Safety in Erection of Steel Structures

SAFETY IN ERECTION OF STRUCTURAL STEELWORK

AKASH TILOKANI121420006

College Of Engineering , PuneForerunners in technical education

References

• IS 7205: 1974 – Code of Safety for Erection of Structural Steel Work

• SP 70: 2001 – Handbook on Construction Safety Practices


Aspects: Clause 9.1 (SP:70-2001) and Clause 2.1 (IS:7205-1974)

Safety in Erection of

Structural Steel

Advance Planning Field Operations


Scheme

Safe

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Ere

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of

Stru

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teel General Provisions

Provisions related to the equipments used

Provisions related to the works


General Provisions• Contained in IS 7205-1974, Clause 5 and its sub clauses• Before a man is engaged in some work, he should be

given thorough medical check up.• The erection gang should have adequate supply of bolts,

washers, rivets, pins, etc., of correct size.• When fitter, riveters, etc., can work from a planked floor

or a planked area, the work can be done safely and more expeditiously. When this is not feasible scaffolding or floats should be used.


Continued…• When the men can work safely from the steel structure itself,

this is preferable to hanging platforms or scaffolds, as it eliminates additional operations, which in turn, reduces the hazard of an accident.

• The men should be taught to clean their shoes of mud, grease, oil, snow, ice or other slippery material before climbing ladder or going on steel or a planked floor, so that they will not slip or drag slippery material for other to slip on.

• Men should avoid carrying tools or other material when using a ladder, they should use a hand rope to raise and lower such material.


Continued…• When a number of trusses or deep girders are

loaded in one car or a truck, all but one being lifted should be tied back unless they have been tied or braced to prevent their falling over and endangering men while unloading.

• If a piece is laterally unstable when picked at its center, use of a balance beam is advisable , unless a pair of bridled slings can be placed far enough for them to be safe lifting points.


Erection Equipments• Contained in respective clauses of SP:70-2001 and IS:7205-1974.1. Cranes • No crane should be used unless a competent person has inspected and

tested it and furnished a certificate specifying the maximum working load.

• Access to and egress from the operator’s stand should be safe from any position of the crane.

• Cranes should not be used to pull out fixed objects with a slanting pull, drag objects or move vehicles.

• Before being put into use for the first time, jib cranes with variable radius should undergo tests of stability and all movements.

• Jib cranes should not be operated in the proximity to the electric power lines.


Continued …1

2. Hoists• Hoists must be enclosed at ground level by substantial enclosures and

gates at least by 2 m high and the enclosures should be extended to accommodate the engine or motor.

• Gates of the same height of 2 m must be provided at all landing stages.• The complete hoist way throughout its height shall preferably be enclosed

with a wire mesh in order to contain the accidentally dislodged material from the hoist platform.

• There must be only one operating position for the hoist and the driver must be trained in the job and able to see the platform throughout the travel.

• Every hoist must be fitted with an automatic device which will support the platform in the event of any failure of the ropes or gear.

• Every hoist must be checked or inspected once in the week.


Continued…23. Wire ropes• Wire ropes should be visually inspected daily or at the

start of shifts – Idea of thorough inspection.• One rope lay: Refers to the axial wire rope length for

one wire rope strand to completely wrap around the wire rope assembly.

• Wires should be stocked for the machines which are in continuous service.

• Signs of rope deterioration and guidelines of replacement are as follows


Continued…3Signs of deterioration Causes of Replacement

Reduction of rope diameter(a) Loss of core support(b) Corrosion(c) Worn out wires

For Rope Dia Reduction more thanUp to 80 mm 4 mm95 mm to 130 mm 8 mm145 mm to 190 mm 12 mm

Broken outside wires (a) 12 randomly distributed broken wires in ORL

(b) 4 broken wires in one strand in ORLWear of individual wires Wear of 1/3rd of the original diameter of

outside individual wiresCorroded, broken, cracked, bent or worn at end

Any of these conditions indicate replacement

Severe crushing, cutting and unstranding

When such faults result in distortion of rope structure


Columns• Contained in SP:70-2001, Clause 9.3 and its sub

clauses.• Get the first four columns of a bay facing

diagonally opposite to one another grouted soon after bracing of the steelwork and its aligning and plumbing the portion of steel structure.

• For levelling, aligning and plumbing of columns, screed bars or level pads shall be provided.


Continued…• Stabilize the erected anchored columns by fastening

temporary wire guys till four column square is completely braced, levelled and plumbed.

• Filled in pits must be either manually rammed or rolled over by a heavy roller and sleepers should be laid over the area.

• Safety nets shall be provided within two stories or 10 m below the height of the work which is performed.


Riveting Operations• Contained in IS 7205:1974, Clause 5.26 and its Sub clauses• Rivets covered with slippery materials should not be used in

fabrication work. Care shall be taken while handling rivets so that they do not fall, strike or cause injury to men and material below.

• Rivet heating equipment should be as near as possible to the place of work. A pail of water should always be ready for quenching the fire, if it develops.

• Rivets, bolts and the like should be kept in the boxes at working area to prevent falling down on men or equipments.


Slinging Operations• While using multi legged slings each sling or leg should be

loaded evenly and the slings should be of sufficient length to avoid a wide angle between legs.

• Only properly tested and marked lifting tackle of adequate strength should be used.

• Allowances should be made for the weight of tackles.• Load shall be free from any obstructions before it is lifted.

Hands should be taken away from the sling and the slinging person should stand clear of the load4

• Crane hook should be centrally placed over the load to prevent the slipping and swinging of the load when it is raised.


Erection of Bridge Girders• Contained in IS:7205-1974, Clause 6.1 and its sub clauses• Careful inspection of machinery required for the purpose

and check for its capacity is needed.• Care to protect the edges of members getting marked or

distorted, in the event of use of chains for lashing.• Temporary bracings shall be provided to care of temporary

stresses from erection equipments or other loads.• Provisions for lateral forces and wind loads as per the local

conditions.


Continued...• Joints shall normally be made by filling not less than

50% of the holes with service bolts and barrel drifts in the ratio 4:1. The service bolts are to be fully tightened up as soon as the joint is assembled.

• In the event of emergency arising, such as the structure in danger of being carried away by floods before the riveting can be completed, the joints shall be made secure by filling 40% of the holes with cylindrical drifts and an equal number with service bolts fully tightened up.


Occupational Safety and Health Administration Provisions

• Safety for erection of structural steel is contained in code 1926 and sub part R of OSHA.

• Provisions are related to; 1. Site layout, site specific erection plan and construction

sequence2. Hoisting and Rigging3. Structural steel stability requirements4. Falling object protection5. Fall Protection







