油气管道穿越黄土冲沟的管线设计参数研究

长输油气管道经过黄土冲沟边坡时常常采用斜井穿越的方式，采用数值强度折减法与实际地形建模结合的方法，以陕西千阳黄土冲沟边坡为例，通过对黄土力学参数的不断折减，以收敛性准则作为边坡是否产生滑动的破坏判据，根据边坡滑动时的位移等值线图确定了边坡潜在滑动面的形状及位置，确定了管线穿越斜井的初始安全设计参数；基于初步设计参数研究了管线斜井开挖过程中井周土体的位移变化规律，并对斜井开挖后黄土冲沟边坡的稳定性安全系数进行了进一步分析计算。分析结果表明，所给出的管线穿越斜井设计参数的确定方法，能在设计阶段有效避开冲沟边坡潜在滑动区，基于这种设计参数使得管道斜井施工对边坡稳定性影响很小，边坡安全系数由1.162变为1.156，变化不大。根据计算结果，对斜井支护区域也提出了合理的建议。

Study of design parameters of oil-gas pipeline traversing loess gully

In order to set the pipeline out of the hazard zone, the numerical strength reduction method and actual landform simulating method are used to evaluate the position and shape of the landslide of Qianyang loess gully. In the process of simulation, convergence is chosen as the failure criteria. By reducing the strength parameters step by step, the surface of the landslide is decided according to the displacement isoline when the landslide happens. After the parameters of the pipeline traversing the loess gully is designed, the distribution of displacement in the loess around the well while excavation and the stability of the slope after excavation are studied. The results indicate that the method given in for designing the parameters of the pipeline traversing the loess gully can set the pipeline out of the hazard zone effectively; and the construction of the pipeline will affect the safety of the slope little. The change of the safety parameters after exaction is not obvious, which is from 1.162 to 1.156. At last, some reasonable advices for support are given based on the numerical simulation.