DUCTOFAB INFRA DIVISION

EXPERTISE

Engineering

Steel structure design and detailing involve the process of creating and analyzing structural steel components to ensure safety, stability, and efficiency in construction projects. Here’s an overview:

Steel Structure Design

Steel design follows national and international codes (AISC & IS 800-2007) & Design Tools (STAAD& MBS) & Design Load code (IS/875Part-1-5 & MBMA) to ensure structural integrity.

Key Design Considerations

  • Load Analysis: Dead load, live load, wind load, seismic load, and temperature effects.
  • Material Selection: Choosing the right grade of steel.
  • Structural Stability: Ensuring lateral stability, avoiding buckling, and designing bracing systems.
  • Connection Design: Bolted and welded connections.
  • Serviceability: Checking deflection limits, vibration, and fatigue resistance.

COMMON STEEL STRUCTURE

  • Buildings: Industrial sheds, warehouses, high-rise buildings.
  • Bridges: Truss, cable-stayed, suspension bridges , OWG, Bowstring Girder Bridge.
  • Frames & Trusses: Rigid frames, portal frames, space trusses.

Steel Structure Detailing

Detailing is the process of preparing shop drawings and erection plans for steel fabrication and installation.

Key Components of Steel Detailing

  • Shop Drawings: Individual components (columns, beams, braces, connections) with exact dimensions and specifications.
  • Erection Drawings: Assembly sequence and on-site installation guidelines.
  • Bolt & Weld Specifications: Types, sizes, and locations.
  • BIM & 3D Modelling: Tools like Tekla, AutoCAD
  • Common Connection Types
  • Bolted Connections: Pre-tensioned and slip-critical bolts.
  • Welded Connections: Fillet welds, groove welds, and moment connections.
  • Gusset Plates: Used for trusses and braced frames.

Engineering -Software.

  • Design Tools: STAAD & MBS
  • Design Code: AISC & IS 800-2007
  • Load Code: IS/875 Part 1-5 & MBA
  • Modelling: Tekla
  • Detailing: Tekla & AutoCAD

Fabrication

At D.S. Ductofab Infra Division , we specialize in high-quality steel structure fabrication, delivering durable, precise, and cost-effective solutions for various industries. Our expertise in fabricating structural steel components ensures strength, longevity, and seamless integration into construction and industrial projects.

Steel Fabrication Capabilities

We provide Custom Steel Fabrication services, including:

  • Structural Beams & Columns – Fabrication of I-beams, H-beams, channels, and tubular, Box sections for buildings, bridges, and industrial structures.
  • Steel Frames & Platforms – Manufacturing of heavy-duty frameworks, mezzanine floors, and load-bearing structures.
  • Brackets & Supports – Precision-cut brackets, gussets, and reinforcement components to enhance structural integrity.
  • Steel Trusses & Roof Structures – Engineered trusses for industrial sheds, warehouses, and large-span buildings.
  • Pre-Engineered Steel Buildings (PEB) – Custom-designed, factory-made steel buildings for quick installation.
  • Fabricated Staircases & Railings – Industrial-grade steel staircases, walkways, and safety railings for commercial and industrial applications.

FABRICATION – Process

Steel structure fabrication and welding is a detailed process that involves cutting, shaping, assembling, and joining metal components to create structural frameworks used in buildings, bridges, industrial plants, and other infrastructure. Here’s a step-by-step breakdown of the process:

Step 1: Design & Planning
  • Engineers and designers create detailed blueprints and CAD models.
  • Structural analysis ensures that the design meets load bearing and safety requirements.
Step 2: Material Selection
  • Different steel grades are chosen based on the structural requirements (e.g., mild steel, stainless steel, or high-strength steel).
  • Steel plates, beams, channels, and pipes are sourced accordingly.
Step 3: Cutting & Shaping

CUTTING METHODS :

  • Plasma cutting
  • Oxy fuel cutting
  • Shearing cutting

SHAPING METHODS :

  • Rolling
  • Bending
  • Pressing
Step 4: Drilling & Machining
  • Holes for bolts, rivets, or connections are drilled using CNC machines.
  • Additional machining processes (grinding, milling) ensure precise fitment.
Step 5: Assembly & Fitting
  • Steel components are temporarily assembled (pre-fitting) before welding.
  • Tack welding is applied to hold pieces together before final welding.

