摘要
以混凝土铰接块+土工布+黏土护坡结构室内模型为研究对象,分别讨论不同含水量及冻融循环次数下接触面间抗剪强度指标的变化规律.分别测定常温下护坡结构含水量在15.7%～28%之间的黏聚力(C)和内摩擦角(φ)值,含水量为18%以及饱和状态下经过10次冻融循环的C值和φ值,采用多元回归法进行分析.结果表明:含水量对护坡结构的抗剪强度指标弱化十分明显,斜面摩擦试验中黏聚力和内摩擦角均随含水量增加而降低;含水量与内摩擦角呈线性相关关系,与黏聚力呈乘幂关系.冻融循环过程水分迁移导致砼护坡界面水分增大,界面抗剪强度指标弱化.随冻融循环次数的增加砼铰接块护坡界面的抗剪强度减小,对于非饱和黏性土,在5次冻融循环时减小幅度较大,但10次冻融循环时减小幅度较小并基本趋于稳定;而对于饱和黏性土,其抗剪强度指标随冻融循环次数的增加减小幅度并不明显.
The indoor model of hinged concrete block, geotextile and clay slope structure was taken to study the interracial shear strength with different soil moisture and different freeze-thaw cy- cles. The cohesion and internal friction angle val- ues were measured with soil moisture between 15.7% and 28% at room temperature, and after 10 freeze and thaw cycles with soil moisture at 18 % as well as with saturated water content. Finally, their relationships are obtained through multiple regression analysis. It is found that： 1） soil mois- ture has apparent effect on shear strength of slope protection structure, and the cohesion and internal friction angle decreases with soil moisture in the inclined plane friction test. There is a linear relation between the soil moisture and the internal fric- tion angle. However, a power relation is found be- tween the moisture content and the cohesion. 2） In the {reeze and thaw process, soil water migration leads to an increase of interracial water in concrete slope protection, with a decrease of interfacial shear strength. The shear strength of the concrete block revetment interface reduces with the number of freeze-thaw cycles. With regard to the unsatu- rated clay, the decreasing extent is relatively large at the fifth freeze-thaw cycle, while after 10 freeze- thaw cycles it is small and verges to a stationary state. However, for the saturated clay, the de- creasing extent of the shear strength is not obvious with increase of the cycles.
出处
《冰川冻土》
CSCD
北大核心
2012年第5期1173-1178,共6页
Journal of Glaciology and Geocryology
基金
黑龙江省科技攻关项目(GZ10A503)
水利部公益性行业专项经费项目(201001027)资助
关键词
季节冻土
冻融循环
砼铰接块护坡
界面抗剪强度特性
试验研究
seasonally frozen soil
freeze thaw cycle
concrete block slope protection
interface shearstrength
experimental study
