低温状态下纤维加筋膨胀土数值模拟试验  

Numerical simulation of fiber-reinforced expansive soil at low temperature

作　　者：张雁[1] 薛晓雨 杨晓蕴[1,2] ZHANG Yan;XUE Xiaoyu;YANG Xiaoyun(College of Energy and Transportation Engineering,Inner Mongolia Agricultural University,Hohhot 010020,China;Department of Civil Engineering,University of Victoria,Victoria V8P5C2,Canada)

机构地区：[1]内蒙古农业大学能源与交通工程学院,呼和浩特010020 [2]维多利亚大学土木工程部,加拿大维多利亚V8P5C2

出　　处：《中国科技论文》2022年第12期1351-1357,共7页China Sciencepaper

基　　金：国家自然科学基金资助项目(52169023,51669025)。

摘　　要：为研究低温状态下聚丙烯纤维(polypropylene fibers,PP)对膨胀土(expansive soil,ES)的力学改良效果,通过冻融循环试验和无侧限抗压强度试验,得到不同土样的应力-应变参数,基于室内试验数据,采用ABAQUS软件建立冻融循环后聚丙烯纤维加筋膨胀土(PP-ES)无侧限抗压强度试验的有限元模型,并对其数值模拟结果进行分析。结果表明:数值模拟结果与试验结果保持一致,利用ABAQUS软件建立的冻融循环纤维加筋土模型合理可行;随着冻融次数的增加,PP可在一定程度上抑制ES受冻融劣化的影响,有效增强ES冻融后的强度;当纤维掺量为0.3%时,在冻融循环1次后,对ES的强度提升幅度最大,达到57.80%。由基体和纤维应力分析得出,0.3%PP-ES抗冻融损伤性最优,对试件的增强效果最好,当纤维掺量大于0.3%时,对试样的影响以增韧为主。研究结果可为寒冷地区ES路基的纤维改良提供参考。In order to study the mechanical improvement effect of polypropylene fibers(PP)on expansive soil(ES)at low temperature,the stress-strain parameters of different soil samples were obtained by freeze-thaw cycling test and unconfined compressive strength test.Based on the indoor test data,a finite element model for the unconfined compressive strength test of PP-ES was established using ABAQUS software and the numerical simulation results were analysed.It shows that the numerical simulation results are consistent with the experimental results,and the freeze-thaw cycle fiber reinforced soil model established by using ABAQUS software is reasonable and feasible.With the increase of the number of freeze-thaw cycles,PP can suppress the influence of ES by freeze-thaw deterioration to a certain extent,and effectively enhance the strength of ES after freeze-thaw.When the content of fiber is 0.3%,the strength of ES increases to 57.80%after one freeze-thaw cycle.According to the stress analysis of matrix and fiber,0.3%PP-ES has the best freeze-thaw damage resistance and the best reinforcement effect on the specimen.When the content of fiber is more than 0.3%,the effect on the sample is mainly toughening.The research results can provide reference for fiber improvement of ES subgrade in cold regions.

关 键 词：岩土工程 膨胀土 冻融循环 抗压强度 

分 类 号：TU411[建筑科学—岩土工程]