格宾网加筋红砂岩粗粒土的强度和变形特性

Strength and deformation characteristics of red-sandstone granular soil reinforced with gabion mesh

开展了不同加筋层数、不同压实度、不同含水率的格宾网加筋红砂岩粗粒土大三轴试验,分析格宾网层数、试样含水率和压实度对红砂岩粗粒土应力应变关系、强度和变形特性的影响,引入强度比参数评价加筋效果,并与土工格栅加筋方案进行对比。试验结果表明:格宾网加筋能明显提高红砂岩粗粒土的峰值强度和土体延性;格宾网加筋使红砂岩粗粒土的黏聚力大幅提升,但其内摩擦角提高幅度不大;在同一压实度下,加筋和未加筋土体的黏聚力随含水率变化呈现非线性变化关系,且在最佳含水率附近达到峰值;在同一含水率下,黏聚力和内摩擦角随试样压实度的增加而增大;加筋效果与加筋层数、土体含水率和压实度有关,格宾网加筋的作用发挥随围压增大而减小。

Large-scale triaxial tests are carried out on gabion mesh reinforced red-sandstone granular soil with different reinforcement layers,compaction degrees and water contents.The effects of gabion mesh reinforcement layers,water content and compaction on the stress-strain relationship and strength properties of red-sandstone granular soil are analyzed.The reinforcing effects are evaluated by introducing the strength ratio parameter.A comparison between the geogrid and the gabion mesh reinforced red-sandstone granular soil is conducted.The experimental results show that the peak strength,cohesion and ductility of the red-sandstone granular soil are obviously improved by gabion mesh reinforcements,but its internal friction angle is not greatly improved.The cohesions of the reinforced soil and the plain soil exhibit non-linear relationships with their water content under the same compaction,moreover,there is a maximum value near the optimum water content.The cohesion and internal friction angle increase with the increase of compaction under the same water content.The reinforcing effect relates with the number of gabion mesh layers,water content and compaction of soil,and the effect of the gabion mesh reinforced soil decreases with the increase of the confine pressure.