Abstract Based on the monitoring data statistical results,the surrounding rock mass displacement magnitude distribution and spatial distribution in underground powerhouse chambers are analyzed. Taking the generator chamber for example,by means of geological information combining with excavation and construction progress, the effects of geological factors and excavation factors on the displacement are analyzed from the aspects of displacement,in-depth laws and strain rate,and the interaction between the two kinds of factors are analyzed. The research results show that:(1) The large displacement positions concentrate in the rock-anchored beam site and downstream side walls. (2) The effect of faults on upstream parts is not obvious,and the displacements are quite different between with or without faults zone. The nearby cross-site construction has a great impact on downstream displacement of surrounding rock,and the construction factors enhanced the impact of geological factors. (3) The displacement is the result of a variety of factors,and the geological factor and excavation factor are the main reasons of displacement appearing and development. (4) The law that the displacements of positions of poor geological conditions are larger is not entirely correct,and the inappropriate construction would intensify the effect of structural surface to cause a great displacement. Even in the case of non-structural surface,the inappropriate construction can also cause large displacement of surrounding rock. (5) Generally speaking,the displacement of locations with faults crossing performs as "open" displacement,and the displacements in the structure of surface area with faults crossing are different obviously. The law that the impact of faults on displacement is complex and diversity,and it has relations with the faults? intensity and location. The blasting is one of the primary means of excavation,and its technical study has a great academic value and economic significance.
|
Received: 03 March 2010
|
|
|
|