Tension-Only Bracing: Slenderness Limits, Slack and Seismic Design
Seismic codes allow tension-only braces in frames of limited ductility. Why they must be…
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Column Base Plate: Pinned or Fixed? Stiffness Assumptions for Design
Column bases are neither pinned nor fixed. Practical stiffness assumptions (SN045) for design forces,…
Should the Bottom Chord of a Roof Truss Be Laterally Restrained?
Does the bottom chord of a roof truss need lateral restraint? Only if uplift…
The Concept of Envelope Combinations and Their Limitations
An envelope pairs extreme forces from different load combinations. Why that misses governing interactions,…
How High Can Earthquake Ground Acceleration Go?
Record ground accelerations from San Fernando to Tōhoku, and a proposed upper limit: about…
RC Columns + Steel Roof
A 30 m steel roof truss on 8 m concrete columns, modelled three ways.…
Resilient Slip Friction Joint
How the resilient slip friction joint stores earthquake energy in disc springs and uses…
Lead Rubber Bearing (LRB) Isolator
A finite element simulation of a lead rubber bearing: heat in the lead core,…
Triple Friction Pendulum Seismic Isolator
How a triple friction pendulum isolator lengthens the period of a structure independently of…
Steel Building Performance Analysis
Can one R factor describe a whole building? A five-storey example where code rules…