Data Analysis of Pile Tunnel Interaction

Abstract

Tunnel construction in interaction with deep foundations is often a matter of concern in urban areas. However, a great deal of uncertainty is still evident in the differences between regulations for minimum tunnel clearance and in the design of preventive measures for the pile–tunnel interaction effects. To address this problem, this paper presents, analyzes, and compares over 50 reports of case studies, physical models, and full-scale and centrifuge tests on a wide range of layouts and soils. The effects of new tunnels on existing piles are described in terms of mechanisms, induced settlements, and structural forces. The data analysis reveals patterns that could not be found within the limited number of tests of each separate study. Quantitative measurements of pile settlements and axial stresses have been related to the pile position, working load, and tunnel volume loss. The results indicate that most piles do not reach failure and that for piles at a lateral distance of more than two times the tunnel diameter, the settlements are less than 1% of the pile diameter.