岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
7期
2111-2118
,共8页
袁万%蔡袁强%史吏%曹志刚
袁萬%蔡袁彊%史吏%曹誌剛
원만%채원강%사리%조지강
移动荷载%2.5维有限元%饱和土%空沟%隔振效果
移動荷載%2.5維有限元%飽和土%空溝%隔振效果
이동하재%2.5유유한원%포화토%공구%격진효과
moving load%2.5D finite elements%saturated soils%open trenches%vibration-isolation effect
基于Biot饱和多孔介质U-W格式动力控制方程,采用Galerkin法和Fourier变换,推导了饱和土体2.5维有限元方程及黏弹性人工边界,建立了饱和土地基中空沟分析模型,并在波数域中进行求解,通过快速 Fourier 变换(FFT)进行波数展开,获得三维空间域中结果。算例分析了移动荷载作用下均质饱和土地基、分层饱和土地基、上覆单相弹性层饱和土地基3种饱和土地基模型中空沟的隔振效果。结果表明:饱和土地基中空沟的隔振效果不仅与空沟自身深度有关,还与地基中成层土体的分界面以及土体参数有关,波在不同土体分界面上的透射和反射会影响空沟的隔振效果;饱和土地基中上覆单相弹性层厚度对空沟的隔振效果影响显著,随着上覆单相弹性层厚度的增加,饱和土地基中空沟的隔振效果变好。
基于Biot飽和多孔介質U-W格式動力控製方程,採用Galerkin法和Fourier變換,推導瞭飽和土體2.5維有限元方程及黏彈性人工邊界,建立瞭飽和土地基中空溝分析模型,併在波數域中進行求解,通過快速 Fourier 變換(FFT)進行波數展開,穫得三維空間域中結果。算例分析瞭移動荷載作用下均質飽和土地基、分層飽和土地基、上覆單相彈性層飽和土地基3種飽和土地基模型中空溝的隔振效果。結果錶明:飽和土地基中空溝的隔振效果不僅與空溝自身深度有關,還與地基中成層土體的分界麵以及土體參數有關,波在不同土體分界麵上的透射和反射會影響空溝的隔振效果;飽和土地基中上覆單相彈性層厚度對空溝的隔振效果影響顯著,隨著上覆單相彈性層厚度的增加,飽和土地基中空溝的隔振效果變好。
기우Biot포화다공개질U-W격식동력공제방정,채용Galerkin법화Fourier변환,추도료포화토체2.5유유한원방정급점탄성인공변계,건립료포화토지기중공구분석모형,병재파수역중진행구해,통과쾌속 Fourier 변환(FFT)진행파수전개,획득삼유공간역중결과。산례분석료이동하재작용하균질포화토지기、분층포화토지기、상복단상탄성층포화토지기3충포화토지기모형중공구적격진효과。결과표명:포화토지기중공구적격진효과불부여공구자신심도유관,환여지기중성층토체적분계면이급토체삼수유관,파재불동토체분계면상적투사화반사회영향공구적격진효과;포화토지기중상복단상탄성층후도대공구적격진효과영향현저,수착상복단상탄성층후도적증가,포화토지기중공구적격진효과변호。
Based on the U-W formula of governing equations of Biot’s theory for the saturated porous medium, the corresponding 2.5D finite element method (FEM) equations and the viscoelastic absorbing boundary are deduced by introducing Galerkin method and Fourier transform. The solution in wave-number domain can be obtained firstly from the built model for open trenches in the saturated ground; then the fast Fourier transform (FFT) is applied to gain the results in 3D space domain. For the moving loads, the vibration-isolation effects of open trenches in three saturated grounds (homogeneous saturated ground, layered saturated ground and saturated ground with upper layer being single-phase elastic medium) are investigated. It’s found that not only is the vibration-isolation efficiency of open trenches related to the trench depth, but also it’s affected by the interface properties and parameters varying of the layered soil media. The transmission and reflection of waves in different soil interfaces have great influences on the vibration-isolation effects of open trenches. Besides, the thickness of the upper single-phase elastic layer can greatly affect the vibration-isolation efficiency of open trenches in the saturated ground; as the thickness of the upper single-phase elastic layer becomes larger, the vibration-isolation efficiency of open trenches in the saturated ground gets improved.