鞋底常态磨损特征再现的研究（Study on the reproduction of normal wear characteristics of sole）Study on the reproduction of normal wear characteristics of soleShao Jiang LANShoe, is a higher rate of evidence at the scene of the crime. Through the inspection and judgment of suspicion and morphological features of the shoe shoes, shoes can confirm to the scene. These material evidences and the expert conclusions made by the tests are important indirect evidences in criminal proceedings. However, some criminals, then wear shoes lost, damaged, unable to make the investigation organ extraction shoes suspected for inspection; some deliberate destruction of the surface of the sole morphological characteristics (such as burning, burning, cutting, digging, and to make the shoes,) completely lost the test conditions; in addition, sometimes because the investigation work delay time is too long, to extract the suspected shoes and after a long time to wear or repair, the sole original morphological features of face are, causing great difficulties to test. Therefore, it is urgent to study the characteristics that can be reproduced on the sole surface and to provide new indirect evidence to prove the crime and expose the offender by means of reproducing these characteristics. Moreover, the research on this subject is of great value both in theory and in practice.The features that may be reproduced on the sole of the sole can only be the normal wear characteristics that reflect the inherent characteristics of the individual. In this paper, the primary recognition value of the normal wear characteristics of sole and its possibility of reproduction are discussed.First, the concept of normal wear characteristics of the soles and their valueAt present, the morphological characteristics of Shoeprint test, according to the cause of its formation can be divided into three categories:1, in the sole production, processing process in the formation of inherent characteristics. Such as: the type and layout of the pattern, the small surface of the sole, the distribution of the pattern and the special shape, the formation of the blowhole, the injection mark, the specific distribution of the surface pattern formed when cutting and the flow direction and so on. The specificity of these characteristics is very strong, and can be used as an important basis for the same identification. But these features are dependent on the original sole and can not be restored once they are lost.2. The characteristics of some external incidental factors in the process of wearing and repairing shoes. Such as cutting defects, scratches, patches, burn marks, distribution, location and shape of the shoes etc. The specificity of these characteristics is very strong, and the use value is the highest in the same identification. But these characteristics are the result of the random combination of several accidental factors. It is impossible to reproduce the conditions for forming these characteristics, so it is impossible to restore such characteristics.3 wear characteristics of soles formed by walking shoes. Wear characteristics are the result of friction between the sole and the ground when walking, and it is also of great significance in the same identification. According to the 159 statistical identification inspection in Tianjin shoe city public security bureau, the wear characteristics of the same identified are 92, accounting for 57.9%, among them only with the wear characteristics of the same as that of 84 pieces of evidence, and other characteristics of the wear characteristics of 8 pieces of application.In Shoeprint test in practice can also be in accordance with the wear characteristics, the possibility of repeated in other soles and the emergence rate and divided into two types,(1) species characteristics (or general features). Including the extent, location and general shape of the wear.(2) specific features (or minutiae). Include:Special (rare) wear patterns;The correlation between several wear characteristics;A change in the depth of a shoes sole as a result of wear;Change of surface shape of sole pattern due to wear;The distribution and number of sole patterns remaining in the worn area;The shape and distribution of the fringe pattern around the worn part;Number and distribution of tread patterns outside worn areas;Deformation of a sole, as of a stumble, band, cap, worn by wear;The hole formed by abrasion, the location and shape of the defect.Of these, there is an accident due to the external mechanical force, such as special wear reasons for climbing, wiping and other special actions or a part of the sole bump deformation, the wear is not formed in normal human walking movement, known as the abnormal wear characteristics.The other is the gradual formation of sole wear in the normal walking of shoes, which is called normal wear characteristics. When walking, the sole