Mechanical Response in Existing Structure under Varied Subsurface Excavation Techniques

Abstract

With the slowdown of urban incremental construction in China, reinforcement and renovation of existing buildings have become a hot topic in the fields of engineering and theoretical research. Underpinning pile foundations and underground excavation are commonly used methods for foundation renovation and reinforcement in existing buildings reinforcement and renovation projects. Nevertheless, there remains a dearth of relevant research concerning the effects of different excavation methods on the stability of existing structures during foundation reinforcement and underground space excavation. In the context of existing building pile foundation underpinning and underground excavation, this paper adopts a numerical simulation research method based on the modification of experimental model parameters, and it compares the overall stress changes and settlement of the underpinning pile foundation and the building under two modes of lateral and vertical excavation. The results indicate that there is a good agreement between the stress and settlement changes of the components in the indoor model experiment and the finite element simulation. Both excavation methods show that lateral and vertical excavation will generate maximum stress on the bottom components of the upper structure and the upper part of the pile. In terms of differences, vertical excavation will cause greater overall settlement of the building, but the settlement in different areas is basically the same. On the other hand, lateral excavation will have smaller overall settlement but may cause the structure to tilt. At the same time, lateral excavation will cause greater stress changes in the columns in the structure. Based on these findings, relevant engineering suggestions are provided to choose different excavation methods and strengthen existing buildings.

Keywords

• existing structural reinforcement
• underpinning
• pile foundation
• finite element analysis
• excavation method
• model test