📋 Case Study

California Data Center Campus – Eccentrically Braced Frame (EBF) Link Connections

Achieving target energy dissipation without excessive link rotation that would compromise cable tray alignment

🏗️ Project Overview

Tier IV data center with strict drift limits (< 0.005h) and redundancy requirements

🎯 Challenge

Achieving target energy dissipation without excessive link rotation that would compromise cable tray alignment

🔧 Design Approach

Two-tiered link design: short links (L ≤ 2.5b) for first story, long links (L ≥ 5b) for upper stories; all links detailed with stiffener plates and ASTM A572 Gr. 50 steel

📐 Design Diagram

L ≤ 2.5b Long Link
L ≥ 5b Energy Dissipation Excessive Rotation Design Parameters: • Mₚ = 1,280 kip-in • Vₚ = 185 kips • ASTM A572 Gr. 50 Short Link Long Link Challenge Foundation Level

AI-generated project design illustration

📐 Key Calculations

Link Plastic Moment

M_p = Z×F_y

Result: 1,280 kip-in

Sets yield point for controlled hysteresis

Link Shear Capacity

V_p = 0.6×F_y×d×t_w

Result: 185 kips

Governs link failure mode

📊 Results

Link rotations limited to < 0.02 rad under DBE; no equipment misalignment observed after simulated shake-table test

💡 Lessons Learned

• •Stiffener spacing must be ≤ 0.75×link depth to prevent local buckling
• •Link replacement protocol must be pre-engineered and stocked onsite

✅ Key Takeaways

• 1Stiffener spacing must be ≤ 0.75×link depth to prevent local buckling
• 2Link replacement protocol must be pre-engineered and stocked onsite