中文摘要：

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。

英文摘要：

The deposition process of the loess in Ili valley in Xinjiang is controlled by circulation of Atlantic Ocean west wind, which is different from the deposition process of East Asia monsoon-controlled loess in Loess Plateau. Based on the in-situ comprehensive soaking tests on a channel project, it is been proved that Ili loess is a kind of strong collapsible loess. Furthermore, the collapsibility is characterized by early development, fast speed and large value. According to the field measurement, the maximum self-weight settlement reaches a large value of 352 cm, and the maximum collapsibility coefficient is 0.18 (p=200 kPa). From the history of sediment, the formation age of Ili loess is young. The deposition process is drier and cooler, and it is not influenced by hot and humid climate. Thus, there is less effect of rainfall-leaching on salinity, especially on calcium carbonate. In consideration of its physical property and mineral composition, the natural density, moisture content and saturation of Ili loess are low, while the dissolved salt content is high. The micro-structure observations indicate that the Ili loess has the characteristics of point contact, aerial structure form and few cementations, which lead to a highly unstable structure and strong potential collapsibility. These are historic and internal factors that cause strong collapsibility.