Seismic Performance of Various Structural Configurations for RC Building on Sloped Terrain Considering Soil-Foundation-Structure Approach

Dhimant Parmar¹Nikhilesh Ponnappan¹Advaitha Thampi¹PRASANTH S^2*

• ¹School of Civil Engineering, VIT Vellore, Vellore, India
• ²Centre for Disaster Mitigatiion and Management, VIT Vellore, Vellore, India

The study aims to evaluate seismic performance of RC buildings on slopes using Soil-Foundation-Structure (SFS) interaction modelling. This study investigates seismic performance of different structural configurations for five-storey RC building on sloped terrain, incorporating bracings, shear walls, grade beams, stub columns, strap footings, and hybrid arrangements. Three critical slope locations—toe, crest, and centre—at 20° inclination were analysed using SFS modelling approach in PLAXIS 3D, incorporating soil non-linearity. The RC building was modelled to assess inter-storey drift ratio (ISDR), lateral displacement as performance parameters. Results indicate that structures on sloping ground have much higher vulnerability than those on level ground, with bare frame structures exhibiting the worst seismic performance at all locations on slopes. Braced and shear wall buildings show remarkable improvements, with up to 90% reduction in both lateral displacement and inter-storey drift ratio compared to typical bare frame systems, and hybrid configurations such as M26 model, achieving reductions in critical shear force and bending moment exploitation ratios by as much as 2.3 times and 1.5 times, respectively, at the observed column. At the crest, optimal configurations showed a reduction in lateral displacement by 91%. For buildings at the center, certain configurations reduced inter-storey drift and roof displacement by up to 79% and 88%.The study provides valuable guidelines for creating seismically resilient structural designs substantially improving safety and performance of RC buildings under seismic loads in mountainous terrain. The study aligns with building sustainable cities and resilient communities (Sustainable Development Goals (SDGs) - 9 & 11), which minimize the damage to the infrastructures and reduces social losses in a community. Limited studies were done on structural configuration of buildings on slopes, where limited guidelines were provided on Indian Standards. The study includes Soil-Structure interaction with varying location of building based on practical scenarios which prove to be novel research to identify the best possible resilient structural configuration for building construction at slopes.