粉粒含量对高吸力作用下非饱和土力学行为的影响  

Influence of the Silt Content on Mechanical Properties of Unsaturated Soil Under High Suction

作　　者：崔宏环 胡淑旗 訾亚丹 CUI Honghuan;HU Shuqi;ZI Yadan(Hebei Provincial Key Laboratory of Civil Engineering Diagnosis,Reconstruction and Disaster Resistance,Zhangjiakou 075000,China;College of Civil Engineering,Hebei University of Architecture,Zhangjiakou 075000,China)

机构地区：[1]河北省土木工程诊断、改造与抗灾重点试验室,河北张家口075000 [2]河北建筑工程学院土木工程学院,河北张家口075000

出　　处：《工业建筑》2023年第12期182-189,197,共9页Industrial Construction

基　　金：河北建筑工程学院创新基金项目(XY202208)。

摘　　要：常年处于寒-旱交替、蒸发远大于降水地区的路基边坡土体,大多数时期呈现高吸力非饱和状态。为研究粉粒含量对高吸力非饱和土的土-水特性及强度的影响规律,利用饱和盐溶液蒸汽平衡法对不同粉粒含量土样施加高吸力并进行非饱和土三轴试验和劈裂抗拉试验。结果表明:粉粒含量对非饱和土进水值影响显著,两者呈负相关,粉粒含量升高,土样持水能力下降;粉粒含量和吸力均对抗拉强度具有劣化作用,双因素同时作用引起土体的开裂深度增大。吸力对土样变形具有抑制作用,吸力越高,吸力提供的黏聚力越大。粉粒含量升高对土体弹性模量劣化作用显著,从模量角度定义脆性指数,对粉粒含量影响下高吸力非饱和土的脆性特征进行评价,发现粉粒含量主要通过影响峰后割线模量改变高吸力非饱和土的脆性。The soil of subgrade slopes in areas with alternating cold and dry seasons throughout the year,where evaporation is much greater than precipitation,is in a unsaturated state with high suction most of the time.To study the influence of the silt content on soil-water characteristics and strength of unsaturated soil with high suction,the vapor equilibrium method of saturated salt solution was used to apply high suction to soil with different contents of silt,triaxial tests and splitting tensile tests were conducted on unsaturated soil.The test results indicated that:the silt content had a significant effect on the water intake value of unsaturated soil,there was a negative correlation between the two.The water-held capacity of the soil decreased with the increase of the silt content.Both the silt content and suction had a deteriorating effect on the tensile strength,and both factors simultaneously led to increase in the crack depth of soil.Suction had an inhibitory effect on the deformation of soil,the larger the suction was,the larger the cohesion provided by the suction was.The increase in the silt content had a significant effect on the degeneration of soil elastic moduli.The brittleness characteristics of unsaturated soil with high suction influenced by the silt content were evaluated by defining the brittleness index from a perspective of moduli.It was found that the brittleness of unsaturated soil with high suction was altered by the silt content mainly through the influence of the post-peak secant modulus.

关 键 词：粉粒含量 高吸力 土水特性 抗拉强度 

分 类 号：TU43[建筑科学—岩土工程]