Study On Tunnel Groups Excavation Influence Of Left Abutment Adits On Deformation And Stability Of Dam Shoulder Slope For Jinping â…  Hydropower Station

Jinpingâ… Hydropower Station dam engineering geological environment is complicated, complex valley slope, slope strongly Epigenetic Reformation, and exposure of the breakdown of deep fractures, and their high rock slope stability for the left slope construction period and operation period of great significance. Left slope based large-scale cavern excavation, resulting in reconstruction of the left bank of the stress, and the support of the left bank abutment rock slope has a softening effect. In this paper, an overview of engineering geological conditions of the left bank, based on careful study of the structural features of the left bank abutment slope, and then analyzes the left bank of the abutment slope deformation and failure characteristics and mechanisms. On this basis, three-dimensional finite element simulation software, on the slope of Jinping Hydropower Station abutment excavation in foundation caverns and caverns under the two schemes do not make the sensitivity of excavation compared. As long as the research results are as follows:(1)According to preliminary geological survey data, combined with the geological conditions of construction review of data to study the slope of Jinping Hydropower Station abutment structure of the rock, revealing the original structure of surfaces, such as lamprophyre veins (X), and construction structural surface, such as f5, f8, f42-9 in the development characteristics, and were described its slope deformation and failure of border control significance.( 2 ) According to the left bank abutment slope engineering geological environment, combined with early exploration and later review of the engineering geological conditions, slope deformation and failure characteristics, and construction of monitoring data, carried out on the abutment slope deformation and failure mechanism and mode of analysis, produce the "compression - expansion - crack" failure mode.(3)Using three-dimensional elastic-plastic finite element analysis, revealed the left bank abutment slope dug caverns in the basic process of dealing with the stress, deformation evolution and characteristics. By comparing the caverns excavation and assumes no excavation by three dimensional elastic-plastic finite element analysis results show that: caverns excavation for the f42-9 footwall deformation is more significant than its effect on the plate deformation ; on weathering unloading strong deformation of the soft rock higher than the rock strength; with the excavation process, caverns excavated slope deformation on the abutment level gradually decreased.(4)Value Type Modular by tracking feature points of deformation can be seen, the left bank of the basis of caverns excavated on the left bank abutment little effect on the stability of slope deformation, deformation convergence; based chamber group on the abutment slope deformation the general impact of the total deformation of 5 ~ 14%; the affected areas mainly in the f42-9 and its footwall near the fault region.