| Since the impoundment of the three gorges reservoir in 2003,the impoundment and operation of the reservoir have become the main and important inducing factors of the wading landslide in the Three Gorges Reservoir Area.There are more than 2,000landslides of different sizes under the influence of 175 m reservoir water level in the Three Gorges Reservoir area,among which there are more than 80 super-large landslides larger than 1 million m3.Some comprehensive measures combine slope-cutting with backfilling,drainage and supporting have been adopted to reinforce the large-scale and thick talus landslides affected by water level fluctuation of Reservoir.Hence,it is necessary to put forward a suitable method to optimize the slope-cutting schemes of the huge thick landslides on reservoir banks.In this paper,the typical hydrodynamic pressure giant landslide in the Three Gorges reservoir area is taken as the research object,and the transfer coefficient method considering the influence of hydrodynamic pressure is improved.On this basis,the typical hydrodynamic pressure giant landslide,Shuping landslide,is taken as an example to study the scheme of slope-cutting.The main contents and achievements of this paper are summarized as follows:?1?The basic principle of the calculation of the factor of safety and the residual sliding force by the transfer coefficient method is introduced.The different expressions of the transfer coefficient method in the case of separate calculation and consolidation of soil and water are discussed.The concept and physical meaning of the hydrodynamic pressure are clarified.The concept and physical meaning of hydrodynamic pressure are clarified,and the hydrodynamic pressure is separated from the seepage force.Based on this,the transfer coefficient method is improved to take into account the influence of hydrodynamic pressure.?2?Based on the study of the optimization of the slope-cutting scheme for the typical huge landslide in the Three Gorges Reservoir Area,the design and optimization ideas of the slope-cutting scheme is determined,which is as follows:Firstly,the working condition of the slope-cutting is determined according to the type of landslide.Secondly,the improved transfer coefficient method is used to calculate the factor of safety and the residual sliding force of the landslide,and the residual sliding force curves of different periods during the sudden drop of reservoir water level are drawn.The approximate location of the slope cutting is determined by the residual sliding force curves.Thirdly,according to the landslide morphological characteristics and local stability requirements,the main control factors and optimization scope of the slope-cutting scheme are determined.Fourthly,the uniform design method is used to design the slope-cutting scheme,and the slope cutting scheme to be optimized is obtained.Finally,the factors of safety of each slope-cutting scheme are calculated by improved transfer coefficient method,and the slope-cutting schemes are optimized by the integrated method of Neural Network and Genetic Algorithm.The optimal slope-cutting scheme,which meets the design safety factor and has the smallest slope-cutting square,is obtained.?3?Taking Shuping landslide,a typical hydrodynamic pressure landslide in the Three Gorges Reservoir area,as an example,according to the design method and optimization idea of the slope-cutting scheme in this paper,the optimal slope-cutting scheme is obtained:The slope i1 of AB is 2.549,the abscissa xb of B is 520.9 m,the slope i2 of CD is 1.763,and the safety factor is 1.201,which meets the requirements of the regulation.The slope i1 of AB is increased by 53.0%and the emergency treatment project is increased by 9.18%.Moreover,the slope-cutting volume is the smallest,which is 509526 m3.Compared with the existing emergency treatment measures,the slope-cutting volume is reduced by 66,248 m3.The result further proves the reliability of the optimization method of the slope cutting scheme in this paper. |
PDF Full Text Request