摘要
以桂林雁山红黏土为研究对象,对经历不同干湿循环次数后的试样进行快剪试验,得到其剪切强度,研究自然状态下反复的降雨和干旱气候对土体强度的影响。试验结果表明,经历多次干湿循环后饱和状态下红黏土样无明显峰值,为应变硬化;干燥状态下土样出现明显峰值,为应变软化,且其曲线前部还出现"平台"状,随着干湿循环次数的增多,饱和状态下和干燥状态下的黏聚力均逐渐降低,而两者的内摩擦角则均呈现整体逐渐增大的趋势,干燥状态下土样的抗剪强度参数均较饱和状态下的土样大,黏聚力和内摩擦角的变化幅度都十分显著。为进一步研究干湿循环对土样抗剪强度及剪切强度参数的影响,量测了干湿循环过程中试样的体积变化情况后发现,随着循环次数的增多,试样体积先不断地减小,然后基本保持不变。
To study the effect of precipitation and drought weather on soil shear strength, a series of quick shear tests is performed on karst red clay samples sampled from Yanshan area of Guilin city, which have been subjected to several wetting/drying cycles. The experimental results show that after several drying and wetting cycles, the red clay samples under fully saturated conditions have no significant peak value in their shear strain-shear stress relationship, showing strain hardening behavior, whereas the oven-dried samples have significant strength peak values, showing strain softening behavior, and their strength tend to be stable as the development of strain. With the increase of the drying/wetting cycle number, both cohesion and frictional angle gradually decrease for both fully saturated and oven-dried samples. Both the cohesion and internal friction angle of oven-dried samples are larger than those of the fully saturated samples, showing more significant variations. In order to study the effects on shear strength and strength parameters of soil samples, the volume changes of the soil samples are also measured after different cycles of wetting and drying. It is found that with the increase of the number of cycles, the volume of the sample decreases first and then remains unchanged.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2017年第S2期191-196,共6页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.11372078
No.51309055)~~
关键词
红黏土
干湿循环
剪切强度
red clay
wetting and drying cycles
shear strength
