水平旋喷桩是在水平钻孔内以高压旋喷的方式压注水泥浆，在隧道开挖外轮廓形成拱形预衬砌，以防护掌子面和地表下沉的超前支护施工方法。实践证明，水平旋喷桩是目前国内外行之有效而又快速经济的隧道超前支护技术，具有广阔的运用前景。 本文在前人大量研究成果的基础上，从高压喷射注浆加固机理、分类构造、影响因素、固结体基本物理力学性质入手，运用理论分析研究和数值模拟研究方法，对水平旋喷桩的作用机理与影响因素进行了较为深入的研究，主要内容包括： 1、对水平旋喷桩加固的适用范围和优缺点进行了说明，同时对水平旋喷桩的施工方法的设计进行一定的分析，总结该工法的施工设备方案、工艺参数设计、流程步骤、成桩检验方法、常见问题及处理措施，最后对几种超前加固方式做了一些比较分析。 2、深入研究了高压喷射流的构造和特性、高压喷射流对土体的破坏作用及水平旋喷桩加固机理。 3、对作用在水平旋喷桩预支护上的荷载进行了探讨，将水平旋喷注浆成拱简化成一个开口圆柱壳体，建立水平旋喷桩预支护隧道开挖过程中的三维力学模型，并求出了其弹性解析解。 4、通过数值模拟软件FLAC3D，对浅埋隧道在有水平旋喷预支护和无水平旋喷预支护两种情况下进行模拟对比，以及模拟结果与理论计算结果对比，得出水平旋喷桩预支护的作用效果和初步结论。

Horizontal rotary jet grouting piles is a pre-support construction method that by way of pressing slurry using high pressure jet in horizontal holes, this technology could form a arching pre-lining at profile in tunnel construction to protect the working face and reduce surface subsidence. The practice has prove that pre-support technology of horizontal rotary jet grouting piles is a well fast and economic pre-support technology in tunnel construction at china, and this technology would have widespread application prospects. The paper is on the basis of the large number of previous research results,including mechanism of the high pressure jet grouting,classification structure,influencing factors,basic physical and mechanical properties of the horizontalsolidification,applying theory analysis, Finite element analysis researchmethods,making a in-depth research on mechanism of the horizontal rotary jet grouting piles and technical factors.The principal contents in paper is: 1、Application range of horizontal rotary jet grouting piles pre-consolidation and its advantages and disadvantages are described. Meanwhile, the design for construction method of horizontal rotary jet grouting piles was analyzed to some extent. And this text concluded some aspects of this construction method including construction equipment, the design of process parameters, process steps, pile-test methods, frequently problems and corresponding treatments. Finally, some pre-reinforced methods were compared and analyzed with each other. 2、This text studied deeply on the structure and characteristics of high-pressure squirt flow, its destructive effect on soil and action mechanism of forming pile by horizontal rotary jet grouting piles. 3、The loads acted on horizontal rotary jet grouting piles pre-support were discussed. The grouting-arching by horizontal rotary jet grouting was simplified into an opening cylindrical shell. A three-dimensional mechanical model of tunnel construction by horizontal rotary jet grouting piles pre-support technology was built and its elastically-analytical solution was derived. 4、By way of numerical simulation software FLAC3D, this text compared the simulated result which used horizontal rotary jet grouting piles pre-support with the simulated result which not, as well as the simulation results compared with the theoretical calculation results. Based on the compare mentioned before, functionary effect and preliminary conclusion by horizontal rotary jet grouting piles pre-support technology was come out.