摘要
降饱和度法是一种处理地基砂土液化的新方法。文中基于降饱和度原理,通过理论分析及数值模拟的方法对强震作用条件下盾构隧道处于不同饱和度粉土地层中的土体及结构响应开展研究。结果表明:降饱和度法的原理是通过提高流体模量来降低超静孔隙压力;粉土地层在强地震动作用下超孔压比随着深度的增加而减小,而隧道结构的存在会使结构下方的土体的超孔压比增大;当饱和度降至0.98时,粉土的超静孔隙水压力下降了45%,土体各位置处的超孔压比有明显下降,隧道结构的最终水平位移从8.9 cm降至0.7 cm;而随着饱和度的进一步下降,超静孔隙水压力和结构水平位移的下降幅度降低。进一步研究发现当饱和度下降至0.60时,土体超孔压比变化不再显著。文中的研究成果为粉土地层盾构隧道抗液化措施设计提供了一定参考。
Desaturation is a new method for the disposal of ground liquefaction.Based on the principle of de saturation,this paper uses theoretical analysis and numerical simulation to study the soil and structure responses of shield tunnels in silt layers with different saturations under strong earthquakes.The results show that the principle of the desaturation method is to reduce the excess pore pressure by increasing the fluid modulus.Under the action of strong ground motion,the excess pore pressure ratio of the silt layer decreases with the increase of depth,and the existence of the tunnel structure will increase the excess pore pressure ratio of the soil under the structure.When the saturation drops to 0.98,the excess pore pressure of the silt has dropped by 45%,the excess pore pressure ratio at each position of the soil has dropped significantly,and the final horizontal displacement of the tunnel structure has dropped from 8.9 cm to 0.7 cm.With the further decrease in saturation,the decrease in excess pore water pressure and horizontal displacement of the structure decreases.Further research found that when the saturation drops to 0.60,the soil excess pore pressure ratio no longer changes significantly.The research results of the thesis provide a certain reference for the design of anti-liquefaction measures for shield tunnels in silt soil.
作者
申玉生
雷龙
闵鹏
朱双燕
甘雨航
王彬光
SHEN Yusheng;LEI Long;MIN Peng;ZHU Shuangyan;GAN Yuhang;WANG Binguang(Southwest Jiaotong University.National Engineering Research Center of Geological Disaster Prevention in Land Transportation,Chengdu 610031,China;Southwest Jiaotong University.Key Laboratory of Transportation Tunnel Engineering Ministry of Education Chengdu 610031,China;China Railway Design Corporation,Tianjin 300142,China)
出处
《地震工程与工程振动》
CSCD
北大核心
2022年第4期17-24,共8页
Earthquake Engineering and Engineering Dynamics
基金
国家重点研发计划项目(2019YFC0605104)
国家自然科学基金项目(51778540)。
关键词
盾构隧道
降饱和度
动力响应
抗液化技术
粉土地层
shield tunnel
desaturation
dynamic response
anti-liquefaction technology
powder soil layer
