饱水作用下红层软岩强度劣化试验研究  

Experimental Study on Strength Deterioration of Red Layer Soft Rock under Saturated Water

作　　者：吴乐珠 贺建清[1] 林滢 刘科宏 范文韬 WU Le-zhu;HE Jian-qing;LIN Ying;LIU Ke-hong;FAN Wen-tao(Hunan Provincial Key Laboratory of Geotechnical Engineering for Stability Control and Health Monitoring,Hunan University of Science and Technology,Xiangtan,Hunan,411100,China)

机构地区：[1]湖南科技大学岩土工程稳定控制与健康监测省重点实验室,湖南湘潭411100

出　　处：《建材技术与应用》2025年第1期40-46,共7页Research and Application of Building Materials

基　　金：国家自然科学基金资助项目(52078211)。

摘　　要：红层软岩是红层中的软弱岩类,具有强度低、抗风化能力差、遇水易软化和失水崩解等特点,受降雨影响,边坡极易沿红层软弱夹层发生破坏。以沅麻盆地红层软岩为研究对象,开展不同饱水时长和围压下的三轴压缩试验,研究红层软岩在水岩作用下的物理力学性质,得到红层软岩水-岩作用下的力学劣化规律。研究结果表明:红层软岩在三轴条件下抗压强度均随着围压的增大而增大,但增大的趋势逐渐变缓。天然状态下的岩石试样在试验前期存在孔隙裂隙压密阶段,经历了弹性变形阶段、塑性变形阶段及在达到峰值应力后存在典型的应变软化现象。随着泡水时间的增长,相同围压下的红层试样三轴抗压强度明显下降;试验前期的孔隙裂隙压密阶段消失,在达到峰值应力后的应力软化特性不明显。三轴压缩条件下,天然状态下红层软岩破坏模式按围压从小到大分别表现为拉应力下的拉断破坏、压应力下拉断破坏、剪切破坏、剪切与局部压碎;随着泡水时间的增加,岩石破坏模式表现为剪切破坏,随机的次生裂纹发育增加。Red layer soft rock refers to the soft rock in the red layer,which has the characteristics of low strength,poor weathering resistance,easy to soften in water and water loss.Affected by rainfall,the slope is easy to damage along the red layer weak interlayer.Taking the red layer soft rock in Yuanma Basin as the research object,this paper carried out the triaxial compression test under different water filling time and surrounding pressure,studied the physical and mechanical properties of red layer soft rock under water rock,and obtained the mechanical deterioration law of red layer soft rock.The results showed that the compressive strength of red soft rock increases with the increase of circumference pressure,but the trend was gradually decreasing.Rock samples in natural state had pore fracture compaction stage in the early test stage,experienced elastic deformation stage,plastic deformation stage,and typical strain softening phenomenon after reaching the peak stress.With the increase of water soaking time,the triaxial compressive strength of the red layer sample under the same surrounding pressure decreased significantly,the pore fissure compaction stage in the early test stage disappeared,and the stress softening characteristic was not obvious after reaching the peak stress. Under triaxial compression condition,the destruction mode of red soft rock showed the pull failure,tensile failure, shear failure, shear and local crushing under tensile stress. With the increase of water soaking time,the rock destruction mode was shear failure, and the development of random secondary cracks increased.

关 键 词：红层软岩 水岩作用 三轴试验 强度劣化 

分 类 号：TU45[建筑科学—岩土工程]