Analysis of Thermo-mechanical Behavior of Single Pile Influenced by Pile Tip Constraint

Energy pile is an innovate technology, which can support the building load and acquire geothermal energy simultaneously. In the actual operation process, the temperature of pile body will change significantly, causing the expansion or contraction of the pile, and due to the constraint of pile end and soil around the pile, the pile will produce additional heat stress. Based on model test and numerical simulation methods, the heat stress and displacement of energy piles under cold-thermal cycling loading with different pile tip constraints are analyzed. The results show that the maximum stress of the pile is in the middle of the pile under the temperature load.In the heating stage the effect of pile tip restraint on the stress distribution of pile is stronger than that in refrigeration stage. The variation of pile displacement is affected by both of temperature and pile end constraint. The displacement of the upper part of the pile is greatly affected by the temperature.