Technical Engineering • Centre Technique

Assemblages Boulonnés vs Soudés sur Chantier

Pourquoi les liaisons 100% boulonnées par boulons HR sécurisent le chantier et réduisent la main d'œuvre.

Auteur : İdris YAĞMAHAN (Architecte) Revue technique par : Celalettin YAĞMAHAN (Ingénieur Principal Structure) Temps de lecture : 7 min de lecture Mis à jour : 2026-02-28
Conception Certifiée Eurocodes 3 & 8
Contrôle Qualité Usine EN 1090-2
Empotage Conteneur 40ft HC en Colis Plat
Assemblage 100% Boulonné (Zéro Soudure)

⚡ Synthèse Rapide / Résumé Exécutif

In modern structural steel engineering, the industry benchmark is a hybrid workflow: 100% Factory Automated Welding for sub-assemblies (robotic submerged-arc welding under controlled EN 1090-2 EXC3 conditions) combined with 100% Bolted Field Connections on the construction site (utilizing preloaded Grade 8.8 and 10.9 high-strength structural bolts per EN 14399). This eliminates dangerous on-site hot-work permits, eliminates weather-dependent field welding defects, reduces crane rental time by 60%, and enables rapid mechanical assembly with calibrated torque wrenches. Bolted moment end-plate connections engineered per Eurocode 3 (EN 1993-1-8) provide identical structural rigidity and seismic ductility to monolithic welded joints.

Points Clés & Avantages Économiques

  • ✔ Zero On-Site Hot Works: 100% bolted field erection eliminates fire hazard, welding fumes, and costly fire-watch personnel
  • ✔ High-Strength Fasteners: SerBuild utilizes Grade 8.8 and Grade 10.9 hot-dip galvanized structural assemblies per EN 14399/15048
  • ✔ Factory Robotic Quality: Primary haunches and gussets are welded in certified shop conditions with 100% NDT inspection
  • ✔ Erection Speed: Bolting portal connections takes minutes with impact wrenches vs hours of multi-pass manual site stick welding
  • ✔ Dismantling & Demountability: Bolted structures can be unbolted, modified, expanded, or relocated with zero structural damage
  • ✔ Calibrated Torque Control: Every connection has an engineered tightening torque table (Nm) ensuring precise joint preload

1. Eurocode 3 Joint Mechanics & Quality Control Principles

The debate between field welding and field bolting was resolved by modern automated CNC fabrication and Eurocode 3 joint design:

  • The Failure Mode of On-Site Field Welding: Manual field welding on European jobsites is fraught with quality risks: wind blowing shielding gas away (causing porosity), rain causing hydrogen embrittlement and cracking, cold ambient steel temperatures, difficult overhead positioning, and prohibitive radiographic/ultrasonic testing costs.
  • Factory Welding Excellence (ISO 3834-2 / EN 1090-2): In the factory, primary beam haunches, baseplates, and crane corbels are welded using automated submerged-arc and GMAW robotics under preheated, dry conditions. Welds achieve ISO 5817 Quality Level B with certified non-destructive testing (NDT).
  • Eurocode 3 Bolted Moment End-Plate Connections (EN 1993-1-8): Extended end-plate connections with Grade 8.8/10.9 bolts act as full-strength, ductile moment joints. Tensile flange forces are transferred through high-strength bolts, while shear forces are transferred through bolt shanks and friction bearing.

2. Cost, Quality & Assembly Comparison Matrix

The table below compares 100% bolted field assembly against manual on-site welded joints for a 2,000 m² steel frame:

📊 Tableau Détaillé des Coûts & Spécifications (€ / m²)

Connection Evaluation Metric 100% Bolted Field Connections (SerBuild) On-Site Field Welded Connections Advantage Difference
Site Labor Cost per Joint €12 – €25 (Fast torque wrench bolting) €85 – €160 (Multi-pass manual welding) ✔ Bolted: 75% Cheaper Labor
Assembly Time per Portal Frame 45 – 75 Minutes (Crane hook time) 4 – 7 Hours (Temporary rigging hold) ✔ Bolted: 4x Faster Crane Time
Weather Delay Sensitivity 0% (Bolt torque unaffected by rain/wind) High (Cannot weld in rain or wind >10m/s) ✔ Bolted: Zero Weather Stoppages
Site Hot-Work Permits & Fire Watch Zero (No fire hazard on site) Mandatory permits + continuous fire watch ✔ Bolted: Zero Fire Risk
Quality Control & NDT on Site Visual torque wrench audit / DTI washers Mandatory on-site Ultrasonic/X-Ray tests ✔ Bolted: Instant Inspection
Future Relocation / Expansion 100% Demountable by unbolting Permanent (Requires oxy-acetylene cutting) ✔ Bolted: Circular Recycling

