Long distance pipeline engineering of natural gas and oil faces the difficulty of traversing loess gully

which has a bad effect on the pipeline construction and operation safety. Based on Duncan-Chang nonlinear constitutive model

mechanical behaviors of slope and soil around inclined shaft have been studied systematically through numerical simulation method

when inclined shaft excavation method is taken to traverse loess gullies. The results indicate that: on the premise of that inclined shaft position is designed outside the most dangerous slide plane of slope

the distance between slope shoulder and inclined shaft entrance at slope top is closer

and the stability of slope and shaft excavated is superior. Aiming at probable situation of vault collapse in inclined shaft

based on numerical simulation analysis results under multiple work conditions

prediction formula for depth of vault yield zone is established by using response surface methods; which has good correlativity and can be used in support design of inclined shaft traversing loess gully or steep slope.