纤维加筋风沙土强度特性试验研究

Test Study on Strength Properties of Fiber Reinforced Aeolian Sandy Soil

对不同纤维加筋方案和围压的聚丙烯纤维加筋风沙土进行三轴试验,研究纤维加筋风沙土应力-应变关系和强度特性。试验表明,纤维掺入明显提高风沙土强度,且随着围压增加而提高。在试验方案内,规格化应力比和强度加筋效果系数(代表加筋材料的利用效率)均在围压为100k Pa时最大。强度加筋效果系数与纤维长度成正比,而与围压成反比。纤维掺入风沙土内摩擦角几乎不变,而粘聚力与纤维长度和纤维掺量成正比。基于以上分析提出适用于纤维加筋风沙土强度经验公式,并讨论了土颗粒与纤维之间的作用机理。

The stress-strain behavior and the strength properties of aeolian sandy soil reinforced with polypropylene fiber are investigated under different fiber schemes and confining pressures through triaxial compression tests. The test results show that,fiber inclusion can significantly enhance the strength of aeolian sandy soil,and the higher confining pressure performs on soil,the higher strength will be. Under the given test scheme,normalized stress ratio and effect coefficient of reinforcement strength（ represent the availability of reinforcement material） both reach the maximum at confining pressure of 100 k Pa. The effect coefficient of reinforcement strength is proportional to fiber length,whereas inversely to confining pressure. Fiber inclusion has almost no affect on internal friction angle of aeolian sandy soil,whereas the cohesion is proportional to fiber length and fiber content. Based on the above analysis,an empirical equation used to evaluate the strength of fiber reinforced aeolian sandy soil is proposed,and the action mechanism between fiber and soil grains is discussed.