
2.1.2.1. Driving techniques
Piles can be driven into the ground using the following methods:
Dropping weight: this is where a hammer (known as drop hammer) with roughly equal
weight with that of the pile is lifted in a guide to an appropriate height then released to strike the
head of the pile, as shown in Figure 3 below. There two common types of drop hammers used
are: compressed-air or single-acting steam and double-acting hammers (The Constructor, 2017).
Figure 3: Pile installation by dropping weight (Engineers Today, 2012)
Vibration: this involves driving piles into the ground using vibratory hammers. The
hammers can be powered hydraulically or electrically.
Explosion: this techniques uses explosion charges installed in the ground to create
cavities in the ground by crush stones or other soil materials (Yan & Chu, 2005).
Jacking: this is the method where a static driving force is imposed on the pile using a
jack. The pile is jacked into the ground using force from a pump and applied through the
hydraulic jack, as shown in Figure 4 below.

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Figure 4: Jacking technique (University of the West of England, (n.d.))
Jetting: in this method, a water jet is used to soften the ground thus easing penetration of
the pile into the ground as shown in Figure 5 below. When a jet of water is directed at one point,
it causes fragmentation of the subgrade soils thus decreasing interlocking force and friction
between adjacent soil particles. As a result of this, the soil’s bearing capacity beneath the pile tip
becomes very low allowing the pile to descend easily (Kimos, 2009).
Figure 5: Schematic diagram of pile jetting (Xu, et al., 2006)
2.1.2.2. Boring methods
These methods include:
Continuous flight auger (CFA): in this method, a flight auger fixed with a protective cap
at its tip is driven or rotated into the ground using a rotary hydraulic motor connected to it and
installed on the earth surface. When the desired depth is attained, workable concreted is impelled
via the auger’s hollow stem as shown in Figure 6 below.

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Figure 6: CFA (Builder's Engineer, 2013)
Underreaming: this technique is used for widening the bottom of a bored pile or for
creating tension piles as shown in Figure 7 below.
Figure 7: Diagram showing underreaming (Franki Foundations, (n.d.))
2.1.3. Soil stabilization methods
Cement – this technique involves mixing cement with soil to increase the soil’s stability
(Kowalski & Starry, 2007).
Lime – the method involves adding lime to the soil resulting to a reduction in plasticity index
and increase in soil strength.