Construction control for engineering geologic body of underground power house chambers

Jiangya underground powerhouse has 33 chambers in different size. Due to the complicated chamber structure and stress state, as well as unfavourable geology structure, the construction is difficult. In order to guarantee the safety in construction and the stability of the chambers, according to the control theory of engineering geologic body, the systematic and comprehensive analysis on the rockmass in the whole construction zone and its environment was carried out and the purpose and means of construction control were determined. In the light of influence extent of the unfavorable geology on the different chambers, the different control ways were taken before, during and after excavation. To some important position, precontrol measures were taken, i.e. carrying out strengthening treatments before excavation. In the process of excavation, the related departments strengthened construction monitoring and feedback control to the whole engineering rockmass, optimized the design successively to guide the construction, guaranteed the safety in construction of the chambers at last.