原状冻土Ⅰ型断裂韧度KIc试验研究

针对原状冻土没有被扰动、土体内在微细观结构没有发生变化的特点，给出了试样制备与加工、初始裂纹预制及采用着色法测量裂纹尺寸的新方法．通过对当地土质进行分层冻胀量的观测，得出了不同埋深处冻胀量、冻深与时间的关系，并以此来严格控制试样制作及试验时的温度，以保证试验时试样的温度变化与实际相同深度冻土层温度变化一致．利用改造后的试验装置得到原状冻土Ⅰ型断裂韧度KIc值，说明了该试验方法是可行的．

Experimental research on fracture toughness KIc of undisturbed frozen soil

According to the undisturbed frozen soil not vibrated and the microcosmic structure inside not changed, compared with the remolding soil in laboratory, a new experimental research on the fracture toughness of the undisturbed frozen soil is presented. The bend test stand is improved. The pre-crack methods and coloring technology to measure the crack size in the rock crack are adopted. With the observation of the layering frost heave of the local frozen soil, the relations of frost heave, melt and time are obtained in different deep soil layers, so that temperature can be controlled in the experiment. The fracture toughness of Test I of crack was obtained by the modified equipment. Experimental results indicate that the undisturbed frozen soil mechanics experiment is completely available, and the pre-crack creation and coloring technology to observe the crack size in the frozen soil experiment is also available.