Phân tích ứng xử hố đào sâu sử dụng ringbeam đường kính lớn

Abstract

This paper presents and analyzes the behavior of deep excavation employing large diameter ringbeam combining with reinforced concrete truss system for bottom-up method. Field monitoring data of a 5-basement deep excavation in the geological area of District 1, Ho Chi Minh City, excavated depth of 20.75 m at main foundations and 26.65 m at pit foundation below ground surface level, were used for the studyed objective. Finite element analysis was employed, by combining the structural analysis of the ringbeam system by the structural software Etabs 2021 and the behavior analysis of the soil layers by Plaxis 2D 2020 model, the author evaluated the displacement and internal force of the retaining structures including diaphragm wall, reinforced concrete truss system and ringbeam. The results of the finite element analysis were compared with the field observation at each excavation stages. The comparison showed that combination of ringbeam structural stiffness simulation and behaviour of soil layers totally consistented with observations, in addition, retaining wall displacement from 2D Plaxis analysis also gave similar results.