Deep Excavation Support in Soft Ground with Parametric Variations for Adjacent Structures

During the construction of a high-rise structure, a deep excavation is required which is subjected to lateral earth pressure from the area surrounding the existing adjacent structures. So, a construction of a cantilever pile wall is necessary to resist and confine this lateral earth pressure. This paper examines cantilever pile walls, an earth support structure to transfer load, minimize deformation, stabilize soil, and maintain structural stability during soft ground excavation. Three distinct foundation conditions—isolated, strip, and mat foundations—are taken into consideration with adjacent structure base load each subjected to loads of 100 and 200 kPa. The focus of this study is the soft soil at the Teku location in the Kathmandu Valley, Nepal, which has an undrained cohesion of 27 kN/m². The study uses finite element analysis and 3D modeling techniques to assess the performance of cantilever piles with diameters ranging from 0.3 to 0.5 m. Numerical modeling is done using Plaxis 3D software for evaluation of the soil-structure interaction. Even though cantilever pile walls and their behavior in different soil conditions have been thoroughly studied, there are still several gaps in our understanding, especially regarding soft ground conditions like those in Kathmandu Valley. There is not enough research incorporating several variables, including supporting pile size, adjacent base loads, and adjacent foundation types. This study makes use of finite element analyses to provide an understanding of the pile wall behavior and deformation of the surrounding soil. The results of this investigation are expected to contribute to the use of efficient support systems for deep excavations in soft ground.