Bolting in Steel Construction

 Bolting, as a fundamental component of steel construction, holds immense significance in ensuring the stability, safety, and resilience of structures. The American Institute of Steel Construction (AISC) provides comprehensive guidelines and standards for the proper use of bolts in steel building projects. Understanding these standards is crucial for engineers, architects, and construction professionals to implement effective bolting practices in their projects.

The Importance of AISC Standards in Bolting

AISC, through its specifications and manuals, outlines precise requirements for the design, installation, and inspection of bolted connections. These standards cover various aspects, including bolt types, materials, installation procedures, and quality assurance measures, ensuring the integrity and performance of the connections in steel structures.

Types of Bolts Specified by AISC

The AISC standards recognize several types of bolts commonly used in steel construction:

1. Structural Bolts (A325 and A490): These high-strength bolts are designed for use in structural connections and have specific mechanical properties and dimensional requirements outlined in the standards.

2. Bearing-Type Bolts (A307): These bolts are suitable for non-critical and light structural connections and have lower strength compared to structural bolts.

Field bolting and Shop bolting

Shop Bolts:

Definition: Shop bolts, also known as pre-fabricated bolts, are bolts that are pre-assembled or fabricated in a controlled environment such as a factory or shop floor. These bolts arrive on-site ready for installation without requiring further fabrication or modification.

Field Bolts:

Definition: Field bolts, also known as site-installed bolts, are bolts installed on-site during the construction phase. These bolts are adjusted and installed according to specific requirements during the assembly of the steel structure.

Common bolt-tightening methods

Torque Control:

Torque Wrench: Using a torque wrench is one of the most common methods for tightening bolts. It involves applying a specific amount of rotational force (torque) to the bolt head, which is measured in units such as foot-pounds or Newton-meters. Torque values are specified based on the bolt size, type, and material to achieve the desired tension.

Turn-of-Nut Method:

This method involves tightening the bolt snugly using a standard wrench or spud wrench and then rotating it a specified additional fraction of a turn. This additional rotation is based on the bolt diameter and length and is intended to achieve the required tension without over-tightening.

Direct Tension Indicators (DTIs) or Load-Indicating Washers:

DTIs or load-indicating washers are specialized washers placed under the bolt head or nut. As the bolt is tightened, these washers deform or indicate a change in shape, providing a visual indication of the achieved tension, helping to ensure proper tightening.

Common bolt-joint types

Snug Tight Joints:

Snug tightness refers to tightening bolts enough to bring the connected parts into firm contact without preloading the bolts. It aims to eliminate gaps between the surfaces being joined.

Pre-Tensioned Joints:

Pre-tensioning involves tightening bolts to a specific tension or preload using torque or other methods, inducing an axial force in the bolt before the structure is loaded.

Slip-Critical Joints:

Slip-critical joints rely on the friction between connected surfaces to resist shear forces without relying on the grip of the bolts. They require high bolt pre-tension to prevent movement or slippage between the connected surfaces.

Fastening Methods in Steel Industry

 Steel buildings have long been celebrated for their durability, strength, and versatility. From warehouses and skyscrapers to residential structures, the use of steel in construction has significantly evolved, largely due to advancements in fastening methods. The efficiency and reliability of these fastening techniques play a pivotal role in ensuring the structural integrity and longevity of steel buildings.

Understanding the importance of proper fastening methods is crucial in constructing safe and resilient steel buildings. Let's delve into some of the prominent fastening methods utilized in steel construction:

1. Bolting:

2. Bolting remains one of the fundamental methods of connecting steel elements in construction. High-strength bolts, typically made of steel and often with corrosion-resistant coatings, are used to join structural steel components. Preloading bolts to a specific tension ensures a secure connection and reduces the risk of loosening due to vibration or structural movement.

3. 
   

4. Welding:

5. Welding, an integral part of steel construction, involves fusing steel pieces together using heat. It offers strong and durable connections, creating continuous joints that enhance structural stability. Modern welding techniques, such as submerged arc welding and gas metal arc welding, have improved efficiency, precision, and the quality of welds in steel buildings.

6. 
   

