Study On Theory & Technology Of Bio-Slope Engineering For Wenchuan Earthquake Area

"5.12" Wenchuan Earthquake which is the largest since the founding of the People's Republic of China have caused tremendous losses in the lives and properties of the people. Numerous landfalls,landslides,mudslides and other disasters are created in earthquakes and the vegetation on the slope are severely damaged.To manage these disasters and restore the ecological effectively in the reconstruction of the disaster area is one of the most important tasks.The soil shearing strength and slope stability can be improved by vegetation root system which has been confirmed by many investigators. A survey in the earthquake affected areas shows that although serious damage has been caused to the vegetation on the slope, the damage to the vegetation on the bottom of the ramp accumulations is relatively minor and most damage is caused by the destruction or the covering of the upper slopes which also shows that vegetation can increase the stability of the shallow slope.The situation of Wenchuan earthquake is introduced in this paper first chapter,the destructions of different types of slope supporting were analyzed and the slope supporting type helps greatly to aseismic is concluded.More researches on stability analysis of shallow slope with vegetative protection under seismic load are made by domestic and foreign researchers, but all researches are analyzed with limit equilibrium method basing on Mohr-Coulomb theory in fact that vegetative protection is flexible protection, when the shearing stress reaches the critical state, the slope with vegetative protection displaces continuously to maintain the stability of the slope. Therefore, the safety factor obtained through the limit equilibrium method will be small. In this paper, method of energy approach is used to analyze the stability of the slope with vegetative protection under seismic load the displacement of the slope with vegetative protection is taken into account so that the safety factor concluded will be reasonable.The numerical analysis software Ansys is used to make a time-history analysis on the slope with vegetative protection. Solid boundary is used all around the model and the acceleration time-schedule is served as dynamic loads basing on which locomotive acceleration response and the displacement variation of the model the effects of roots on the stability of the slope under seismic load and other situations when the earthquake is happening are researched. The average minimum safety factor of the slope with vegetative protection is figured out respectively with both limit equilibrium method and energy approach method and then be compared.Finally, comprehensive protection methods more situable for seismic slope are put forward according to the location, gradient,height,the situation of the destruction after the earthquake and different global stabilities of the slope along the highway in earthquake-stricken areas in wenchuan.