摘要
通过数值模拟研究了盾构隧道施工应力释放和施工扰动引起的土体模量衰减对盾构隧道后期地震响应的影响,结果表明:(1)应力释放程度越大,施工完成后隧道周围土体的剪应力和剪应变越大,地震时隧道底部土体的剪应变越大,地震引起的管片轴力和管片弯矩也越大,40%应力释放率时地震引起的管片轴力和弯矩分别为20%应力释放率时的205%和148%;(2)土体模量衰减程度越大,地震时隧道底部土体的剪应变越大,地震引起的管片弯矩越大,模量衰减程度较大时地震引起的管片弯矩为模量无衰减时的113%;(3)由于土体阻尼比越大,传至管片的地震能量越小,地震引起的管片轴力越小;(4)土体模量衰减范围对隧道周围土体变形和地震引起管片内力的影响与模量衰减程度的影响趋势一致,模量衰减范围为5R时地震引起的管片弯矩为模量衰减范围为1R时的120%。因此,盾构隧道的前期施工历史对其后续的地震响应有明显影响,在抗震理论分析和抗震措施研究中应对其进行充分考虑。
The effects of the shield tunnel construction stress release and the soil modulus attenuation caused by construction disturbance on the subsequent seismic response of the shield tunnel are studied by numerical simulation.The numerical calculation results show that:(1)The greater the degree of stress release was,the greater the shear stress and shear strain of soil around the tunnel after the construction,the greater the shear strain of soil at the bottom of the tunnel during the earthquake,and the greater the segment axial force and bending moment caused by the earthquake.The segment axial force and bending moment caused by the earthquake under the stress release rate of 40%were 205%and 148%,respectively,of those under the stress release rate of 20%;(2)The greater the degree of modulus attenuation of the soil was,the greater the shear strain of soil at the bottom of the tunnel during the earthquake,the greater the segment bending moment caused by the earthquake.The segment bending moment caused by the earthquake with large degree of modulus attenuation was 113%of that with no modulus attenuation.The smaller the seismic energy transmitted to the segment due to the damping ratio of the soil was greater,and the smaller the segment axial force caused by the earthquake;(3)The influence trend of range of soil modulus attenuation on the deformation of the soil around the tunnel and the internal force caused by the earthquake was consistent with that of degree of soil modulus attenuation.The segment bending moment caused by the earthquake with the modulus attenuation range of 5R was 120%of that with the modulus attenuation range of 1R.Therefore,the previous construction history of shield tunnel has a significant impact on its subsequent seismic response,which should be fully considered in the seismic theoretical analysis and the seismic measure research.
作者
加瑞
高天润
杨岗
Jia Rui;Gao Tianrun;Yang Gang(School of Civil Engineering,Tianjin University,Tianjin 300350,P.R.China;Key Laboratory of Coast Civil Structure Safety of Ministry of Education,Tianjin University,Tianjin 300350,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2022年第S02期916-925,共10页
Chinese Journal of Underground Space and Engineering
基金
天津市科技计划项目(21JCYBJC00380)
国家自然科学基金(51890911,51509181)
关键词
盾构隧道
地震响应
施工扰动
应力释放
模量衰减
shield tunnel
earthquake response
construction disturbance
stress release
modulus attenuation
作者简介
加瑞(1982—),男,山西运城人,博士,副教授,主要从事岩土工程、地下工程等领域的教学与科研工作。E-mail:jiarui@tju.edu.cn
