关键词: 龟裂, 研究方法, 室内试验, 现场试验, 数值模拟, 图像处理

Abstract: Soil desiccation cracking is a common natural phenomenon, which has significant negative impacts on engineering properties of soil, and is the direct cause of many engineering geology and environmental geology problems. It is a key to choose appropriate methods for studying soil desiccation cracking behavior. Based on the research work conducted on soil desiccation cracking behavior in recent years, the applied research methods are reviewed and summarized systematically. Meanwhile, the advantages and disadvantages of each method are compared and analyzed; and then the following understandings are obtained: (1) There are generally two categories of research methods for soil desiccation cracking: experimental study and numerical simulation. The experimental study contains two aspects: laboratory test and field test. At present, the former one is more popular. (2) There are commonly two types of specimens are used for laboratory test: slurry specimen and compacted specimen, and the former one is also more popular. (3) There are two types of equipment are usually applied in soil desiccation cracking test: one is used to control the environmental conditions like environmental chamber; and another is used to monitor the development of desiccation cracking and the geometrical characteristics of crack network, including crack image capture device, laser scanner, CT machine, ERT, distributed optical fiber and so on. (4) During the test, factors (i.e. specimen initial condition, size, thickness, mineral composition, environment temperature, specimen-container contact condition and wetting-drying cycles) affecting crack initiation and propagation are well studied by control variate method. (5) Digital image processing technique is efficient to quantify the geometrical and morphological characteristics, showing more promising as compared with other techniques. (6) The field test can reflect the real law of the formation and development of cracking; however, very few information can be found in literature because such field test is usually time and cost consuming. (7) Numerical simulation is one of the important methods to study soil desiccation cracking behavior. Because at this stage there is no uniform understanding of the mechanism on cracking, the related research on this topic is still in its infancy. Based on the current research, this paper puts forward the research focus of this topic in the future.

Key words: desiccation cracking, research method, laboratory test, field test, numerical modeling, image processing