Model Test And Numerical Analysis Of Bearing Characteristics Of Inclined Piles Under The Combination Of Vertical Load,horizontal Load And Torque Load

Bridges,docks,wind turbines and other structures used more inclined pile foundation,because of the particularity of the stress environment(such as torque,curved bridge pile foundation suffered Marine pile gene of wind load,wave load torque)and the effect of non-uniform lateral force,leading to the pile foundation under vertical load and horizontal load on(pull/press)also bear large torque effect,and at present of inclined pile under combined load bearing character study is less,so in pile under vertical load,horizontal load and torque load combination of the inclined pile bearing deformation behavior research has important guiding significance for engineering practice.First of all,the load-bearing deformation behavior of inclined piles under the combined action of uplift load(V),horizontal load(H)and torque load(T)was studied by indoor model test.Firstly,a constant uplift load is applied on the top of the inclined pile,and then a synchronous increase of horizontal load and torque load is applied after the stability,and compared with the vertical pile under the same load condition.The results show that the torsional bearing capacity of inclined pile is always smaller than that of straight pile,and the greater the inclination Angle of pile body is,the smaller the torsional bearing capacity is.The increase of uplift load will reduce the torsional bearing capacity of straight pile and inclined pile,and the reduction effect on straight pile is more obvious.The maximum torque of the pile body of straight pile appears at the section of pile top,and the maximum torque of the pile body of inclined pile appearsbelow the section of pile top.Both straight pile and inclined pile have effective load transfer depth,which is deepened with the increase of uplift load.Then,the bearing deformation behavior of straight pile and 15° inclined pile under the combined action of uplift load,horizontal load and torque load is studied numerically.First,the constant uplift load and horizontal load are applied on the top of the pile,and then the torque load is increased step by step after the pile is stable.The analysis results of the straight pile and the inclined pile are compared.The results show that the horizontal load can increase the torsional bearing capacity of straight pile and decrease the torsional bearing capacity of inclined pile.The pile torque decreases with the increase of horizontal load.The variation of pile body torque with horizontal load is related to the relative depth of pile body.The effective load transfer depth of straight pile is obviously less than that of inclined pile.Finally,the bearing deformation behavior of 15° inclined pile under the combined action of downforce load(P),horizontal load(H)and torque load(T)was studied by numerical method.The constant down pressure load and horizontal load shall be applied before the pile top,and the gradually increased torque load shall be applied after stabilization,and the results are compared with the numerical analysis results of inclined pile subjected to v-h-t combined load.The results show that the torsional bearing capacity of inclined piles will be reduced with the increase of downforce load.The torsional bearing capacity of inclined pile subjected to p-h-t combined load is smaller than that of inclined pile subjected to v-h-t combined load.At the initial stage of torque loading,the settlement of pile top appears rebound phenomenon.The effective load transfer depth of inclined pile subjected to p-h-t combined load is less than that of inclined pile subjected to v-h-t combined load.