Research On The Stress Characteristics And Failure Modes Of The Rigid Pile Foundation In Embankment Widening

With the rapid economic development,coastal and other economically developed areas have higher requirements for road traffic.A large number of existing roads increase traffic by widening.However,soft soil is widely distributed in coastal areas.In order to improve the stability of soft soil embankments,piles are usually used to reinforce the foundation.The domestic and foreign design codes generally use the limit equilibrium method to calculate the stability of embankments.According to the current research,this method has the possibility of overestimating the stability of the composite foundation,and the stress characteristics and failure characteristics of the rigid pile composite foundation before embankment widening will occur.change.Based on ABAQUS,this paper established a three-dimensional numerical model of the composite foundation of the rigid pile of the widened embankment.A concrete damage model that reflects the tensile and compressive failure of the concrete is introduced into the pile body.,And the effect of widening pile layout on its stress characteristics.The results show that:(1)widening the embankment rigid pile composite foundation can effectively reduce the uneven settlement caused by widening the embankment and improve the stability of the widening embankment;(2)the failure of the pile body in the widening embankment rigid pile composite foundation under the uniform load The mode is progressive failure.The pile located at the outermost slope foot will be destroyed first.When the damage develops to the middle of the embankment to a certain degree,it will cause secondary failure of the middle and upper parts of the outer pile body;(3)Anti-slide of the pile body before and after the embankment widening The zoning changes;(4)When the settlement requirements of the widened embankment are high,the length of the widened pile can be appropriately increased,and the length of the widened pile can be appropriately reduced when the settlement requirements are met,so as to achieve the purpose of economic and environmental protection;(5)widening The depth,pile diameter,and pile spacing of the pile entering the bearing layer can affect the force of the widening embankment of the rigid pile composite foundation.The comprehensive force and economics of the pile result that the depth of the widening pile entering the bearing layer is 0.27 t and the pile diameter When it is 0.28 d and the pile spacing is 3R?4R,it is more reasonable;(6)Moving the widening pile position can change the stress of the pile body and can increase the cracking load of the widening pile.The moving distance is about 1.5 E-2?2.08E-2 times Pile spacing.