人工冻融软弱土融沉特性研究-《郑州大学学报(工学版)》

文章信息/Info

Author(s):: Zhuang Huimin; Yang Ping; He Wenlong; School of Civil Engineering, Nanjing Forestry University, Nanjing, Jiangsu, 210037

Keywords:: artificial frozen soil; thaw-settlement coefficient; water source supply; loaddry density

摘要:: 随着人工冻结法在地铁建设中的广泛应用,控制工后融沉已成为软弱地层冻结需要解决的难题.以苏州地铁典型软弱土层为研究对象,通过室内试验研究,得出不同补水条件下原状土开放融沉系数大于封闭融沉系数;融前卸载加压方式下,融沉系数随上部荷载增大呈指数型减小;无黏性重塑土融沉系数与原状土接近,黏性土重塑后融沉系数变大,其差值随该土灵敏度增大而增大;对于非饱和黏土和淤泥质粉质黏土,开放冻融条件下融沉系数与干密度变化关系均存在临界干密度,对应土体融沉系数最小.

Abstract:: With the widespread application of artificial freezing method in subway construction, controlling post-construction thaw settlement has become a difficult problem to be solved for soft ground freezing. Taking the typical soft soil layer of Suzhou Metro as the research object, through laboratory experiments, it is concluded that under different water replenishment conditions The open thaw settlement coefficient of undisturbed soil is greater than that of closed thaw settlement coefficient; under unloading and pressure before melting, the thaw settlement coefficient decreases exponentially with the increase of upper load; The thaw-sedimentation coefficient becomes larger after soil remodeling, and the difference increases with the increase of the soil sensitivity; for unsaturated clay and muddy silty clay, there is a critical relationship between the thaw-sedimentation coefficient and dry density under open freeze-thaw conditions. The dry density corresponds to the minimum thaw settlement coefficient of the soil.