WELDING – Process

Welding is the process of fusing metal pieces using heat and pressure.

Step 6: Welding Techniques

Common welding techniques for steel structures include:

  • Shielded Metal Arc Welding (SMAW) – “Stick Welding”
  • Gas Metal Arc Welding (GMAW) – “MIG Welding”
  • Flux-Cored Arc Welding (FCAW) – Used in heavy structures
  • Submerged Arc Welding (SAW) – For thick steel plates
Step 7: Weld Inspection & Quality Control
  • Visual Inspection: Checking for surface defects.
  • Non-Destructive Testing (NDT):
    • Ultrasonic Testing (UT)
    • Radiographic Testing (X-ray)
    • Magnetic Particle Testing (MPT)
    • PWHT

SURFACE TREATMENT & FINISHING – Process

  • Cleaning: Removal of rust, scale, and welding residues by abrasive blasting up to SA 2.5
  • Coating & Painting: Enamel, Epoxy, Fireproofing (Intumescent, Vermiculate) & C5 categories paint

Erection & Installation

Erecting and installing a steel structure involves several critical steps to ensure safety, efficiency, and durability. Below is a general step-by-step guide to the process:

1. Planning & Preparation

Site Survey & Preparation
  • Conduct a site survey to assess ground conditions.
  • Clear and level the site for foundation work.
  • Ensure access roads and storage areas are ready.
Material Inspection
  • Verify steel components (beams, columns, trusses, etc.) for quality and accuracy.
  • Check for any damage during transportation.
  • Confirm all fasteners (bolts, nuts, and welding materials) are available.
Safety Planning
  • Prepare risk assessment and safety protocols.
  • Ensure workers are equipped with PPE (helmets, gloves, harnesses, etc.).
  • Provide proper training on lifting and working at heights.

2. Foundation Work

  • Lay concrete foundations with anchor bolts installed at precise locations.
  • Allow sufficient curing time for the foundation before proceeding.
  • Verify anchor bolt placement with engineering drawings.

3. Safety Measures

  • Always follow local building codes and safety regulations.
  • Use certified equipment for lifting and rigging.
  • Implement fall protection measures.
  • Conduct regular safety briefings and hazard assessments.

4. Steel Structure Erection

Column & Beam Installation
  • Erect vertical columns using cranes or mobile lifting equipment.
  • Secure columns with anchor bolts and temporarily brace them.
  • Lift and position horizontal beams or girders onto columns.
  • Bolt or weld beams into place per design specifications.
Bracing & Alignment
  • Install diagonal and lateral bracing for stability.
  • Check vertical and horizontal alignment with surveying instruments.
  • Tighten all bolts to the required torque levels.
Roof & Wall Framing
  • Install roof trusses or purlins.
  • Position and secure sidewall girt.
  • Ensure proper alignment and spacing for roofing and cladding installation.

5. Welding & Bolting

  • Perform on-site welding as needed, ensuring proper joint penetration.
  • Tighten all bolts progressively and check for proper tension.
  • Inspect all connections per quality and safety standards.

6. Roofing & Cladding Installation

  • Install metal sheets or sandwich panels on the roof and walls.
  • Ensure proper overlapping and fastening for weather resistance.
  • Seal joints and edges to prevent leaks.

7. Safety Measures

  • Conduct structural integrity tests (load tests if necessary).
  • Inspect all bolts, welds, and connections.
  • Check for misalignments and correct any deviations.
  • Ensure all bracing and safety features are in place.

8. Handover & Maintenance

  • Conduct a final walkthrough with the client and engineers.
  • Provide documentation of quality tests, material certifications, and maintenance guidelines.
  • Schedule periodic maintenance for long-term structural integrity.