柔性混凝土的长期特性及对三峡二期围堰运行的影响

Long term characteristic of flexible concrete and its effect on phase-Ⅱ cofferdam in Three Gorges

通过柔性混凝土长龄期的力学特性试验研究 ,得出龄期对力学性质的影响非常显著 ,无论是单轴压缩试验还是三轴压缩试验 ,抗压强度和初始弹性模量都随龄期的增大而增大 ,模强比在龄期较大时有减小的趋势 ;并由三轴试验得出各力学性质指标与龄期和围压的近似定量关系。采用邓肯 -张模型对三峡二期围堰进行不同龄期的应力变形计算 ,得出随龄期的增长 ,围堰安全程度增加。

Based on experimental study of long term mechanica l characteristics of flexible concrete, it is known that ages have a notable eff ect on mechanical property.For whatever uniaxial compression test or triaxial co mpression test, compressive strength and initial elastic modulus notably increas e with ages, and the ratio of modulus to strength has a decreasing tendency when the age is long. Approximate quantitative relations between mechanical index an d age and confining pressure are obtained by triaxial compression test. Through computing stress and displacement of phase-Ⅱcofferdam in Three Gorges by use o f Duncan-Chang E-μ model, it is known that the safe degree increases with ages.