【摘要】 [目的]探究福建省崩壁碎屑层土壤在不同硫酸钙施用条件下的力学强度及微观特征，为今后崩壁土壤恢复和水土保持治理提供数据支撑。[方法]以福建省典型花岗岩崩岗碎屑层土壤为研究对象，以硫酸钙为改良剂，设置0,5,10,15 g/kg 4个浓度梯度，通过室内重塑土试验，使用直剪试验获得了不同剂量下改良土壤的黏聚力和内摩擦角，采用扫描电子显微镜获得了不同浓度下土壤的表观孔隙率。[结果]添加15 g/kg硫酸钙土壤抗剪强度提升效果最佳，在300 kPa垂直荷载条件下，抗剪强度增加9.04%。随着使用量增加，土壤黏聚力比对照处理依次增加27.24%,53.57%,49.39%。改良后土壤内摩擦角变化均不显著，但随着施用浓度的增加均表现出先降低再增加的趋势，且低于空白对照，依次降低8.73%,17.35%,3.91%。添加硫酸钙通过促进土壤形成大团聚体改变了碎屑层土壤的微观结构，低浓度硫酸钙添加下，土壤颗粒呈现大块片状为主，各颗粒之间相距较远且孔隙度大，添加量为15 g/kg时，土壤形成特殊堆叠书页状为主的结构，随着施用浓度增加，土壤表观孔隙率依次减小了15%,25%,47.5%。[结论]添加硫酸钙可以增加碎屑层土壤的力学强度，对治理崩岗有重要指导意义。更多还原

【Abstract】 [Objective]The aims of this study are to explore the mechanical strength and microscopic characteristics of soil in the debris layer of collapsed walls in Fujian Province under different conditions of calcium sulfate application, and to provide data support for future soil restoration and soil and water conservation management. [Methods] This study focuses on the debris layer soil of typical granite collapsed rock gullies in Fujian Province. Calcium sulfate was employed as the ameliorating agent, with four concentration gradients(0, 5, 10, 15 g/kg). Through indoor remolding soil tests and direct shear tests, cohesive force and internal friction angle of the ameliorated soil at different doses were obtained. The apparent porosity of soil at different concentrations was obtained by using Scanning Electron Microscopy(SEM). [Results] The optimal enhancement in shear strength is achieved with the addition of 15 g/kg calcium sulfate, resulting in a 9.04% increase under a 300 kPa vertical load. As the dosage increases, the soil cohesive force sequentially increases by 27.24%, 53.57%, and 49.39% compared to the control treatment. The change in the internal friction angle of the ameliorated soil is not significant, but it exhibits a trend of initial reduction followed by an increase with increasing application concentration, consistently lower than the blank control, decreasing by 8.73%, 17.35%, and 3.91%, respectively. The addition of calcium sulfate promotes the formation of large aggregates in the soil and changes the microstructure of the detrital layer soil. With the addition of low concentration calcium sulfate, the soil particles are mainly in the form of large blocks and flakes, and the distance between each particle is far and the porosity is large. When the addition amount is 15 g/kg, the soil forms a special stacked book page structure, and as the application concentration increases, the apparent porosity of the soil decreases by 15%, 25%, and 47.5%, respectively. [Conclusion] In summary, adding calcium sulfate can increase the mechanical strength of soil in the debris layer, which has important guiding significance for the Benggang management.更多还原