Stability Analysis Of Typical Loess Landslide In Heifangtai Based On High-precision Monitoring Information

The area of loess in my country accounts for about 6.6% of the total land area.Due to the particularity of the loess structure,it is prone to landslide disasters under the influence of its own movement and deformation and the external environment,which has caused serious harm to the sustainable development of regional social economy and the safety of residents' lives and property.Therefore,carrying out research on the stability of loess landslides has important practical significance for landslide disaster prevention and mitigation.The research and analysis of landslide stability has always been one of the difficulties and hotspots in the engineering field.However,most of the current landslide stability studies are mostly numerical simulations under different working conditions.The lack of adequate consideration of the external monitoring information of the landslide body is an important indicator of the internal deformation and instability of the landslide,which will lead to the existence of the stability evaluation results and the real situation.difference.In response to the above problems,this paper selects the typical loess landslide area in Heifangtai,Gansu,my country as the study area,taking into account the high-precision monitoring of the external deformation information of the landslide body and using this as a constraint,while considering the significant external influence factors(precipitation,irrigation,groundwater effect)influence,by establishing a reasonable landslide stability analysis model,the deformation and development process of the landslide body is analyzed,and a reasonable evaluation of its stability is made.The main results of the thesis are as follows:(1)Taking into account the characteristics of the geological structure of the Heifangtai loess landslide,combined with UAV image data,a finite element stability model of the research domain was constructed,which quantitatively revealed that rainfall has a strong disturbing effect on the top of the loess landslide.The disturbance effect of the middle and bottom of the slope is less;the irrigation factor has a stronger infiltration rate than the rainfall,which can increase the saturation of the loess landslide,reduce the shear strength of the loess landslide,and easily promote the landslide movement;the effect of the groundwater level change is compared with that of the rainfall It has a stronger disturbing effect with irrigation factors and is the most important external factor to promote the development of landslides.(2)According to the characteristics of the actual geological structure and activity of the Heifangtai loess landslide,the Beidou/GNSS high-precision monitoring network for typical landslide bodies in the region was deployed,and the landslide body length time-series highprecision displacement data were obtained,and the support vector machine-based Particle swarm and genetic algorithms have carried out in-depth analysis of high-precision monitoring data and high-precision prediction of deformation trends,laying a solid foundation for the subsequent construction of landslide stability model and stability analysis under high-precision monitoring deformation constraints.(3)The finite element stability analysis model of the landslide under the constraints of high-precision monitoring deformation information was constructed,which finely described the internal stress,strain and stability changes of the slope during the development of the landslide,and further combined the influence of external hydrological factors(precipitation,irrigation,groundwater),and obtained the characteristics of the influence of water content changes on the internal stress and stability of the landslide.The research results have important theoretical reference value for the in-depth understanding of the formation mechanism and stability of typical loess landslides.