Longitudinal Deformation Model and Parameter Analysis of Canal Lining under Nonuniform Frost Heave

Abstract

Due to the unique hydrothermal environments, the frost heave failure of the concrete lining of water conveyance canals in cold regions is still frequent. The deformation of lining after frost heaving and the stress distribution calculated by the mechanical model can be the reference for the lining design. However, previous research mainly focused on the mechanical model of the cross-section while having little attention for the longitudinal nonuniform frost heave damage. In this study, a mechanical model of the bottom lining under the nonuniform frost heave deformation is built based on the Euler–Bernoulli beam and the Pasternak foundation model, and the analytical solution of the model is obtained. The internal stress of the lining is analyzed during the changes of subgrade coefficient, shear rigidity, transition section length, and frost heave amount inside the model. Also, the calculation process is proved to be correct. The result shows that dangerous cross-sections are at the start and the end of the transition sections. The maximum normal stress and the tangential stress increase when the subgrade coefficient and the frost heave amount increase and the shear modulus and transition section length decrease. The frost heave amount in the frozen ground subgrade increases constantly, while the temperature decreases, but at the same time, the shear rigidity of the subgrade increases with it. The former increases the stress of lining, and the latter decreases it. Therefore, during the frost heaving process, the internal force of lining is coupled with these two elements. By analyzing a water conveyance canal lining under the nonuniform frost heave in the Xinjiang Tarim irrigation district, the maximum normal stress of the dangerous lining cross-section is greater than its tensile strength when the transition section length smaller than 7 m at the frost heave amount is 0.031 m.

Concrete canals lining with modern materials: A Review of hybrid fiber reinforced concrete

“…Through the investigation of a water transportation lined canal in the Xinjiang Tarim irrigation district, it was found that the extreme normal stress in the critical lining cross-section exceeds its tensile strength. This repetitive occurrence leads to a detrimental cycle of frost heave, leakage, damaged lining, and further intensified frost heaving in the canal water transportation system [105].…”

Experimental Study on Freezing Strength of Soil-Concrete Lining Interface in Cold Regions

“…Due to the volume expansion of the water in the soil pores after freezing and the moisture migration along capillaries under the action of the temperature gradient which forms ice lenses, constructions on the frozen ground regions are often damaged by frost heave [2][3][4][5]. For water conveyance canals built in frozen soil areas, if the leakage water in the canal foundation soil cannot be drained after the water is stopped, the gradual freezing of the soil during winter will cause severe frostheaving damage, and sometimes, the maximum frostheaving amount can reach 15 cm [6,7]. In addition, in the spring, ice thawing increases the water content of the foundation soil, and the decrease in soil strength and carrying capacity can easily cause damage, such as canal-slope-sliding collapse [8].…”