不同直径对非开挖近孔壁位移响应数值分析

非开挖水平定向钻进敷设管道的质量直接受到水平孔壁的位移特征影响，而水平孔直径则是影响孔壁位移的重要因素之一。采用快速拉格朗日的计算方法，利用Mohr—Coulomb准则对粘土地层中不同直径条件下的近水平孔壁位移响应特征进行了数值计算分析。获得了在不同钻孔直径（0．6-1．6m）条件下近水平孔壁X、Y和Z三个方向的位移矢量、应力分布数据。分析结果表明，随着水平钻孔直径的不断增加，近孔壁各点的Z位移也不断增加，其中水平孔下部各点Z方向变化更为明显。同时，位移变化区域随着环形区域的不断向外扩展，增加幅度不断降低。因此，合理控制施工的终孔直径对于减少孔壁位移扰动具有重要意义。

Horizontal Borehole Displacement Analysis Based on Drilling Diameter

The quality of pipeline construction with Horizontal Directional Drilling is affected by the displacement of the borehole, and the drilling borehole diameter is one important reason which affects the horizontal borehole displacement. The method of Fast Lagrangian Analysis of Continua and the rule of Mohr-Coulomb are introduced in this paper. The author analyzes the pipeline construction in clay stratum by FLAC3D. 3D Displacement and stress distribution near the surface of borehole have been got under different drilling diameter （0.6-1.6m）. As the result shown, z displacement is increasing coupled with the drilling diameter increasing. Especially for the points at the bottom of borehole, z displacement increases more than any other parts. Typically, z displacement increases less coupled with the distance increases between the center and any point. That means, final drilling diameter control is one key which can keep the horizontal borehole stability.