摘要
为探究巴东组红层在风化作用下发生的强度损失效应,该文以巴东组紫红色粉砂岩为研究对象,开展了反复干-湿循环过程下强度折损试验。试验结果显示:巴东组泥质粉砂岩在15次干-湿循环之前,波速缓慢降低,而当干-湿循环次数超过15次后,波速降低速度增大。泥质粉砂岩的强度和变形指标总损失率均随干-湿循环次数的增加而增大。初始阶段泥质粉砂岩的强度折损并不明显,单轴抗压强度σ_(c)损失率仅为1.41%,弹性模量E损失率1.08%,随着干-湿循环次数的增加,单轴抗压强度σ_(c)损失率达到46.62%,弹性模量E损失率达到49.24%。总体而言,在风化程度较低的状态下,巴东组粉砂质泥岩的抗风化能力相对较强。而当风化强度达到某一程度时,岩体内孔隙、裂隙等将加速发展,风化速度加快。
In order to explore the strength loss effect of the red layer of Badong Formation under weathering,the strength loss test under repeated dry-wet cycling is carried out with the purplish red siltstone of Badong Formation as the research object.The test results show that the wave velocity of argillaceous siltstone in Badong Formation decreases slowly before the dry-wet cycling 15 times,but increases when the dry-wet cycling exceeds 15 times.The total loss rate of strength and deformation index of argillaceous siltstone increases with the increase of the number of dry-wet cycling.In the initial stage,the strength loss of argillaceous siltstone is not obvious.The loss rate of uniaxial compressive strength σ_(c) is only 1.41%,and the loss rate of elastic modulus E is 1.08%.With the increase of dry-wet cycling times,the loss rate of uniaxial compressive strength σ_(c) is 46.62%,and the loss rate of elastic modulus E is 49.24%.In general,the silty mudstone of Badong Formation has a relatively strong weathering resistance under the condition of low weathering degree.When the weathering stress reaches a certain degree,the pores and cracks in the rock mass will develop accelerately and the weathering speed will be accelerated.
作者
高波
孙狂飙
曾俊源
周峙
张家铭
Gao Bo;Sun Kuangbiao;Zeng Junyuan;Zhou Zhi;Zhang Jiaming(Anhui Transport Consulting&Design Institute Co.,Ltd.;Highway Transportation Energy Saving and Environmental Protection Technology Research and Development Center of Transportation Industry;Anhui Transportation Holding Group Co.,Ltd.;China University of Geoscience(Wuhan))
出处
《勘察科学技术》
2022年第5期19-23,共5页
Site Investigation Science and Technology
基金
安徽交通控股集团科技项目(JKKJ-2021-04)
关键词
巴东组红层
泥质粉砂岩
干湿循环
波速
强度折损
Badong Formation red layer
argillaceous siltstone
dry-wet cycling
wave velocity
strength loss
