摘要
红层泥岩填料易软化崩解、强度低、蠕变特性显著且具有膨胀性,诱发了大量工程地质灾害,准确掌握红层泥岩物化特性及力学行为对揭示灾害诱因至关重要.以兰州红层泥岩填料为研究对象,采用室内土工试验、扫描电镜、X射线分析及三轴剪切试验,先测试红层泥岩填料的物理力学指标,再分析红层泥岩矿物成分及微观结构机理,最后基于Duncan-Chang模型探究符合红层泥岩填料最佳归一化因子并验证归一化模型.结论表明:兰州红层泥岩填料为肉眼可分辨的红色沉积岩,属于CL,有明显的压缩回弹特性,矿物成分含有大量的亲水性物质,微观结构为层状和层-链状的面-面接触或点-面接触结构.红层泥岩应力-应变曲线呈三阶段发展,随着围压增加应力-应变曲线由应变稳定型过渡为应变硬化型,当归一化因子选用(σ1-σ3)ult时,Duncan-Chang模型预测结果与试验结果吻合度较好,归一化效果最佳.
The red-layered mudstone fill is easy to soften and disintegrate, whichhas thecharacteristicsof low strength, significant creep and well expansion, and it is likely tocause a large number of engineering geological disasters.The physical and mechanical indexes of red mudstone fillings were tested by indoor geotechnical tests, scanning electron microscopy, X-ray analysis and triaxial shear test, then the mineral composition and microstructure mechanism of red mudstone fillings is analyzed.The results show that the red sedimentary rock of Lanzhou red mudstone filler is visible to the naked eye, which belongs to CL and has obvious compression rebound characteristics.The mineral composition contains a large amount of hydrophilic substances, and the microstructure is layered, layer-chained surface-surface contact, and point-surface contact structure.The stress-strain curve of red mudstone develops in three stages.With the increase of confining pressure, the stress-strain curve changes from strain stable type to strain hardening type. When the normalization factor is(σ1-σ3)ult,the prediction results of Duncan-Chang model are in good accordance with the experimental results, among which the normalization effect is the best.
作者
罗崇亮
余云燕
包得祥
王鹏
陶婧衍
崔文豪
LUO Chong-liang;YU Yun-yan;BAO De-xiang;WANG Peng;TAO Jing-yan;CUI Wen-hao(School of CivilEngineering,Lanzhou Jiaotong University,Lanzhou730070,China;GansuNew Urban Development&Construction Operation Group Co.Ltd.,Lanzhou 730000,China;Gansu Heng-shi Highway Inspection Technology Co.,Ltd.,Lanzhou730070,China)
出处
《兰州交通大学学报》
CAS
2023年第1期1-8,37,共9页
Journal of Lanzhou Jiaotong University
基金
中央引导地方科技发展资金(22ZY1QA005)
甘肃省科技计划资助项目(21YF5GA050)
甘肃省教育厅产业支撑计划资助项目(2021CYZC-28)
甘肃省交通运输厅科技研发资助项目(2021-12)
甘肃省基础研究创新群体资助项目(21JR7RA347)。
关键词
红层泥岩填料
微观结构机理
三轴剪切试验
归一化模型
red mudstone filler
microstructure mechanism
triaxial shear test
Duncan-Chang model
normalized model
