摘要
文章基于统一强度理论,考虑中间主应力的影响,采用卸载状态下冻结壁-周围土体共同作用的冻结壁力学模型,推导得到冻结壁弹性区和塑性区的应力场、位移场,并分别建立了冻结壁弹性极限外载、塑性极限外载、弹塑性外载的统一解,分析了冻结壁的应力场、位移场随半径、强度理论参数的变化规律,讨论了半径比、强度理论参数及冻结壁计算深度对各个统一解的影响。结果表明,半径和强度理论参数对冻结壁的应力场、位移场均有一定程度的影响,考虑中间主应力的影响可得到更精确的计算结果;冻结壁的弹性极限外载、塑性极限外载均随半径比和强度理论参数的增大而增大;弹塑性状态下冻结壁的外载随冻结深度的增大而减小,随强度理论参数的增大而增大;冻结壁的外载比原始水平应力低,是由卸载状态下冻结壁与周围土体共同作用决定的。该结果可为冻结壁的设计及工程应用提供一定的参考。
Based on unified strength theory and a mechanical model of the interaction between a frozen soil wall and the surrounding soil mass in an unloaded state, the stress and displacement fields of the elastic zone and plastic zone, as well as the unified solutions of the elastic limit external load, plastic limit external load and external load in the elastic-plastic state, are derived considering the intermediate principal stress. The laws of how the stress field and displacement field vary with the radius and the parameters of strength theory are analyzed. The effects of the ra- dius ratio, the parameters of unified strength theory and the calculation depth of the frozen soil wall on the unified solutions are discussed. The results show that： 1） the radius and parameter of the unified strength theory have certain influence on the stress and displacement fields, and the calculation results are more accurate when they take the in- termediate principal stress into consideration ; 2） the elastic limit external load and the plastic limit external load in- crease with an increase of the radius ratio and the parameters of the unified strength theory; 3） the external load in the elastic-plastic state decreases with an increase of the depth of the frozen soil wall and increases with an increase of the parameters of the unified strength theory; and 4） the external load on the frozen soil wall is lower than the origi- nal horizontal stress because of the interaction between the frozen soil wall and the surrounding soil mass in an un- loaded state.
出处
《现代隧道技术》
EI
CSCD
北大核心
2017年第5期24-29,共6页
Modern Tunnelling Technology
基金
国家自然科学基金项目(41202191)
中国博士后科学基金项目(2014M562358)
陕西省自然科学基础研究计划项目(2015JM4146)
中央高校基本科研业务费专项资金项目(310828173402)
长安大学优秀博士学位论文培育资助项目(310828150018)
关键词
冻结壁
统一强度理论
卸载
共同作用
外载
Frozen soil wall
Unified strength theory
Unloading
Interaction
External load
