Study On The Deformation Characteristic Of Soft Rock Embankment--Take Xichang-Panzhihuang Express Highway As Example

Deformation problem is one of the most important problems in the roadbed filling engineering. Research on deformation characteristic of roadbed is not only basis of rightly acquainting and valuing stability of roadbed, but also effective ways of improving roadbed-design level and developing construct-controlling technique. According to the question of foundationengineering from test section ( LKO+900 to LK1+000 ) of Xichang--Panzhihuang expresshighway, this paper put up important systems analysis and study on the deformation of roadbed which is filled by special stratum on site--Xigeda stratum.Firstly, this paper traversed engineering geological condition, physics and mechanics characteristic of foundation soil in the test section of the express highway by the detailed exploring. At the same time, by the large quantity of testing of Xigeda stratum soil, physics and mechanics characteristic of soil were acquired, intensity and deformation characteristic were mastered, the use for roadbed- filling was discussed. Then, based on deformation observed results of roadbed in loading period, the settlement and condensation rules of many parts of roadbed and were studied. Combining with local geological conditions, the roadbed model were founded and were numerically simulated by FEM. The simulating results and observed results were compared. At one time, many influencing factors were studied by founding all kinds of roadbed models and FEM numerically simulating. At last, according to observed results of deformation of roadbed after loading period, the settlement and condensation rules of roadbed were studied. The future settlement was forecasted by some common forecasting models, fit precision and results were evaluated and analyzed. The most suitable forecasting model was selected to use, to guide future construction and optimize design.By the research, some creative conclusions about deformation problem are put out as follows. To control the settlement of roadbed, the degree of compaction regulated by current criterion is notenough, the mechanics parameter of filler compacted--deformation parameter should beconsidered and dual control criterion should be put in practice. To get upper deformation parameter of Xigeda stratum filler, the percentage of mudstone should be controlled. The thickness of filling layer regulated by current criterion can be increased if the compaction car has proper function.