Graphic calculation method for thermal expansion length of partly restrained section in directly buried hotwater pipings

Explores the relationship between the ratio of the thermal expansion length of partly restrained section to its maximum thermal expansion length and the ratio of the length of partly restrained section to its maximum length under different buried depths. Gives the dimensionless thermal expansion length calculating graph which can be used to calculate the thermal expansion length conveniently, and the error between the graph calculating result and the theoretical value is less than 5%.