Integrated System of Back Analysis for Geotechnical Survey

在岩土工程中，必须对地下状态进行准确的估计，地质测量起着至关重要的作用。然而，众所周知，地面材料不可避免地是不均匀的，并且经常是非线性的。传统的板载试验、孔压试验、吕根试验等原位试验获得的材料性能通常是在解析解的基础上确定的，不能考虑材料的不均匀性、层间的无序性或边界形状的不规则性等。从这个意义上说，逆向分析对于识别材料性能具有重要意义。不幸的是，逆问题通常是病态的，因此很难建立一个通用的、准确的方法。Ichikawa基于对偶边界控制概念开发了一种足够通用的方法，并将其应用于线性弹性问题（Ichikawa and Ohkami 1992）和粘弹性问题（Ohkami and Ichikawa 1996）。这种理论概念必须应用于实际工程问题，因此我们开发了一个三维有限元程序，提供了一个设计良好的输入输出接口。参与该国际项目的成员有：y.i hikawa， T.Seki, x.u u（日本名古屋大学）；g.s oboda（奥地利因斯布鲁克大学）；G.Gioda， A.Cividini（意大利米兰工业大学）。

In geotechnical engineering, we must estimate the underground state precisely, thus the geological surveying plays an essential role. However, as well-known, the ground materials are inevitably inhomogeneous, and are frequently of nonlinearity. The material properties obtained by conventional in situ tests such as the plate loading test, bore hole pressure test, Lugeon test have been determined on the basis of analytical solutions usually, which cannot take the inhomogeniety of materials, disorder of layrs or irregular shape of boundary, et al.into account. In this sense, the inverse analysis for identifying material properties is of important meaning.Unfortunately the inverse problem is usually ill-posed, so it is difficult to establish a general and accurate method. Ichikawa developed a sufficiently general method based on a dual boundary control concept, and it is applied to the linear elastic problem (Ichikawa and Ohkami 1992), and the viscoelastic problem (Ohkami and Ichikawa 1996).This kind of theoretical concept must be applied to practical engineering problems, so we have developed a three dimensional finite element code which provides a well-designed input-output interface.The members involved in this international project are as follows : Y.Ichikawa, T.Seki, X.Wu (Nagoya University, Japan) ; G.Swoboda (Innsbruck University, Austria) ; G.Gioda, A.Cividini (Technical Univresity of Milano, Italy).