生物炭-植被协同防护膨胀土边坡的抗裂防渗特性研究OA

To enhance the cracking resistance and anti-seepage performance of expansive soil slope surfaces in wetting-drying cycles while maximizing the ecological benefits of vegetation,a novel synergistic protection method combining biochar and vegetation was proposed.Outdoor wetting-drying cycle tests were conducted on expansive soil slopes,with real-time monitoring of volumetric water content,vegetation growth parameters and crack morphological indicators.The influence of the biochar-vegetation synergistic effect on crack evolution and rainwater infiltration behavior were elucidated.The results indicate that the synergistic protection significantly strengthens the cracking resistance of expansive soil slopes.During wetting-drying cycles,extensive cracks develop on surfaces of bare expansive soil slope(S1)and the vegetation-only protected slope(S2),where adjacent primary and secondary cracks rapidly intersects to form complex networks.In contrast,crack development on biochar-vegetation protected slope(S3)is relatively slow,with the peak crack ratio reduced by 51.92%and 40.89%compared to S1 and S2,respectively.The synergistic mechanism primarily involves mitigating the swell-shrink potential,reducing the dehydration-induced tensile stress field,and enhancing the tensile strength of the soil.Consequently,the anti-seepage performance of the slope is significantly improved due to crack suppression.Under the influence of preferential flow through cracks,transient saturated zones are formed within S1 and S2,leading to a sharp decline in matric suction.Conversely,the volumetric water content and matric suction within S3 remain relatively stable.These findings provide a theoretical basis and practical reference for the ecological protection design of expansive soil slope surfaces.