🔍 Matrice Comparative d'Ingénierie

Structural Joint Type Fastener Grade / Spec Eurocode Standard Primary Load Transfer Mode Best Application
Extended End-Plate Moment Joint Grade 8.8 / 10.9 (Preloaded) EN 1993-1-8 / EN 14399 Bending moments & vertical shear Eave haunches & apex portal crowns
Column Baseplate Connection Grade 8.8 Anchor Rods + Grout EN 1993-1-8 Axial compression, uplift & shear Concrete footing foundation fixing
Purlin & Girt Cleat Overlap Grade 8.8 M12/M14 Galvanized EN 1993-1-3 / EN 15048 Direct shear & wind uplift tension Secondary Z/C purlin to rafter fixing
Cross-Bracing Tension Rod Grade 8.8 / S355 Tension Cleats EN 1993-1-1 Pure axial tension & wind sway Longitudinal roof & wall wind bays

📋 Déroulement du Projet Étape par Étape

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1. Tekla Connection Modeling

Joint components (end-plates, bolt hole centers, stiffeners) modeled to ±0.5mm precision.

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2. Factory CNC Plasma Drilling

High-definition CNC tables punch and drill bolt holes with perfect geometric alignment.

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3. Shop Robotic Welding & NDT

Gusset plates and haunches welded under certified ISO 3834-2 conditions.

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4. Container Packaging with Hardware

Hardened bolts, nuts, and load-indicating washers sorted and labeled by joint code.

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5. On-Site Crane Alignment & Pinning

Portal rafters hoisted into position; spud pins align holes instantly.

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6. Calibrated Torque Tightening

Bolts tightened in cross-pattern to specified torque values using calibrated torque wrenches.

Besoin d'un Dimensionnement & Devis Spécifique à Votre Projet ?

Transmettez dimensions, portées et coordonnées géographiques. Notre bureau d'études structure fournit une offre détaillée et une pré-analyse Eurocode 3 sous 24 à 48h.

Demander un Devis de Projet → Support Technique WhatsApp

Foire Aux Questions (FAQ)

Réponses détaillées sur l'ingénierie Eurocode, la fabrication, l'exportation et le montage.

Bolted field connections eliminate on-site fire hazards, remove the need for certified site welders and X-ray testing, reduce mobile crane rental time by 60%, and ensure 100% predictable structural quality independent of site weather conditions.

We exclusively utilize high-strength structural bolting assemblies: Grade 8.8 (yield strength 640 MPa, tensile strength 800 MPa) and Grade 10.9 (yield strength 940 MPa, tensile strength 1000 MPa) per EN 14399 and EN 15048.

No. Because 100% of the framing members are pre-drilled and bolted together mechanically, zero cutting torches, grinders, or arc welding machines are used on site, eliminating all hot-work permits and insurance surcharges.

Yes. Eurocode 8 specifically defines bolted moment end-plate connections as high-ductility seismic dissipation mechanisms. The bolted joint is engineered to develop full plastic moment capacity without brittle fracture.

Every SerBuild 3D erection manual includes an exact Bolt Torque Specification Table (e.g. M16 = 175 Nm, M20 = 340 Nm, M24 = 590 Nm, M30 = 1,180 Nm) verified with standard calibrated torque wrenches.

Demandez une Étude Technique & Devis

Transmettez-nous vos dimensions ou plans pour une analyse d'ingénierie et une offre détaillée sous 24 à 48 heures.

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Étape 1 : Quel type de bâtiment en acier prévoyez-vous ?

Étape 2 : Emplacement du Projet & Dimensions Souhaitées

Étape 3 : Mode de Livraison & Équipements du Bâtiment

Étape 4 : Calendrier du Projet, Incoterms & Avancement

Étape 5 : Coordonnées & Téléversement de Plans / CAD

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