Prediction and Mitigation of Instability in Ultra Long Drilling Shaft Lining Structures Using the Cusp Catastrophe Model

This paper deals with the stability prediction of an ultralong drilling shaft lining structure and how to mitigate its structural instability.Based on catastrophic characteristics of the instability process, the catastrophe method and a cusp catastrophic model is applied in analyzing the instability optimization measure.The process and mechanism of catastrophe instability is analyzed, and its corresponding instability criterion is founded.A case study and numerical results show that this optimization measure can increase its critical depth by 45% and mitigate structural vertical instability, which provides a theoretical possibility for the stability control technology of ultra long shaft lining structures.