Model tests on bearing capacity of single pile influenced by excavation

Deep excavation unloading can decrease the bearing capacity of piles.It may cause the lose of skin friction of bored piles and the soil pressure of pit bottom decreased.Indoor model tests are used to analyze the bearing capacity characters of single pile under the excavation unloading.And analysis of the load transmission process of single pile and measurement of its ultimate bearing capacity are carried out by simulating vertical static load experiments of test pile at ground and pit bottom.The influence of excavation unloading on bearing capacity of piles is studied.Compared with normal condition,the settlement of pile top and pile bottom increase.Meanwhile,the axial force of piles and the tip resistance have enlarged after the excavation unloading.The ultimate bearing capacity of model pile declines.