Area Of High Seismic Intensity On The Geotechnical Engineering Of Large Hydropower Projects Influence Of The Nature

2008, magnitude 7.8 occurred in Wenchuan, Sichuan earthquake, Wenchuan in China's major north-south seismic belt of the Longmen Shan fault zone which is very important seismogenic structure, history has repeatedly earthquake. After the earthquake, some media and experts attributed the occurrence of the earthquake in Southwest China's hydropower development. So, give the public raised the question:in general hydropower project on the geotechnical properties of high seismic intensity area impact is, in the end how much of the earthquake can induce it?Construction and operation of hydropower projects will significantly change the hydrogeological conditions of reservoir banks, thereby affecting soil stability. Analysis of its impact, many aspects, this paper mainly on the geological structure, rock structure, rock weathering, water immersion effect, the impact of groundwater and other aspects of research and elaboration.1. Tectonic effects, when the rock in the fractured reservoir water in the atmosphere or rain soaked, under the influence of fluctuations, the shear strength of fissure filling material dramatically reduced, rock will be unstable.2. Soil structure, slope of the rock and soil physical and mechanical properties will determine the extent of bank collapse, so that the slope degree of soil structure and the Collapse of the scope of bank collapse in a major internal factors. Under the same conditions, a variety of rock slope, with different shear strength, anti-erosion ability and disintegration, their bank collapse of the range, speed and type of control has some effect.3. Rock weathering and unloading of Rocky Bank stability is an important factor, rock weathering and unloading more intense development, Rocky Bank of the greater extent and scope of bank collapse.4. Reservoir after the water soaking water mainly in the role:the role of clay by softening and reduce soil strength; through shrinkage, swelling and disintegration, destruction of soil structure; through the pore water pressure effect, reducing soil effective in the destruction of the body surface of normal stress. Long immersion in the reservoir water, the soil stability of the corresponding lower part of the water front in a critical state of the sliding masses would be unstable deformation, instability and water before being deformed landslide will exacerbate deformation.5. Groundwater, mainly in the groundwater when the water level above the water table, surface water, groundwater recharge, resulting in the rapid water-filled earth and rock layers, resulting in flooding of the bottom layer, the intensity decreased, resulting in reservoir bank erosion and collapse.Reservoir induced earthquake is caused by the water storage reservoir area and reservoir water adjacent areas affected as a seismic phenomenon emerging, or existing significant changes in seismic activity. Since 1975 the First International Conference induced earthquake since the water storage reservoir through research and seismic activity related to rapid increase in instances of change. In which some activity (frequency, intensity) increased, some of these hundreds of cases of proven cases; activity has weakened a few examples of the vast majority of seismic activity after the reservoir water has not changed.