Deformation Analysis of the Seepage Cutoff Wall at Mud Mountain Dam, Washington�

Abstract

A seepage cutoff wall being installed at Mud Mountain Dam, Washington, was analyzed by means of a two-step process. Load-deformation characteristics of the embankment were first established using finite element techniques in conjunction with a range of assumed soil parameters. The computed load-deformation soil response characteristics were then utilized as supports in a grid structure model of the wall to predict deformations and stresses. It is hoped this exercise will provide a means of evaluating data obtained from monitoring instrumentation to be installed at the project. It should also be useful in the evaluation of similar installations and therefore have some potential application in the design of such. The diaphragm wall as a method of controlling seepage in embankment dams has only recently been gaining acceptance in this country and information on the analysis of these structures is still relatively scarce. However, with the great number of dams in the United States which are in need of remedial action, it is important that a suitable method for their analysis be developed. The methodology utilized in this analysis provides a possible approach to this problem and may be suitable for many applications.