Abstract:The principal stress rotation will be involved in these activities such as establishing lunar bases, exploring mineral resource and operating vehicles on Moon surface. Two sets of tests were performed using the hollow cylinder apparatus (HCA) at Tongji University, China to investigate the effects of principal stress rotation on the deformation behavior and non-coaxiality of dry TJ-1 lunar soil simulant. One set of tests enabled pure principal stress rotation at different constant levels of the intermediate stress parameter, while the deviatoric stress ratio and intermediate stress parameters were maintained as constant with a variation of mean stress in the other set. The test results show that intermediate stress parameters and mean stress have significant influence on deformation behavior of TJ-1 lunar soil simulant under the principal stress rotation. Their effects on the development of strain components and the volumetric strain, and the non-coaxiality of TJ-1 lunar soil simulant were studied.