7. Riveting:

8. Though less commonly used today, riveting was historically a primary method for fastening steel structures. It involves inserting a heated metal rivet into holes in steel plates and then hammering or compressing the tail end to form a strong, permanent joint. While riveting has been largely replaced by welding and bolting due to advancements in technology, it still holds historical significance in steel construction.

Exploring the Role of Steel Shear Connections

 Exploring Steel Shear Connections: Enhancing Structural Integrity

Steel shear connections play a pivotal role in ensuring the stability and resilience of steel structures, forming the backbone of their structural integrity. These connections are crucial elements that transmit shear forces between various steel members, contributing significantly to a structure’s ability to withstand lateral loads and maintain stability.

Understanding Shear Connections

In structural engineering, shear connections facilitate the transfer of shear forces between steel components, primarily beams and columns. Shear forces occur parallel to the plane of the material, often arising from lateral loads, such as wind or seismic forces. The effectiveness of shear connections determines a structure’s resistance against these lateral forces.

Types of Steel Shear Connections

1. Bolted Shear Connections: Bolted connections are one of the most common types of shear connections used in steel structures. These connections involve the use of high-strength bolts to secure steel elements together. Properly designed and installed bolted connections distribute shear forces effectively, providing stability and load-bearing capacity.

2. 
   

3. Welded Shear Connections: Welding steel elements creates robust connections that effectively transfer shear forces. Welded connections offer advantages in terms of strength and stiffness, contributing to the overall rigidity of a structure. They are particularly useful in environments where high shear force transfer is required.

4. 
   

5. Shear Angles and Shear Plates: Shear tabs and plates are additional components often incorporated into bolted connections to enhance their shear capacity. These plates or tabs help distribute the shear forces and provide additional support to the connection.

