考虑轴力和剪切效应的盾构隧道纵向变形分析  

Analysis of Longitudinal Deformation of Shield Tunnel Structures with Consideration of Axial Force and Shear Effect

作　　者：杨成永[1] 马文辉[1] 费腾 韩薛果 程霖[1] YANG Chengyong;MA Wenhui;FEI Teng;HAN Xueguo;CHENG Lin(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《西南交通大学学报》2022年第1期139-147,共9页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金(51478032)。

摘　　要：采用傅立叶级数法研究了不同荷载作用下轴力和剪切效应对盾构隧道变形的影响.计及剪切变形所产生的地基反力,建立了弯曲变形的控制微分方程,推导了剪切变形的计算公式;采用与既有理论解对比的方法,验证了级数解的正确性;通过对比计算,分析了截面形式、端承条件、荷载形式、长高比以及有无弹性地基对盾构隧道剪切变形的影响,剪切刚度对弯曲变形、剪切变形及内力的影响,以及装配力对弯曲变形和弯曲内力的影响.研究结果表明:盾构隧道的剪切变形在总变形中的占比可以达到20%以上,是由于盾构隧道圆环截面的形式及较低的剪切刚度共同造成的;考虑剪切变形后,隧道的总变形是增加的,但弯曲变形及弯矩较不考虑剪切变形时要小;随剪切刚度的降低,剪切变形增大,其在总变形中的占比也增大,当剪切刚度从8 GN减小到1 GN,总变形增加了15.7%,弯曲变形及弯矩分别减小了11.7%、17.1%,剪切变形增加5.77倍,剪切变形在总变形中的占比从4.64%增加到27.17%;装配产生的轴向压力增大了隧道的弯曲变形和弯矩,但影响幅度不大,一般对挠度的影响不超过2%,对弯矩的影响不超过3%.The influence of axial force and shear effect on the longitudinal deformation of shield tunnel structures under different loads is investigated by Fourier series method.Taking into account the foundation reaction caused by shear deformation,the governing differential equation of bending deformation is derived,and a formula is proposed to calculate the shear deformation.The correctness of the Fourier series solution is verified by comparison with analytical solutions.Through comparative calculation,the main work is focused on addressing the influence of cross section,end support,type of load,ratio of length to height,and elastic foundation on the shear deformation of shield tunnel,the influence of shear rigidity on bending deformation,shear deformation and internal forces,and the influence of axial load exerted by installation of segment rings on bending deformation and bending moment.Results show that the shear deformation of shield tunnel accounts for more than 20%of the total deformation,which is caused by the form of annular section and low shear rigidity of shield tunnel.When shear deformation is counted,the whole deformation gets larger,but the bending deformation and bending moment are smaller than those without consideration of shear deformation.As shear rigidity decreases,shear deformation increases,and its proportion to the entire deformation also increases.In our case studies,when the shear rigidity decreases from 8×10^(6) to 1×10^(6) kN,the whole deformation goes up by 15.7%;the bending deformation and bending moment go down by 11.7%and 17.1%,respectively;the shear deformation increases 5.77 times;and the percentage of shear deformation to the whole deformation increases from 4.64% to 27.17%. Besides, the bending deformation and bending moment are also increased by installation-caused axial load, but the influence range is limited, often less than 2% in deflection and less than 3% in bending moment.

关 键 词：盾构隧道 纵向变形 剪切效应 轴向受力 傅立叶级数 弹性地基 

分 类 号：U455[建筑科学—桥梁与隧道工程]