基于数值模拟的“适变断面”衬砌渠道抗冻胀机理探讨

能适应渠基冻胀变形的衬砌渠道简称“适变断面”渠道。为了探明其抗冻胀机理及削减冻胀效果，应用ADINA软件对混凝土衬砌“适变断面”渠道冻胀进行数值模拟，计算渠道冻胀的温度场、变形场和应力场，研究衬砌板应力和变形规律，并与弧形坡脚梯形渠道比较分析表明：“适变断面”渠道能降低最大法向冻胀量55.11%、最大法向冻胀力51.65%、最大切向冻结力56.85%；通过冻胀量均方差及冻胀力分析比较，“适变断面”使渠道受力状态得到显著改善，冻胀变形分布更加均匀；衬砌板法向错位值总计1.3 cm，纵向伸缩缝周向压缩值总计为9.7 cm，揭示了“适变断面”渠道利用宽纵缝既能释放衬砌板法向冻胀变位，又能吸收周向冻胀变位，从而适应渠基冻胀变形减轻冻害的抗冻胀机理。最后通过模拟计算了“适变断面”渠道冻胀量均方差对边坡系数的敏感性，指出边坡系数i约为1∶1.7～1∶1.4时，“适变断面”渠道抗冻胀效果很显著，为“适变断面”渠道的推广及优化设计提供了参考。

Exploration on anti-frost heave mechanism of self-adjusting lining canal based on computer simulation

Self-adjusting lining canal can adapt to frost-heaving deformation. In order to explore its effect and mechanism of anti-frost heave, finite element software ADINA was applied to simulate canal heaving process, and calculate the temperature field, deformation field and stress field, and study the rules of lining plate about stresses and deformation. Compared with trapezoidal canal with curved slop toe, self-adjusting lining canal can reduce maximum normal frost heaving quantity by 55.11%, maximum normal frost-heave force by 51.65% and tangential adfreezing force by 56.85%. It also can make frost heaving distribution more uniform to reform stress states remarkably. Total normal dislocation value between lining plates is 1.3 cm and total circumferential compression value of longitudinal elastic joints is 9.7 cm. This fact demonstrates that self-adjusting lining canal can makes full use of the joints to release normal deformation and absorb the circumferential, which is the mechanism of anti-frost heave. Sensitivity analysis of mean square deviation of frost heaving quantity to slope ratio shows that the best effect of anti-frost heave will be achieved while setting slope ratio i between 1:1.7 and 1:1.4. These works will provide scientific reference for further application and optimization design of self-adjusting lining canal.