By means of the measuring the natural frequencies of a beam on a elastic foundation together with the transfer matrix method and the computer algebraic language ， the paper deduces the high - order equation ， which contains unknown quantity of the stiffiness of supports . this method ， the validity of which has feen verified by experiments ， can be applied to identifying the foundation coefficient 本文通过实测弹性地基梁的固有频率，以传递矩阵法为基础，利用计算机代数语言，导出以支承刚度为未知数的高次方程，从而识别出地基系数，并通过实验验证该方法的正确性。
The following contents are included : ( 1 ) based on the fundamental seepage theory , the basic differential equation of saturated - unsaturated seepage in porous mediums has been deduced , in which the pressure head is the fundamental unknown quantity . furthermore , the equation for rcc dam is deduced too 主要内容包括： ( 1 )从渗流基本理论出发，以压力水头为基本未知量推导多孔介质三维饱和非饱和渗流微分方程，并根据碾压混凝土坝的特点得出适合其自身的渗流控制方程：进而对碾压混凝土的渗流基本理论、渗流特性开展深入的研究工作。
