Key Factors Affecting the Deformation and Failure of Surrounding Rock Masses in Large-Scale Underground Powerhouses

Table 1

Overview of large-scale underground powerhouses in southwest China [1–11].

Project name	Basin	Dimensions of the main powerhouse (length × width^a × height (m))	Lithology of the surrounding rock mass	Overburden depth (m)
Wudongde (left bank)	Jinsha River	333 × 32.5 × 89.3	Limestone, marble, and dolomite	280–550
Baihetan (left bank)		438 × 34 × 88.7	Basalt	260–330
Xiluodu (left bank)		400 × 31.9 × 71.5	Basalt	340–480
Xiangjiaba		255.4 × 33.4 × 85.5	Sandstone	105–225
Lianghekou	Yalong River	275.94 × 28.4 × 66.8	Sandstone	410–560
Jinping I		276.99 × 28.9 × 68.8	Marble	160–420
Jinping II		352.4 × 28.3 × 72.2	Marble	231–327
Guandi		243.4 × 31.1 × 76.8	Basalt	420
Ertan		242.9 × 30.7 × 55.7	Orthoclase	250–350
Shuangjiangkou	Dadu River	198 × 29.3 × 63	Granite	421–598
Houziyan		219.5 × 29.2 × 68.7	Limestone	400–660
Changheba		228.8 × 30.8 × 73.35	Granite	285–480
Huangjinping		204.3 × 28.8 × 67.3	Granite and diorite	<290
Dagangshan		226.6 × 30.8 × 74.3	Granite	390–530
Pubugou		294.1 × 30.7 × 70.15	Granite	200–360
Xiaowan	Lancang River	298.1 × 30.6 × 86.43	Granite and gneiss	380–480
Nuozhadu		418 × 29 × 77.8	Granite	184–220

Note.^aThis width is the width above the rock anchor beam.