evaluation of the soil properties effect on upheaval buckling of subsea pipelines

Different parameters contribute on the upheaval buckling of subsea pipelines. seabed is a surface that pipeline contact with it directly. so seabed is one of the most important parameters in the upheaval buckling of subsea pipeline. subsea pipeline includes imperfection shape and characteristics of the seabed soil. in this paper, different soil types are considered for seabed and modeled with abaqus standard code. seabed is modeled as a twodimensional springs. the task of these springs is to react like soil against forces. the calculation of spring stiffness is based on standard code of american lifelines alliance. the critical stress increases due to the soil cohesion increasing. soil cohesion is more effective parameter than soil angle friction of the soil. in this study, the effect of temperature difference is evaluated for different types of soil. 10 difference temperature is considered for this evaluation. 50 ℃ to 110 ℃ is the range of mentioned temperature. the effect of difference temperature on the upheaval buckling increases due to increasing of angle friction.