Research On Rapid Construction And Settlement Control Of High Filled Subgrade

Compared with general roadbed, high backfill subgrade has the characteristics such as higher height, larger cumulate settlement and it's stability should be technical analysed. High backfill subgrade is one of the most important project in highway engineering.The roadbed settlement in highway construction, especially the differential settlements, may lead to the cleft and stagger of pavement, and largely affect the quality of driving as well as the operational life span. So how to reduce the settlement and get rid of the danger made by the settlement has been an important subject in highway construction field and the research has important reality significance.According to the highway construction condition and actual engineering problem, fast construction techniques and settlement calculate as well as analysis method of high backfill subgrade are studied based on a airdrome road.(1) There are many methods to reinforce soft ground. Different Subgrade treatment approaches have different effects and scope of application which also vary in the economic. Based on the analysis and comparison of various treatment methods for highway soft ground s, convenient construction and reliable technology and rapid economic weak foundation treatment programs are elected aimed at project's exceptional circumstance.(2) Compaction quality of different ways to fill the embankment is studied and the reasonable rapid filling construction technology programs of high roadbed are recommended. The optimum fill standard and fill thickness are confirm by the result of finite element method analysis.(3) Dynamic finite element method is used to analysis the role of crushed stamping method played in reducing differential settlement of the embankment.The efficiency treat depth and the influence of settlement and fill are demonstrated. Finite element strength reduction method is used to analyze slope stability for special sections of complicated geological condition and reasonableness of the treatment program is also verified.(4) The characteristics of high backfill subgrade are studied through elasticity-plasticity character of the rock and soil material, compressed character of the subgrade material and rules of the foundation soils surface stress. The settlement process of special load is analysed from observed dates and the results of digital simulation compute to the deformation by self-resepect.(5) Settlement deformation observation system is established and implemented and settlement occurring and changes of the soft-high filled embankment in the process of fast construction and bearing a special working load are made by tracking observations and conditions of the deformation of the settlement and different settlements of the subgrade are concluded and analyzed, which accumulate large amounts of valuable original data and useful practical experiences in engineering during the development period of China's high-speed road construction.(6) Fairly accurate prediction and analysis of late settlement of high filled subgrade are made through the application of the theory of gray system. Taking into the account of non-spacing factors of the special nature of road construction and the observation of embankment settlement, improved non - interval GM (1.1) model is established based on the interval GM (1.1) model and corresponding computer program is also established (see Appendix 2). To predict high filled subgrade settlement by using the improved non-spacing GM (1.1) model, the forecasting results consistent with actual situation which verifies that the improved GM (1.1) prediction model can fully meet actual needs. Check error also shows that the modeling accuracy is qualified and the precision is higher than normal GM (1.1) model.