Experimental Study on the Complex Contact Frictional Property of an Ultralong Distance Large-Section Concrete Pipe Jacking and Prediction of Pipe String Stuck

Table 1

Comprehensive rock mass properties of the Guanjingkou pipe jacking project.

Stratum	E (GPa)	ρ (kg·m^−3)	μ	Φ (°)	c (kPa)
Dolomite	1.2	2500	0.30	31.3	0.60
Quartz sandstone	2.0	2500	0.32	31.0	0.40
Mudstone	1.7	2550	0.36	24.7	0.25
Siltstone and sandstone	2.0	2550	0.33	23.5	0.27