Borehole Stability Research on Weihe HDD Crossing

In the last 20 years, with the improvement of horizontal directional drilling (HDD) crossing technology, it has become a popular and increasingly viable method for infrastructure installation in different areas within the construction industry, such as natural gas, electrical power and communication industries. Based on Geotechnical Generalized Plastic Mechanics, establish the stability model of borehole that is multilevel reamed with finite element method (FEM), a case is studied on Weihe HDD crossing of west-east gas pipeline engineering second-line. In the research, the tensile and shear failure criterion of geotechnical material is set simultaneously. Through the dynamic simulation of the shear and tensile stress, not only the stability judgment and instability failure process but also a mechanical estimate method to the stability of borehole could have been gotten, and the paper presents a suite of the precautionary measures. For the reaming and pipeline lying safely, the available numerical solutions supply theoretical basis and technical support.