| The geological condition in Jinping I Hydropower Station is complicated. In these areas, the slope is steep and accompanies with drastic superficial action. The problem with high slope stability there is significant. The inside slope of intake diversion canal of Jinping I Hydropower Station is an important part of the whole project and it is vital for the stability of project construction. The combination methods of prototype investigation and indoor analysis, mechanism analysis and simulation studying have been used. On the basis of investigation of the deformation damage phenomena disclosed in the excavation process, the slope monitoring analysis, calculation of limit equilibrium and slope numerical simulation etc, the inside slope of intake diversion canal of Jinping I Hydropower Station stability has been analysis and the support measures has been analyzed. These will make sure the slope long-time stability. The acquired results are as follows:(1) On the basis of the engineering geological condition investigation, combined with the slope excavation, the rock mass structure characteristic of the inside slope of intake diversion canal have been fully studied. These include fault, interlayer extrusion belts and joints of engineering geological character and quality; and. carried out on the slope rock mass quality classification. Then, the rock mass structure model of the slope has been established.(2) Based on the failure traces of slope, considering the characteristic of rock mass structure, the mechanism of deformation and the mode of deformation is analyzed.(3) Inferred from the monitoring data analyzed result, the slope deformation mainly caused by lower elevation slope excavation unloading. During the excavations, the displacement fast increased. But, along with the supporting measure implemented and the excavation finished, the displacement velocity has been obviously lowered, and tended to stable.(4) The overall stability of the excavated slope has been analyzed by using numerical simulation. The result is that the deformation of the whole slope is small and the surface of excavation is towards the outer face slope. After taking some measurements, the displacement decreases compared with the condition without measurements. The displacement history id of the model shows that the slope goes towards the inner of the slope. The monitoring data also showed that the real displacement is decreased with the time and some parts of slope have deformation towards the inner slope. The modeling is according to the real monitoring data.(5) The stability of different operating modes has been calculated by using limit equilibrium method on the typical section of excavation slope and post-support slope. The result is that the stability coefficient of post-support can basically satisfy the requirement of engineering specifications。Taking into account the stability of the upstream side natural slope and the slope after partial collapse, it is recommended that the support of the upstream side natural slope and the slope after partial collapse should be strengthened.(6) Several aspects of the above studies have shown that the inside slope of intake diversion canal of Jinping I Hydropower Station is on the stable situation after the excavation and supporting finished, which will satisfied the engineering demand.
|
PDF Full Text Request