Safety State Evaluation Method Based on Attribute Recognition Model for Ancient Timber Buildings

Table 3

Safety grade classification for wood column.

Safety grade	Evaluation indexes
	Decay	Insect attack	Crack	Bending degree
		No insect holes along the length, no hollowing sounds while knocking	No penetrating cracks along its longitudinal direction; maximum depth of crack
		No obvious insect holes along the length, no hollowing sounds while knocking	No penetrating cracks along its longitudinal direction; maximum depth of crack between and
		Has obvious insect holes along the length, no hollowing sounds while knocking	Penetrating cracks along its longitudinal direction exist; maximum depth of crack
		Has obvious insect holes along the length, hollowing sounds are heard while knocking	Penetrating cracks along its longitudinal direction exist; maximum depth of crack between and

is the percentage of decayed area of cross section; is the column diameter; is the column height.