Corrosion Investigation of Rock Anchors Served over 10 Years in Underground Powerhouse of a Hydropower Station

Table 2

Groundwater aggressivity in the drainage galleries near the tailrace surge chamber.

Item	1^st floor gallery		2^nd floor gallery
	Sample 1	Sample 2	Sample 1	Sample 2
pH	7.41	7.75	7.86	7.99
HCO3^− (mmol/L)	2.10	2.13	2.85	2.95
Mg^2+ (mg/L)	3.930	3.315	8.915	10.890
SO4^2− (mg/L)	66.510	59.858	77.888	88.131
Cl^− (mg/L)	14.679	9.986	14.724	17.628