Application of High-Strength Lightweight Concrete in Gob-Side Entry Retaining in Inclined Coal Seam

Table 2

Orthogonal table L₉ (3⁴).

Test number	Factors
	A	B	C	D
1	I	I	I	I
2	I	II	II	II
3	I	III	III	III
4	II	I	II	III
5	II	II	III	I
6	II	III	I	II
7	III	I	III	II
8	III	II	I	III
9	III	III	II	I
I	KAI	KBI	KCI	KDI
II	KAII	KBII	KCII	KDII
III	KAIII	KBIII	KCIII	KDIII
R	RA	RB	RC	RD