A Data-driven NDT based Estimation of In-situ Concrete Strength of Existing Residential Buildings for Rapid Seismic Risk Assessment

Accurate estimation of in-situ concrete strength (finsitu) is of the utmost importance for the seismic risk assessment of existing residential buildings located in the regions prone to earthquake hazard. The seismic vulnerability assessment of these structures requires rigorous surveying, material sampling and testing. A typical seismic risk assessment procedure requires both destructive (e.g. core sampling) and non-destructive (e.g. Rebound hammer, RH) tests for material characterisation. In the regions under immediate seismic risk; however, the requirement of destructive tests (DT) causes loss of very valuable time and resources to achieve earthquake preparedness in a timely fashion. Therefore, there is an urgent need for non-destructive testing (NDT) based tools that are capable of performing rapid and accurate estimation of finsitu. An NDT, preferably RH, based material characterisation will significantly reduce the time needed for the risk assessment of residential buildings. This can be achieved my developing reliable ‘Conversion Models’ (CMs) that are capable of predicting finsitu based on only RH readings without the need of any core-sample. This proposal aims to examine the feasibility of utilizing a data driven approach to develop locally adapted CMs using well classified comprehensive datasets so that CMs can be customized with respect to multiple factors such as building age, construction technology, local workmanship, district, etc. Such locally-customized CMs will reduce the uncertainty in in-situ material characterisation, and hence will improve the reliability of overall rapid risk assessment. To investigate and showcase the feasibility of the proposed approach, Project Lead (PL) plans to visit two renowned institutions, the University of Bordeaux (UB), France and Kandilli Observatory and Earthquake Research Institute (KOERI), Turkey. A visit to KOERI will provide PL to collaborate with the leading experts in Earthquake Engineering (EE) and gain practical skills on seismic vulnerability estimation, mitigation, and preparedness techniques. During the visit, a database consists of in-situ test results collected from a variety of residential buildings located in Istanbul will be constructed. This database will lay the foundation to develop a data driven NDT tool. KOERI will also be very instrumental in reaching out to the international community in EE as it is one of the leading institutes in Europe and hosts the European Association for Earthquake Engineering. The other visit will be to UB, home to the distinguished Institute of Mechanics and Engineering (I2M), which is at the forefront of research in non-destructive testing. This visit will support the partnership with leading researchers in the area of Uncertainty & Reliability in NDT, helping to develop reliable conversion models for RH measurements. UB will not only provide the perfect research environment to achieve the project goal but will also play a key role to reach out an extensive network of NDT experts in/around Europe. In summary, the proposed Overseas Travel Grant (OTG) will allow PL to establish new collaborations with the leading experts in NDT and EE, and bridge the gap between these two major disciplines. The expected outcome, which is the development of a reliable NDT tool for in-situ material characterisation, holds a great value to perform rapid and reliable risk assessment for the millions living under the threat of immediate seismic hazard. The OTG will not only increase PL’s knowledge and expertise in the said areas but will also expand his network for future collaborations via the existing networks of the host institutions.