Green Function To Saturated Porous Medium Of Drainage And Engineering Application

The problems to saturated porous medium in soil dynamics include the problemof moving load, explosion source, dynamic foundation, cylindrical piles or thedynamic rigidity of piles, plane wave in layer half-space, the diffraction problem ofwave field, crack propagation of wave field, etc. From the practical engineering, thereare two methods to solve the above problems, the numerical solution and analyticsolution. Numerical method includes boundary type, in which BEM is a common one,and regional type. The Green function of BEM is an effective method to solveengineering fluctuation and soil-structure interaction. FEA, FDM and transfer matrixmethod (the effective method for solving layered medium) are regional type. BEM isparticularly suit for solving infinite and semi-infinite domain, and also has importantmeaning to research wave displacement field and wave scattering field.Based on the previous researches, the paper solved the problems of moving loadto saturated porous medium and dynamic response of cylindrical pile, by thenumerical method, beyond Biot’s dynamic equation and the solid-phase Green’sfunction derived by my teacher. The main studies are as following:Firstly, used the dynamic reciprocity theorem of BEM, the expressions ofsolid-phase and flow-phase to saturated medium subjected to a moving load isobtained. Then an example about dynamic solution to moving load in boundary areaof half space is caculated, by the Lamb’s integral equation in the condition of drainage,which is derived by my teacher, after anglicized, the pore pressure and the verticaldisplacement influence diagram are showed out.Secondly, the cylindrical coordinate transformation and Sommerfeld are used. And the stress of free face equals to zero, also add free face influence field, theGreen’s function to the saturated porous medium subjected to a concentrated force inhalf space, from this method, take torsional vibration as an example. Also a group ofcohesive soil is anglicized the influence of permeability, frequency and depth to facedisplacement, respectively.Finally, using the solid phase Green’s function of the infinite domain incylindrical coordinate, and Darcy low, the Green’s function expression of drainage isderived. Then according to the Lamb integral equation of drainage, the propagationpore pressure and displacement in drainage to the saturated porous medium areintroduced.