中文摘要：

对高喷插芯组合桩（JPP桩）的四种常用组合形式进行了模型试验研究，通过在芯桩上粘贴应变片和在桩底埋设土压力盒等仪器对JPP桩轴力、桩侧摩阻力及桩端阻力进行了测量，得到如下结论：水泥土与芯桩的不同组合形式对JPP桩承载力有较大影响；水泥土分段后，形成类似葫芦状的表面，增大了桩与桩周土的粗糙度，并且每段水泥土端部均能提供一定的端阻力，桩承载力提高明显；组合段位置对桩承载力也有较大影响，水泥土与芯桩下部组合时桩侧摩阻力增大明显，下组合的JPP桩承载力表现出比分段组合1的JPP桩承载力大的特点，组合段宜设计在JPP桩下部；工程设计中，JPP桩宜采用3段以上的分段组合形式，并将分段组合放在芯桩的中下部，根据土层性质分段高压旋喷水泥土，从而达到节约造价、提高桩承载力的目的。

英文摘要：

Model test was carried out for four kinds of combinations of jet grouting soil-cement-pile strengthened piles （JPP pile）. Axial force, shaft resistance and pile-top resistance were measured by strain gages pasted on core pile and earth pressure cells buried in pile bottom, and the following conclusions were obtained that different combinations forms of cement-soil and core pile have great impact on bearing capacity of JPP pile. The gourd-shaped similar surface caused by the cement-soil segment increases interface roughness between the JPP pile and soil, and each cement-soil top can provide some top resistance, which improves bearing capacity significantly. Segment locations have great impact on the bearing capacity of JPP pile. Shaft resistance increases significantly under cement-soil combination with the lower core pile. Bearing capacity of lower combined JPP pile is larger than segment-1 JPP pile, so combined segment should be set in the lower part of JPP pile in engineer design. In the engineering design, JPP pile should adopt three sub-combinations above. Combined segment should be placed in the lower of core pile, and jet grouting cement-soil should be segmented according to soil characteristics, so as to save cost and imorove bearing, eaoacitv.