为抑制干湿循环下炭质泥岩崩解与强度劣化作用,开展干湿循环作用下有机硅改性炭质泥岩无侧限抗压强度及崩解试验,研究干湿循环次数、有机硅掺量对改性炭质泥岩无侧限抗压强度、粒径级配、不均匀系数与曲率系数等参数的影响,明确有机硅对炭质泥岩强度劣化及崩解特性的抑制作用,并通过扫描电镜分析有机硅改性炭质泥岩在干湿循环作用下微观结构的变化规律,揭示其抑崩解机制。结果表明：改性炭质泥岩的无侧限抗压强度与有机硅掺量成正相关,与干湿循环次数成负相关；有机硅的团聚作用可有效增大炭质泥岩粒径,掺入有机硅后,改性炭质泥岩大于2mm的粗颗粒含量、最大粒径Dmax和最小粒径Dmin均显著增大,且崩解过程中[10mm, 20mm)、[5mm, 10mm)和[2mm, 5mm)粒组的改性炭质泥岩颗粒含量变化最为剧烈,但有机硅掺量越多,粒径变化幅度越小；改性炭质泥岩的中值粒径d50、Weibull分布参数(λ、k)、分形维数D、耐崩解指数Idn与崩解比Dr等参数均与有机硅掺量呈正相关,与干湿循环次数呈负相关,而不均匀系数Cu的变化规律与之相反。有机硅主要是通过网状结构胶联炭质泥岩颗粒并在其表层形成疏水膜等作用抑制其强度劣化及崩解。

s: To reduce the degradation of strength and inhibit the disintegration of carbonaceous mudstone by wet and dry cycling, tests on the unconfined compressive strength and disintegration of silicone-modified carbonaceous mudstone under wet and dry cycling were carried out. The effects of the number of dry and wet cycles and the amount of organosilicon on the unconfined compressive strength, grain size gradation, inhomogeneity coefficient and curvature coefficient of the modified charcoal mudstone were studied, and the inhibition effect of organosilicon on the strength deterioration and disintegration characteristics of the charcoal mudstone was clarified. The changing law of microstructure of organosilica-modified carbonaceous mudstone under dry and wet cycling was also analyzed by scanning electron microscopy to reveal its mechanism of inhibiting disintegration. The results showed that the unconfined compressive strength of modified carbonaceous mudstone was positively correlated with the organosilicon dosing and negatively correlated with the number of wet and dry cycles. Organosilicon can effectively increase the grain size of carbonaceous mudstone, and the content of coarse particles larger than 2mm, the maximum grain size(Dmax) and the minimum grain size (Dmin) of modified carbonaceous mudstone were significantly increased after the incorporation of organosilicon. Meanwhile, the particle content of modified carbonaceous mudstone in the [10mm, 20mm), [5mm, 10mm) and [2mm, 5mm) grain groups changed most drastically during the disintegration process, but the greater the organosilicon doping, the smaller the magnitude of the change in grain size. Moreover, the higher the silicone doping, the smaller the change in particle size. The median grain size (d50), Weibull distribution parameters (λ, k), fractal dimension (D), disintegration resistance index (Idn) and disintegration ratio (Dr) of modified charcoal mudstone were positively correlated with silicone dosing and negatively correlated with the number of wet and dry cycles. However, the variation rule of the inhomogeneity coefficient (Cu) is opposite to it. The organosilicones mainly inhibit the strength deterioration and disintegration of carbonaceous mudstone particles through the network structure of the colloidal link and the formation of hydrophobic film on the surface layer of the carbonaceous mudstone particles.

TU375.4

(Foundation item)：国家自然科学基金资助项目(52378440,52078066,52078067)；交通运输行业重点科技项目(2022-MS1-032)；湖南省自然科学基金杰出青年(2023JJ10045)；长沙市杰出创新青年培养计划(kq2305023)；长沙理工大学“双一流”科学研究国际合作拓展项目(2019IC04)；桥梁工程安全控制教育部重点实验室开放基金资助项目(15KB01)