Numerical Analysis of Pipeline Uplift Resistance in Frozen Clay Soil Considering Hybrid Tensile-Shear Yield Behaviors

Abstract

Pipeline uplift resistance plays an essential role in the design of buried pipelines in permafrost regions or artificially frozen ground. The uplift resistance of a frozen soil is dependent on the soil's mechanical properties, which are needed to characterize plastic zones in the frozen soil that surrounds pipes. Owing to the presence of unfrozen water, frozen soils (especially frozen clay) display complex mechanical properties that vary with temperature. There are limited amount of research studies with a focus on frozen soil-pipe interactions that consider temperature change within the literature. In this study, numerical modeling is conducted to investigate frozen soil-pipe interactions at different temperatures. A pipe is simulated with vertical displacement-controlled or vertical load-controlled conditions. The temperature-dependent mechanical parameters of frozen clay soil are examined in the simulation. Both tensile yield and shear yield behaviors are included in the modeling with the consideration of temperature-dependent failure criterions. Simulated stress paths in monitoring points are collected and displayed. The results from the Mohr-Coulomb model with the Rankine tensile cut off, and the hyperbolic Drucker-Prager model are compared and analyzed. The results indicate that hyperbolic Drucker-Prager model is effective for analyzing soil plastic zones surrounding a pipe. The applied hyperbolic Drucker-Prager model with reduced strength parameters can produce a more conservative uplift resistance-displacement relation when compared with that from the Mohr-Coulomb model. Thermally induced plastic strain may have a significant impact on the uplift resistance analysis, since a significant thermally induced uplift displacement is expected if there is a heat transfer process from a buried pipe to the surrounding frozen soil.

Numerical investigation of the thermal response and Mechanical Behavior of Water Distribution Pipelines subjected to extreme Cold Wave

“…The mechanical behavior of the soil was modeled using the Mohr-Coulomb constitutive model, as also adopted by other researchers [26,46], with the soil considered as an isotropic material, having same behavior at all temperatures. The water pipe was however modeled as an elasticplastic material.…”

“…Studies on the mechanical behavior of buried pipelines under low temperature have been conducted using numerical simulations [20][21][22][23][24][25][26][27], experimental methods [22,[28][29][30][31] and analytical methods [23,32,33]. Wu et al [23] investigated the mechanical behavior of underground oil pipeline in permafrost region using an elastic-plastic finite element model, considering the effects of temperature and moisture fields.…”

Analysis and Evaluation on Residual Strength of Pipelines with Internal Corrosion Defects in Seasonal Frozen Soil Region

“…The pipeline engineering inevitably goes through permafrost regions and seasonal permafrost regions. Due to the severe cold climate along the pipeline in permafrost regions, the physical state of frozen soil occurs periodic and irreversible frost and thaw under the effect of the cyclical change of the surface temperature and the temperature of the medium in the pipeline [1,2], the differential frost heave of the soil often occurs. According to the survey, differential frost heave is one of the main pipeline-soil diseases in frozen soil areas.…”

Special Issue on “Analysis, Design, Construction and Performance of Buried Structures”

“…This Special Issue of the International Journal of Geosynthetics and Ground Engineering aims to provide the readers with selected contributions that are broadly within the area of underground structures, namely pipelines [1][2][3], tunnels and buried bridges [4,5], culverts [6], and buried wave barriers [7]. The contributions came from both the practicing engineers and the researchers to provide insights into the current state of practice as well as the recent developments in analytical solutions, numerical modeling and data analysis.…”

“…The first article by Akhtar and Li [1] deals with a simplified approach to analyze the buried pipes in frozen ground. Finite element analysis has been used to investigate the frozen soil-pipe interaction under different temperatures.…”