chinmoy pathak choudhury_iocl internship report

WINTER INTERNSHIP IN

INDIAN OIL CORPORATION LIMITED, BONGAIGAON REFINERY

SUBMITTED BY CHINMOY PATHAK CHOUDHURY

2nd JAN, 2013 – 17th JAN, 2013

DEPARTMENT OF CIVIL ENGINEERING

ASSAM ENGINEERING COLLEGE, JALUKBARI

GUWAHATI – 781013

Table of Contents

Chapter 1 Occupational safety and health in construction industry 1

1 Hazards and their solutions 2

2 Safety checklists for Personal Protective Equipment (PPE) 6

3 Common violations on-site 7

4 Safety rules 11

5 Overview of statutes applicable to construction industry 13

Chapter 2 Structural welding 14

1 Welding terminology 14

2 Common types of welds 16

3 Welding positions 20

4 Weld symbols 21

Chapter 3 Storage of cement bags in warehouse 23

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Chinmoy Pathak Choudhury

Assam Engineering College, Jalukbari

Guwahati - 781013

CHAPTER 1: OCCUPATIONAL SAFETY AND HEALTH IN CONSTRUCTION INDUSTRY

Construction Sector is very essential and an integral part of Infrastructure development

which gives tremendous boost to our country’s economy. The construction industry had

registered enormous growth worldwide in recent years. Although the development of

technology is rapid in most of the sectors, construction work is still labour intensive.

In India, the construction sector employs around 33 million people, which is next to

agriculture. The construction workers are one of the most vulnerable segment of the

unorganized labour in our country. Workers being exposed to wide variety of serious hazards,

the rate of fatal accidents in this industry is 4 to 5 times to that of manufacturing. The workers

are also exposed to a host hazardous substances which have a potential to cause serious

occupational diseases such as asbestoisis, silicosis, lead poisoning, etc. There is also a

serious potential of fires dues to the storage and use of flammable substances and a potential

for disasters due to collapse of the structures and the subsidence of the soil on which the

construction activity is being carried out.

There are numerous challenges of Construction Industry in construction activities in

India. Some of them are listed as the following.

1. Transport

2. Infrastructure

3. Migrating Work force

4. Social hazards at site

5. Culture

6. Competent Man power

7. Awareness

8. Unorganized Sector

9. Labour Camps

10. Training Infrastructure

Each year, there are thousands of injuries and triple-digit numbers of fatal accidents

related to machine and equipment operation. A lot of these accidents involve the operator, but

over half involve people on the ground - spotters, co-workers, laborers, shovel hands, passers-

by and sidewalk superintendents who get too close. And because of the forces and physics

involved, these are usually not first-aid injuries; there is often an ambulance called to the

jobsite.

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Potential hazards for workers in construction include:

Falls (from heights);

Trench collapse;

Scaffold collapse;

Electric shock and arc flash/arc blast;

Failure to use proper personal protective equipment; and

Repetitive motion injuries.

1. Hazards and their solutions: Some hazards and their solutions are enumerated below.

1.1. Scaffolding: When scaffolds are not erected properly, fall hazards can occur.

Solutions:

Scaffold must be sound, rigid and

sufficient to carry its own weight plus

four more times thr maximum intended

load without settling or displacement. It

must be erected on solid footing.

Unstable objects, such as barrels,

boxes, loose bricks or concrete blocks

must not be used to scaffolds or planks.

Scaffolds must not be erected, moved,

dismantled or altered except under the

supervision of a competent person.

Scaffold accessories such as braces,

brackets, trusses, screw legs or ladders

that are damaged or weakened from

any cause must be immediately repaired

or replaced.

A competent person must inspect the

scaffolding and, at designated intervals,

reinspect it.

Synthetic and natural rope used in

suspension must be protected from

heat-pruducing sources.

Scaffolds must be at least 10 feet from

electric power lines at all times.

Fig 1: A Scaffold

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1.2. Fall Protection: Each year, falls consistently account for the greatest number of fatalities in

the construction industry. A number of factors are often involved in falls, including unstable

working surfaces, misuse or failure to use fall protection equipment and human error.

Studies have shown that using guardrails, fall arrest-systems, safety nets, covers and

restraint systems can prevent many deaths and injuries from falls.

