摘要
为分析浅埋风化岩质隧道围岩初支护后变形随时间变化的黏弹性效应,首先采用逆反分析法推导出圆形隧道围岩的等效弹性模量和等效侧压力系数的解析解;然后结合具体工程实践,选择典型断面采集围岩初支护后的位移实测数据,采用数理统计方法,获取该类型隧道围岩初支护后的等效侧压力系数与等效弹性模量之比随时间的变化规律,建立围岩初支护后的黏弹性模型,研究隧道围岩初支护后变形随时间变化的黏弹性效应。研究结果表明:浅埋风化岩质隧道围岩初支护后在无降雨等外部因素作用下等效侧压力系数与等效弹性模量之比随时间呈Monomolecular增长模式并最终稳定于某一常数,即围岩变形随时间变化的黏弹性效应也符合此规律,并且其应变与等效侧压力系数成反比变化;在围岩刚度较大和地下水活动较弱的地段,初支护后围岩变形将较快趋于稳定。
In order to analyze the viscoelastic effect deformation with time after preliminary support, equivalent coefficient of confining pressure were of shallow-buried decomposed-rock tunnel surrounding rock the analytic solutions of equivalent elastic modulus and derived adopting inverse back analysis methods firstly. Secondly, taking the concrete engineering practice of shallow-buried and blind excavated decomposed-rock tunnel for example, which belongs to the shore segment of Xiang＇an subsea tunnel engineering in Xiamen, Fujian Province, and the representative sections and collecting their surrounding rock measured displacement data after preliminary support are selected, the regularity of the ratio of equivalent coefficient of confining pressure to equivalent elastic modulus varying with time after surrounding rock preliminary support of this type tunnel was derived by the analytic means of mathematic statistics; and the representative sections and collecting their surrounding rock measured displacement data after preliminary support are selected. Finally, the viscoelastic model of surrounding rock deformation after preliminary support is established; and its viscoelastic effect of deformation with time was researched. The research results show that in the first place, the ratio of equivalent coefficient of confining pressure to equivalent elastic modulus increases in monomolecular growth model without external action such as rainfall after shallow-buried decomposed-rock tunnel surrounding rock preliminary support： and it will finally be stabilized. Namely, the viscoelastic effect of surrounding rock deformation varying with time agrees with this regularity also; and the surrounding rock deformation varies in the inverse ratio of equivalent coefficient of confining pressure. In addition, in the tunnel segment of surrounding rock with higher stiffness and weak groundwater moving, the deformation of surrounding rock may converge more rapidly after its preliminary support.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2007年第9期1781-1786,共6页
Chinese Journal of Rock Mechanics and Engineering
基金
中国博士后科学基金资助项目(20060390165)
上海市博士后科研资助计划(06R214152)
关键词
隧道工程
浅埋风化岩质隧道
逆反分析法
数理统计
黏弹性效应
tunnelling engineering
shallow-buried decomposed-rock tunnel
inverse back analysis method
analytic means of mathematic statistics
viscoelastic effect
