加筋率对稻秸秆加筋土开裂特性的试验研究

针对花岗岩残积土边坡生态防护采用的稻秸秆加筋土，通过室温与模拟日照条件下的加筋土开裂试验研究稻秸秆加筋率对土体开裂性能的影响规律，结果表明:室温条件下稻秸秆加筋率为0.3%，0.4%和0.5%的试样均未发生开裂；模拟日照条件下加筋土试样开裂过程按裂缝宽度发展速度可分为缓慢发展Ⅰ、快速发展Ⅱ、缓慢发展Ⅲ和稳定发展Ⅳ4个阶段，快速发展阶段加筋率0%，0.4%，0.5%的试样均完成70%以上的裂缝开裂宽度，加筋土样含水率呈现出快—慢—快—慢的变化过程，而裂缝宽度呈现快—慢—稳定的变化过程，稻秸秆对试样具有保湿作用，但加筋率过多会导致土样中的空隙增大，为水分蒸发提供通道；稻秸秆加筋土开裂的界限加筋率应为0.3%，其结果可为稻秸秆加筋土生态防护设计提供借鉴。

An experiment study of cracking properties of rice straw reinforced soil with different ratios

In order to reduce the effect of dry cracking on the protective effect of rice straw in ecological protection of granite residual soil slope, the effect of rice straw reinforcement rate on soil cracking behavior and the interaction between rice straw and soil are examined by the cracking test of reinforced soil under the simulated temperature and simulated sunshine conditions. The results show that the samples with the straw reinforcement rates of 0.3%, 0.4% and 0.5% at room temperature do not crack at room temperature. According to the width of the crack growth rate, the cracking process of reinforced soil samples under simulated sunshine conditions can be divided into 4 stages: slow development Ⅰ, rapid development Ⅱ, slow development Ⅲ and stable development Ⅳ. Rice straw reinforced has a moisturizing effect on the samples. But too much blending ratio will lead to the gap in soil to increase, which provides a convenient channel for water to escape into the atmosphere. In this paper, the limit reinforcement ratio of the rice straw reinforced soil cracking should be 0.3% ~ 0.4%, and the results provide reference for the protection of the ecological design of rice straw reinforced soil.