伊犁深厚湿陷性黄土浸水入渗及沉降变形特征分析

发布时间：2018-07-10 10:31

本文选题：深厚湿陷性黄土 + 现场浸水试验　；参考：《岩土力学》2017年02期

【摘要】：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。
[Abstract]:The in-situ test data of Yili loess in Xinjiang are very short. In order to study the law of infiltration and the characteristics of gravity settlement, the field soaking test of undisturbed soil and remolded soil is carried out, and the surface subsidence and moisture are observed. The results show that the saturation at any point has obvious transient saturation region, and the pore gas pressure, the transient mechanical equilibrium between pore water pressure and inlet gas are the main reasons for the existence of the saturation at any point. Because of loess structure and stratigraphic structure, the subsidence characteristics of undisturbed soil have obvious stages, which can be described by subsection function, but the deformation stage is not obvious because of structural failure of remolded soil. After 21 days of soaking, the wetting front reaches 8.8 m, the settlement of remolded soil (S4) is 120 cm, the settlement of undisturbed soil (S5) is 78 cm, the former is 35 and 35 cm larger than the latter, in view of the stress concentration in weak soil, the deformation of adjacent saturated soil above wetting front is not stable. The unsaturated soil does not deform under the soil, so the settlement of the undisturbed soil is not stable above the wetting front, which is less than 85 cm of the calculated value of the self-weight collapsibility. The results lay a foundation for the calculation of soaking deformation mechanism and humidification deformation of Yili loess.
【作者单位】：长安大学地质工程与测绘学院;西北农林科技大学水利与建筑工程学院;中国水利水电科学研究院;
【基金】：国家自然科学基金项目(No.51379220,No.51279171) 中国博士后科学基金项目(No.2016M602740) 中央高校基本科研业务费(No.310826161001)~~
【分类号】：TU475.3

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