摘要
川中红层泥岩是四川盆地广为分布的陆相红色沉积碎屑岩层,具有强度低、易风化、吸水易膨胀的特征,对川中地区变形控制严格的高铁无碴轨道构成了长期潜在的威胁。依托川中地区某客运专线路基持续上拱病害处治工程,开展弱风化泥岩原位膨胀变形试验和室内压力水膨胀变形试验,分析川中弱风化泥岩的吸水膨胀特性、压力水头对泥岩吸水膨胀的影响及关联特征。研究发现,弱风化泥岩吸水膨胀具有显著的时效性,原位膨胀变形试验历时近一个月未收敛,仍具有较大的膨胀潜势,表明自然环境影响下的弱风化泥岩膨胀变形是一个长期缓慢的历程。室内压力水膨胀变形试验表明,红层泥岩吸水能力随着水压增加而增加,膨胀时程曲线经历快速增长、减速增长、渐趋稳定3个阶段,泥岩试样在14.4~49.1 h内完成了90%的吸水变化,在145.2 h完成了98%的试样稳定吸水量。基于上述试验研究成果,进一步对比分析室内外泥岩膨胀变形规律的差异性及其内在机制,为泥岩路基持续变形成因探讨提供思路。
The red mudstone with the characteristics of low strength,easy weathering,and easy expansion of water absorption,which is widely distributed in the Sichuan Basin and resulting a high threat to the high-speed rail operations due to strict control of rail deformation in Sichuan.In reference to the continuous implementation project of subgrade deformation for certain transportation line,the swelling characteristics of the weakly weathered mudstone were correlated with the influence of the mudstone by the pressure head,which were described in this essay.It has been found that the swelling characteristic of weakly weathered mudstone shows a significant time lapse and there is no observation of converging about one month for in-situ swelling test.However,there is still a great potential of swelling which indicates a long and slow process of the swelling of weakly weathered mudstone in the natural environment.The indoor test infers that the absorption capacity of the red mudstone increases with a growing water pressure and the time lapse curve shows three stages:rapid growth,decelerating growth,and gradual stabilization.The specimen reaches 90%of its capacity within 14.4 to 49.1 hours and achieves 98%in 145.2 hours.Based on the research results,the differences in the expansion deformation characteristics of indoor and outdoor mudstones and their internal mechanisms were compared and analyzed,which inspires the exploration of continuous deformation of mudstone subgrade.
作者
冯高顺
余飞
戴张俊
陈善雄
李剑
FENG Gaoshun;YU Fei;DAI Zhangjun;CHEN Shanxiong;LI Jian(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2022年第S01期2780-2790,共11页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金青年基金资助项目(41702337)
关键词
岩石力学
红层泥岩
原位试验
吸水膨胀
压力水
路基上拱
吸水状态
rock mechanics
red-bed mudstone
in-situ test
water absorption swelling
pressure water
subgrade uplift
water absorption condition
