Research On Developmental Characteristics And Prevention Measures Of G1006Electric Tower In Jinping Hydropower Station

There’s a large number of under construction or proposed EHV transmission line project in the southwest vast mountainous areas, electric transmission towers are easily affected by the landslides and debirs flows and other geological disasters because of complex mountainous conditions, causing a huge threat to the safety of the transmission lines. By the end of August,2012, the slope of G1006electric tower in the left bank of Jinping hydropower station collapsed partially because of the heavy rain. The landslide made the foundation of the G1006electric tower exposed and the C leg suspended. What’s more, the landslide directly threatened the safety of the G1006electric tower and the transmission line.On the basis of engineering data and detailed field survey, starting from engineering geological conditions of the G1006, the landslide is partitioned and its development characteristics are researched in this paper. This paper also analyses its formation mechanism and induced factors,then some key points of electric tower location are concluded. The stability of the landslide is calculated and analyzed, its stability under natural and storm conditions are simulated by using FLAC3D, finally two measures are put forward and one is recomended. Here are the some important contents and achievements:1.According to landslide plane shape, spatial position and accumulation characteristics, it is partioned two areas:sliding wall area, landslide accumulation area, the characteristics of each region is described..2.On the basis of its formation conditions and predisposing factors, the formation mechanism and process is probed.Some key points of electric tower location are concluded.3.The stability of the landslide is calculated using limit equilibrium theory, the results show that it is unstable in storm conditions and consistent with the reality. Factor sensitivity analysis shows that the impact angle of internal friction slip surface for sliding stability is more sensitive than cohesion.4.The stability of the landslide under natural and storm conditions are simulated by using FLAC3D. It shows that it is stable and no displacement in natural condition, but unstable in storm condition and has a large displacement.5.Two countermeasures are put forward according to its characteristics and protected objects, the recomended one is active protection network, lattice frame anchor and lattice dam.