Field Experimental Study on the Broken Rock Zone of Surrounding Rock and the Rock Borehole Shear Tests of the Large Deformation Tunnel

Table 2

The results of borehole shear tests.

Number of measuring points	Normal stress (MPa)	Shear stress (MPa)	Number of measuring points	Normal stress (MPa)	Shear stress (MPa)	Notes
#1	0.5	0.35	#2	0.5	0.3	DK41 + 990
	2.5	0.9		0.8	0.45
	3.7	1.3		1.4	0.6
	4.9	1.5		2	0.7
Cohesion force	232.6 kPa		Cohesion force	210.5 kPa
Inner friction angle	15.05°		Inner friction angle	14.42°
#3	0.5	0.3	#4	0.6	0.35	DK42 + 000
	1.1	0.6		1	0.5
	1.8	0.7		2	0.7
	2.5	0.85		2.8	0.9
Cohesion force	231 kPa		Cohesion force	228.7 kPa
Inner friction angle	14.5°		Inner friction angle	13.5°