基于灰关联分析的加筋土挡墙频率敏感因子

加筋土挡墙振动频率反映其抗震性能,基于ABAQUS建立了加筋挡土墙频率计算有限元模型,计算5种工况下结构体系的前三阶频率,发现墙后土体弹性模量对结构体系的振动特性影响较明显.引入灰关联分析法,以填土弹性模量、泊松比、重度等5个参数为影响因素,分析其与振动频率之间的关联度,得到加筋挡土墙振动特性敏感因子.通过算例分析得到:加筋挡土墙振动特性对土体的弹性模量变化最敏感,其次为内摩擦角,对填土泊松比、重度、黏聚力敏感度较低;土体弹性模量与振动频率呈线性关系,而内摩擦角与振动频率呈二次函数关系,内摩擦角为32°时频率变化最为敏感;两个敏感因子对三阶振动影响趋势是一致的,即先增加后减小,再增加.泊松比、填土重度、黏聚力对振动频率的影响不规律.

Study on frequency sensitive factors of reinforced earth retaining wall based on grey correlation analysis

The vibration frequency of reinforced earth retaining wall reflects its seismic performance. Based on ABAQUS, a finite element model for calculating the frequency of reinforced earth retaining wall is established, and the first three frequencies of the structure system under five working conditions are calculated. It is found that the elastic modulus of soil behind the wall has obvious influence on the vibration characteristics of the structure system. The grey correlation analysis method is introduced to analyze the correlation between the elastic modulus, Poisson"s ratio and the vibration frequency of the reinforced retaining wall. The sensitivity factors of the vibration characteristics of the reinforced retaining wall are obtained. The results show that the vibration characteristics of reinforced retaining wall are most sensitive to the change of elastic modulus of soil, followed by the internal friction angle, which is less sensitive to Poisson"s ratio, gravity and cohesion of soil; the elastic modulus of soil is linear to the vibration frequency, while the internal friction angle is quadratic to the vibration frequency, and the frequency change is most sensitive when the internal friction angle is 32 °; two sensitive factors The trend of influence on the third-order vibration is the same, that is, increase first, then decrease, and then increase. The influence of Poisson"s ratio, the gravity of fill and cohesion on the vibration frequency is irregular.