【摘要】 为研究渠基土在水分与温度变化下的力学特性与冻胀特性变化特征及在水分与温度变化下衬砌渠道的冻胀响应，本文通过对渠基土进行力学特性与冻胀特性试验，研究了不同水分、不同温度条件下渠基土力学特性和冻胀特性的变化规律。并以此为依据，采用有限元数值模拟，基于水热耦合变化，对渠基土冻胀下衬砌渠道冻胀响应进行了研究。结果表明：渠基土力学特性与冻胀特性在水热耦合下呈现出复杂性。温度差异小时，水分差异对衬砌渠道冻胀变形影响小。温度差异大时，水热耦合对衬砌渠道冻胀变形影响显著。-2℃、-12℃下，衬砌渠道最大冻胀变形相较渠道底部变形大54%、70%。温度差异越大，不同温度条件下法、切向冻胀力差距越大。-5℃下最大法向、切向冻胀力相较-2℃大175%、173%,-15℃下最大法向、切向冻胀力相较-5℃大408%、200%。水分差异相较温度差异对冻胀作用影响小。在水热耦合下，渠基土冻胀作用分布具有非均匀性特征且衬砌渠道裂缝发展与分布特征具有一定规律性。温度差异越大，不同水热条件下衬砌渠道冻胀应力差距越大。-6℃下最大冻胀应力相较-4℃大57%。-14℃下最大冻胀应力相较-6℃大183%。温度越低，水分越多，对衬砌渠道冻胀应力影响越显著。本研究可为衬砌渠道在水热耦合变化下防冻胀设计与结构优化提供参考。更多还原

【Abstract】 In order to study the change characteristics of mechanical properties and frost expansion characteristics of canal subsoil under the change of moisture and temperature and the frost expansion response of lined channel under the change of moisture and temperature,the mechanical properties and frost expansion characteristics of canal subsoil were tested,and the change rules of mechanical properties and frost expansion characteristics of canal subsoil were studied under the condition of different moisture and different temperature.And based on this,using finite element numerical simulation,based on the water-heat coupling change,the lining channel frost expansion response under the frost expansion of the channel subsoil is studied.The results show that the mechanical properties and freezing and expansion characteristics of the channel subsoil show complexity under hydrothermal coupling.When the temperature difference is small,the moisture difference has little effect on the frozen deformation of lined channels.When the temperature difference is large,the hydrothermal coupling has a significant effect on the freezing and expansion deformation of lined channels.Under-2℃ and-12℃ ，the maximum freezing deformation of the lined channel is 54% and 70% larger than that of the bottom of the channel.The larger the temperature difference,the larger the gap between normal and tangential freezing expansion force under different temperature conditions.The maximum normal and tangential freezing expansion force at-5℃ is 175% and173% larger than that at-2℃ ，and the maximum normal and tangential freezing expansion force at-15℃ is408% and 200% larger than that at-5℃ .Moisture difference has a small effect on frost heave compared to temperature difference.Under the hydrothermal coupling,the distribution of freezing and expansion of channel foundation soil has non-uniform characteristics and the development and distribution of cracks in lined channels have certain regularity.The larger the temperature difference is,the larger the gap between the freezing and expansion stresses of lined channels under different hydrothermal conditions is.The maximum freezing expansion stress at-6℃ is 57% larger than that at-4℃ .The maximum freezing expansion stress at -14℃ is 183% larger than that at-6℃ .The lower the temperature,the more moisture,the more significant effect on the freezing and expansion stress of lined channels.This study can provide a reference for the design and structural optimisation of anti-freezing and expansion of lined channels under the change of hydrothermal coupling.更多还原