This study focuses on the analytical prediction of subsurface settlement induced by shield tunnelling in sandy cobble stratum considering the volumetric deformation modes of the soil above the tunnel crown.A series of...This study focuses on the analytical prediction of subsurface settlement induced by shield tunnelling in sandy cobble stratum considering the volumetric deformation modes of the soil above the tunnel crown.A series of numerical analyses is performed to examine the effects of cover depth ratio(C/D),tunnel volume loss rate(h t)and volumetric block proportion(VBP)on the characteristics of subsurface settle-ment trough and soil volume loss.Considering the ground loss variation with depth,three modes are deduced from the volumetric deformation responses of the soil above the tunnel crown.Then,analytical solutions to predict subsurface settlement for each mode are presented using stochastic medium theory.The influences of C/D,h t and VBP on the key parameters(i.e.B and N)in the analytical expressions are discussed to determine the fitting formulae of B and N.Finally,the proposed analytical solutions are validated by the comparisons with the results of model test and numerical simulation.Results show that the fitting formulae provide a convenient and reliable way to evaluate the key parameters.Besides,the analytical solutions are reasonable and available in predicting the subsurface settlement induced by shield tunnelling in sandy cobble stratum.展开更多
三维数字图像相关法(three-dimensional digital image correlation,3D-DIC)又称三维数字散斑相关法(threedimensional digital speckle correlation method,3D-DSCM),是一种新型的非接触式全场光学测量方法。与比长仪等传统方法相比,...三维数字图像相关法(three-dimensional digital image correlation,3D-DIC)又称三维数字散斑相关法(threedimensional digital speckle correlation method,3D-DSCM),是一种新型的非接触式全场光学测量方法。与比长仪等传统方法相比,三维数字图像相关法具有测量精度高,可准确测量物体表面的三维形貌和变形等优点。本文介绍了三维数字图像相关法的基本原理、关键技术和精度分析等,并结合水泥基材料的特点,讨论了三维数字图像相关法在水泥基材料变形研究中的应用。展开更多
基金This study was supported by the National Natural Science Foundation of China(Grant Nos.51538001 and 51978019).
文摘This study focuses on the analytical prediction of subsurface settlement induced by shield tunnelling in sandy cobble stratum considering the volumetric deformation modes of the soil above the tunnel crown.A series of numerical analyses is performed to examine the effects of cover depth ratio(C/D),tunnel volume loss rate(h t)and volumetric block proportion(VBP)on the characteristics of subsurface settle-ment trough and soil volume loss.Considering the ground loss variation with depth,three modes are deduced from the volumetric deformation responses of the soil above the tunnel crown.Then,analytical solutions to predict subsurface settlement for each mode are presented using stochastic medium theory.The influences of C/D,h t and VBP on the key parameters(i.e.B and N)in the analytical expressions are discussed to determine the fitting formulae of B and N.Finally,the proposed analytical solutions are validated by the comparisons with the results of model test and numerical simulation.Results show that the fitting formulae provide a convenient and reliable way to evaluate the key parameters.Besides,the analytical solutions are reasonable and available in predicting the subsurface settlement induced by shield tunnelling in sandy cobble stratum.
文摘三维数字图像相关法(three-dimensional digital image correlation,3D-DIC)又称三维数字散斑相关法(threedimensional digital speckle correlation method,3D-DSCM),是一种新型的非接触式全场光学测量方法。与比长仪等传统方法相比,三维数字图像相关法具有测量精度高,可准确测量物体表面的三维形貌和变形等优点。本文介绍了三维数字图像相关法的基本原理、关键技术和精度分析等,并结合水泥基材料的特点,讨论了三维数字图像相关法在水泥基材料变形研究中的应用。
