摘要
弯月面水膜的存在会影响非饱和土的抗剪强度。土的亲水性和疏水性影响着其物理-力学行为、接触角和毛细压力。在非饱和土力学领域,迄今积累的岩土技术知识多局限于亲水性土。该文利用人工合成的疏水性砂,研究了弯月面水膜的存在对疏水性和亲水性非饱和砂剪切性能的影响,讨论了基质吸力对剪切强度的作用。结果显示:弯月面水膜对非饱和状态砂的剪切行为存在较大的影响。亲水性砂的剪切强度和剪胀性均大于疏水性砂。对于疏水性砂,砂中水分并非以弯月面水膜的形态存在,而是以水珠的形态存在于颗粒表面,初始饱和度对剪切强度影响较小,但对剪胀性影响较大。对于亲水性砂,剪切强度随着初始饱和度的减小而增大。
Meniscus water affects the shear strength of unsaturated soils.The soil wettability affects the physio-mechanical behavior,the contact angle and the capillary pressure.The current geotechnical knowledge of these effects in unsaturated soils is mostly limited to hydrophilic soils.This paper analyzed hydrophobic and hydrophilic sands to show how meniscus water affects the shear behavior of unsaturated soils using artificially synthesized hydrophobic sands.In addition,the measured shear strengths were analyzed based on the suction stress.The results show that the meniscus water greatly influences the unsaturated shear behavior.The shear strength and dilatancy of hydrophilic sands are greater than those of hydrophobic sands.For hydrophobic sands,the water in the soil is not in the form of meniscus water,but in the form of water droplets on the particle surface.Therefore,the initial saturation has little effect on the shear strength,but a large effect on the dilatancy.For hydrophilic sands,the shear strength increases with decreasing initial saturation.
作者
陈宇龙
孙欢
CHEN Yulong;SUN Huan(State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084.China)
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2019年第12期961-966,共6页
Journal of Tsinghua University(Science and Technology)
基金
中国博士后科学基金资助项目(2017M620048,2018T110103)
关键词
弯月面水膜
亲水性砂
疏水性砂
非饱和土
吸力
meniscus water
hydrophilic sand
hydrophobic sand
unsaturated soil
suction