Solutions:

Use of aerial lifts or elevated platforms

to provide safer elevated working

surfaces.

Erecting guardrail systems with

toeboards and warning lines or

installing control line systems to protect

workers near the edges of floors and

roofs.

Using safety net systems or personal

fall arrest systems (body harnesses).

Fig 2. A worker with fall protection

equipments

1.3. Hazard Communication: Failure to recognize the hazards associated with chemicals can

cause chemical burns, respiratory problems, fires and explosions.

Solutions:

Maintain a Material Safety Data Sheet (MSDS) for each chemical in the facility.

Make this information accessible to employees at all times in a language or formats that

are clearly understood by all affected personnel.

Train employees on how to read and use the MSDS.

Follow manufacturer's MSDS instructions for handling hazardous chemicals.

Train employees about the risks of each hazardous chemical being used.

Provide spill clean-up kits in areas where chemicals are stored.

Have a written spill control plan.

Train employees to clean up spills, protect themselves and properly dispose of used

materials.

Provide proper personal protective equipment and enforce its use.

Store chemicals safely and securely.

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1.4. Stairways: Slips, trips and falls on stairways are a major source of injuries and fatalities

among construction workers.

Solutions:

Stairway treads and walkways must be free from dangerous objects, debris and

materials.

Slippery conditions on stairways and wlakways must be corrected immediately.

One should make sure that the treads cover the entire step and landing.

Standways having four or more risers or rising than 30 inches must have at least one

handrail.

1.5. Ladders: Ladders are another source of injuries and fatalities among construction workers.

Solutions:

Using the correct ladder for the task.

A competent person should inspect a

ladder before use of any defects

such as structural defects; grease or

dirt that could cause slip or fall;

paints or stickers that could hide

possible defects.

It should be ensured that the ladders

are long enough to reach the work

area.

One should mark or tag damaged or

defective ladders for repair or

replacement, or destroy them

immediately after coming into notice

that the same ladder in unsuitable for

use.

Never load ladders beyond the

maximum intended load or beyond

the manufacturer’s rated capacity. Avoid using ladders with metallic

components near electrical work and

overhead power lines.

Fig 3. A worker using a ladder

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1.6. Trenching: Trench collapses cause dozens of fatalities and hundreds of injuries each year.

Solutions:

One should never enter an unprotected trench.

Employ a registered professional engineer to design a protective system for trenches 20

feet or greater.

Always provide a way to exit the trench wall at an angle inclined away from the

excavation not steeper than a height/depth ratio of 11-2:1, according to the sloping

requirements for the type of soil.

Keep spoils at least two feet back from the edge of the trench.

1.7. Cranes: Significant and serious injuries may occur if cranes are not inspected before use

and if they are not used properly. Often these injuries occur when a worker is struck by an

overhead load or caught within the crane's swing radius. Many crane fatalities occur when

the boom of a crane or its load line contact an overhead power line.

Solutions:

All crane controls should be checked to

ensure proper operation before use.

Inspecting wire rope, chains and hook

for any damage.

Knowing the weight of the load that the

crane is to lift.

Ensuring that the load does not exceed

the crane's rated capacity.

One should not move a load over a

workers.

Barricade accessible areas within the

crane's swing radius.

Watch for overhead electrical

distribution and transmission lines and

maintain a safe working clearance of at

least 10 feet from energized electrical

lines.

Fig 4: A Crane

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2. Safety Checklists for Personal Protective Equipment (PPE): The Following checklist

helps to take steps to avaoid hazards that causes injuries, illnesses and fatalities.

2.1. Eye and Face Protection:

Safety glasses or face shields prevents foreign objects from getting into the eye such as

during welding, cutting, grindling, nailing.

Eye and face protectors are selected based on anticipated hazards.

Safety glasses and shields are worn when exposed to any electrical hazards including

work on energized electrical systems.

2.2. Foot Protection:

Construction workers should wear safety shoes or boots witgslip-resistant and puncture-

resistant soles.

Safety-toed footwear is worn to prevent crushed toes when working around heavy

equipment or falling objects.

2.3. Hand Protection:

Gloves should fit snugly.

