Model test of static drilling and rooted energy pile considering over-consolidated behavior of soft soil

Abstract

In order to study the bearing characteristics of static drilling and rooted energy piles in soft soil with different consolidation states， based on the energy pile model test， the thermal response of the model piles in normal consolidated soil and over-consolidated soil is tested. The results show that the heat diffusion in the soil around the pile decreases with the increase of the distance away from the heat exchange tube （heat source）. The over-consolidation state of the soil layer affects the generation and dissipation of pore water pressure in the soil layer. Compared with the normal consolidated soil， the dissipation rate of the pore pressure in the over-consolidated soil layer is slower. The vertical deformation of the soft soil around the pile first manifests as rebound after the temperature rises， and then becomes settlement. Compared with the normal consolidated soil， the over-consolidated soil rebounds significantly， and the subsequent settlement is smaller. The additional temperature stress of the pile body increases first and then decreases； in the case of over-consolidated soil， the maximum additional temperature stress position of the pile body is higher than that in the case of normal consolidated soil， and the negative friction caused by heating is smaller. The bearing characteristics of statically drilled rooted energy piles are closely related to the over-consolidated state of soft soil， and comprehensive consideration is required in engineering design to ensure operational safety. <fig fig-type="abstract-image" id="F1" orientation="portrait" position="float"><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="SP.J.1249-2022-39-1-93/6E4E2FEE-B986-4675-B4CC-9CA8241BD5AC-F001.jpg"/></fig>