承台-倾斜桩体系承载力性状分析

预应力管桩在施工中发生桩身倾斜的现象屡见不鲜。为得到承台连接下倾斜桩的承载力特性,通过现场实测数据反演得到了合理的土层及桩体参数,之后建立数值模型,分析了承台下有2根桩且其中1根桩为倾斜桩的结构体系,在3种不同倾斜方向工况下的承载力性状。研究结果表明:单根桩体倾斜对承载力的影响不大,特别是工况1条件下,桩体倾斜对承载力的影响甚微;桩身轴力随着桩体倾斜程度的增加而增大,仅在工况1中倾斜桩的轴力发展趋势为先增大后减小。3种工况下桩身弯矩分布特征类似,且桩顶弯矩最大;但是当桩体倾斜方向不同时,桩顶正负弯矩也不同。综合来看,3种工况的承载力大小为工况1>工况2>工况3。

Bearing Capacity Behavior of Inclined Pile-cap System

Accidents such as inclination of pile shaft are common in the construction of prestressed concrete pipe pile.In order to get the bearing capacity behavior of inclined pile-cap system,firstly,we carried out in-situ tests and obtained rational parameters for strata and pile shaft.Then,we computed the structure system of cap with two piles, one of which is inclined,and discussed the system under 3 working conditions.The results show that:bearing ca-pacity of the system is not much affected on the condition of inclination of one pile,in particular,the effect can be negligible under the working condition 3;then the pile's axial force increases with the increase of tilt degree of the pile shaft,only in the case 1,the axial force increases first and then decreases;furthermore,the distribution charac-teristics of moment is similar in three conditions:the maximum moment is located at the top of pile,but when the tilt direction is different,the pile moment's symbol is also different;in the general,the maximum value of bearing capac-ity for three conditions is case 1,followed by case 2,case 3.