Seismic & Wind Load Calculations

Roben, Mfg., Inc. specializes in the custom engineering and fabrication of seismic and wind loads calculations for chemical, fine chemical, petrochemical, pharmaceutical, food and beverage, defense, and power-generation industries. Every project is designed to ASME Section VIII Division 1 (with optional Division 2), is National Board registered, complies with the European Pressure Equipment Directive (PED 2014/68/EU) for CE marking, and is registered under the Canadian Registration Number (CRN) system for all Canadian provinces.

What Seismic and Wind Loads Calculations Are

Seismic and wind load calculations quantify the dynamic forces a tall pressure vessel or column experiences during earthquakes and high-wind events. These calculations are required by ASCE 7, the International Building Code (IBC), the Canadian National Building Code (NBC), and EN 1991 in Europe. They drive the design of the column shell, support skirt, anchor bolts, and foundation.

Why Seismic and Wind Loads Calculations Matter

Tall, slender columns are highly sensitive to wind and seismic loads. Inadequate seismic or wind-load design can cause vessel buckling, base failure, or vortex-induced fatigue. Code-compliant calculations are required by every Authorized Inspector and Notified Body, and a key input to the foundation engineer's design.

Seismic and Wind Loads Calculations — Specifications and Capabilities

Wind: ASCE 7-16/22, NBC, EN 1991-1-4, vortex shedding (helical strakes when required)

Seismic: ASCE 7-16/22 equivalent lateral force or modal response spectrum, IBC, NBC, EN 1998

Calculation outputs: Base shear, overturning moment, anchor bolt tension, skirt stresses

Foundation interface: Anchor bolt patterns, base plate dimensions, grout requirements

Software: Compress, PV Elite, ANSYS for dynamic verification

Certifications and Codes

ASME Section VIII Division 1 — U-stamp

ASME Section VIII Division 2 — available on request

National Board registration — R-stamp

PED 2014/68/EU — CE marking with Notified Body coordination

CRN — registered for all Canadian provinces

NACE MR0175 / ISO 15156 — sour-service compliance

AWS D1.1 / ASME Section IX — qualified welding procedures and welders

Frequently Asked Questions About Seismic and Wind Loads Calculations

What codes does Roben Mfg. follow for seismic and wind load calculations?

ASCE 7-16 or 7-22 for U.S. projects, IBC, NBC for Canada, and EN 1991-1-4 (wind) and EN 1998 (seismic) for European projects. Site-specific seismic spectra are used when provided.

What is vortex shedding and when is it a concern?

Vortex shedding occurs when wind flowing past a slender cylinder generates alternating vortices that can drive resonant vibration. It is a concern on tall, slender columns. We check the critical wind speed and add helical strakes or guy wires when vortex shedding is a risk.

What is the difference between equivalent lateral force and modal response spectrum analysis?

Equivalent lateral force (ELF) is a simplified static method valid for regular structures within code limits. Modal response spectrum analysis is a more detailed dynamic method required for taller, more flexible columns or where ELF limits are exceeded.

Does Roben Mfg. design the foundation?

We design the anchor bolt pattern, base plate, and provide the loads to the foundation engineer (overturning moment, base shear, vertical reaction). The civil/structural engineer designs the concrete foundation to match.

What FEA verification is performed on tall columns?

We run a modal analysis to determine natural frequencies, then a response spectrum or transient dynamic analysis to verify the static seismic calculation. ANSYS or PV Elite Dynamic is used for this verification.

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Contact Roben Mfg., Inc. to discuss your project specifications, timeline, and material requirements.

📞 (732) 364-6000 ✉ sales@robenmfg.com 📍 760 Vassar Ave, Lakewood, NJ 08701

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Seismic and Wind Load Calculations for Columns