高铁路基粗粒土填料静力特性大型三轴试验研究

选取宁杭高铁德清站路基填料站现场典型粗粒土填料制备试样,在100,150,200,300 kPa围压下开展大型三轴固结排水剪切试验,得到相应的应力-应变和体变特性曲线.试验表明:围压越大,偏应力达到稳定值所需的轴向应变越大,当围压为300 kPa、轴向应变达到15％时,偏应力仍在继续增长.不同围压条件下的试样剪切初期均...

Study on Large Scale Triaxial Test on the Static Characteristics of Coarse Grained Soil Filling for High-speed Railway Subgrade

The typical field grained soil filling for high-speed railway embankment at the roadbed filling station of Deqing Station of Nanjing—Hangzhou Highway was selected to prepare samples, and large-scale triaxial consolidation drained shear tests were carried out under different confining pressures of 100, 150, 200, 300 kPa, and the corresponding stress-strain and volume strain characteristic curves were obtained. The test results showed that the larger the confining pressure is, the larger the axial strain required for the deviatoric stress to be stable. When the confining pressure is 300 kPa, the deviatoric stress still increases when the axial strain reaches 15 %. Under different confining pressures condition, specimen shows shear shrinkage at the initial shearing stage, with the increase of axial strain, the volume strain gradually decreases and even transits to shear dilatancy. According to the triaxial test results, the peak strength under different confining pressures was taken as the normalization factor to analyze the stress-strain relationship of the filling. The fitting curve between the normalized deviatoric stress and the axial strain was obtained. After determining the relevant parameters from the curve, the stress-strain relationship of the filling can be well predicted.