考虑循环变温的软土热固结模型

Thermal consolidation model of soft soil considering cyclic varying temperature

在能源岩土工程发展需求背景下,土体工程特性的温度效应研究受到了国内外学者的广泛关注。针对现有关于循环变温热固结理论研究的不足,提出考虑循环变温条件下土体先期固结压力随温度循环次数变化的关系式,计算多次循环变温后软土的固结压缩量。在此基础上,推导考虑循环变温的太沙基固结修正公式,分析整个循环变温过程中孔压和固结沉降的变化规律。最后通过与单元体测试结果进行对比,验证该计算模型的可靠性。研究结果表明,在循环变温和瞬时荷载的耦合作用下,土体的沉降变形和孔压随温度循环次数的变化而变化,且影响程度与循环次数相关;新型热固结模型为涉及循环变温的岩土工程问题分析提供了一定的理论支撑。

Under the background of the development needs of energy geotechnical engineering,the research on the temperature effect of soil engineering characteristic has received extensive attention from scholars.Aiming at the shortcomings of the existing theoretical research on cyclic variable temperature thermal consolidation,this paper gives a relationship between the change of the soil preconsolidation pressure and the number of temperature cycles under the condition of cyclic temperature change to calculate the consolidation and compression of soft soil after repeated temperature changes.On this basis,the modified Terzaghi consolidation formula considering the cyclic temperature change is derived to predict the change of pore pressure and consolidation settlement during the whole cycle of temperature change.Finally,the reliability of the calculation model is verified by comparing with the unit test results.The research indicates that under the coupling action of cyclic temperature change and instantaneous load,the settlement deformation and pore pressure of the soil will change with the number of temperature cycles,and the degree of influence is related to the number of cycles;the proposed thermal consolidation model provides certain theoretical support for the analysis of geotechnical engineering problems involving cyclic temperature variations.