摘要
硬填料是一种筑坝新材料,在坝工建设中有广阔的应用前景。其应力-变形特性介于堆石体和混凝土之间。通过进行硬填料不同龄期的大型三轴试验,着重分析了硬填料的胶结作用在不同龄期对应力-应变关系的影响,进一步揭示了硬填料的强度和应力-应变特征。将表征硬填料初始形成状态的堆石体概化为"堆石元件",将胶凝材料的胶结作用概化为"胶结元件",进而提出了基于应变一致假定的二元并联概念模型,确定了模型参数并与试验结果进行对比,表明该模型既能描述硬填料应力-应变非线性特征又能描述变形模量随着龄期增长的特征。结合二元并联模型的特点,提出了求取模型参数的简化方法。
Hardfill is a new type of architectural material for dam construction, with a wide application prospect. It is produced by adding low content cementitious material and water to rock-based material, and mixing them with simple device. Its mechanical performance lies between concrete and rockfill material. For further understanding and appreciating the mechanical behavior of hardfill material, a series of large-scale triaxial tests were performed on hardfill specimens at different ages. And strain-stress behavior of hardfill was investigated, showing that the failure strength of hardfill material follows the Mohr-Coulomb strength theory; with the age increasing, cohesion varies a lot while friction angle differs little. By subtracting stress-strain curves of rockfill, which represent the initial conditions of hardfill, from that of hardfill, the effect of cementation on stress-strain relationship was discussed. Based on the analysis of these results, an age-related constitutive model of hardfill was developed, which is a parallel model consisting of two components, rockfill component and cementation component. The rockfill component represents the conventional rockfill without any cementitious material, which reflects the influence of rockfill by playing a role of skeleton of this cement-rockfill mixture. The cementation component characterizes the impact of cementation. Moreover, comparison was made between simulated and experimental results, showing that the parallel model could reflect the mechanical characteristics of both rockfill-like nonlinearity and concrete-like age-relativity. In addition, a simplified method for determination of parameters was proposed.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2011年第8期2241-2250,共10页
Rock and Soil Mechanics
基金
自然科学基金(No.10932012)
科技部对欧盟专项合作经费(No.0820)
中国科学院科学出版基金(规字[2011]5号)
关键词
硬填料
应力发-应变关系
三轴试验
本构模型
hardfill material
stress-strain relationship
triaxial tests
constitutive model
