220kV高压输电线路群桩基础应用与研究

发布时间：2018-03-09 16:13

本文选题：输电线路　切入点：单桩极限承载力　出处：《东南大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着高压输电线路基础类型的多样性发展,钻孔灌注桩群桩基础日益受到关注。本文结合某220kV输电线路的群桩基础,通过有限元分析软件ABAQUS就竖向荷载作用下单桩以及群桩基础的承载性状进行了数值分析。分析了单桩在不同土质条件、桩径、桩长和桩身强度情况下的承载性状,得出桩土界面摩擦系数、桩径、桩长、桩身混凝土及土体弹性模量等因素对单桩极限承载力的影响。研究了群桩基础在竖向荷载作用下的竖向承载性状,群桩基础中基桩与单桩数值分析结果的对比表明：在本文各因素水平下,群桩基础中的基桩较单桩的荷载-沉降曲线平缓；由于群桩基础承台下基桩对土体存在约束挤压作用,故基桩较单桩的侧摩阻力大；土质越好的地层,桩土界面摩擦系数也相对越大,群桩的基桩之间相互影响也越强,群桩效应更加明显；群桩基桩的桩径增大,使基桩之间的相互影响程度变大,在相同布置情况下大桩径基础比小桩径基础的群桩效应强；桩长变化对群桩效应的影响不明显;桩距的大小对群桩效应有较为明显的影响,桩距越小,群桩效应越明显；随着桩数的增加,基桩对内部土体的约束作用愈明显,群桩效应也越明显。
[Abstract]:With the development of high voltage transmission line foundation, the pile group foundation of bored cast-in-place pile has been paid more and more attention. This paper combines the pile group foundation of a 220 kV transmission line. Through finite element analysis software ABAQUS, the bearing behavior of pile under vertical load and pile group foundation is numerically analyzed. The bearing behavior of single pile under different soil conditions, pile diameter, pile length and pile body strength is analyzed. The effects of friction coefficient of pile-soil interface, pile diameter, pile length, pile concrete and soil elastic modulus on the ultimate bearing capacity of single pile are obtained. The vertical bearing behavior of pile group foundation under vertical load is studied. The comparison of numerical analysis results between pile group foundation and single pile shows that the load-settlement curve of pile group foundation is slower than that of single pile foundation under each factor level in this paper. Therefore, the side friction of pile group is greater than that of single pile, and the better soil quality, the greater the friction coefficient of pile-soil interface, the stronger the interaction between pile groups, the more obvious pile group effect is, the larger the pile diameter of pile group is, Under the same arrangement, the pile group effect of large pile diameter foundation is stronger than that of small pile diameter foundation, the influence of pile length change on pile group effect is not obvious, and the influence of pile spacing on pile group effect is obvious. The smaller the pile spacing, the more obvious the pile group effect is, and with the increase of pile number, the more obvious the restraint effect of foundation pile on the internal soil is, the more obvious the pile group effect is.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU476

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