Research on the Assessment Method for Stability of Railway Crossing Small-sized Mined-out Region

Research purposes: According to the survey of the small-sized mined-out region of the Shangzhichang Mine along the Shanghai-Kunming Railway,this paper introduces the survey methods for the small-sized mined-out region,discusses the methods for analysis of the stability of small-sized mined-out region,gives the disposal ideas on the railway engineering and summarizes the experiences of railway crossing the small-sized mined-out region for providing the reference to the similar works. Research conclusions:(1) For the small-sized mined-out region,the survey should be conducted from the big area to small area for knowing the overall condition of the mined-out region in macroscopic view first and then studing the area where has impact on the railway construction.(2) For the survey,first of all,the geological survey should be conducted,then the geophysical prospecting should be conducted and finally the exploration drilling should be conducted for verification,supplement and combination each other.(3) The key points of the survey should be made clear and appropriate method for the stability assessment should be chosen according to the different types of the mined-out region and the engineering features.(4) With the roof collapse blocking up method and the manual method,the checking calculation was made for the stability of the mined-out region.From the calculation result,it was concluded it was unnecessary to treat the mined-out region of Shangzhichang Mine.