Open AccessTransversal deformation mechanism of shield tunnels caused by micro-disturbance grouting
Author(s) -
Lujie Wang,
Rulu Wang,
Yan Jing-ya
Publication year - 2020
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/580/1/012024
Subject(s) - geotechnical engineering , deformation (meteorology) , displacement (psychology) , disturbance (geology) , shield , stress (linguistics) , superposition principle , structural engineering , nonlinear system , geology , subgrade , engineering , petrology , psychology , paleontology , linguistics , oceanography , philosophy , physics , quantum mechanics , psychotherapist
Micro-disturbance grouting has been widely used in the control of transversal deformation of shield tunnel. It is proved that the grouting not only effectively controls the further deformation in the future but also reduces the existing large deformations. However, the study on grouting mechanism is relatively limited. By using the analytical model with the soil expressed by the Mohr-Coulomb yield criterion, the nonlinear relationship between soil stress and displacement in elastic-plastic zone of the grouting area are derived based on cavity expansion theory. The grouting pressure and required volume for different grouting distance between grouting holes and tunnel linings, and the grouting depth are given. The analytical results are compared with the monitoring data to validate the proposed model. According to the comparison results, the construction sequence of grouting hole can be optimized which can avoid short-time stress superposition to squeeze the tunnel segments and produce structural diseases. Moreover, the optimal grouting volume can effectively keep the effect of the reduction of the tunnel deformation by micro-disturbance grouting technology. The proposed micro-disturbance grouting and its associated optimized construction scheme can be quite helpful to the practical control of the large deformation.