Session: SE-01-01 Earthquake Resistance and Seismic Margin

Paper Number: 65103

Start Time: Tuesday, July 13, 2021, 09:00 AM

65103 - Using an Innovative Seismic Resilient Anchorage System for Industrial Tanks and Vessels 

Enhancement of the seismic performance of liquid containers, especially strategic tanks or those with valuable contents used in the winery, dairy or petrochemical industry, has been in the center of attention during recent years given the damages and economic loss experienced after severe events. The liquid storage systems are anchored to the ground with a limit number of connections and are taken into account as structures with minimum redundancy. Therefore, in such structures, the connection details are key design factors on the force and deflection demands imposed during an event. The conventional connections make the tanks to be either fully restrained or free for rocking motion, which generally creates a high level of force due to lack of ductility or large displacement demand due to uplift resulting in severe damage of the tank. However, a new approach is using a partially restrained connection to control both the deflection and force at the desired levels.

An innovative generation of anchorage system has been introduced by employing Resilient Slip Friction Dampers (RSFDs) as ductile self-centring hold-downs for industrial tanks and silos. This new tension-only damage-free anchorage mechanism mitigates the transmitted earthquake force to storage tanks by dissipating the input energy through friction without experiencing any damage, contrary to other common ductile yielding hold-downs. The self-centring feature of this damper also allows to control and limit the rocking motion of the tank and restore it to its original position, crucial for tanks with large height to base aspect ratios. Therefore, this new system does not require post-event maintenance and is able to resist against the possible aftershocks. Also, RSFD is flexible to be tuned for a different type of vessels depends on force and deflection demands.

In this study, through the validated experimental results, a comparison of the effect of RSFD anchorage system to other ductile concepts (necked-rod and buckling-restrained system) considering a real case study of steel cylindrical storage tanks has been conducted. This damage-free, tension-only, self-centring mechanism due to the flexibility of design compared to other systems considerably decreases the transmitted force which leads to less demand for designing tank’s barrel and also foundation. As a part of this presentation also some of the projects which have been equipped with this system will be introduced and discussed.

Presenting Author: Kaveh Sahami Tectonus Ltd

Authors:

Kaveh Sahami Auckland University of Technology
Pouyan Zarnani Auckland University of Technology
Pierre Quenneville University of Auckland