Abstract:When plate loading test is carried out,the deformation properties of surface layer will be different from that of inner layer because of the existence of disturbance. Deformation parameters obtained according to the surface measuring points can only reflect the integrated properties of underground rock mass which includes the disturbed area,but not undisturbed rock mass. More information about undisturbed rock mass should be achieved in plate loading test with a central hole because that the inner deformation can be gotten in this test method. While,how to make more use of these in site data is still a confusing problem for most researchers. To solve this problem,synthetic research work is carried out,which indicates that,if exact deformation information of inner undisturbed rock mass can then be achieved,substituting the data into the formula in regulations,reasonable deformation parameters of undisturbed rock mass can be obtained. Based on the research,some suggestions are given as follows. Before carrying out plate loading test,the depth of disturbed area should firstly be determined using methods of sound waving test and so on. Then,most inner measuring points should be set in the undisturbed area;and the surface measuring points are also needed. In the data processing,the deformation parameters of undisturbed rock mass should be achieved firstly by substituting the data of deep measuring points into the analytical formulas;and then the deformation parameters of disturbed area can be back analysed by numerical simulation according to the deformation of the surface measuring points and the parameters of undisturbed rock mass that have been calculated.