Research On Filling Technology And Stability Monitoring Of High-Filled Embankment Soaked In Water

The station of Chong-gang freight railway is located in the Three Gorges reservoir area, with a maximum filling height of 74m. After the Three Gorges Reservoir is stored water, the water level of Yangtze River will reach up to 175m. The embankment is below the impounded water level of 30.0m and hundred-year flood water level of 37.0m. Once the embankment is constructed improperly, it will turn out some problem during the construction process and operation period, such as slope instability and embankment settlement caused by the humidification of filling material, and excessive differential settlement caused by uneven distribution of filling thickness. Consequently, it will seriously affect the overall stability of high-filled embankment soaked in water of Chong-gang freight railway, and bring out serious threat to constructional and operational safety. Therefore, the filling technology of high-filled embankment soaked in water is studied in this paper based on the construction project of Chong-gang freight railway, and the deformation monitoring system is set up to control the deformation and to guide the construction and operations. The effect of controlling settlement and ensuring the stability for the construction technology is assessed. The variation law of settlement and the stability of embankment are analyzed by means of theoretical calculations and numerical simulation.The project of Chong-gang freight railway high-filled embankment soaked in water is characterized by huge filling volume, large filling height, water immersion and short construction period, which produce some special difficulties. Firstly, the particularity of high-filled embankment soaked in water is analyzed, then, a comprehensive reinforcement consisted of soft foundation treatment, filling material choice, compaction technology and slope protection is presented.Secondly, the stress distribution, settlement characteristics and overall stability of high-filled embankment are investigated by field monitoring, which adopts the sensors, high precision total station. The analysis results show that:the maximum settlement of high-filled embankment is 89.7mm and the maximum lateral horizontal displacement is 46.5mm. The maximum deformation area is concentrated in the center of high-filled embankment shoulder and the deformation is inclined to stability with the time. The monitoring results show that the comprehensive reinforcement is effective to control the settlement.Finally, the numerical simulations of deformation and stability and dynamic response are conducted by using the GEO-SLOPE's SIGMA/W, SLOPE/W and QUAKE/W, under self-weight load and imposed load. The results show that:the safety factors of Morgenstern-Price, Bishop, Janbu and Ordinary are more than 1.7. which meet requirements completely.