This procedure is useful for building construction based upon the steel structure erection work. Based on the design and specification, this document provides a proper step wise procedure and quality and safety management of the steel structure work.
The following items/equipments are basic requirements for building construction of steel structure works at a large scale project.
Lifting Equipment, Ropes & Lines.
- 01 No. of 45 MT Crane
- 01 No. of 20 MT Crane
- 04 Nos. of 12 MT Crane
- Assorted slings in various sizes and lengths
- Steel guy lines for temporary bracing
- Ropers for hand lines
Electrical Equipment’s
- Welder Machine
- Extension Leads and pigtails
- Heavy Duty Drill ½”
- Heavy Duty Drill ¼”
- Heavy Duty Screw gun w/Hex Sockets
- Electric Nibbler
- Electric Shear
- Angle Grinder
- Concrete Drill
Necessary Hand Tools
- Socket Wrench ¾” or 1” drive with asst. Sockets
- Open ended wrenches assorted imperial size
- Spud wrenches 15/16” opening up to 1-1/8”
- Crescent wrench – ½”
- Pipe wrench
- Screw drivers Standard and Philips
- Aviation snip – Left and right
- Vice grips
- Pop rivet puller
- 4bl Sedge hammer
- Hacksaw frame and blades
- Wood saw
- Spirit level and plumb – bob
- Chalk line
- Steel measuring tapes 30m and 8m
- Utility knife
- Staple applicator
- Oxy-Acetylene cutting outfit
- Welding hood
- Hard hats
- Safety belts – Bolt bags
- Masonry drill bits 12mm
- Extension ladders
- Step Ladders
- Scaffolding System
- Hilti gun, cartridges and nails
Health & Safety Requirements
Each workers shall be physically qualified to perform the duties to which he is assigned.
- Workers shall always wear hard helmets, shoes, uniforms and gloves.
- Workers working at height shall always wear safety belts.
- Goggles, face masks shields or helmets are required for scaling, grinding, cutting, and welding operations.
- Maintenance of machines used in the steel structure erection work shall be done properly.
- Setting of safety rope is mandatory on Roof when carry out the roofing work.
- Setting of signboard, and barricade by ropes around working area, do not permit any person without duty to enter the working area.
- The crane condition (including machine parts, wire rope) must be checked everyday.
- Safety meeting shall be done everyday before starting work.
- Scaffolding’s shall be arranged properly.
- Site housekeeping and cleaning shall be done everyday.
Steel Column Base Treatment Procedure
Cleaning of concrete column top surface.
Marking center line of steel column.
Leveling mortar base (using high grade mortar G150 ) at middle of 4 anchor-bolts with the same level of bottom of column-base-plate.
Checking level of column.
Grouting mortar for column base i.e. Sika- grout 212-11.
Steel Structure Erection Procedure
Phase 1: Anchor Bolt Setting
Step 1: Marking for boundary line of starting column on footing
Step 2: Check and adjust position of starting column-rebar if necessary.
Step 3: Set form for starting column and support them carefully.
Step 4: Marking for bolt-group-center line on side of form.
Step 5: Set template with anchor bolts. The template position is higher than concrete surface level. Marking line of bolt-group-center and each bolt must be matched on the template.
Adjust position of the template according to marking line on footing by plum bob.
Step 6: Welding diagonal supporting bar to column rebar and anchor bolt.
Step 7: Check position of anchor bolt again.
Step 8: Protect bolt heads by masking tape
Step 9: Cast concrete for starting column
Step 10: After casting concrete, re-check anchor bolt position. Adjust the template if necessary.
Phase 2: Steel Structure Erection
Step 1:
- Set up 2 side columns of braced bay (between Grid 4 and Grid 5), including bracing beams.
- Erect interior columns (along grid C1-4 and C1-5) with temporary bracing.
- Tighten anchor bolts and nuts sufficiently to prevent columns from rocking.
- Assemble rafter components of Grid 4 on the ground into connection.
- Install all bolts in rafter splices to proper tension, using turn-off-nut method and torque wrench.
- Raise the first assembled rafter on top of column by cranes.
