A Numerical Study of Underground Cavern Stability by Geostress Characteristics

Table 1

Layout of three main chambers (unit: m).

Characteristic	Chamber
	Main power house	Main transformer chamber	Tailrace surge chamber
Excavation span of crown	28.30	18.00	20.00
Excavation height	67.05	26.50	80.20
Rock pillar thickness	43.00	43.00, 42.00	42.00