冻土参数对斜坡段埋地管道应力影响的数值模拟

当冻土周围温度发生变化时,土体含水率会随之改变,而此时冻土的内摩擦角、内聚力和重度都会相应地发生变化。对处在斜坡段的埋地管道,随着冻土的融化,土体产生沿斜坡方向向下的摩擦力,使管道受到额外的拉应力。为了正确认识冻土参数对管道应力的影响,为确定科学有效的管道防害方法提供依据,针对发生冻融滑坡时土体各参数对管道应力的影响进行了模拟计算及分析。结果表明,当发生冻融滑坡时,随着土体内聚力与冻土重度的增加,管道所受应力变大;随着土体内摩擦角的增加,管道所受应力减小;冻土内摩擦角对管道应力的影响大,冻土重度次之,冻土内聚力对管道应力的影响最小。

The Numerical Simulation of the Frozen Soil Parameters on the Ramp Portion of Buried Piping Stress

The moisture content of soil will change when the ambient temperature changes in permafrost, and by this time the internal friction angle, cohesion and severe of permafrost will change accordingly. And for slope segments of buried pipelines, the soil will produce friction on the pipeline along the slope direction with the thawing of permafrost occurrence, to make the pipeline generate the additional tensile stress. Understanding the impact of frozen soil parameters on the pipeline stress correctly was convenient to the analysis of pipeline stress, and it had practical significance for the development of scientific and effective method of preventing damage. When the frozen soil around the buried pipeline of slope section thaws, the degree of influence on pipeline stress with different soil parameter was investigated, and yields the conclusion by the numerical simulation. The results show: when thaw landslide occurs, with the increasing of soil cohesion and weight of soil, the pipeline stress increased; and with the increasing of internal friction angle, the pipeline stress decreased. Moreover, the friction angle of the frozen soil was the most sensitive to the pipeline stress, weight of soil followed, and the influence of permafrost cohesion on pipeline stress was minimal.