高压旋喷型圆形复合支护桩在深厚填土质斜坡工程中的应用及探讨

Application of high pressure rotary jetting circular composite support pile in deep fill soil slope engineering

以某市政道路项目为实例,阐述了普通圆形支护桩在深厚填土质斜坡实施过程中遇到的刚度不足及塌孔等问题,提出了一种较为稳定可靠的高压旋喷圆形复合支护桩。该结构主要由高压旋喷复合土及钢筋混凝土圆形支护桩组成,为桩土复合支护结构,由高压旋喷固结体及圆形支护桩一起承担水平土压力,具有防止垮孔,提高支护桩刚度及桩周土体物理力学指标等优点。在分析复合型支护桩受力特征基础上,通过理论推导,得到桩截面刚度提高公式。应用结果表明:采用高压旋喷型圆形复合支护桩可以有效提高桩身刚度,减小支护桩使用阶段水平位移,同时解决了桩基施工过程中垮孔问题,对填土斜坡上的支护桩有一定的普适性。

This article takes a municipal road project as an example to illustrate the problems of insufficient stiffness and hole collapse encountered by ordinary circular support piles during the implementation of deep fill soil slopes.A relatively stable and reliable high-pressure rotary jet grouting circular composite support pile is proposed.This structure is mainly composed of highpressure rotary jet composite soil and reinforced concrete circular support piles.It applies high-pressure rotary jet consolidated body and circular support piles to bear horizontal soil pressure and has the advantages of preventing hole collapse,improving the stiffness of the support pile,and improving the physical and mechanical indicators of the soil around the pile.Based on the analysis of the mechanical characteristics of the composite support piles,a formula for increasing the stiffness of the pile section is obtained through theoretical derivation.Practical engineering applications have shown that high-pressure rotary jet grouting circular composite support piles can effectively improve the stiffness of the pile body,reduce the horizontal displacement of the support pile,and solve the problem of hole collapse during pile foundation construction.This can be applied to almost all support piles on fill slopes.