核电厂边坡地震动力响应研究

 将大型、复杂条件核电厂边坡简化为含结构面的单自由面柱体模型和多自由面斜坡模型，研究地震波前处理和输入、人工透射边界设置，模拟简谐波和地震波的传播、反射、振荡和衰减规律，比较理论解和数值解的吻合性，采用强震记录分析边坡地震时程响应规律。研究表明：地震波在柱体模型的单自由面上产生放大效应和反射，在软弱夹层处产生反射和透射。约束边界反射地震波，设置黏滞吸收边界和自由场透射边界则有效消除反射现象。地震波在斜坡模型的斜面上产生多次自由面放大效应，且放大效应随着高程增大而增大。地震作用下各向异性斜坡的自由面放大效应较之各向同性斜坡强烈，软弱夹层处产生较大的相对滑移和永久变形，各向异性条件下更不利于边坡的抗震稳定。

RESEARCH ON SEISMIC RESPONSE ANALYSIS OF SLOPES IN NUCLEAR POWER PLANT

The large and complicate slopes in nuclear power plants are simplified into cylinder model and slope model with free surfaces and structural planes，then the pretreatment and input of seismic wave，setting of dynamic artificial boundaries are studied. The seismic spread，reflection，oscillation and attenuation of designed simple harmonic wave and macroseism wave are simulated and verified by dynamic theory solution. Finally，the dynamic response of slope under macroseism wave is discussed by time-history dynamic analysis. The results showed that：The seismic wave has amplification effect and reflection on the free surface of slope，the weak structural plane leads to the reflection and transmission of the seismic wave. Constraint boundary gives rise to the reflection，while viscous absorption boundary and free-field boundary eliminate the reflection. The seismic wave would come into being several reflections on the slope face，and the amplification factor increases with the increasing elevation. The amplification effect of free surface of anisotropic slope is more intense than that of isotropic slope，which increases obviously on the weak structural plane. The relative slip and permanent deformation of anisotropic slope is greater than that of isotropic slope. Anisotropic condition is detrimental to the seismic stability of slope.