施工应力释放对单层衬砌内水承载能力影响研究
Effect of construction stress release on internal water pressure bearing capacity of single-layer lining
袁煦 1张燎军1
作者信息
- 1. 河海大学 水利水电学院,江苏 南京 210098
- 折叠
摘要
为探究施工应力释放对隧洞衬砌结构内水承载能力的影响,以扩大杭嘉湖南排后续西部通道工程为例,采用有限元法建立地层-结构精细模型,分析了不同施工应力释放率下,大断面水工TBM隧洞在软岩地层条件下其单层管片衬砌作为永久支护结构承受不同内水压力时的受力变形规律.结果表明:管片衬砌向外膨胀,管片拉应力、接缝张开量和螺栓应力均随着内水压力增大呈非线性阶跃增大特征;对于穿越Ⅴ类围岩的洞段,应综合考虑三者因素来判断是否达到正常使用极限状态,且衬砌内外压差不宜超过0.2MPa;较小施工应力释放率下的管片环间拼缝薄弱位置容易开裂,而过大施工应力释放率下的接缝张开量和螺栓应力容易达到正常使用极限状态.
Abstract
In order to explore the influence of construction stress release on the internal water pressure bearing capacity of tun-nel lining structure,taking the follow-up western channel project of expanding south row of Hangjiahu Lake as an example,a fine stratum-structure model was established by finite element method,and the stress and deformation law of single-layer segment lining of large-section hydraulic TBM tunnel under different internal water pressure and different construction stress release rates was analyzed.The results showed that the segment lining expanded outward under water pressure,and the tensile stress,joint o-pening and bolt stress of the segment increased in a step and nonlinear way with the increasing of internal water pressure.For the tunnel section passing through the Ⅴ grade surrounding rock,the above three factors should be considered comprehensively to de-termine whether the lining reaches the normal service limit state,and the pressure difference between the inside and outside of the lining should not exceed 0.2 MPa.The weak position of the joint between the segment rings under the smaller construction stress release rate is easy to crack,and the joint opening and bolt stress under the excessive construction stress release rate are easy to reach the normal service limit state.
关键词
管片衬砌/应力释放/内水压力/受力变形Key words
single-layer segment lining/stress release/internal water pressure/stress and deformation引用本文复制引用
基金项目
江苏省自然科学基金项目(BK20220986)
出版年
2024
国家科技期刊平台
NSTL
万方数据