Study On Rayleigh Wave Propagation And Groundwater In Saturatd Soil

Wave propagation in saturated, porous media is an important subject ingeotechnical and earthquake engineering.The Rayleigh wave has the uniquecharacters that the propagation distance is long and it's attenuation is slow.Generally, the Rayleigh wave has the influence to the soil which is far away fromthe epicenter .So in this paper, it is our focus that the influence of the Rayleighsurface waves on saturated, porous media and the dynamical reflection of thegroundwater level. The main work of this paper is summarized in prief asfollows:(1) The first part of this paper is the investigation of dynamical model insaturated soil media. Up to now, two phase dynamical model can be summed upto three categories: soil mechanics'model,Boit's model and Menfulu's model.Basing on the supposition of the three theories, the different expression form ofthese three models are deduced, and on these bases, the similarities anddifferences of them are analyzed. From the above discussion, the suitibility ofthese three equations are discussed at the same time.(2) The second part of this paper is the analysis of the Rayleigh wave'sresponse in the saturated media. In the analysis, soil mechanics mode isconsidered as numerical method. By deducing the formulas which are expressedby potential function, the expressions of media's stresses and displacements aregained. According to the expressions and the different terminal conditions, thedifferent Rayleigh characteristic equations have be gotten, which are consistentwith the different boundary conditions. And then, the solutions of Rayleighcharacteristic equations are discussed. Basing on the above result, the examplesare given to discuss the influences of Rayleigh wave on two-phase medium'sstresses and displacements. Finally, there are several conclusions which can beheld as following: 1) the feasibility of saturated soil's liquification is more biggerwhen the Rayleigh surface wave is acted on the saturated soil;2) when the samepresses act on the surfaces of saturated soil, the possibility of liquification innon-watertight ground is smaller than in water-tight ground;3) on the sameconditions of water-tight, the possibility of liquification is more bigger whenthere are press act on the surface. And this consecution is also applicable to theno-watertight condition.(3) The third part of the paper is the generalization about the stress'sinterchange which is derived from the change of groundwater levels. There arethree ways which are considered in this paper, the first one is based on theparameter of hydrologic geology;the second one is based on the effect of solidtide;the third one is based on the effect of atmospheric pressure. In this part,physical mechanism, deducible course and theory are given. Basing on thesefoundations, the merits and shortcomings of these methods are analyzed, andsome advices are given. On the basis of these theories, some examples are given ,aiming to compare with the methods which are derived from the above part ofthis paper. The compute results are compared with the results which are derivedfrom the first part's examples.At last, the research works are generalized, and the problems which need tobe researched in future are discussed.