摘要
高喷插芯组合桩(简称JPP)是由高压旋喷桩和预应力混凝土芯桩构成的一种新型组合桩,为了对其荷载传递机制有更深入的认识,以自行开发的大型土工试验模型槽为依托,进行了JPP桩、灌注桩和高压旋喷水泥土桩静载荷对比试验。通过埋设在JPP桩中的监测仪器对桩身轴力、桩端阻力以及桩体沉降等进行了直接量测,进而分析了JPP桩中管桩与水泥土轴力的分布和内外侧摩阻力的分布。试验结果表明,JPP桩与同桩长、同桩经灌注桩相比承载力高30%以上;JPP桩变形由芯桩控制,管桩轴力分布与水泥土轴力分布规律不一致,但同一截面上管桩和水泥土的轴力比值约为其弹性模量的比值;内外摩阻沿桩身的分布规律类似,内摩阻是外摩阻的1.62倍左右,约为JPP桩直径和管桩直径的比值;桩侧摩阻力与桩土相对位移近似双曲线分布,桩端阻力和桩端位移也近似双曲线分布。
Jet grouting soil-cement-Pile strengthened Pile（JPP） is a new kind of composite pile composed of high pressure jet grouting pile and prestressed concrete core pile.In order to make a further research on load transfer mechanism of JPP under vertical loads,the full-scale model test of JPP,cast-in-place pile and jet grouting soil-cement pile have been done in the test room which is developed for this test.With the pre-arranged instrument in JPP,the axial stress,dip resistance and settlement of pile have been measured;and distribution of axial force and friction resistance are also analyzed.Experimental results show that： bearing capacity of JPP is thirty percent higher than that of cast-in-place pile which has the same length and diameter with JPP.The deformation of JPP is controlled by core pile;axial force distribution of PHC is different with soil-cement;and their axial force ratio in same section is their elastic modulus ratio.Distribution of inner and outer friction resistance is similar;and the inner friction is about 1.62 times of the outer one;it is about the ratio of JPP diameter and PHC diameter.Furthermore,the relation between friction resistance and relative displacement is similarly hyperbolic;and the relation between dip resistance and displacement is also hyperbolic.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2010年第5期1395-1401,共7页
Rock and Soil Mechanics
基金
江苏省自然科学基金攀登学者创新项目(No.BK2008040)
河南理工大学博士基金(No.B2010-52)