- Install bolts of rafter through column connection and tighten to snug position.
- Secure all temporary, wire ropes bracings, plumb and align the column and rafter before releasing the crane.
Step 2:
- Using same procedure to assemble other parts of the rafter of Grid 5 (A – F).
- Place it on top of interior columns.
- Bolt to column connections and tighten.
- Secure temporary bracings.
Step 3:
- Assemble the rafter of Grid 6 (same as the first erected rafters). Connect and bolted to column splices. The crane has to keep holding the rafter in position until sufficient purlins ( 1/3 of total purlins at that area ) have installed to provide rigid support for the bay. The crane can release if having temporary bracing cables for both sides at interval of maximum 10 m.
- Continue erecting the next rafters of the brace bay.
- Completing purlins, flange braces, roof bracings.
- Plumb and align before proceeding to erect the next bays.
- After checking the alignment and squareness, tighten again anchor bolts, column connection, girts bolts, and eave strut bolts to required tension by torque wrench.
Step 4:
- Continue erecting columns rafters for the next bays, using same procedure described in Step 1.
- Complete installation of purlins and girts.
- Complete roof angle bracings, and all secondary members.
Step 5:
- Fabrication and installation of roofing panels. (See “Erection Procedure for roof Panel”)
Step 6:
- Install wall panels, downspouts and gutters.
- Complete trims and accessories.
Inspection & Quality Control for Metal Building Works
Inspection is necessary at all steps of erection process, from the times materials are first received until the structure is completely installed. Inspection during the steel erection process shall be continuous in order to prevent the occurrence of possible damage and to require the maintenance of high standard workmanship. Inspection shall include members, painting, connection, alignment, bracings, roofing and wall cladding, equipment and false work.
Inspection of Members
- Inspect members for damage due to mishandling or careless storage.
- Make sure that each member is placed in its proper position in the structure and that fillers, shims, and washers required for the type of connection are properly used.
- Prevent abuse of material by bending, straining, or heavy pounding by sledges.
- Inspect the accuracy of match-marked connections.
- Check the painting work.
- After finishing the painting work, all steel members shall be checked to make sure that small area of steel members is painted.
Inspection of Steel Connection
a. Anchor bolts:
– Check the tolerance of dimensions between anchor bolts to meet the required tolerance (5mm).
– Check the tightness of anchor bolts to meet the require forces.
b. Bolts connection:
– The supervisor has to assure himself that the wrenches used are calibrated properly so that bolts are tightened the proper amount. Also the proper lengths of bolts shall be checked.
– After connecting, all bolts shall be tightened to obtain the required tension values
- Using turn-off nut method: Tighten more 120o+/-30o for bolt diameter >12mm, tighten more 60o-0+30o for bolt diameter = 12mm.
- Torque wrench: the actual value must be within the recommended value +/-5_10%.
– Every connection point shall be inspected with the inspection record that is made by the team leader, with the confirmation of responsible engineers and Site Manager. The actual value of tension or torque moment of every bolt in the connection shall be shown on the record.
Bolt Tension Required (Table 1)
|
Bolt diameter |
Minimum Tension |
Recommended Torque |
|||
|
D |
N |
M |
|||
|
mm |
KN | N.m | |||
|
12.7 |
53 |
136 |
|||
|
15.9 |
84 |
271 |
|||
|
19.0 |
125 |
481 |
|||
| 22.2 | 173 |
773 |
|||
|
25.4 |
226 |
1153 |
|||
|
28.6 |
249 |
1437 |
|||
|
31.7 |
317 |
2027 |
|||
|
35.0 |
378 |
2658 |
|||
|
38.1 |
459 |
3526 |
|||
Alignment Inspection of Steel Structure
- After the first bay (braced bay) is erected, the columns shall be made plumb and the rafters shall be straight.
- After completing the erection of main frames the alignment check shall be done again, before continuing the erection of the successive bays.
- The tolerance of column plumb must be within the value of 1/500 of column height, but can not be more than 25mm.
- The tolerance of Rafter alignment (from straight rafter – line) must be within the value of 1/300 of Span.
