玄武岩纤维加筋黄土力学参数优化试验研究

Experimental study on optimization of mechanical parameters of reinforced loess with basalt fiber

为了研究玄武岩纤维加筋黄土的力学性能,通过正交试验设计进行无侧限抗压强度试验,并采用极差分析和方差分析相结合的方法对试验结果进行分析,研究了含水率、纤维掺量、压实度等3个主要因素对玄武岩纤维加筋黄土无侧限抗压强度影响的主次顺序。随后还基于分析结果进行固结不排水三轴压缩试验,进一步研究了纤维掺量对玄武岩纤维加筋黄土抗剪强度指标的影响规律。研究结果表明:影响玄武岩纤维加筋黄土抗压强度的主次因素顺序依次为纤维掺量、含水率、压实度;方差分析得到的最优水平组合为纤维掺量0.4%、含水率11%、压实度0.95;玄武岩纤维的掺入能够有效提高抗剪强度,凝聚力随掺量的增加先增后减,而内摩擦角波动区间较小;玄武岩纤维加筋黄土的应力-应变关系总体能够较好地符合双曲线模型,其拟合结果b值随围压增大而减小,随纤维掺量增加而先增后减,且纤维掺量存在0~0.2%这一临界区间。

In order to study the mechanical properties of reinforced loess with basalt fiber,orthogonal design was used to carry out unconfined compressive strength test.The test results were analyzed using a combination of range analysis and variance analysis to study the influence of water content,fiber content,compactness on the unconfined compressive strength of basalt fiber-reinforced loess.Furthermore,based on the analysis results,the consolidated undrained triaxial compression test was conducted to study the the effect of fiber content on shear strength index of basalt fiber loess.The study results showed that the primary and secondary factors affecting the compressive strength of the basalt fiber loess were fiber content,water content,and compactness.The optimal level combination obtained by analysis of variance was 0.4%fiber content,11%water content,and compaction degree 0.95.The basalt fiber can effectively improve the shear strength,the cohesion increased first and then decreased with the increase of the fiber content,and the internal friction angle fluctuation range was small.The stress-strain relationship of the basalt fiber loess can generally follow the?hyperbola curve model,the b value of the fitting result decreased with increasing of the confining pressure,and increased first and then decreased with the blending amount.The critical fiber blending amount was closely related to the b value of the fitting result,and the critical interval is 0~0.2%.