Tankshal ni Masjid: Bridging the gap between the virtual and the tangible – Structural Strengthening and Rehabilitation

The construction sector in India contributes 18% to the nation's GDP and is experiencing rapid growth. Therefore, preserving existing structures is crucial for sustainable development. European countries have made significant advancements in conserving old and heritage structures, with repair and rehabilitation contributing up to 26% of their construction industries. Given India's vast cultural heritage, it is vital for the country to keep pace with these developments to connect future generations to their history

The Faculty of Technology at CEPT University has introduced a pioneering studio focused on the structural strengthening and rehabilitation of buildings. This program offers hands-on experience in damage diagnosis through site visits, non-linear structural analysis, and the proposal of strengthening interventions. Real-life case studies primarily involve masonry, timber, steel, and concrete structures. One notable case study is the Tankshal Pol Mosque, a single storey composite structure located in Ahmedabad’s Old City. The mosque, constructed mainly of flat brick masonry and timber, is one of the few surviving timber mosques in the region. The site includes the mosque itself, an entrance structure that was demolished, an Imam’s room, a go-down and an open cultural space in between.

During a site visit to the mosque, significant damage was observed in both the brick masonry and timber structures. The brickwork, approximately 270 years old, showed extensive deterioration, while the timber roof members were severely compromised by termite damage and weathering. The study focused on assessing these damages and classifying them based on material.

To evaluate the mosque's seismic behaviour, a Pushover analysis was conducted using DIANA Finite Element Analysis software. This analysis helps understand the deformation and cracking of the structure under seismic loads. By modelling the building without the roof, researchers aimed to accurately assess how cracks propagate through the brick masonry.

The findings revealed that the modelling correlated well with actual site conditions, with cracks in the model matching those observed on-site. The study highlighted the effectiveness of tie rods in controlling deflection and demonstrated the importance of simulations of different iterations of strengthening techniques and interventions to identify the most effective strategies.

The study has highlighted the overall importance and accuracy of such analysis which can help to identify the best scientific solutions for different kinds of deterioration in a historic building. In the future a Time History analysis can be included for more accuracy. It will help to develop strengthening options that consider economic factors and minimal damage to this historically significant structure.