(1. Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;2. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China;3. First Highway Survey and Design Institute,China Communications Construction Group,Xi?an,Shannxi 710075,China)
Abstract:The calculation formula of frost-heave ratio of saturated rocks is modified according to experimental results of rock frost-heave ratio. The possibility of frost-heave of saturated fracture is analyzed and the corresponding linear frost-heave ratio is given. Calculation formula of frost-heave ratio of rock mass is achieved,assuming that the distribution of rock fracture morphology is layered. The frost-heave ratio of various lithological rock masses of different grades in open system is calculated. In the open system,the frost-heave ratio of rock mass has the following characteristics. For non-frost-heave susceptible rocks,frost-heave is mainly caused by the freezing of field water in the pore or fissure,the larger porosity or cranny ratio of rock mass will induce bigger frost-heave ratio. For frost-heave susceptible rock,frost-heave is roughly affected by the water migration during freezing:the more the water migration is,the bigger the frost-heave ratio is. With the increase in surrounding rock grade,cranny ratio of rock mass increases,and also the frost-heave ratio of the rock mass increases. The frost-heave ratio of frost-heave susceptible rocks increases faster than that of non-frost-heave susceptible rocks. In addition,the frost-heave susceptibility of rock mass is classified,considering the effects of frost-heave susceptibility of rock and fissure filling,grade of rock mass,rock porosity,and groundwater recharge conditions. The frost-heave susceptibility of surrounding rocks of three tunnels in cold regions is evaluated using the proposed method. The cost of the tunnel can be reduced by choosing proper support parameter according to site-specific frost-heave susceptibility of rock mass.
王海彦,周敏娟,冯雪芹. 高寒地区隧道的冻害机制综述[J]. 石家庄铁路职业技术学院学报,2007,6(2):29-32.(WANG Haiyan,ZHOU Minjuan,FENG Xueqin. On the frost action mechanism of tunnels in severe cold districts[J]. Journal of Shijiazhuang Institute of Railway Technology,2007,6(2):29-32.(in Chinese))
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