Mechanical Characteristics of Sandstone under High Temperature and Cyclic Loading in Underground Coal Gasification

In the process of underground gasification coal, top rock coal seam will experience a certain high temperature action and be in complex stress environment. Therefore, it is great theoretical engineering significance to study effect cyclic unloading loading on mechanical properties rocks under action. this thesis, stress–strain curves sandstone different high-temperature treatments are obtained by conducting graded tests treated at room 200 °C, 400 600 800 respectively. The research content paper as follows: peak stress, strain, elastic modulus, Poisson’s ratio, internal friction angle, cohesion destruction stage sandstone. results show that strain an increasing trend with increase from °C; shows decreasing modulus elasticity tends °C decrease rest period; ratio angle increases sharply within decreases slowly 200–600 when exceeds °C. provide important reference for design application gasifier coal-bed project.