In meniscus, the curvature of the liquid surface is helped by adhesion forces that act between the wall of the container and the liquid. The adhesion force increased with the soil moisture and then decreased when exceeding the moisture content threshold. However, as the soil dries out, the pore size increases and gravity starts to turn capillary water into gravitational water and it moves down. adhesion of soil to the metal interface under different tem-peratures, as shown in Figure 2. The project was supported by Natural Science Foundation and Doctoral Foundation of China. In the classical soil mechanics it is believed that cohesion is the relation and inter-connection between soil particles due to water polar molecules and soil polar particles. The adhesion and cohesion forces, both vary in their strengths. Adhesion is the bonding of one material to another, namely an adhesive to a substrate, due to a variety of possible interactions. The wettability and normal soil adhesion of polytetrafluoroethylene (PTFE) sheet, polyethersulforne (PES)-PTFE coating, enamel coating, iron base alloy-epoxy composite coating and the conventional material were determined. Copyright © 2021 Elsevier B.V. or its licensors or contributors. The contact models of the soil adhesion interface are given and mechanism of the normal adhesion is discussed. 1 For the soil-engaging components of agricultural machinery, soil adhesion has been an important problem affecting agricultural production, 2 which increased the working resistance and energy consumption of these machines. Hence water droplets are spherical. The addition of lime causes adhesion of soil particles and also prevents or reduces the loss of soil. Polymers can reduce both normal adhesion and sliding resistance, whereas, enamel coating or iron base alloy-epoxy composite coating can reduce the sliding resistance to some extent. Similar soil properties such as texture, soil organic matter, and cation exchange capacity (CEC) could explain this observation. Long-term pressure can also make soil cohesive. In the fifth video in the Bare Essentials of Soil Mechanics series, Professor John Burland explains how important water pressure in the voids between soil particles is in determining the soil’s strength. Cohesive soil does not crumble, can be excavated with vertical sideslopes, and is plastic when moist. Polymers can reduce both normal adhesion and sliding resistance, whereas, enamel coating or iron base alloy-epoxy composite coating can reduce the sliding resistance to some extent. The adhesion is found to be entirely due to the water film between the joined surfaces, and its magnitude is approximately equal to the moisture tension in this film multiplied by its area. 14, No.3, 1968) RELATIONSHIP BETWEEN SOIL COHESION AND SHEAR STRENGTH Hajime YOKOI National lnsfltute of Agricultural Sciences, Tokyo, Japan RECEIVED NOVEMBER 6, 1967 Introduction Cohesion of soil is an important factor of soil consistency. John describes how major disasters can take place if geotechnical engineers don’t take into account water pressure in soils. Soil adhesion assays. The soil surface at the soil-solid interface displays rough structure at various sizes. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. Characteristics of adhesion between soil and solid surfaces. Cohesion of soils is the characteristic of the fine materials with particle size below about 0.002 mm (clay). 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