Monitoring And Stability Analysis Of Subgrade Deformation With High Filling Square

In recent years,China’s expressway construction has made outstanding achievements and achieved remarkable results.The total mileage of mountainous highways is also steadily increasing.High-filled roadbeds are often used as an important part of mountainous highways.However,due to their high filling,compression and settlement of fillings,Slope instability phenomenon frequently occurs.Therefore,ensuring the long-term stability of high-fill roadbed sections is of vital importance to Chinese road builders.Based on the load characteristics and natural environmental conditions of highways in mountainous areas of Hebei Province,combined with the construction of Chengchi Expressway in Hebei Province,this paper proposes an appropriate observation method for roadbed settlement and long-term stability of slope stability,and conducts in-depth study of high-fill roadbed through measured data.Long-term stability,and based on the finite element method to summarize the long-term degeneration law and characteristics of high fill subgrade.The specific content can be summarized as follows:(1)Design of high fill subgrade deformation monitoring program.According to the engineering and technical characteristics of the high-filled roadbed of Chengchi Expressway,especially the characteristics of earth-rockfilling of high-filled roadbed filling materials,the suitable observation methods for subgrade settlement and longterm stability of slope are determined,including the test section.Selection,section layout,instrument burying,setting of monitoring parameters,organization and management of personnel for on-site monitoring,etc.,provide guarantee for accurately collecting monitoring data of high fill subgrade;(2)Analysis of settlement law of high fill subgrade settlement.The data of subgrade settlement deformation are summarized,and the variation law of vertical settlement and lateral displacement of subgrade with filling height and monitoring time is analyzed.Finally,the stress characteristics of foundation soil and the effect of foundation treatment are studied based on stress monitoring.Measures to complement and improve the status quo of roadbed instability;(3)Indoor pull-out test study of high-filled reinforced embankment.The reinforcement mechanism of the reinforced embankment is analyzed.The interface friction characteristics of three different types of geogrids under different vertical loads are compared by the pull-out test,which lays a theoretical foundation for the numerical analysis of the post-high fill reinforced embankment.(4)Numerical analysis of high fill reinforced embankments.Based on the Mohr-Coulomb theory,the FLAC 3D large-scale finite element software was used to establish the high-fill embankment model with or without geogrid.The main area of subgrade settlement was obtained,and the vertical settlement deformation and slope level of geogrid were analyzed.The effect of displacement improvement finally simulates the influence of the number of reinforcement layers,the reinforcement position and the reinforcement spacing on the stability of the embankment,and provides a technical reference for guiding the application of geogrid in the construction of high fill subgrade.