CAJ | 학술논문

在常规的场地地震响应有效应力分析法中，通常只考虑Gmax随有效应力和孔隙比的变化，而最新的试验研究表明， Gmax在大应变幅振动下存在附加衰减。收集了不同类型土体在大幅振动下的298组Gmax数据，拟合并给出了对应于两种Gmax附加衰减模式的计算模型，通过编制可考虑 Gmax附加衰减影响的一维场地地震响应有效应力分析程序，分别对典型场地和离心机振动台模型场地的地震响应进行分析对比。结果表明：Gmax附加衰减对场地加速度和剪应力响应均有较大影响，将加速场地液化进程和扩大场地最终液化范围；考虑 Gmax附加衰减可较好地模拟动力离心模型试验场地动力响应；但在强震情况下，场地迅速液化，Gmax附加衰减对场地动力响应的影响反而减弱。
재상규적장지지진향응유효응력분석법중，통상지고필Gmax수유효응력화공극비적변화，이최신적시험연구표명， Gmax재대응변폭진동하존재부가쇠감。수집료불동류형토체재대폭진동하적298조Gmax수거，의합병급출료대응우량충Gmax부가쇠감모식적계산모형，통과편제가고필 Gmax부가쇠감영향적일유장지지진향응유효응력분석정서，분별대전형장지화리심궤진동태모형장지적지진향응진행분석대비。결과표명：Gmax부가쇠감대장지가속도화전응력향응균유교대영향，장가속장지액화진정화확대장지최종액화범위；고필 Gmax부가쇠감가교호지모의동력리심모형시험장지동력향응；단재강진정황하，장지신속액화，Gmax부가쇠감대장지동력향응적영향반이감약。
In the conventional effective stress method of site seismic response analysis, the changes of small strain shear modulus Gmax are only with the effective stress and void ratio. While the latest experimental studies show that under large amplitude vibration, there exists additional attenuation of Gmax. 298 groups of Gmax data of different types of soil under large amplitude vibration are collected and analyzed, based on which the computational equations corresponding to two additional attenuation modes of Gmax are provided. A one-dimensional site seismic response analytical program has been compiled based on effective stress principle, to account for the influence of additional attenuation of Gmax. A typical example and a dynamic centrifuge model test of sand field are separately simulated using the compiled program. It turns out that, the additional attenuation of Gmax has influence on both the response of accelerations and shear stresses. Besides, it can speed up the liquefaction of site and expand the final liquefied range. Numerical simulation of the centrifuge model test shows that, the acceleration and pore pressure responses are in good agreement with the experimental results when considering additional attenuation of Gmax. However, in case of strong acceleration, liquefaction comes soon, and the influence of additional attenuation of Gmax on site dynamic response becomes weakened instead.