摘要
针对三峡库区软岩的变形特性问题,对不同含水状态下T2b2紫红色泥质粉砂岩的蠕变特性展开试验研究。从桃树垭隧道现场采集新鲜的T2b2泥质粉砂岩,进行四种含水状态下T2b2泥质粉砂岩的单轴蠕变试验,获得不同含水状态下五级荷载的单轴应变-时间曲线,得到蠕变随应力水平变化及含水条件变化的一些基本规律和特征。结果表明:对于任何一种含水状态的试验,总体上初始瞬间应变随应力水平的增大而增大,由蠕变效应引起的蠕变应变也随应力水平的增大而增大,且随着应力水平的增加,蠕变达到稳定蠕变阶段时的应变速率也由零逐渐向非零常数转化;相同荷载水平不同含水条件的对比分析表明,随着含水率的提高,同级荷载情况下岩石蠕变进入稳定阶段所需的时间基本上会越长,蠕变加载瞬间应变越大,总应变量也越大,而岩石长期强度则呈减小的趋势。
Aimed at grasping the deformation properties of soft rock in the Three Gorges Reservoir Area,a study on the creep properties of T2 b2 purple siltite in different moisture state was carried out.The fresh T2 b2 siltite for test was collected from Taoshuya tunnel site,and through uniaxial creep test of T2 b2 siltite in four kinds of moisture states,uniaxial strain-time curves of under 5 load levels in different moisture states were got,based on which some basic creep features and laws of the siltite with the changes of stress level and moisture state were presented.The results show that in any moisture state,initial instantaneous strain and strain caused by creep effect increases are both increase with the growth of stress level,and the strain rate in the stable creep stage is transformed from zero to non-zero constant with the growth of stress level;in the condition of being in same stress level and different moisture state,the time for entering the stable creep phase under the same stress level becomes longer with the growth of the water content of rock sample,the instantaneous strain and total strain are also increased with the growth of the water content of rock sample,but the long-term strength of it has a decreasing trend.
出处
《工业建筑》
CSCD
北大核心
2011年第1期77-81,85,共6页
Industrial Construction
基金
福州大学校人才基金项目(022356)