- After completing the erection of main frames, the final check of alignment (plumbing and straightness) for the all columns and rafters of whole building shall be done.
Adjustment of bracing
Adjustable diagonal bracing is fixed after all parts of the structure are in place. In bolted structures having diagonal bracing, wall bracings are adjusted after the columns are plumbed, and roof bracing are adjusted when rafters are in straight line.
Inspection of Roofing and Wall cladding
Check sequence of roof panels on roof.
Check correct starting- end position of roof and wall panels.
Check right screws using.
All screws must be perpendicular to panels, and rubber washer thickness must be from 1.00 to 1.20 mm.
Final Inspection of Steel Structure
- After completing all trims and accessories, a final inspection of the building shall be done:
- All bracings in position and tightened.
- All bolts in place and high strength bolts tightened to correct tension value.
- Check that roof and gutters are clear of debris and ferrous metals.
- Check improper drilled screws.
- Check opening for joinery.
- Touch up any damaged paint
Additional Resources for Steel Fabrication & Building Construction Works
Below is comprehensive list of additional tools and tackles that you may need for doing the steel structure construction works.
| Heavy Duty Machinery | |
|
1 |
Portable Roll former |
|
2 |
Portable Air Compressor |
|
3 |
Seamer |
|
4 |
Electric Hydraulic Engine Unit |
|
5 |
Diesel Engine Unit |
|
6 |
Uncoiler |
|
7 |
Crimper |
| Tools & Instruments | |
|
1 |
Combination Wrench |
|
2 |
Allen key Set |
|
3 |
Strap Wrench 18″ |
|
4 |
Screw Driver |
|
5 |
Adjustable Wrench 24″ |
|
6 |
Wrench |
|
7 |
Sweeping Broom |
|
8 |
Stapler for insulation |
|
9 |
Mastic Gun (Silicon) |
|
10 |
Goggles |
|
11 |
Fire Extinguisher |
|
12 |
Nibbler |
|
13 |
Cutting Snip 10″ |
|
14 |
Hack Saw |
|
15 |
C Clamps various size |
|
16 |
Electric extension 50M |
|
17 |
Screw Gun |
|
18 |
Drill machine |
|
19 |
Grinder (small) |
|
20 |
Nylon Rope |
|
21 |
Riveter (heavy duty) |
|
22 |
Vernier Caliper (digital) |
|
23 |
Vice Grip 8″ |
|
24 |
Utility Knife |
|
25 |
Line Man’s Pliers 8″ |
|
26 |
Long Nose Pliers 6″ |
|
27 |
Side Cutter 8″ |
|
28 |
Digital tester (VOM) |
|
29 |
First Aid Kit |
|
30 |
Plastic tarpaulin cover 8mx10m |
|
31 |
Plastic Gallon 20 litter |
|
32 |
Feller Gauge mm |
|
33 |
3 Claw Mechanical Puller small |
|
34 |
Hydraulic Jack 20 tons |
|
35 |
Level |
|
36 |
Scow Bar 1m length |
|
37 |
Electric soldering Iron 100 watts |
|
38 |
Oiler |
|
39 |
Ball Peen Hammer (medium) |
|
40 |
Torch |
|
41 |
Tape 8 meters |
|
42 |
Tape 30 meters |
|
43 |
Tape 5 meters |
| Supporting | |
|
1 |
Scaffolding 1.5 meters |
|
2 |
Bracing for scaffolding |
|
3 |
Platform for scaffolding |
|
4 |
Jack for scaffolding |
|
5 |
Wheel for scaffolding |
|
6 |
Spreader bar |
|
7 |
Stair for scaffolding |
|
8 |
Extension Cord (Cable 3×16+1×10) |
|
9 |
Electrical box |
|
10 |
Stand Conveyor |
|
11 |
Roof Panel Carriage |
| Safety Gears | |
|
1 |
Safety Clothes |
|
2 |
Universal Harness (1008833 size M) |
|
3 |
Rope Lanyard 2m with G) |
|
4 |
Safety rope (14mm Polyamide Rope) |
|
5 |
Helmet |