Effect of Excavation on the Settlement of Adjacent Structures

The requirement of increased infrastructure and limitation of space due to urbanization has resulted in the use of subsurface structures to meet the demands. There are many challenges in performing construction activities such as excavation adjacent to existing buildings and settlement is perhaps the most challenging among them. This paper studies the effect of excavation adjacent to existing buildings in the Delhi region for DMRC site carried out by CSIR—Central Building Research Institute. The excavation was carried out for a shaft opening of size 20 m × 20 m and the depth of excavation was around 18 m. The offset distance from the adjacent buildings varied from 4 to 15 m. The analysis was carried out using PLAXIS 3D software. The actual soil data of the site with realistic loadings of the buildings were considered. The results revealed that the settlement of the existing buildings doubled due to the adjacent construction activity as compared to the case of static load due to buildings. Post-excavation settlement was found to be more than the permissible limit indicating the need for improvement measures to be undertaken to minimize the damage to existing structures.