直斜组合高压旋喷桩基础抗压承载性能数值试验研究

Numerical Experimental Study on Compressive Bearing Capacity of Vertical and Inclined Combined High-Pressure Jet Grouting Pile Foundation

山地区域高压线铁塔基础施工具有难度大、周期长、成本高、机械化施工程度低等特点。为提高塔基基础施工效率,本文提出了一种新型的塔基基础形式——直斜组合高压旋喷桩。利用有限元软件PLAXIS 3D对直斜组合高压旋喷桩基础的竖向承载性能及桩身内力演化规律开展数值试验研究。研究结果表明:1)斜桩倾角相同时,桩身弯矩变化规律基本相同,其最大弯矩值位于桩顶附近且随桩长径比的增加而减小;2)竖向荷载作用下,直桩的轴力大于斜桩;3)桩长径比相同时,直斜组合高压旋喷桩基础抗压承载力随斜桩倾角(0°、10°、20°)的增大而呈非线性递增关系;直斜组合高压旋喷桩基础竖向承载性能较好,值得推广与应用。

The construction of high-voltage tower foundations in mountainous areas is characterized by high difficulty,long cycle,high cost,and low degree of mechanized construction.To improve the construction efficiency of tower foundation,this article proposes a new type of tower foundation form:straight inclined combination high-pressure rotary jet grouting pile.Using the finite element software PLAXIS 3D,numerical experiments were conducted to study the vertical bearing performance and internal force evolution of the vertically inclined combination high-pressure rotary jet grouting pile foundation.The research results indicate that:1)When the inclination angle of the inclined pile is the same,the variation law of the bending moment of the pile body is basically the same,and the maximum bending moment value is located near the pile top and decreases with the increase of the pile aspect ratio;2)Under vertical load,the axial force of straight piles is greater than that of inclined piles;3)When the length to diameter ratio of the pile is the same,the compressive bearing capacity of the high-pressure rotary jet grouting pile foundation of the straight inclined combination shows a nonlinear increasing relationship with the increase of the inclined pile inclination angle(0°,10°,20°).The vertical bearing performance of the vertically inclined combination high-pressure rotary jet grouting pile foundation is good,and it is worth promoting and applying.