EFFECTS OF THE CONSTRUCTION OF DEEP FOUNDATION PITS BY THE OPEN EXCAVATION METHOD ON THE DEFORMATION OF NEIGHBORING HOUSES

Abstract

The open excavation method is a common technique for constructing shallow underground works in foundation pits. The incident of settlement and cracking of resident houses around a 2-basement deep foundation pit of a 26-storey twin tower office building constructed in Hanoi by the open excavation method has been studied. The methods employed were a combination of site investigation and numerical and analytical simulations of a real problem. For the numerical simulation problem, two sections, North-South and East-West, were analyzed using the finite element method, plane strain problem, according to different excavation stages. The simulation results showed that the measures to protect the western slope of the foundation pit by using only bored piles without reinforcing the slope of resident houses adjacent to the excavation pit led to large ground deformation, endangering the stability of the pit and the structure of the adjacent houses. The above-simulated ground settlement results were consistent with those calculated by the method of the beam on an elastic foundation.