Deformation Feature Of Subgrade And Cutting Stability Analysis Based On The Claw Ditch Topography

Mountainous freeway commonly has many prominent characteristics, such as complex geologic condition of cross-over areas, various shapes of deep cut and high fill, and so on. Based on Sichuan freeway from Nachong to Guangan of claw ditch topography, research on deformation of subgrade and high & steep cutting stability are carried out.Firstly, for changeable height of landform and thick soft soil, deformation problem of subgrade is studied. From the start of engineering geological factors, physical and mechanical characteristic of soil parameter, then by monitoring outcomes of subgrade experimentation site, subgrade deformation and pore water dissipation course are stuied ,and eventual deformation post-construction settlement are discussed by hyperbolic prediction. By applying FLAC and site monitoring, deformation and stability of subgrade are studied, and mechanism of geo-grid is introduced when adopting geo-grid or not. At the same time, subgrade deformation and pore water dissipation orderliness are analyzed by PDSS numeric analysis theory when adopting plastics drainage plate or not.Secondly, as for earlier hazard of rock slope freeway construction, matter element model based on AHP is applied to build rock slope stability analysis method. The engineering examples analyze typical rock slope synthetic stability. Fundus-friction resembling model experiment has been done to reappear the whole failure process of the high rock slope and preview its instable mode or condition. Site experiment and FLAC numerical analysis are carried on, in order to study whole stability and deformation character in the condition of excavation and effects of strengthening and protecting measurements.The innovation of this thesis lies in one new uncertain stability grade appraise method of rock slope, namely, method of matter element model based on analytic hierarchy process(AHP). AHP is adopted to establish weight aggregation, and the grade of its optimum order is brought out according to the synthetic relational degree. Corresponding analytical program is made. The result of the appraise is in accord with the survey on site, offer economical, reasonable, reliable theoretic basis for strengthening and protecting measurements of the high & steep cutting. The method can be popularized in other engineering problems.