SHEAR ANGLE CONNECTION

SHEAR PLATE CONNECTION

END PLATE CONNECTION

Comprehensive List of Steel Detailing and Engineering Abbreviations

1. DWG: Drawing

2. BOM: Bill of Materials

3. CAD: Computer-Aided Design

4. CNC: Computer Numerical Control

5. NC: Numerical Control

6. RFI: Request for Information

7. RFQ: Request for Quote

8. CJP: Complete Joint Penetration

9. AWS: American Welding Society

10. AISC: American Institute of Steel Construction

11. HSS: Hollow Structural Section

12. PO: Purchase Order

13. RFP: Request for Proposal

14. SOW: Scope of Work

15. BIM: Building Information Modeling

16. ISO: International Organization for Standardization

17. ACI: American Concrete Institute

18. IBC: International Building Code

19. GMAW: Gas Metal Arc Welding

20. HVAC: Heating, Ventilation, and Air Conditioning

21. OSHA: Occupational Safety and Health Administration

22. QA/QC: Quality Assurance/Quality Control

23. RC: Reinforced Concrete

24. SWL: Safe Working Load

25. PEB: Pre-Engineered Building

26. SEOR: Structural Engineer of Record

27. GOL: Gauge on Leg

28. BOBP: Bottom of Base Plate

29. T.O.G: Top of Grating

30. ANSI: American National Standard Institute

31. ASD: Allowable Stress/Strength Design

32. AISE: Association of Iron and Steel Engineers

33. ASCE: American Society of Civil Engineers

34. ASME: American Society of Mechanical Engineers

35. ASTM: American Society of Testing and Materials

36. ATLSS: Advanced Technology of Large Structural Systems

37. AESS: Architecturally Exposed Structural Steel

38. AWS: American Welding Society

39. AGS: American Galvanizers Society

40. CFR: Code of Federal Regulation for the construction industry

41. CISC: Canadian Institute of Steel Construction

42. CMAA: Crane Manufacturers Association of America

43. CMTR: Certified Mill Test Record

44. LRFD: Load and Resistance Factor Design

45. MBMA: Metal Building Manufacturers Association

46. NACE: National Association of Corrosion Engineers International

47. NBCC: National Building Code of Canada

48. NISD: National Institute of Steel Detailing

49. OSHA: Occupational Safety and Health Administration

50. RCSC: Research Council on Structural Connections

51. SSPC: Steel Structures Painting Council/Society of Protective Coating

52. SSRC: Structural Stability Research Council

53. WSD: Working Stress Design

54. SJI: Steel Joist Institute

55. NDE: Non-Destructive Examination

56. NDT: Non-Destructive Testing

57. BIF: Bill Interchange Format

58. CJP: Complete Joint Penetration

59. PJP: Partial Joint Penetration

60. E70LH: E70-Low Hydrogen

61. ERW: Electric Resistance Welding

62. FCAW: Flux Cored Arc Welding

63. GMAW: Gas Metal Arc Welding

64. SMAW: Shielded Metal Arc Welding

65. SAW: Submerged Arc Welding

66. FR: Fully Restrained Moment Connection

67. PR: Partially Restrained Moment Connection

68. SC: Slip-Critical

69. SDNF: Steel Detailing Neutral File

70. SER/EOR: Structural Engineer of Record

71. SOP: Standard Office Practice

72. GTSM: Gouge to Sound Metal

73. CAD: Computer Aided Drafting

74. CC: Centre to Centre

75. CG: Centre of Gravity

76. CL: Centre Line

77. CNC: Computer Numeric Control

78. DXF: Drawing Interchange Format

79. GA: Gage

80. GOL: Gage on Angle/Gage Outstanding Leg

81. HSS: Hollow Structural Section

82. HVAC: Heat Ventilating and Air Conditioning

83. KSI: Kips per Square Inch

84. LBS: Pound

85. LHE: Left Hand End

86. LLH: Long Leg Horizontal

87. LLV: Long Leg Vertical

88. LSL: Long Slot

89. LSLP: Long Slotted/Load Parallel Holes

90. LSLT: Long Slotted/Load Transverse Holes

91. MC: Miscellaneous Channel/Moment Connection

92. NS: Near Side

93. OSL: Outstanding Leg

94. OVS: Oversized

95. RD: Running Dimension

96. RFI: Request for Information

97. SSL: Short Slot

98. SSLP: Short Slotted/Load Parallel Holes

99. SSLT: Short Slotted/Load Transverse Holes

Overview of Common Structural Shapes in Construction and Engineering

1. I-Beams (or H-Beams): These have an I or H shape and are commonly used for horizontal structural elements like beams in buildings and bridges.

2. C-Channels: These are C-shaped structural elements used in various applications, especially in construction and manufacturing.

3. Angle (L-shaped): Angles are L-shaped structural elements used to reinforce corners, support, or join structural components.

4. T-Beams: These are structural beams shaped like the letter T and are often used in construction for load-bearing purposes.

5. Tubes and Pipes: Circular or hollow cylindrical structures used in various applications like columns, support structures, and fluid transportation.

6. Rods and Bars: Long cylindrical solid structures often used for reinforcement or as tension members.

7. Plates and Sheets: Flat and thin structural elements used as base materials for various construction and manufacturing purposes.

These shapes vary in their structural properties and are selected based on the specific requirements and load-bearing capacities in construction or engineering projects.

Bolt Edge Distance Chart

 

Anchorbolt Hole Diameter as per AISC Table 14-2

 

OSHA: Navigating Workplace Safety Regulations

Welcome readers to the blog, emphasizing the importance of workplace safety and compliance with OSHA regulations. Highlight the purpose of the blog, aiming to educate, inform, and guide both employers and employees.

Section 1: Understanding OSHA

1. What is OSHA

    - Explain the establishment, role, and mission of OSHA in ensuring safe and healthy working conditions.

    - Discuss the scope of OSHA's authority and the industries it covers.

2.OSHA Standards and Regulations

    - Detail the different standards set by OSHA, such as general industry standards, construction standards, and specific guidelines for hazardous materials, machinery, etc.

    - Discuss the penalties for non-compliance and the importance of adhering to OSHA regulations.

 Section 2: Employer Responsibilities

1. Safety Training and Education

    - Explain the employer's duty to provide adequate training and resources for employees to recognize hazards and work safely.

    - Discuss the importance of safety programs, regular training sessions, and hazard communication.

2. Workplace Inspections and Hazard Assessment

    - Outline the process of conducting workplace inspections to identify and rectify potential hazards.

    - Discuss hazard assessment methods and how to mitigate risks.

3. Record-Keeping and Reporting Requirements

    - Explain the importance of maintaining accurate records of workplace injuries, illnesses, and incidents.

