Predicting Responses of a Single Pile Considering Lateral Load to Tunnelling Induced Ground Movement: Analytical and Numerical Insights

Pile foundations are essential for supporting structures built on clay, such as high-rise buildings. These piles must withstand both vertical loads and lateral loads, such as those caused by wind forces. In urban areas, subway tunnelling often takes place in densely populated regions, impacting nearby buildings. This study examines the influence of different tunnelling depths on the mechanical response of a single pile subjected to lateral loading through numerical modelling in clay. A hypoplastic soil model is used for the clay, while a concrete damage plasticity model assesses pile damage. The results show that lateral loads significantly increase lateral deflection, bending moments and tensile damage in piles during adjacent tunnelling. The combined effects of tunnelling and lateral loading result in the most pronounced pile failure, while tunnelling alone causes no damage in the absence of lateral loads. By examining the lateral load effects on pile responses during tunnel excavation at various depths, the study proposes an analytical solution based on the Pasternak foundation—Timoshenko beam model to estimate tunnelling-induced lateral displacement and bending moments in piles. The validity of this method is confirmed through comparisons with centrifuge test data and numerical modelling.