Early-age shrinkage and bond of LC-TRM strengthening in rammed earth

The wide dissemination of earth-based structures as contemporary, vernacular or heritage constructions in re-gions with important seismic hazard demands the design of solutions that improve the typical low structural performance resulting from intrinsic material limitations. Only in this way, it is possible to promote a comprehensive seismic protection of this heritage and of the life of their inhabitants. One relevant and innovative solution proposed recently to address this problem consists in the strengthening with low-cost textile meshes embedded in a mortar matrix (LC-TRM). The purpose of this solution is similar to that of fibre reinforced polymers (FRP) systems used in masonry structures, where it works as an externally bonded reinforcement. Nevertheless, LC-TRM is addressed to elements constituted by materials with low mechanical properties, such as rammed earth and adobe. The further development of this strengthening solution demands comprehending with detail the interaction between the substrate and the matrix, where the shrinkage behaviour is relevant for the success of the system. The capacity of non-destructive tests based on digital image correlation (DIC) suggest the possibility of using this technique to monitor mortar shrinkage in LC-TRM strengthened rammed earth walls. On this regard, an experimental program was conducted and provided many important conclusions, among which are that DIC provides an adequate monitoring of the shrinkage behaviour of LC-TRM strengthened systems and that the strengthening mesh is a key element for controlling shrinkage development. Additionally, the interaction between the substrate and the LC-TRM system was characterised by the means of pull-off tests, favouring a discussion on the suitability and limitations of these tests on rammed-earth/LC-TRM systems.This work was partly financed by FEDER funds through the Opera-tional Programme Competitiveness Factors (COMPETE 2020) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project SafEarth-PTDC/ECM-EST/2777/2014 (POCI-01-0145-FEDER-016737) . This research was partly funded by the Portuguese Foundation for Science and Technology (FCT) through the Grant No PD/BD/150385/2019. The funding provided by the Erasmus ELARCH (Euro Latin-America Partnership in Natural Risk mitigation and protection of the Cultural Heritage) 552129-EM-1-2014-1-IT-ERA MUNDUS-EMA21 Program is also gratefully acknowledged

Parametric and machine learning-based analysis of the seismic vulnerability of adobe historical buildings damaged after the September 2017 Mexico earthquakes

In September 2017, two strong earthquakes hit the central region of Mexico, producing substantial damage to the historical buildings. A retroactive analysis for assessing the pre-event seismic vulnerability of these constructions allowed for testing the suitability of an existing parameter-based approach based on material and geometrical features. More than 160 adobe buildings in four municipalities of the State of Morelos were surveyed and included in a vulnerability-oriented GIS database. Data were collected on-site and managed by resorting to open-source GIS software combined with a Python-based database management tool and a cloud-based platform for onsite data collection using mobile devices. The parameter-based approach was used for assessing the analytical seismic vulnerability of the buildings and implementing a secondary, more conservative assessment that considers uncertainties associated with the data acquisition process. The capabilities of the database were further used to train a Machine Learning algorithm aimed at overcoming some representativeness limitations of the parameter-based analytical method. This third approach was found to be suitable for assessing the vulnerability of the building typologies addressed in this investigation. Although the implementation discussed in this paper is limited to a specific vernacular typology, it can be used to conduct customized local calibrations.- This work was partly financed by FCT/MCTES through national funds (PIDDAC) under the R & D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020. This research was funded by the Portuguese Foundation for Science and Technology (FCT) through grant number PD/BD/150385/2019. The field campaigns in the State of Morelos were financed by the Instituto de Ingenieria - Universidad Nacional Autonoma de Mexico (Institute of Engineering - National Autonomous University of Mexico) through the project R562

Implementing open-source information systems for assessing and managing the seismic vulnerability of historical constructions

The characterisation of the seismic vulnerability of historical constructions represents a complex problem in which the typological variability, the difficulty of performing reliable large-scale assessments and dealing with a large database all play a role. Nevertheless, reducing the uncertainty regarding the structural vulnerability of the existing building stock (mostly for small and/or isolated human settlements) is key for risk assessment and management. The present work proposes a novel approach based on the integration of a series of open-source tools for assembling a vulnerability-oriented database that is linked to a series of external services for increasing its capabilities. The database was implemented in a Geographical Information System (GIS) environment and contains the survey of a seismic vulnerability index for masonry constructions based on an adapted version of the GNDT-II approach. A customised Python-based software for reading, managing and editing the database is herein presented. This program allows the execution of the most typical operations with no assistance from the GIS environment, facilitating user interaction. Furthermore, the calculations regarding the vulnerability index and levels of damage have been implemented in this program. Alternatives for distributing the database are implemented and discussed, such as cloud-based distribution and the use of the Transactional Web Feature Service (WFS-T) protocol for its virtual publishing. The entire framework herein presented is a replicable and feasible workflow that can be set even with reduced infrastructure, allowing a progressive enlargement