Date of Award

7-7-2020

Publication Type

Master Thesis

Degree Name

M.A.Sc.

Department

Civil and Environmental Engineering

Keywords

Base Isolation, Earthquakes, Elastomeric Bearings, Residential Structures, Structural

Supervisor

Niel Van Engelen

Rights

info:eu-repo/semantics/embargoedAccess

Abstract

For many years now, structural engineers have researched different ways to improve the safety of humankind against earthquakes. Besides improving safety, they also investigate ways to develop earthquake-resilient buildings. In the world today, earthquakes are capable of causing tremendous damages. The majority of the earthquake events in Canada occur on the west coast of British Columbia and southeastern Canada (i.e. southern Quebec and southeastern Ontario). A mechanism that has been developed to counteract the motion of structures due to earthquake excitation is known as base isolation. In Canada, the National Building Code is used for the design and analysis of buildings. In this code, Part 9 provides a prescriptive method to design residential structures, which means an engineer is not required. Furthermore, Part 9 does not have any provisions to design a base isolated structure. Whereas, Part 4 has extensive provisions that require engineering input and testing. In the United States, ASCE 7-16 is used to design and analyze structures. ASCE 7-16 provides guidelines for the design of a structure with base isolation including a simplified method known as the equivalent lateral force procedure. For base isolation to be widely applied in residential structures it is necessary to eliminate barriers such as the need for in-depth engineering. To eliminate the need for costly engineering, a simplified method appropriate for Part 9 of the NBCC is proposed. An online resource was developed using the equivalent lateral force procedure outlined in ASCE 7-16 but following the NBCC provisions. The resource outputs all the key performance indicators, such as the maximum displacement, base shear, distribution of the forces, number of isolators, and the efficiency. To validate the online resource, time history analyses were done on eight model cases. These model cases were chosen to represent real-life single-family homes that are commonly built. It was concluded that base isolation systems are beneficial for residential structures and that the developed online resource is a good representation of the design requirements for residential structures. More functionality (e.g. considering complex geometry and soil conditions) can be added to the online resource to expand the application. Detailed provisions also must be added to Part 9 of the NBCC to aid the user in the construction and installation of the system. Furthermore, manufacturers must develop isolation devices appropriate for residential structure and provide the specifications for the online program. Additional requirements are identified and explained. When base isolation is implemented in residential structures, it will prevent tremendous costly damages and protect lives in the event of an earthquake.

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