Influence of Ali Al -Gharbi Earthquake on Braced Excavation in Silty Clay Soil (Numerical Study)

The design of the braced excavation system is one of the important and necessary matters for the implementation of various projects. The braced excavation system is used to support excavations in temporary projects, so there are shortcomings in the study of this aspect, although sometimes there are many projects that take long periods of time especially the projects of underground tunnels and high buildings. This was the main reason for the study. Therefore, the possibility of exposing the drilling system to earthquakes is great, especially in seismically active areas. If the drilling system is exposed to an earthquake, it can cause great human and material losses, so it must be designed against earthquakes so that ensure complete collapse and failure does not occur. This study aims to investigate the behavior of braced excavations under the influence of the Ali Al-Gharbi earthquake in both x- and y- directions. A numerical study is carried out on braced excavation system of (14×6) m and depth 9m using software Plaxis 3D. The braced excavation system consists of three type of bracing system with three levels of strut and wales connected with sheet pile wall to support sides of excavation and prevent them from collapsing. The results of study showed that the horizontal displacement of braced excavation system is (100-155) % more than vertical displacement (settlement) with seismic time when system is subjected to Ali Al-Gharbi earthquake in both directions with the other factors remaining constant. The stiffness of sheet pile wall also play an important role increases and decreases lateral displacement in both direction. Also, the results showed that the movement of of braced excavation system depends on several factors like as type of soil, time acceleration and the direction of earthquake. Settlement of Ali Al-Gharbi earthquake in Y- direction is 13% more than in X-direction.