Static Analysis For High Fill Loess Slope Strengthened By New Compositional Retaining Structure

The development of the economy in China demands more and more construction land.There is large loessal mountainous area in northwest part.The construction space for the infrastructure of cities and transportation in this area is in shortage day by day.Cutting hills and filling ravines is an effective means to create land space.Along with cutting hills and filling ravines,a large number of filling slope projects will be encountered.Compared with previous slope engineering,the filling slope engineering appeared in recent years has the characteristics of steep slope ratio,high height and large filling volume.Slope engineering itself contains the influence of complex factors such as rock,soil,structure,geology,and so on,which results into frequent engineering accidents.Therefore,today's slope engineering has put forward higher requirements for slope reinforcement design.There are many kinds of supporting structures for strengthening slopes.However,when applied to high fill slopes,the single traditional structure type does not meet the requirements of deformation,displacement and slope stability.Aiming at high fill slope engineering in loess area,through putting forward a theory,conducting a field monitoring test,and analyzing a numerical model,this paper introduces and deeply analyzes the design theory and working mechanism of a new structure,fame with prestressed anchor-plate.Taking an actual high fill loess slope as background,the strengthening effect of the compositive retaining structure,frame with prestressed anchor-plate and sheet-pile wall with prestressed anchor cables is comprehensively studied,analyzed,and evaluated.The results provide a guidance for similar high fill loess slope engineering.The main research contents and conclusions are as follows:(1)Aiming at present problems in high fill loess slope engineering,the design theory of the new structure,frame with prestressed anchor-plate,was put forward,which includes the design method and stability calculating method of frame with prestressed anchor-plate are given.The rationality of the method was verified by applying numerical simulation methods.(2)The finite element analysis model was established,and the stress distribution of anchor-plate during filling construction was studied by numerical analysis method,so as to reveal its working mechanism.The results prove that the frame with prestressed anchor-plate has a good reinforcing effect on filling slope,and rational suggestions are made for the design and application of the structure.(3)Through on-site monitoring tests of practical engineering,the distribution law of earth pressure on a pile of the sheet-pile wall,the axial force development law of anchor cable were studied and analyzed,which provides a guidance for high fill loess slope engineering applying sheet-pile walls with anchor cables.(4)After field sampling,indoor geotechnical tests were carried out to obtain the fill's parameters for the numerical analysis model of the high fill loess slope strengthened by the compositive retaining structure,frame with prestressed anchorplates and sheet-pile wall with prestressed anchor cables.The influence of environmental factors in the field on soil parameters in different areas was analyzed.The numerical analysis of the high fill loess slope model proves that the unique advantages of prestressed anchor-plates and the structure's good effect for strengthening the slope cooperated with sheet-pile wall with prestressed anchor cables.