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Evaluation of seismic performance of a pre-cast concrete block arch system through testing and numerical modeling

University of British Columbia

Lock-Block Ltd. from Vancouver, Canada, has developed an arch structural system made from modular pre-cast concrete blocks. The intention of the arch is to provide an easy to construct, cost effective and long lasting structure. This could be achieved with a modular, steel-free system. This study aims to assess the seismic performance of these arches characterizing their seismic behavior using a combination of experimental testing and numerical modeling. Several small scale unreinforced and reinforced arch models were subjected to quasi-static and dynamic testing. For the dynamic testing, a suite of earthquake records was selected of varying magnitudes, types and locations, and applied on a shake-table. From the results of the shake-table testing on the unreinforced models it was found that the arches tend to collapse by the four-hinge mechanism which is typical for these types of structures. For the reinforced arch testing, a steel band was instrumented to provide information on the loads. The reinforced arch performed well when subjected to the same suite of earthquakes. A numerical distinct element model was developed using 3DEC software and calibrated to the quasi-static test. The response of the numerical model matched the experiments with the arch exhibiting the same four-hinge failure mechanism. From numerical analysis, sensitivity studies were performed on various parameters of the arch. This included geometry, material properties and boundary/interface conditions. It was found that in this configuration, the arches are vulnerable to seismic excitation and at risk of collapse when unreinforced and unconfined. There are several solutions to reduce that risk based on the results of this work: 1) addition of external or internal reinforcement to prevent hinge opening 2) restraint of the bottom courses of blocks and 3) modification of the geometry at the base to improve stability.

Text

2016-05-31

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/58202

Civil Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/