中文摘要：

研究高分子材料改性粉土的破坏模式及应力-应变特性,为解决粉土地区路基工程稳定和变形提供重要依据.通过对高分子材料改性粉土进行不固结不排水（UU）、固结不排水（CU）和固结排水（CD）三轴试验.结果表明：改性粉土的破坏模式在UU和CU试验中,主要为鼓胀型;在CD试验中,破坏模式较为复杂,有压裂型、剪切型和V字形;改性粉土具有结构性土体的特性,应力-应变曲线的类型取决于围压与屈服应力的关系.对比改性粉土与纯粉土3种试验条件下的抗剪强度指标,表明高分子材料对粉土具有很好的改性效果;同时也表明排水与固结条件不同,改性粉土表现出的抗剪强度指标不同,为此工程稳定性分析中,参数的选取应该与实际的固结排水条件相对应.

英文摘要：

The study on failure mode and stress-strain characteristics of polymer material modified silty soil could provide all animportant basis for solving the stability and deformation of roadbed projects in silty areas.The test results of triaxial research unconsolidation undrained/consolidated undrained/consolidation drainage （UU/CU/CD） on modified silty soil showed that：the mainly failure mode of modified silt in the UU and CU tests is bulging type;while in the CD test,the failure mode is more complex,called the fracture type,shear type and ＂ Ⅴ＂ type.The characteristics of modified silty soil were identical with the structure soil;meanwhile the stress-strain curve depended on the type of the confining pressure and the yield stress.By comparing shear strength indexes of modified silty soil with pure silty soil under triaxial conditions,the better effects were achieved by using polymer material to modify silty soil.Meanwhile,the shear strength indexes of modified silty soil were different under different drainage and consolidation conditions.Hence,when analying the stability of projects,the selection of indexes should be in agree ment with actual consolidation and drainage conditions.