Author(s)

Zhouyv Tian, Qiuling Yao, Shunfu Zhang, Nan Qiao

Corresponding Author

Qiuling Yao

ABSTRACT

The contact areas near culvert pipe through levee are prone to contact erosion, esp. contact erosion due to culvert pipe cracks or holes. In order to reveal the development process of soil erosion damage and levee collapse, physical model tests are carried out by using visual test device to study the development process of contact erosion due to the holes of pressure less culvert pipe. Influence mechanism of hole location and its diameter on erosion failure process are discussed by observing and measuring water head, outlet flow, the amount of soil erosion and the size of pit due to soil collapse. The test results show that:(1) The erosion process can be divided into five typical stages: no obvious infiltration failure stage, erosion initiation stage, erosion development stage, erosion intensification stage and comprehensive failure stage. (2) The larger of the hole diameter and its distance to downstream outflow, the lower the critical water head required for erosion intensification and comprehensive failure;(3) The diameter of hole affects the rate of sand erosion and its position determines the length of silted sand in the culvert pipes. Silted sand has inhibitory effect on erosion processes. When the rate of soil erosion equals that of its transport in the culvert pipe, the erosion pprocess will be the most intense until it collapses.

KEYWORDS

Contact Erosion, Pressure less Culvert Pipe, Culvert Pipe Holes, Seepage Deformation, Erosion Mechanism