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新疆伊犁黄土原位试验实测资料非常缺乏,为了研究其浸水入渗规律和自重沉降特征,开展了原状土和重塑土的现场浸水试验研究,并对表面沉降和水分进行观测。研究表明:浸水过程中,任一点的饱和度存在明显的暂态饱和区,封闭压缩气体上收缩膜承受的孔隙气压力、孔隙水压力和进气值的短暂力学平衡是其存在的主要原因;原状土因黄土结构性和地层结构性,其沉降特征具有明显的阶段性,其可用分段函数进行描述,重塑土因结构性破坏,其变形阶段性不明显;浸水21 d,湿润锋面到达8.8 m,重塑土(S4)的沉降量为120 cm,原状土(S5)的沉降量为78 cm,前者比后者大35%;鉴于软弱土层存在应力集中,湿润锋面以上相邻饱和土变形尚未稳定时,其下非饱和土不发生增湿变形,因此,原状土沉降变形为湿润锋面以上饱和土尚未变形稳定的沉降量,小于自重湿陷量的计算值85 cm。研究结果对伊犁黄土浸水变形机制和增湿变形计算奠定了基础。
In order to study the law of infiltration and infiltration and the characteristics of self-weight subsidence, the in situ test data of undisturbed loess and remolded soils are carried out, and the surface subsidence and moisture are observed. The results show that there is a clear transient saturated zone at any point during the soaking process, and the short-term mechanical equilibrium between the pore pressure, the pore water pressure and the intake air pressure on the compressed gas is the main reason for its existence. The undisturbed loess is characterized by structural and stratum structural features, and the settlement features of the undisturbed loess have obvious phases, which can be described by the piecewise function. The settlement of remolded soil (S4) is 120 cm. The settlement of undisturbed soil (S5) is 78 cm. The former is 35% larger than the latter. In view of the stress concentration in the soft soil, the adjacent saturation above the wetting front When the deformation of soil is not stable yet, the deformation of undisturbed soil does not occur. Therefore, the deformation of undisturbed soil is not stable and stable, and the settlement is less than the calculated value of self-weight collapsibility of 85 cm. The results laid a foundation for calculating the deformation mechanism and the calculation of humidification deformation of the loess in Yili.