鉄骨構造接続の完全ガイド。ボルト締結 момент 接合、ブレースフレーム接続、デザイン要件について学びます。
Types of Structural Connections
Structural steel connections fall into several categories: 1. Moment Connections: - Transfer bending moment between members - Column-beam connections - Require full-depth end plates or angles - Critical for frame stability 2. Shear Connections: - Transfer only shear forces - Simple beam-column connections - Seat and clip angles - Used in simply supported beams 3. Braced Frame Connections: - Connect braces to frames - Gusset plate connections - Design for tension/compression in braces 4. Base Plates: - Connect columns to foundations - Anchor bolts transfer forces - Design for compression, tension, shear
High Strength Bolts for Structural Connections
Structural connections require high-strength bolts: ASTM Specifications: - A325: High-strength bolts (120 ksi) - A490: Higher strength (150 ksi) - F1852: A325X (twist-off bolts) Installation Methods: 1. Pretensioned (Turn-of-Nut): - Snug tight then turn nut specified rotation - Most common method 2. Direct Tension Indicator: - Bolts with built-in indicators - Compressible washer or spline 3. Alternative Design: - Calibrated wrench method - Twist-off bolts
Connection Design Requirements
Key design considerations: 1. Capacity: - Shear capacity of bolts - Bearing capacity of connected plates - Net section rupture 2. Serviceability: - Deflection limits - Connection flexibility 3. Detailing: - Clearances for erection - Access for welding/bucking - Corrosion protection