Abstract：With regard to the research on the expansibility of rock with both directions restricted, there is no ready and perfect apparatus to use.In order to obtain the relations between expansibility of temperature and rock which belong to roof and motherboard of stove used for subterranean gasification of coal, the both direction restriction frame is developed in the paper.Pansibility of rock sample was calculated integrating to expanding characteristic, parameter of the frame was choosed, calculation model was predigested, distortion, and intension were checked.Then, some parts'standard of the frame were selected according to mechanism design criterion.The apparatus could be used to test the expansibility of rock which is under 900℃ combined with static state strain apparatus and stress sensor.

Keyword：rock mechanics;high temperature;swelling stress;testing device;