Research on Construction Optimization of Three-Connected-Arch Hydraulic Underground Cavities Considering Creep Property

Table 5

Comparative table of phase-excavation surrounding rock stress in different construction methods.

Construction method	Maximum pressure stress (MPa)	Maximum tension stress (MPa)	Ratio
Side cavity method	2.04	0.58	3.52
Middle cavity method	2.04	0.16	12.75
PBA method	3.30	0.26	12.69