Workers should wear the right gloves for the job (for example, heavy-duty rubber gloves

for concrete work, welding gloves for welding, insulated gloves and sleeves when

exposed to electrical hazards).

2.4. Head Protection:

Workers shall wear hard helmets where there is a potential for objects falling from

above, bumps to their heads from fixed objects, or of accidental head contact with

electrical hazards.

They should also be routinely inspected for dents, cracks or deterioration. They are

maintained in good condition.

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3. Common Violations on-site: The following set of pictures describe some of the most

common violations committed on-site. Such malpractices should be avoided.

Fig 5: Bad Storage – Sagging Rack

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Fig 6: Cement Storage – Loading against wall and upto the ceiling

Fig 7: Badly maintained fire protection

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Fig 8: Gas Cylinders kept horizontally in the open

Fig 9: Unsafe Ladder

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Fig 10: Unsafe Access

Fig 11: Unsafe Act – standing on moving vehicle

Fig 12: Unsafe mechanical material handling equipment

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4. Safety Rules: Safety awareness and caution when performing the most routine operation

are characteristics of a good operator. The larger or more complex the machine, the more

in-depth the training should be. Some common construction safety rules are summarised

below.

a. Keeping mind on work at all times. Injury or termination or both can be the result due to

such carelessness.

b. Personal safety equipment must be worn as prescribed for each job, such as: safety

glasses for eye protection, hard hats at all times within the confines of the construction

area where there is a potential for falling materials or tools, gloves when handling

materials, and safety shoes are necessary for protection against foot injuries.

c. If any part of the body comes in contact with an acid or caustic substance, the affected

part must be washed immediately in the nearest water available site and medical aid must

be secured.

d. One should watch where he/she is walking.

e. The use of illegal drugs or alcohol or being under the influence of the same on the project

is strictly prohibited.

f. One should not distract the attention of fellow workers and should not engage in any act

which would endanger another employee.

g. To keep the working area free from rubbish and debris.

h. To never move an injured person unless it is absolutely necessary. Further injury may

result. Instead, keep the injured as comfortable as possible and utilize job site first-aid

equipment until an ambulance arrives.

i. To know where fire-fighting equipment is located and be trained on how to use it.

j. Nobody but operator is allowed to ride on equipment.

k. To not use power tools and equipment until one have been properly instructed in the safe

work methods and become authorized to use them.

l. One should be sure that all guards are in place. Do not remove, displace, damage, or

destroy any safety device or safeguard furnished or provided for use on the job, nor

interfere with the use thereof.

m. Do not enter an area which has been barricaded.

http://www.forconstructionpros.com/topics/safety

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n. If one must work around power shovels, trucks, and dozers, make sure operators can

always see him/her. Barricades are required for cranes.

o. Never oil, lubricate, or fuel equipment while it is running or in motion.

p. Defective ladders must be properly tagged and removed from service.

q. To keep ladder bases free of debris, hoses, wires, materials, etc.

r. Never throw anything "overboard". Someone passing below may be seriously injured.

s. One must securely engage the entire hand and foot to avoid a toe-hold or finger-hold grip.

Use of a step ladder for access when no hand or foot holds are provided and one should

avoid carrying objects while climbing.

t. Using proper tie-down procedures. If using compression chain binders, use caution when

opening the handle. The load may shift just enough to add tension to the chain and the

handle may spring open.

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5. Overview of statutes applicable to construction industry:

Building & other construction Workers (regulation of Employment and Conditions of

Service Act, 1996) (BOCWA)

Building & other Construction Workers (Regulation of Employment and Condition of

Service) Central Rules, 1998 (BOCWR)

Petroleum act, 1934 (PA)

Petroleum Rules, 2002 (PR)

Explosives Act, 1884 (EA)

Explosives Rules, 1983 (ER)

Gas Cylinder Rules, 1981 (GCR)

Static & Mobile Pressure Vessel (Unfired) Rules, 1981 (SMPVR)

Electricity Act, 2003 (EA)

Indian Electricity Rules, 1956 (ER)

Motor Vehicles Act, 1988 (MVA)

Central Motor Vehicles Rules, 1989 (CMVR)

In 1996, the Building and other construction Workers (Regulation of Employment and

Conditions of Service) Act, 1996 was promulgated. The Central Rules under this Act were

notified in November, 1998. The Central Government has notified its Chief Labour

Commissioner as the Central enforcement agency under the above act.

