【摘要】 以杭州西险大塘新建路堤工程为研究对象，探究非饱和土路堤在施工及运营期的变形特性。首先，基于巴塞罗那基本模型(BBM)，依托实际工程截面建立数值模型；其次，结合工程实际设定初始压实荷载、初始含水率及运营期车辆荷载的工程条件，构建多工况组合；第三，采用应力-屈服曲线关系理论，分析不同工况下路堤土层的力学响应；最后，设定“饱和路堤+车辆荷载”的不利工况，重点分析各工况下路堤土层的应力-屈服曲线关系及变形特征，并明确各工程条件对路堤变形的控制作用。研究结果表明：初始压实荷载对抑制路堤后期塑性变形具有显著效果，提升初始压实水平可有效降低运营阶段的路堤变形；相较于最优含水率状态，初始含水率偏低会削弱土体的初始压实效果，导致运营阶段对路堤变形的控制能力下降；湿化过程会明显降低土体力学强度，使得诱发路堤塑性变形的临界车辆荷载显著低于初始压实荷载。湿化条件下路堤的承载能力存在明显衰减。更多还原

【Abstract】 Taking the new embankment project of Hangzhou Xixian Dyke as the research object, the deformation characteristics of unsaturated soil embankment during construction and operation periods were investigated. Firstly, a numerical model was established based on the Barcelona Basic Model(BBM) and the actual engineering section. Secondly, engineering conditions including initial compaction load, initial water content, and vehicle load during operation were set according to engineering practice, and multiple working condition combinations were constructed. Thirdly, according to the stress-yield curve relationship theory, the mechanical response of embankment soil layers under different working conditions was analyzed. Finally, the unfavorable working condition of "saturated embankment with vehicle load" was set. The stress-yield curve relationship and deformation characteristics of embankment soil layers under various working conditions were specifically analyzed. The control effects of each engineering condition on embankment deformation were clarified. The results show that initial compaction load has a significant effect on restraining the subsequent plastic deformation of the embankment. Increasing the initial compaction level can effectively reduce embankment deformation during the operation period. Compared with the optimum water content state, low initial water content weakens the initial compaction effect of the soil, resulting in a reduced ability to control embankment deformation during the operation. The wetting process significantly decreases the mechanical strength of the soil, making the critical vehicle load inducing embankment plastic deformation considerably lower than the initial compaction load. The bearing capacity of the embankment significantly decreases under wetting conditions.更多还原