宁波深厚软土动力特性研究及其地震响应分析

Analysis of Dynamic Characteristics and Seismic Response of Deep Soft Soil in Ningbo Area

利用Davidenkov模型对宁波深厚软土地区土动力试验数据进行拟合分析,确定相关拟合参数,结果表明该模型能较好地描述软土的动剪切模量和动阻尼比随动剪应变的变化规律。然后,基于等价线性化方法以及ANSYS软件的APDL语言进行简单的二次开发,编写Davidenkov模型计算程序,并利用经典的SHAKE软件进行验证,结果表明该程序计算结果很好,能解决目前商业软件中缺乏合适的土体非线性动力本构模型的不足。最后,利用开发的模型计算分析宁波深厚软土的地震响应规律,并与规范推荐的简化计算公式进行比较分析,结果表明规范推荐的公式得到的土体响应偏大,对于地下结构的抗震设计偏于保守。研究成果对确定深厚软土地区土体动力特性及其地震响应研究提供了合理的计算方法。

In this study,we used the Davidenkov model to conduct a fitting analysis on dynamic test data of deep soft soil in the city of Ningbo and then determined the relevant fitting parame-ters.The fitting results demonstrate that the Davidenkov model can describe the dynamic charac-teristics of the Ningbo deep soft soil well.We wrote the computation program for Davidenkov model in APDL language using ANSYS software based on the equivalent nonlinear method and verified its correction by the classic earthquake response program SHAKE.The results show that the program is effective and can address the lack of nonlinear constitutive soil models in existing commercial software.We used the above program to compare relevant codes and analyzed the seismic responses of the Ningbo deep soft soil.The analysis results indicate that the soil displace-ment obtained by the formula recommended by the code is actually greater than expected,which means that the underground structure that was designed according to code is conservative.The research results from this study provide a reasonable method for calculating soil dynamic charac-teristics and conducting seismic response analysis of deep soft-soil areas.