''This research aims to address a post-earthquake urgent strengthening measure to enhance the residual seismic capacity of earthquake-damaged reinforced concrete wall structures with coupling beams. The study consists of a series of tests on half-scale prototype coupling beams with various detailing options, including confined with reduced confinement, partially confined, and unconfined bundles, under cyclic loading conditions. The methodology employed involved subjecting the specimens to displacement-controlled reversal tests, and carefully monitoring their response using strain gauges and potentiometers. The main results obtained reveal that GFRP wrapping significantly enhances the seismic performance of earthquake-damaged coupling beams, even in cases where specimens experienced strength loss and main reinforcement rupture. The strengthened beams exhibit commendable ductility, maintaining high levels of deformation capacity, and satisfying the requirements of relevant seismic design codes. The significance of the study lies in providing valuable insights into the behavior and performance of damaged coupling beams and assessing the effectiveness of GFRP wrapping as a rapid and practical post-earthquake strengthening technique. The findings can be particularly useful for developing urgent post-earthquake strengthening strategies for high-rise buildings with structural walls. The method may be particularly useful for mitigating potential further damage in aftershocks and eventual collapse. In conclusion, this study represents a significant advancement in understanding the post-earthquake behaviors of coupling beams and provides valuable guidance for practitioners in making informed decisions regarding post-earthquake strengthening projects. The findings contribute to the overall safety and resilience of structures in earthquake-prone regions.''
DOCUMENT
Out-of-plane (OOP) collapse is one of the most observed damage types in masonry structures during strong earthquakes. OOP strength of a masonry wall depends on several parameters such as the dimensions of the wall, vertical restoring force, boundary conditions and material properties, which are parameters creating complex kinematics during an earthquake. Testing of OOP response of a masonry wall is thus a challenging task, also because additional to the complexities mentioned, the seismic forces triggering OOP are caused by inertia of the wall itself, a phenomenon that needs dynamic testing. All these facts make shake table tests of masonry walls for capturing the OOP response extremely relevant. This paper presents shake table tests on a total of four wall specimens, two of which were reference walls and the other two were strengthened solid masonry walls. The tested walls built to represent the characteristics of Groningen houses built before the Second World War and also the historical masonry structures in the region. The strengthening methods applied are the deep-mounted carbon strips embedded in flexible epoxy and helical bars applied in mortar beds. The shake table tests presented here show that OOP specimens not including the additional masses imposed by the floors may oversee important kinematic response characteristics of the walls. Furthermore, tests have also shown that even serious cracks caused by OOP response close when the shaking stops, which causes damage on the walls and significant decrease in the stiffness, but they are extremely difficult to be caught by human inspection. This has consequences in terms of ongoing damage inspection and compensation efforts taking place in the Groningen gas field. The strengthening methods applied to the two specimens have shown clear improvement in strength, and a partial improvement in progression of damage.
DOCUMENT
A major challenge in the textile sector is achieving true circularity while preventing fraud, including false sustainability claims and material mislabelling. The complexity of supply chains and outdated certification systems have resulted in a lack of accountability and transparency. This project addresses these issues by developing and implementing Digital Product Passports, integrated with digital trust mechanisms as verifiable credentials, to create a transparent, responsible, and accountable textile supply chain. The project traces the journey of a corporate fashion t-shirt from cotton sourcing in India to production and distribution in the Netherlands, ensuring full transparency and traceability. Its goal is to drive a shift towards a circular economy by fostering collaboration across the supply chain and empowering stakeholders, particularly Tiers 3 and 4 in the Global South. Schijvens Corporate Fashion leads the effort with regenerative cotton sourcing through Raddis®Cotton, utilising Aware™’s technology solution. Adopting a ‘Fibre-Forward’ approach, the consortium ensures traceability by integrating data from raw material sourcing to end-user. This approach benefits all stakeholders, from farmers to garment producers, by providing verifiable information on fibre origins, social conditions, and ecological impacts. By tracking each fibre and collecting direct data, the project removes the opacity that can undermine sustainability claims. The project enhances accountability and sustainability compliance by utilising decentralised technologies for product verification. Integrating digital identity wallets for individuals and organisations, secured with verifiable credentials, enhances trust and accountability, fostering circular economy practices. Rather than seeing DPPs as the end goal, the project views them as catalysts for systemic change. It prioritises continuous improvement, collaboration, and shared benefits, aiming to establish a regenerative circular economy. Through a practical toolkit, the project will help organisations and policymakers navigate DPP adoption, strengthening transparency and creating a scalable, inclusive system for supply chains across the Global South and -North.
In recent years, human-induced seismicity in the northern part of the Netherlands increased rendering the seismic response of unreinforced masonry (URM) structures critical. Majority of the existing buildings in the Netherlands are URM, which are not designed to withstand earthquakes. This issue motivates engineering and construction companies in the region to research on the seismic assessment of the existing structures.The companies working in the structural engineering field in the region were forced to adapt very quickly to the earthquake related problems, such as strengthening of existing buildings after earthquake. Such solutions are of prime importance for the Groningen region due to the extent of the earthquake problems and need for strengthening the houses. The research published in the literature show that the connections play an important role in seismic resistant of the houses. Fixing or improving the poor wall-to-wall or floor-to-wall connections may have a large positive impact on the overall seismic behaviour. Some strengthening solutions are already provided by SMEs, and an extensive experimental campaign was carried out at TU Delft on retrofitted connections. In this project, a new experiment will be run on a large shake-table, unique in the Netherlands, that can simulate earthquake vibrations. These tests, together with the previous experience, will complement the overall knowledge on the strengthening solutions and their performance under real-time actual earthquake vibrations.
In recent years, human-induced seismicity in the northern part of the Netherlands increased rendering the seismic response of unreinforced masonry (URM) structures critical. Majority of the existing buildings in the Netherlands are URM, which are not designed to withstand earthquakes. This issue motivates engineering and construction companies in the region to research on the seismic assessment of the existing structures. The companies working in the structural engineering field in the region were forced to adapt very quickly to the earthquake related problems, such as strengthening of existing buildings after earthquake. Such solutions are of prime importance for the Groningen region due to the extent of the earthquake problems and need for strengthening the houses. The research published in the literature show that the connections play an important role in seismic resistant of the houses. Fixing or improving the poor wall-to-wall or floor-to-wall connections may have a large positive impact on the overall seismic behaviour. Some strengthening solutions are already provided by SMEs, and an extensive experimental campaign was carried out at TU Delft on retrofitted connections. In this project, a new experiment will be run on a large shake-table, unique in the Netherlands, that can simulate earthquake vibrations. These tests, together with the previous experience, will complement the overall knowledge on the strengthening solutions and their performance under real-time actual earthquake vibrations.
