伊犁黄土强烈自重湿陷性的影响因素分析

发布时间：2018-07-14 17:20

【摘要】：新疆伊犁河谷的黄土,在沉积过程中受大西洋西风环流控制,不同于受东亚季风控制的黄土高原黄土,需要专门研究。对伊犁一大型渠道工程湿陷性黄土渠基的现场大型浸水试验证明,伊犁黄土湿陷性强烈,现场实测自重湿陷量达到352 cm,最大湿陷系数达到0.18(p=200 k Pa),且湿陷具有沉降发展早、速度快和量值大的特点。为了弄清引起伊犁黄土强烈湿陷的原因,开展了伊犁黄土沉积历史调查,及大量的黄土物理、矿物组成和显微结构试验工作,研究表明:伊犁黄土形成年代较晚,沉积过程中气候更为干冷,也基本未经受湿热气候的影响,盐分特别是碳酸钙受雨水淋滤的作用小,是典型的风积黄土样本;伊犁黄土具有天然密度、含水率和饱和度较小,易溶盐含量较高的特点,且其颗粒之间以点接触、架空结构和少胶结形式为主,结构极不稳定,这些因素是造成其强烈湿陷的历史原因和内在原因。
[Abstract]:The loess of the Yili River Valley in Xinjiang is controlled by the westerly circulation of the Atlantic Ocean during the deposition process, which is different from the Loess Plateau Loess Plateau which is controlled by the East Asian monsoon. The field large-scale soaking test of collapsible loess foundation in Yili a large canal project proves that the collapsibility of Yili loess is very strong, the measured collapsibility of Yili loess is 352 cm, the maximum collapsibility coefficient is 0.18 (200 KPA), and the subsidence of Yili loess has the early development of subsidence. High speed and large value. In order to find out the causes of the strong collapsibility of Yili loess, the sedimentary history of Yili loess was investigated, and a large number of tests of loess physics, mineral composition and microstructure were carried out. The results show that Yili loess was formed in a late age. During the deposition, the climate is more dry and cold, and it is not affected by the humid and hot climate. The salt, especially calcium carbonate, is a typical sample of aeolian loess because of its small leaching by Rain Water, and Yili loess has natural density, low moisture content and low saturation. The high content of soluble salt is characterized by point contact, aerial structure and less cementation. The structure is unstable. These factors are the historical and internal causes of its strong collapse.
【作者单位】：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;新疆伊犁河流域建设管理局;新疆水利水电勘测设计研究院;
【基金】：国家自然科学基金项目(51379220,51279171)
【分类号】：TU444

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