Abstract
A structural analysis of "YUKIZURI" was conducted using a model equation in order to show the dynamic effect of tree damage caused by heavy snow cover. 1 ) a questionnaire survey was done on the visually balanced angles of straw ropes. 2 ) the crossbar was used to simulate the lowest branch of a tree for the experiment to verify the theoretical value (the axial force) of the crossbar, the straw rope for lifting and the pole based on the model equation. 3 ) experiments were done to examine the greatest tensile strength of the straw rope. Results showed that the optimum angle for the lifting straw rope was around 40 degrees which reduced the snow load on trees by a maximum of 40%. The number of lifting straw ropes for "YUKIZURI" was determined by the tacit knowledge and past experience of landscape gardeners. However this study demonstrated that the appropriate number of lifting straw ropes can be calculated by the model formula used here.