  Detail OSHA's reporting requirements for severe injuries and fatalities.

Section 3: Employee Rights and Protections

1. Workers' Rights

    - Discuss employees' rights to a safe workplace, the ability to report unsafe conditions anonymously, and protection against employer retaliation.

2. Whistleblower Protection

    - Explain the protections offered to employees who report unsafe conditions or violations of OSHA standards.

Section 4: Industry-Specific Guidelines

1.Construction Industry

    - Highlight specific OSHA regulations relevant to the construction industry, including fall protection, scaffolding, and electrical safety.

2. Healthcare Industry

    - Discuss unique safety considerations and OSHA guidelines for healthcare professionals, including handling hazardous materials and infection control.

 Section 5: Ongoing Compliance and Resources

1. OSHA Compliance Assistance

    - Provide resources and tools available for businesses and individuals to ensure ongoing compliance with OSHA regulations.

    - Include links to OSHA's official website, compliance guides, training resources, and consultation programs.

GAUGE THICKNESS IN INCH CHART

Here is chart to find the thickness of steel specified in gauge. Should be a helpful chat for every steel derailers...
If you like the article, please keep support.

Share your doubts and express your comments

See below Link for Downloading Chart

https://www.dropbox.com/s/lmbth7s7jx8k65q/metalgauge-chart.pdf?dl=0

ANGLE HOLE GAGES

When we take look at the sketch,
we can see three values as g,g1 & g2. When it use ?????????

• The g1 will be used for the angles with less than or equal to 4" Leg. When the angle leg size exceeds 4" the angle may be needed for two rows of bolts. So we use the g1 & g2  values for those long leg angles.

Check the below dropbox link for downloading Angle hole gage Chart.

If you like the article, please support and express your comments.....


https://www.dropbox.com/s/y2d5jilfdp0bft3/ANGLE%20GAGE.pdf?dl=0

HOLE TOLERANCE FOR ANCHOR BOLT & BOLTS

ANCHORBOLT & HEADED ANCHOR ROD

DIFFERENCE BETWEEN PIPE AND POST

In structural and construction terminology, the terms "post" and "pipe" refer to different structural elements with distinct characteristics and applications:

Post

-A post typically refers to a vertical structural member that is sturdy and designed to support loads or provide structural integrity. Posts are commonly used in construction to bear the weight of beams, joists, or other structural elements, transferring these loads to the foundation. They are usually larger in size and are often made of solid wood, steel, or concrete.

Pipe

-A pipe, on the other hand, is a tubular-shaped hollow section generally designed for the transportation of fluids or gases. In construction, pipes are more often used for plumbing, drainage, or conveying substances from one place to another. They come in various materials such as steel, PVC (Polyvinyl chloride), copper, or other metals or plastics depending on the intended use.

While both posts and pipes are cylindrical in shape, their primary functions, construction materials, and applications are notably different. Posts are typically utilized for structural support, while pipes are commonly employed for fluid or gas transportation and distribution systems.

If a vertical member weight falls below 300 pounds according to OSHA regulations, it is referred to as a "post." However, if the weight exceeds 300 pounds, it is categorized as a "column."

COMPARISON BETWEEN ASTM A500 & A1085

ASTM A500 has been the preferred material specification in the United States for cold formed, welded carbon steel hollow structural sections (HSS) since the late 1970s. In April of 2013, a new material specification, ASTM A1085, was released for steel tubes used in structural applications.

See the below link for download
https://www.dropbox.com/s/psicoq0jg3ymdpf/hss-flyer.pdf?dl=0

Courtesy:www.aisc.org & internet

ARCHITECTURALLY EXPOSED STRUCTURAL STEEL

Architecturally exposed structural steel (AESS) can express the structural integrity of a building in a striking way and put the structural system at the aesthetic forefront. Today, many buildings showcase AESS to provide an identity and even create iconic structures. AESS elements feature higher degree of finish and are handled with a higher level of care during fabrication and erection. Beautiful and creative expression can be achieved in the broad range of shapes, tapered forms, curves, colors, glossy or matte finishes, as well as seamless or tectonic expression.

ABRASIVE NOSING