THE TEST AND ASSESSMENT OF CONSOLIDATION GROUTING IN RIVER BED DAM FOUNDATION OF XILUODU HYDROPOWER STATION

Xiluodu hydropower station is located on the Jinshajiang River, with a 285.5m high arch dam. The bedrock of the dam foundation consists of basalt, which can be dominantly classified as Ⅲ-1 class with some local distribution of disturbed Ⅲ-2 class. The average acoustic velocity of the bedrock is originally 4652ms-1, with about 28% being slower than 4000ms-1.After consolidation grouting treatment, the average velocity is greater than 5200ms-1, with less than 5% being slower than 4000ms-1.After treatment, the average velocity of the Ⅲ-1 class bedrock has reached 5300～5500ms-1, being increased by 2%～5%; the Ⅲ-2 class 4200～4700ms-1, being increased by 12%～18%; the disturbed belt 3600～4200ms-1, being increased by 10%～28%, respectively. The rock permeability are less than 3 Lu and the average borehole deformation modulus is 10-15GPa. Consolidation grouting has dramatically improved the geological condition of the Ⅲ-2 class rock mass and the disturbed belt, which has effectively improved the integrity and homogeneity of the riverbed dam foundation.