Luan Yingcheng, Lu Wei, Fu Kun
Research Center of Geotechnical and Structural Engineering, Shandong University, Jinan 250061, China.
School of Transportation, Southeast University, 2# Southeast University Road, Jiangning District, Nanjing 210096, China.
Polymers (Basel). 2023 Oct 23;15(20):4187. doi: 10.3390/polym15204187.
The subgrade soil of asphalt pavement is significantly susceptible to changes in moisture content, and therefore many projects introduce polymer-based reinforcement to ensure soil performance. This paper aims to incorporate a variable representing the dry-wet cycle into the prediction model of resilient modulus of polymer reinforced soil. The polymer adopted is a self-developed subgrade soil solidification material consisting of sodium dodecyl sulfate and polyvinyl oxide. The current resilient modulus prediction model is improved, notably involving the effects of the dry-wet cycle. Combined with finite element method (FEM) analysis, the actual stress state of pavement and the coupling effect of dry-wet cycle and vehicle load on the resilient modulus are studied. The deterioration in resilient modulus with the variation in seasonal climate and load response is also investigated. Results show that the deviator stress is negatively correlated with the resilient modulus while the bulk stress has a linearly positive relation. The decreasing rate at low deviator stress is larger than that at the high level. Moreover, the dry-wet cycle can reduce the resilient modulus and the reducing amplitude is the largest at the first dry-wet cycle. FEM analysis shows that the middle position of the subgrade slope has the largest initial resilient modulus with decreasing amplitude in the first year of dry-wet cycles, while the upper position shows a smaller change. The variation in resilient modulus is closely related to the changes in cumulative volumetric water content. Considering that different positions of subgrade bear the external vehicle load, the equivalent resilient modulus is more realistic for guiding the subgrade design.
沥青路面的路基土对含水量变化极为敏感，因此许多工程引入聚合物增强材料以确保土壤性能。本文旨在将一个代表干湿循环的变量纳入聚合物加固土回弹模量的预测模型。所采用的聚合物是一种由十二烷基硫酸钠和聚乙烯氧化物组成的自主研发的路基土固化材料。对现有的回弹模量预测模型进行了改进，特别考虑了干湿循环的影响。结合有限元法（FEM）分析，研究了路面的实际应力状态以及干湿循环与车辆荷载对回弹模量的耦合效应。还研究了回弹模量随季节气候和荷载响应变化的劣化情况。结果表明，偏应力与回弹模量呈负相关，而体应力呈线性正相关。低偏应力下的降低速率大于高偏应力下的降低速率。此外，干湿循环会降低回弹模量，且在第一个干湿循环时降低幅度最大。有限元分析表明，路基边坡中部的初始回弹模量最大，在干湿循环的第一年降低幅度最大，而上部位置变化较小。回弹模量的变化与累积体积含水量的变化密切相关。考虑到路基不同位置承受外部车辆荷载，等效回弹模量对于指导路基设计更为实际。
