The Analysis Of The Deformation Characteristics And The Stability Of A Talus Slope Under Strong Earthquake

Sichuan Zipingpu water conservancy project, located in the upper streanm of the Min Jiang River, is a large scale project with comprehensive functions like power generation, flood prevention, and with the main function of irrigation and water supply. After the key water control project was completed, the sections from YingXiu town to MaAnshi tunnel of the original National Road No.213 had all been inundated and changed line. The talus slope of JiZhong village XuanKou town locate in the left bank of ShouJiang great bridge of the 213 national highway realignment engineering of the surrounding area of the ZiPingpu hydraulic engineering and its deformation signs are obvious under the influence of the public highway slope excavation. The distance from the talus slope which is deeply covered to GuXi ditch which is the tiny view epicenter of WenChuan earthquake is only 5.7 km. The talus slope's deformation characteristics are obvious but it didn't lost lost its overall instability after the earthquake. The research value of the deformation characteristics and the situation of the stability of the accumulation body which is deeply covered under the influence of the strong earthquake is enormous.The paper studied the engineering geological conditions of the venue, and identified the deformation mechanism which is named creep-rupture of the talus slope by analyzing the phenomenon and characteristics of the talus's deformation and failure before WenChuan earthquake. The creep-rupture is multi-level , and the total deformation volume is 200000~320000 m3. The paper selected borehole inclinometer as the main monitoring instruments, five measured slant-hole have layout to monitor slope deformation in both longitudinal section 1-1' and 3-3'. The apparent slope dislocation position be revealed by monitoring results and the potential sliding surface of the slope is determined. the slop before the earthquake major move to the slope outside and to Shoujiang River along the longitudinal section 1-1', the deformation of the slope of the upper is obviously to the deformation of the downstream side. The deformation of the slop after the earthquake is increase along the body surface dislocation before the earthquake and the deformation is large. The displacement of 7mm before the earthpuake increased to 204mm after the earthquake of the lalnt-hole orifice INSJ-2a. The displacement of 1mm before the earthpuake increased to 126mm after the earthquake of the lalnt-hole orifice INSJ-5. The displacement increases with the height, the location of potential slide surface was not obvious, and deformation characteristics is dump, the development of deformation of talus is slow and the deformation effect of talus after shocks is not great.The establishment of three-dimensional numerical model, using FLAC3D on a variety of conditions before the earthquake in which slope of the accumulation of numerical simulation, analysis and evaluation of the accumulation of a variety of conditions in the slope of the deformation characteristics and the stability of the situation. The role of the slope with the accumulation which under the earthquake of ??rical simulation, from the acceleration response characteristics of the incremental shear strain characteristics, distribution of plastic zone, deformation characteristics of the various aspects of the accumulation of overburden to expose the deep slope in the strong ground motion under deformation characteristics and the stability of the state. Numerical simulation results show that the strong role of surface monitoring points downhill relative acceleration input PGA venues are a phenomenon of shrinking. Low-elevation monitoring sites department to reduce the phenomenon of acceleration is more distinctive than high elevation department acceleration to significantly reduce the number of phenomena, suggesting that the accumulation of deep cover body can be a very good energy absorption of seismic waves, which explains very well in such a strong earthquake loads slope accumulation of the reasons there is no instability.The use of limit equilibrium theory based on the transmission coefficient on the stability of rock and soil shear strength parameters and the sensitivity of seismic intensity analysis to determine the stability of parameters suitable for calculating the three selected for the stability of the calculation section , to analyze the various conditions calculated the potential profile of the stability condition of sliding surface. Analysis results show that the combination of heavy rain loads downhill body + earthquake is likely to instability, it is recommended that a further addition of an excavated slope cable to strengthen the support to ensure the safety of 213 National Road running smooth.