Analysis of Cusp Catastrophic Model for Vertical Stability of Drilling Shaft Lining

Table 2

Analysis comparison table between catastrophe model and finite element calculation.

Catastrophic calculation model									Finite element calculation
H (m)	Hw (m)	E (GPa)	I (m^4)	qc (10^5 N/m)	qw (10^5 N/m)	Hcr (m)	Judgment criteria	Conclusion	First-order eigenvalue	Second-order eigenvalue	Conclusion
28.275	13.4	45.247	114.9	4.211	3.770	593.48		Stable	−937.190	−937.190	Stable
216.275	55.203	45.105	141.134	5.45	3.316	588.95		Stable	24.493	24.493	Stable
361.275	89.800	42.54	142.718	5.378	3.23	583.10		Stable	5.40050	5.40050	Stable
505.275	171.064	40.76	138.46	5.105	3.364	568.69		Stable	1.98960	1.98960	Stable
565.275	216.739	40.12	134.47	4.947	3.428	566.83		Stable	1.44130	1.41130	Stable
659.675	291.703	38.85	139.66	4.69	3.51	557.12		Unstable	0.90531	0.90531	Unstable