The National Safety Council (national and unit levels) has been conducting training

programmes, safety audits, information dissemination, producing awareness material and

organizing campaigns for the construction industries for over a decade.

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CHAPTER 2: STRUCTURAL WELDING

Welding is a fabrication or sculptural process that joins materials, usually metals or

thermoplastics, by causing coalescence. In other words, welding is the process of fusing

multiple pieces of metal together by heating the filler metal to a liquid state. This is often done

by melting the workpieces and adding a filler material to form a pool of molten material

(the weld pool) that cools to become a strong joint. This is in contrast

with soldering and brazing, which involve melting a lower-melting-point material between the

workpieces to form a bond between them, without melting the workpieces.

Many different energy sources can be used for welding, including a gas flame,

an electric arc, etc. While often an industrial process, welding may be performed in many

different environments, including open air, under water and in outer space. Welding is a

potentially hazardous undertaking and precautions are required to avoid burns, electric shock,

vision damage, inhalation of poisonous gases and fumes, and exposure to intense ultraviolet

radiation. A properly welded joint is stronger than the base metal.

Welding is a common method for connecting structural steel. Many fabrication shops

prefer welding rather bolting. There are several welding processes, types, and postions to be

considered in building construction.

1. Welding Terminology:

Fig 13: A Tee Joint

http://en.wiktionary.org/wiki/coalesce

http://en.wikipedia.org/wiki/Melting

http://en.wikipedia.org/wiki/Weld_pool

http://en.wikipedia.org/wiki/Soldering

http://en.wikipedia.org/wiki/Brazing

http://en.wikipedia.org/wiki/Energy_source

http://en.wikipedia.org/wiki/Fire

http://en.wikipedia.org/wiki/Electric_arc

http://en.wikipedia.org/wiki/Underwater_welding

http://en.wikipedia.org/wiki/Outer_space

http://en.wikipedia.org/wiki/Burn

http://en.wikipedia.org/wiki/Electric_shock

http://en.wikipedia.org/wiki/Ultraviolet_radiation#Human_health-related_effects_of_UV_radiation

http://en.wikipedia.org/wiki/Ultraviolet_radiation#Human_health-related_effects_of_UV_radiation

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a. Actual Throat: It is the minimum distance between the weld root and the weld face.

b. Convexity: It refers to the convex nature of the outer surface of weld.

c. Effective Throat: It is the distance from the root of a weld to the face of the weld, with the

amount of weld reinforcement subtracted.

d. Weld Leg: It is the distance from the root to the toe of the fillet weld. The size of

the fillet weld is determined by the length of its legs.

e. Weld Size: (a) Fillet weld size – For equal fillet welds, the leg lengths of the largest

isosceles right triangle which can be inscribed within the fillet weld

cross- section. For unequal leg fillet welds, the leg lengths of the largest

rights triangle that can be inscribed within the fillet cross-section.

(b) Groove weld size – The joint penetration of a groove weld.

f. Theoretical Throat: It is the distance from the beginning of the joint root perpendicular to the

hypotenuse of the largest right triangle that can be inscribed within the

cross-section of the fillet weld. This dimension is based on the

assumption that the root opening is equal to zero.

Shown below are types of structural joints which are established by positions of the

connected material relative to one another. Lap, Tee and Butt or Groove Joints are the most

common.

Fig 14: Types of Welding Joints

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2. Common Types of Welds: The most common types of welds are discussed below.

2.1. Fillet Weld: A fillet weld is the most common type of weld. The fillet weld is used to join two

pieces of flat steel at a 90-degree angle. A fillet weld is produced by running a weld bead at a

45-degree angle to a 90-degree corner; it resembles a triangle when viewed from the side.

Hence, fillet welds are theoretically triangular in cross-section. The weld is used to fill the area

where two pieces of steel meet, hence the name fillet weld.

It is used to make lap, corner and ‘T’ joints, the fillet weld is the most basic of welds. The

depth of the penetration, as in all welds, determines the strength of the fillet weld. It is

imperative when creating a fillet weld that the welding rod travel the same distance up both

sides of the joint when welding. Failure to get sufficient penetration on both pieces of the joint

will result in a weld that has far less strength than a weld that has equal distribution on both

sides of the joint.

