HEC-RAS is a very powerful and practical software which was developed by the Hydrologic Engineering Center. In this paper, this software is introduced to calculate the backwater height which is caused by a floating bridge on the yellow river. We can easily obtain the backwater height through using this software.

Desiccation cracks form on the surface of foundation soils due to matric suction and surface shrinkage with water loss. This paper investigates the effect of tea waste on the change of water content and cracking characteristics of foundation soil during drying. Digital image processing was carried out based on laboratory experiments. The characteristics are monitored with a variation in water content. The effects of different amounts of tea waste on soil drying and cracking were obtained, in order to provide an efficient and new green sustainable material for improving soil evaporation cracking under drought conditions. The results show that the development of cracks of soil samples with tea waste can be categorized into three stages in accordance with the fractal dimension of the desiccation cracks: Stages I, II, and III. The desiccation cracks in Stage III are wider and longer than those in Stages I and II, however, the maximum fractal dimension and stability are also obtained in Stage III. The residual water content of the sample without tea waste is 1.5%. The residual water content of the samples containing 4% and 8% tea waste is 4.6% and 5.4%, respectively, which shows that the tea waste can effectively improve the residual water content of the foundation soil and the water holding capacity of the soil. The fractal dimension of cracks on the soil samples increases gradually with drying. The total length of cracks increases and the development of cracks is more complex. The cracking time of soil samples with different tea waste contents is different. The soil samples with 8% tea waste content crack first. Combined with the variation characteristics of water content, tea waste has water absorption and improves the water holding capacity and stability of foundation soil.

Bagasse is the residue after juicing sugarcane, and bagasse is a recyclable biological resource that can be used in many ways. Under arid climatic conditions, the clay material shrinks and loses water. Many crisscross drying shrinkage cracks formed on the surface and inside the soil will affect the stability of the soil. In this article, the cracking characteristics of clays with different bagasse contents during the evaporation process have been studied. The cracks were extracted and calculated by digital image processing technology, and the crack characteristics of samples with different bagasse contents were studied by fractal dimension and crack entropy. The results show that when moisture content maintains 34%, the clay material forms only one main crack without bagasse, forms no crack with bagasse content of 9%, and forms a crack network with the bagasse content of 3%. Adding bagasse to the clay can advance the cracking time of the clay, and different contents of bagasse have different effects on the cracking time of the clay. Among these five experimental groups, the clay was affected the most with 3% bagasse content, while the least effect happened with 6% bagasse content. The time can be advanced when the clay crack entropy appears and increases the size of the crack entropy.