Abstract:Research purposes:The survey and design results of the second line of Lanzhou - Qinghai Railway,the second double line of the Lanzhou - Xinjiang Railway and the upgrading of the Xining Station show the tertiary mudstone with gypsum rock of the tertiary strata in Xining has the special engineering properties. This paper analyzes the basic mechanical characteristics and the disintegration of the tertiary mudstone with gypsum rock fist,then compares and determines the specification of its expansibility,and discusses the problem of whether there is corrosion existed in the mudstone with gypsum rock to the reinforced concrete,and finally analyzes the impact on the railway engineering.
Research conclusions:In a certain environment,the mechanical properties of the tertiary mudstone with gypsum rock in Xining have the different characteristics. In the natural state,it has good engineering property,but after being immersed into water and exposed to the air for long time,it easily swells,corrodes,softens and disintegrates,resulting in reduction of its intensity and basic bearing capacity and making the environmental water corrosive.The engineering measures should be taken for its expansion characteristics in building railway embankment,cutting and tunnel and in building bridge and construction of the pile foundation of building,the attention should be paid to the environmental water corrosion to the reinforced concrete caused by mudstone with gypsum rock dissolution.
Qu Yongxin,Xu Xiaolan,Shi Mengxiong,etc. The Engineering Classification of Mud Rock and Its Rapid Forecast of Swelling Power [ J ]. Journal of Hydrogeology and Engineering Geology,1988(5) : 36-39.
Wei Yufeng,Nie Dexin,Xun Xiaohui,etc. Influences of Thick Gypsum Layer in Mudstone of Foundation of Huangfeng Hydropower Plant on the Yellow River[J]. Hydro - Science and Engineering,2007(2) : 71-75.
Qian Weiping, Bi Huanjun. Engineering Geological Characteristics and Achievement of Northwest Railway [J]. Journal of Railway Engineering Society,2010(S) : 68-84.