A new device so-called ground strain simulator have been built by which an arbitrary deformation can be applied to the soil in the test vessel, in order to study on the soil-structure interaction of such structures as trench type tennels. And by using the device, a series of test of a tunnel model subjected to sinusoidal ground deformation has been performed.
　This paper describes the mechnism and performance of the device and discusses the results of the test using the device.
　According to the test result, both the axial reaction coefficient which is connected with the axihl strain and the transverse reaction coefficient connected with the bending of themodel, obtained from the test are quite different from those calculated using the Young's modulus presumed through propergation velocfites of
elastic waves.
　The latter gives use the value more than ten times greater than the former.