Stability Analysis Of Composite Retaining Structure Of Multistage High Fill Slope

In recent years,due to the adjustment of national economic strategy,the process of infrastructure construction in Northwest China has been accelerated,and more and more engineering projects have been carried out,along with the emergence of many high fill slopes.Because of the particularity of its stress mechanism,the high fill slope is very easy to lose stability and cause serious engineering accidents.However,due to the complexity of its own situation,people's research on it is seriously lagging behind,lacking of relative system and mature reinforcement theory and measures.At present,the research of high fill slope support engineering is mostly under the assumption of idealization,which is quite different from the actual engineering.It is difficult to be applied in practical engineering.In view of this situation,based on the baidaoping unstable slope support project in Chengguan District of Lanzhou City,this paper starts with the composite support structure of the multi-level high fill slope,and makes a deep research on the reinforcement measures of the multi-level high fill slope.The main conclusions are as follows:(1)This paper sums up the existing theories of slope instability,uses the discounted landslide theory which is similar to the field situation as the calculation theory of the landslide thrust of the combined support structure,and then through the stability analysis and calculation of the original slope using straightening and slide software,determines the reinforcement measures in the case of insufficient stability of the original slope,and different support The scheme is compared and optimized.(2)The optimized composite support structure is designed and calculated by straightening and slide software,and then simulated and analyzed by FLAC3 D.It is discussed that(1)the displacement of the supporting structure changes with time and space from the initial stage of filling to the completion of filling;(2)the influence of prestressed anchor cable on the axial force and bending moment of the pile body of the supporting structure after the completion of construction.(3)The distribution of bending moment of pile body with different time and position.(4)the distribution of the horizontal thrust of the composite support structure at different time and position,and the horizontal earth pressure of the rock and soil mass on the pile sheet wall are compared and analyzed.(5)The difference and connection between the potential slip surface area after support and the potential slip surface area before reinforcement.(3)Through the detailed introduction of the application engineering examples of the multi-level high fill slope composite support structure,from the stability analysis and calculation of the original slope to the optimization of the support scheme,as well as the detailed and systematic elaboration of the support design,construction,inspection and acceptance scheme formulation and specific implementation measures of the optimization scheme.(4)Through the field health monitoring of multistage high fill slope support structure.This paper mainly analyzes the following aspects:(1)the effect of automatic health monitoring on the high fill slope support engineering in the construction process,the later operation stage and the later continuous research.(2)The influence of the anchor cable tension on the composite support structure and the overall stability of the slope.(3)In the process of slope reinforcement,the displacement,velocity and acceleration of composite support structure are analyzed.(4)the change rule of prestressed anchor cable in the process of primary and secondary tensioning(5).The working stages of pre-stressed anchor cable of composite support structure are divided and the change characteristics of the tension of anchor cable in each stage are analyzed.