青藏高原高温冻土旁压蠕变试验研究

Experimental Study on the Lateral Pressure Creep of Warm Permafrost in Qinghai-Tibet Plateau

为研究高温多年冻土的蠕变特性,在青藏铁路北麓河试验段开展不同温度、不同含水量的多年冻土旁压蠕变试验。试验结果表明:在冻土的短时旁压蠕变试验(尤其是高温—低含冰量冻土的旁压蠕变试验)中,瞬时变形在总变形中占有较大比例;在温度相同时,该比例随含水量的增大而减小;在含水量相同时,该比例随温度的升高而增大。因此,在高温—低含冰量冻土蠕变试验数据处理过程中,必须首先提取瞬时变形,才能够分离出蠕变变形。对于高温—低含冰量冻结黏土,随含水量的增加或温度升高,冻土流变性增强。

In order to study the creep characteristics of the warm permafrost, a series of tests were carried out on the lateral pressure creep of the permafrost at Beiluhe test site along Qinghai-Tibet Railway at different water content and temperature. The test results indicate that the instantaneous deformation takes a large proportion in the whole deformation referring to the short-term creep tests （especially for the warm and ice-poor permafrost）. At the same temperature, the proportion decreases with the increasing of water content. Meanwhile, at the same water content, it increases with the increasing of the temperature. When the creep data with a pressuremeter for the warm and ice-poor permafrost is processed, the instantaneous deformation information must be extracted firstly, and then the creep deformation information can be separated from it. For warm and ice-poor frozen clay, its theology behavior increases with the increase of water content or temperature.