Seismic Fragility Analysis of the Reinforced Concrete Continuous Bridge Piers Based on Machine Learning and Symbolic Regression Fusion Algorithms

Table 9

of column pier vulnerability curve.

Direction	IMs	Damage states
		DS1	DS2	DS3	DS4
Transverse	Machine learning and symbolic regression fusion algorithms	0.385	0.375	0.372	0.371
	Single	1.257	1.246	1.242	1.240
	Kiani	1.362	1.355	1.353	1.352
	Lv Dagang	1.455	1.431	1.423	1.420
	Liu Tingting	1.271	1.265	1.262	1.261
Longitudinal	Machine learning and symbolic regression fusion algorithms	0.112	0.106	0.105	0.105
	Single	0.867	0.834	0.827	0.825
	Kiani	1.145	1.126	1.122	1.121
	Lv Dagang	1.141	1.066	1.052	1.047
	Liu Tingting	0.919	0.882	0.875	0.873

Note. DS1, DS2, DS3, and DS4 represent four types of damage states: slight damage, moderate damage, severe damage, and complete damage.