The squeezing and swelling deformation cause serious damage to tunnel. For the design of countermeasure, it is necessary to predict the tunnel deformation. For that, the mechanical behaviour of squeezing and swelling of ground is needed to consider, in addition to swelling behaviour after stress relief. In this paper, the relationship between swelling strain, pressure and time are introduced. And the strength reduction law is considered to this relation. Furthermore, this relationship is incorporated into elasto-plastic analysis considering the tension off by finite element method. Additionally, swelling strain in unloading process of initial stress of the tunnel by laboratory test is incorporated in this analysis. This paper presents the results of a numerical back analysis of measured deformation in the ground and surface with a simple constitutive model using field observation and laboratory tests. And the residual heaving is predicted by the result of above test. Finally, design concept of the countermeasure for residual heaving in mountain tunnel is introduced.

 In tunnel construction in the gravel ground, it is important to predict a risk of large deformation of the ground and the extrusion of the area. However, distribution and shape of the gravel is difficult to reproduce the situation depending on the individual site.

 Therefore, a questionnaire was given to the engineers engaged in the tunnel construction, and the matters to be considered in the case of constructing the tunnel in the gravel ground were clarified. In addition, numerical analysis was performed using Voronoi division model with voxel method. The model of the gravel ground model considering the randomness and heterogeneity which appeared in the actual phenomenon was able to be generated, and the large deformation of the rock extrusion and the sandy ground was also reproduced.

 As a result, similar to the results of numerical analysis in which gravel is arranged in all the analysis areas by setting the area outside the area considering gravel to be 2.0D or more as substrate physical property and setting the area outside to be 1.0D or more It was found that the side and top displacements in the tunnel can be obtained.

 Some mountain tunnels in service suffer from floor heave, and some of them require countermeasures. Case analysis and literature survey were conducted in order to clarify the mechanism of floor heave. From these, it was found that the information at the time of construction couldn’t explain the floor heave after completion enough though floor heave and water was closely related to the floor heave. Furthermore, rock tests and a model test were carried out. These results reveal even if there is little spring water at the time of construction, water will be supplied in some way after completion, and that may lead ground deterioration, and sudden change in water content may lead sudden floor heave. Based on these results, the authors have shown some scenarios of floor heave mechanism of the mountain tunnels, focusing on the amount of spring water at the time of construction and the water supply after completion.

 In the soft clay ground, a shield tunnel suffers from an additional load which is generated due to the consolidation of ground that is caused by the water leakage into the tunnel. Therefore, it is important to make precise prediction of additional load in a future, when designing reinforcement of the tunnel. In this paper, the change of the soft soil performance has been obtained by three dimensional fully coupled seepage-stress FEM analysis and the mechanism of generation of additional load has been demonstrated. The comparison has been made between the calculation result and the output of the previous two dimensional fully coupled seepage-stress FEM analysis. As a result, it was clearly shown that convergence value of additional load can be accurately calculated with the previous method by two dimensional FEM analysis.

 NEXCO’s lining inspection system is a combination of desktop inspection using lining image recording and recording using lining vehicle imaging technology using traveling vehicles and detailed implementation inspection on site by technicians It consists of. In this study, for the purpose of high precision and advanced use of the lining inspection system, we conducted a trial test on the lining inspection in a real tunnel about the possibility of using the image photography as a substitute of the visual inspection. As a result, it was clarified that although there was a problem of grasping the internal defect, it could be replaced by changing the inspection content according to the number of inspections, excluding the rebar section.

 In recent years, the thickness of the artificially frozen ground walls is increasing and application case of the ground freezing method to the hard ground is also increasing. Due to the recent tendency, the technologies to minimize the pressure acting on the adjacent underground structures such as vertical shaft are the important issue of the ground freezing method. In this paper, a method to evaluate the performance of the existing freeze expansion pressure reduction technologies which absorb the freeze expansion displacement is proposed and verified its reliability of the method with these construction cases. Finally, a method how to select the reasonable measure for the specific freeze expansion pressure reduction issue is proposed.

 It is considered that lifting and spalling concrete of arch crown is important for the maintenance of mountain tunnels, and it is assumed that these deformations are caused by repeated expansion and shrinkage around the cracks due to changes in the environment inside the tunnel. In addition, it is considered that the surface layer quality of the lining concrete of arch crown affects the long-term deterioration of the concrete surface. It is assumed that these surface deteriorations are affected by the quality of the construction method. In this study, it is focusing on the residual laitance at the overlapping part of arch crown. The overlapping part of arch crown was simulated, and the air permeability test, bending test, and restrained drying shrinkage test were performed. Furthermore, by comparing with the situation where the lining concrete was applied in the actual scale, the effects of residual laitance at the overlapping part of arch crown on cracks patterns and the surface quality were investigated.

 This research investigated the deformation of shield tunnels based on loading tests and numerical calculation. Based on the loading test with arch-shaped segmental lining models, the progress of cracks and other defects and deformation behavior was grasped, and it was observed that they are affected by the location of joints. The deformation behavior was compared with those of non-rebar lining and RC lining. This research proposed the modelling method of joints considering the yield of joint materials and verified this method by means of the simulation of the loading tests with beam-spring structural analysis. The relationship between the limit states considered at design stages and the progress of cracks and other defects was investigated based on the calculation results.

 Road tunnels in Japan had mainly constructed during the high economic growth period in Japan, and they have already been estimated from 30 to 50 years old and more. The aging of road tunnel will progress rapidly in the future. Therefore, each local governments establish the life extension plan for establish the appropriate maintenance and management plan of road tunnel. The authors applied already the Tunnellining Crack Index (TCI) to each tunnel lining as a quantitative health evaluation method by the increase in TCI indicates a decrease health of the tunnel lining. However, it has not been possible to know the change of TCI whether the increase in crack lengths or the increase in widths. In this study, the contribution of crack width and length to the increase of TCI was separated, and evaluate the crack progression of each contents for tunnel lining.