将激光散斑法用于冻土材料，得出了裂纹尖端存在一个微裂纹损伤区（或称为断裂过程区）的结论．通过对裂纹尖端一系列散斑图的逐点分析，绘出了微裂纹区随载荷增加而发展的形貌及其全过程，测定了裂纹嘴张开位移的临界值δＣ，从而为冻土材料的宏微观力学行为研究及弹塑性断裂韧度测试分析提供了有效的途径． The laser speckle method is applied to the permafrost material, and the conclusion that there exists a micro-crack damage zone (or fracture zone) exists at the crack tip. Through the point-by-point analysis of a series of speckle patterns at the crack tip, the morphology and the whole process of the microcrack area with the increase of the load are plotted, and the critical value δC of the crack opening is measured, Macro and micro mechanical behavior and elastoplastic fracture toughness test provides an effective way.