水平定向钻井（HDD）是一种相对较新的无螺纹管道安装技术。事实证明，这是一种有效、节约成本的方法，可用于安装聚乙烯（PE）管道，用于市政供水和污水处理。在安装过程中，管道被拉入预钻孔中，在钻孔中，管道被钻井泥浆和土钻屑（泥浆钻屑）的混合物包裹。施工技术以及管道上安装的接地负载与明挖沟槽中安装的管道不同。因此，常用的埋地管道设计公式通常不适用于定向钻孔管道。本文讨论了安装和POST- 定向钻孔聚乙烯管的安装设计考虑。在安装过程中，管道必须安全承受拉入力（或管道从交叉口一侧拉回至另一侧时的“拉回力”）。拉回力是克服管道与井壁、管道与地面之间摩擦阻力所需的力。此外，钻井泥浆在管道上产生外部流体压头压力。管道必须足够坚硬，以抵抗这种压力。管道安装后，由于土壤重量、活荷载和地下水，荷载基本上是径向压力。土壤负荷将取决于土壤- 钻孔的特征。在某些土层中，钻孔是稳定的，不会变形，因此其作用很像隧道。在其他土壤中，钻孔可能会变形，并将土压力传递给管道。当土壤具有可测量的内摩擦角时，压力通常小于地应力（棱柱荷载）。本文还讨论了定向钻孔管道的安装荷载、安装后荷载和管道反力的计算。管道反应包括纵向拉伸应变、环屈曲和环挠度。建议PE管的安全系数和允许挠度。包括10个参考文献、表格和图表。

Horizontal directional drilling (HDD) is a relatively new technology fortrenchless pipe installation. It has proved to be an effective, cost-savingmethod for installing polyethylene (PE) pipes for municipal water and sewerapplications. During installation, pipes are pulled into a pre-drilled boreholewhere they are encapsulated by a mixture of drilling mud and earth cuttings(mud-cuttings slurry). The construction technique as well as the installed earthloads on the pipe differs from pipes installed in open-cut trenches. Thus,commonly used design equations for buried pipes are frequently inappropriate fordirectionally drilled pipes. This paper discusses both installation andpost-installation design considerations for directionally drilled PE pipes.During installation the pipe must safely withstand the pull-in force (or"pullback force" as pipes are pulled back from one side of the crossing to theother). The pullback force is the force required to overcome the frictionalresistance between the pipe and the borehole wall and the pipe and the groundsurface. In addition, the drilling mud creates an external fluid head pressure onthe pipe. The pipe must be sufficiently stiff to resist this pressure. After thepipe is installed, the loads are essentially radially directed pressures due tosoil weight, live-load and groundwater. The soil load will depend on thesoil-characteristics of the borehole. In some soil formations, the borehole isstable and does not deform thus acting much like a tunnel. In other soils, theborehole may deform and transfer soil pressure to the pipe. Where the soil has ameasurable internal-friction angle, the pressure is usually less than thegeostatic stress (prism load). This paper also discusses the calculation ofinstallation loads, post-installation loads, and pipe reactions for directionallydrilled pipes. Pipe reactions include longitudinal tensile strain, ring buckling,and ring deflection. Safety factors and allowable deflections are suggested forPE pipes. Includes 10 references, tables, figures.