Although this is a very common procedure, there is a number of parameters which are

necessary to take in special attention before doing such a welding, because among others, it

requires a higher heat transfer rate when compared to other types of joints of an equivalent

thickness, and with less experience welders, this could take to the lack of penetration and/or

fusion defects that are not easily identifiable through visual inspection or other non-destructive

techniques. Even excess welding which will lead to extra spending of consumable materials

will not result in achieving a higher global resistance.

Fig 15: Symbolic and Actual Profiles of a fillet weld

http://www.wisegeek.com/what-is-a-fillet.htm

http://www.wisegeek.com/what-is-a-welding-rod.htm

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2.2. Butt or Groove Weld: Butt-welding is the process of joining two pieces of material together

along a single edge in a single plane. This process can be used on many types of materials,

though metal and thermoplastics are the most common. When two sheets of steel are laid

side-by-side and joined together along a single joint, this is an example of butt-welding.

Welding can be done using a large machine or a simple portable welder. The machine

applies heat to the two materials that are being joined, which causes them to melt slightly to

form a liquid. A filler material or a metal alloy is often added in between the two objects and

melted into the pool of liquid. When the heat from the welding machine is turned off, the

liquefied metal and filler will quickly solidify to form a single unit. When this process is done

correctly, the edges of each object are not distinguishable beneath the filler material.

There are three basic types of butt-welding, and each is chosen based on the thickness

of the objects being joined. For thin sheets of metal or plastic, a square weld joint can be used.

In this instance, the edges of the objects form 90-degree angles to one another, and can be

butted together like two building blocks. This is the simplest and most economical type of butt-

welding joint.

2.2.1. Types of Butt Welding: There are many types of butt welds, but all fall within one of

these categories:

(a) single welded butt joint,

(b) double welded butt joint, and

(c) open or closed butt joint.

A single welded butt joint is the

name for a joint that has only been welded

from one side. A double welded butt joint is

created when the weld has been welded

from both sides. With double welding, the

depths of each weld can vary slightly. A

closed weld is a type of joint in which the

two pieces that will be joined are touching

during the welding process. An open weld

is the joint type where the two pieces have

a small gap in between them during

welding.

Fig 16: Butt Joint Geometries

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2.2.1.1. Square Butt joint:

The square-groove is a butt welding joint with the two pieces being flat and parallel to

each other. This joint is simple to prepare, economical to use, and provides satisfactory

strength, but is limited by joint thickness. The closed square butt weld is a type of square-

groove joint with no spacing in between the pieces. This joint type is common with gas and arc

welding.

For thicker joints, the edge of each member of the joint must be prepared to a particular

geometry to provide accessibility for welding and to ensure the desired weld soundness and

strength. The opening or gap at the root of the joint and the included angle of the groove

should be selected to require the least weld metal necessary to give needed access and meet

strength requirements.

2.2.1.2. Bevel Butt joint:

Single-bevel butt welds are welds where one piece in the joint is beveled and the other

surface is perpendicular to the plane of the surface. These types of joints are used where

adequate penetration cannot be achieved with a square-groove and the metals are to be

welded in the horizontal position. Double-bevel butt welds are common in arc and gas welding

processes. In this type both sides of one of the edges in the joint are beveled.

2.2.1.3 V-joints

Single-V butt welds are similar to a bevel joint, but instead of only one side having the

beveled edge, both sides of the weld joint are beveled. In thick metals, and when welding can

be performed from both sides of the work piece, a double-V joint is used. When welding thicker

metals, a double-V joint requires less filler material because there are two narrower V-joints

compared to a wider single-V joint. Also the double-V joint helps compensate for warping

forces. With a single-V joint, stress tends to warp the piece in one direction when the V-joint is

filled, but with a double-V-joint, there are welds on both sides of the material, having opposing

stresses, straightening the material.

