摘要
通过分析岩石冻胀试验数据,修正岩石冻胀率的计算公式;分析裂隙冻结时可能出现的冻胀情况并给出相应的线冻胀率值;将岩体裂隙分布形态简化为"层状",推导岩体冻胀率的计算公式。计算开放条件下不同岩性不同级别岩体的冻胀率范围。开放条件下,岩体冻胀率的特点有:非冻胀敏感性岩石构成的岩体的冻胀主要来自于孔隙、裂隙中的原位水冻胀,孔隙/裂隙率越大,冻胀率越大;冻胀敏感性岩石构成的岩体的冻胀主要受水热迁移作用的影响,水热迁移作用越强烈,冻胀率越大;随着围岩级别增大,裂隙发育,岩体的冻胀率随之增大,冻胀敏感性岩石构成的岩体的冻胀率增长幅度大于非冻胀敏感性岩石构成的岩体。考虑岩石及裂隙填充物的冻胀敏感性、围岩级别、岩石的孔隙率以及地下水补给条件的影响,对岩体冻胀性进行分级,并评估依托工程围岩的冻胀性,根据围岩的冻胀性选择合理的支护参数将节约工程成本。
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. Inaddition, 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.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2013年第9期1876-1885,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
西部交通建设科技项目(20113184901070
2011318799740)
关键词
岩石力学
岩体工程
寒区隧道
冻胀率
冻胀性分级
rock mechanics
rock mass engineering
cold region tunnel
frost-heave ratio
classification of frost-heave susceptibility
