The Effect of Neighbor surcharge on the Stability of Deep Excavations Supported by Nailing Method (Case Study in the North&South of Tehran-IRAN)

Abstract

Today in civil project in densely populated mega city is in high attention due to the neighbor infrastructure and need to deep excavation. Also, the needs to enforcement of the wall of excavations are developing. One of the economically developed methods is “nailing” that is a fast and well accepted method in civil society. In this research work it was tried to investigate the main causes of lateral displacement and finally instability of the wall of excavation that are enforced by “nailing” method. For this purpose the software of Plaxis was employed that works based on finite element modeling. One of the possibilities could be the effect of overloading of neighbor buildings that is not considered properly in the modeling. The works about this shortcoming is very rare. Thus in this thesis the effect of neighbor and even far Surcharge of infra structure and its distance on the decrease in safety factor and displacement using the data of soil characteristics were investigated in Northern and Southern Tehran. It was found that lateral displacement will decrease proportional to the increase of the surcharge distance from the edge of excavation. However, for the part that in located within the wedge of failure, the safety factor will decrease with the distance of the surcharge that and will increase again with increasing in the distance.