冻融循环对木质纤维水泥土抗剪强度劣化特性的试验研究  

Experimental Study on Deterioration of Shear Strength of Lignocellulosic Cement Soil Under Freeze-thaw Cycles

作　　者：范留军 路晓明[1] 李伟 FAN Liu-jun;LU Xiao-ming;LI Wei(Zhengzhou Key Laboratory of Geosynthetics,Zhengzhou University o£Science and Technology,Zhengzhou 450064,China;School of Civil Engineering and Architecture,Linyi University,Linyi 276000,China)

机构地区：[1]郑州科技学院郑州土工复合材料重点实验室,河南郑州450064 [2]临沂大学土木工程与建筑学院,山东临沂276000

出　　处：《水电能源科学》2022年第7期167-170,共4页Water Resources and Power

基　　金：国家自然科学基金项目(11902134);河南省教育厅高校重点研究项目(20B110020)。

摘　　要：在季节性冻土地区,水泥土因反复冻融引起内部微观结构破坏,导致抗剪强度指标劣化,而木质纤维在水泥土中能形成拉结网状结构,有效减轻冻融对其的劣化。为此,对冻融循环作用下木质纤维水泥土开展质量劣化和剪切试验,研究了冻融循环对木质纤维水泥土抗塑强度指标的影响。结果表明,随着冻融循环次数的增加,不同纤维掺量水泥土质量损失率线性增加,粘聚力先快速减小后趋于收敛稳定,呈指数型分布,而内摩擦角呈线性降低的趋势,且冻融作用对粘聚力的劣化程度要远大于内摩擦角。基于三维曲面图和试验数据,给出了粘聚力、内摩擦角与纤维掺量、冻融次数的拟合公式,并指出木质纤维最佳掺量为1%。In seasonally frozen soil regions, the internal microstructure of cement soil is damaged due to repeated freezing and thawing, resulting in the degradation of shear strength index. While wood fiber can form a tensile network structure in cement soil to effectively reduce the degradation caused by freezing and thawing. Therefore, the quality degradation and shear tests of wood fiber cement soil under freeze-thaw cycle were carried out, and the effect of freeze-thaw cycle on the shear strength index of wood fiber cement soil was studied. The results show that with the increase of the number of freeze-thaw cycles, the mass loss rate of cement soil with different fiber content increases linearly;The cohesion first decreases rapidly and then tends to converge and stabilize, showing an exponential distribution;While the angle of internal friction decreases linearly, and the degradation degree of freeze-thaw on the cohesion is much greater than the angle of internal friction. Based on the three-dimensional surface diagram and experimental data, the fitting formulas of cohesion, angle of internal friction with fiber content and freeze-thaw times are obtained, and it is pointed out that the best content of wood fiber is 1%.

关 键 词：冻融循环 水泥土 木质纤维 抗剪强度 劣化 

分 类 号：TU47[建筑科学—结构工程] TV41[建筑科学—土工工程]