2.2.1.4. J-joints

Single-J butt welds are when one piece of the weld is in the shape of a J that easily

accepts filler material and the other piece is square. A J-groove is formed either with special

cutting machinery or by grinding the joint edge into the form of a J. Although a J-groove is

more difficult and costly to prepare than a V-groove, a single J-groove on metal between a half

an inch and three quarters of an inch thick provides a stronger weld that requires less filler

material. Double-J butt welds have one piece that has a J shape from both directions and the

other piece is square.

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2.2.1.5. U-joints

Single-U butt welds are welds that have both edges of the weld surface shaped like a J,

but once they come together, they form a U. Double-U joints have a U formation on both the

top and bottom of the prepared joint. U-joints are the most expensive edge to prepare and

weld. They are usually used on thick base metals where a V-groove would be at such an

extreme angle, that it would cost too much to fill.

Butt welds are specified when a fillet weld is not appropriate for the job such as in the

case when the configuration of the pieces may not permit fillet welding or strength greater than

that provided by a fillet weld is required. However, butt welds also have their own

disadvantages. Fillet welds generally require less weld metal than butt welds. Additionally, fillet

welds do not generally require beveling and similar base metal preparation. As a result, fillet

welds are generally more economical to make than groove welds. Thus, fillet welds are

preferred.

2.3. Plug and Slot Welds: These are the least common type of welds. Plug weld is a type of

weld made by joining one metal part with a circular hole to another metal part positioned

directly beneath it whereas slot weld is a type of weld made by joining one metal part with an

elongated hole to another metal part positioned directly beneath it. Hence, a slot weld is similar

to plug weld, but the hole is elongated and may extend to the edge of a member without

closing. Weld metal is deposited in the holes which penetrates and fuses with the base metal

of the two members to form the joint.

Fig 17: Plug and Slot Welds

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3. Welding Positions: There are four recognized welding positions which are given below.

Flat – The face of the weld is approximately horizontal and welding is performed from

above the joint.

Horizontal – The axis of the weld is horizontal.

Vertical – The axis is approximately vertical or in the upright position.

Overhead – Welding is performed from below the joint.

The flat position is preferred because it is easier and more efficient to weld in this

position.

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Fig 18: Welding Positions

4. Weld Symbols: Weld symbols are used to communicate the specific details and

requirements of each weld to the welder. These are included on fabrication and erection

drawings.

Fig 19: Weld Symbols Chart

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Fig 20: Representation of Weld symbols in a drawing

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CHAPTER 3: STORAGE OF CEMENT BAGS IN WAREHOUSE

Portland cement should be protected against moisture at all times, whether the cement

is being transported on a truck or being held in storage or on the jobsite. For large construction

site, this is usually a secure storage area. Broadly, protection includes –

1. keeping out water which may fall as rain,

2. preventing water on the bed of truck from splashing upward against the sacks,

3. protection from water on the ground, such as puddles of rain or water from the mixing

operations.

All too often, cement bags may be observed sitting in water or on moist concrete or

receiving spray of water over the sacks. There is a very good reason for protecting cement

from exposure to water before it is batched into the mixture since Portland cement starts to

hydrate as soon as water touches it. Hydration of cement simply means that the cement

combines chemically with the water. It is not desirable that water combines with the cement

until the start of mixing the plaster, mortar or concrete because if the cement becomes moist

prior to mixing and placement, there will be some loss of strength and value in the ultimate

product. Portland cement is a valuable commodity and should be treated with reasonable care.

Cement should be held in a dry and protected area that has a dry floor. When rain or

mist is falling or imminent, the cement should be covered with a tarp before the load is

exposed to the weather. Generally cement bags are stacked closely together on pallets to

reduce air circulation and to raise the cement above any moisture sources. When removing

these bags for use, it should be sone done on a ‘first in, first out’ system. This means that the bags are stacked separately as they arrive eith the date of arrival placards attached to each

pile. The bags are to be rolled over when these need to be taken out for use.

Water-repellant bags may cause an ambiguity. They may be made repellant by having a

plastic coating on the shell of the bag or they may have a plastic liner to aid in keeping out the

moisture. One reason that the water-repellant bags must and do not have tiny perforations in

the walls to allow release of air from the sack during the bag-filling operation. Without those

holes to release air from the bag, filling would be virtually impossible using the typical packing

machines.

chinmoy pathak choudhury_iocl internship report

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construction activity

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