层状横观各向同性地基性质对刚性条基摇摆振动的影响

摘要

Influences of transversely isotropy and layered property of soils on rocking vibration of a rigid strip foundation were analyzed.The total stiffness matrix for the plane transversely isotropic layered soils was obtained by employing the analytical layer-element method.Based on the mixed boundary conditions of the contact problemn,a pair of dual integral equations was established.Meanwhile,with the aid of Jacobi orthogonal polynomials,the dynamic compliance coefficients could be obtained.Numerical results were carried out by computer programs.The results agree well with the present theory and existing references.Further numerical examples show that with the decrease of the ratio of horizontal elastic modulus to vertical elastic modulus of soils,the dynamic flexibility coefficient is getting larger.It is also demonstrated that the increase of the ratio of vertical shear modulus to elastic modulus and the increase of the ratio of horizontal Poisson's ratio to vertical Poisson's ratio will lead to the increase of the dynamic flexibility coefficient.Moreover,the decrease of the elastic modulus of the upper soil will lead to the increase of the dynamic flexibility coefficient.%分析了土体的横观各向同性及层状性质对刚性条形基础摇摆振动的影响.首先利用解析层元法得出层状横观各向同性地基的总刚度矩阵.再根据刚性条形基础与地基相互作用的混合边值条件,建立了一组对偶积分方程,并借助Jacobi正交多项式求解了该对偶积分方程,从而得到地基动力柔度系数.计算结果与已有文献的结果吻合较好.同时,算例结果表明:土的水平向与竖向弹性模量比的减小、竖向的剪切模量与弹性模量比的增大,以及水平向泊松比与竖向泊松比比值的增大,都将导致地基动力柔度系数增大;而且,层状地基中上层土的弹性模量的减小使得地基动力柔度系数也增大.