Laboratory experiments were carried out to clarify the mechanism of crack on tunnel lining using the specimens with plain concrete and steel fiber reinforced concrete considering the length and mixture ratio of fiber. Steel fiber reinforcement was expected to slack the occurrence and the development of crack by shrinkage and to restrain the strain from the results of experiment. Field measurements and observation as for tunnel lining with SFRC were also done in two tunnles. The behaviors of tunnel lining such as stress and width of crack were grasped with time and the effect of reinforcement by SFRC was also found in terms of the occurrence and the width of cracks on site.

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In recent years, uplift has occurred in pavement slabs of some expressway tunnels, adversely affecting road comfort and tunnel stability. When the magnitude of uplift is small, the pavement is usually repaired by overlay. In some sections where the displacement was significant, however, the tunnel invert was newly constructed. Since in the latter case the tunnel bottom is excavated, it is necessary to restrict traffic with lane closure.
The study on the establishment of the rational measures has been carried out to cope with the uplift phenomenon.
The model experiments are planned and implemented for the replication of the invert uplift phenomenon. The numerical analysis using the finite differential method (Code FLAC) is carried out for the analysis of the experiment, and the replication of invert uplift phenomenon is evaluated on the basis of results of the experiments and numerical analysis.
This paper deals with the results of the model experiments and the numerical analysis and the evaluation of the replication of invert uplift phenomenon.

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In order to make clear the quantitative effects of pipe roof supports on the decrease of the ground settlements caused by tunnel excavations, centrifugal model tests have been conducted. An excavation robot is newly developed and is applied to the model tests. The robot is three-dimensionally controlled by programs and can excavate the tunnel face in arbitrary shape. Effects of the difference between the excavation methods such as the full-face-excavation and the ring-cut-excavation on the ground displacements are discussed.

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Soft rock has the characteristic of strain softening and time dependency, that is to say, creep and/or deterioration of strength. Ground-pressure toward tunnel lining due to plasticity with deterioration of strength of the surrounding rocks is expressed using a finite difference method, which is especially proposed by Cundall and is well expressed plastic flow and large-strain deformation. In this paper, the formulation proposed by Sato is adopted as the model of time-dependent deterioration of strength of the surrounding rocks and is applied for the expression of evolution of plastic zone. Furthermore, the effect of the reinforcement method is investigated.

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In recent years, there have been numerous studies on the behavior of tunnel face reinforced with bolt, but in most of studies the parallel installation of bolts regardless of displacement mode in tunnel were assumed. In this study, we compare the parallel installation and the inclined installation under different displacement mode in tunnel.
By comparing calculated value with parallel installation, it is found that proposed installation methods are more effective than parallel installation according to under some circumstance. Also the effectiveness of the face reinforcement depends greatly on the installation angel when consider the same field construction

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In weak rock tunnels, we often estimate a dimension of support system using design methods based on similar conditions of the past or by numerical analysis. So the methods are imperfect to simulate a tunnel behavior, it is necessary to examine some basic mechanical model of how a tunnel behaves and how the support system acts to control this behavior.
In order to clarify the behavior of weak rock tunnel supported by rockbolts under biaxial stress field, we have performed loading tests with an artificial ground modeled on soft and squeezing rock tunnel. As a result of testing, it was mainly clarified that: i) the support effect increases with the decrease of bolt spacing rather than bolt length when bolts are in the elastic zone; ii) the axial force of bolt near the crown is not appear under vertical/horizontal pressure ratio=0.5.

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The objective of this research is to present a new method of performance based design in order to search and determine the executive conditions which assure the stability of a tunnel and the minimum construction cost. The method employs both the genetic algorithm as an optimization technique for construction cost and the limit state design for performance warranty of tunnel supports. The method has been applied to a tunnel constructed in the ground of the serpentine with squeezing characteristics of time dependency, and the optimum relationship between the cost and the executive conditions has been made clear.

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A finite element analysis procedure considering strain softening behavior is applied for identification and prediction of deformational behavior around a shallow NATM tunnel. The proposed approach produced a strain distribution, deformational mechanism and surface settlement profile, which are in good agreement with the results of the field measurement conducted at two cross sections with different deformational characteristics. The predictive capability of the method was also tested at three different stages in which higher accuracy of prediction was achieved accordingly in latter stages.

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High quality shotcrete (HQSC) is a new type of shotcrete utilizing own viscosity generated by a mixed powder for the improvement in a construction performance on the tunnel site. Authors investigated the relation among the mix proportion at job site, the physical characteristics of fine aggregate, the correlation, and the properties of strength based on the data from 1997 to 2005 of 119 sites for which HQSC was used, and examined there.

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We performed case studies and simulation analyses to clarify deformation behavior of tunnels at adjacent construction. We found relations between deformation modulus of ground, geometrical shape of adjacent construction and influence on existing tunnels from case studies. We confirmed those relations from parametric analyses assuming in situ tunnels. Based on the results, we proposed guidelines for judgment of adjacent level which consider deformation modulus of ground and geometrical shape of adjacent construction

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This paper presents an investigation on deterioration mechanism of a tunnel lining concrete constructed in around 1928. In this tunnel, the surface area of the concrete changed in quality into a powder and became weak. It was found that diatom earth was mixed in the concrete as a cement substitute material. Investigation by using concrete specimens suggested that compressive strength of diatom earth blended concrete declined with carbonation. Study results showed that the tunnel lining concrete was deteriorated by carbonation of diatom earth contained as a cement substitute material.

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An analysis was made of the effect of the advance of tunnel boring machine (TBM) for constructing double railway tracks under an existing another shield driven tunnel of NTT (Nippon Telegraph and Telephone Corporation) with a clearance of approximately 3 m. The convergence of the NTT tunnel and displacement of the ground transverse to the tunnel were measured using the reflection of laser beam from the target in the fiber optic cable laid in the tunnel. To determine the effect of tunneling in the vicinity of the NTT tunnel by advancing a shield across the NTT tunnel, changes in resultant stress in the NTT tunnel were calculated

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A fire in the current shield tunnel on a highway or railway would cause explosive spalling of concrete lining due to high temperature that mostly result in significant damages to the tunnel structure. The conventional fire protections for the tunnel structure have utilized separate ceramic panels being attached or spraying fireproof materials on the surface of the lining. However, the ceramic panels are rather costly, and the spraying induces poor working conditions. As a substitute, the concrete segments with enhanced fireproof performance have been developed by the use of short fiber resin. A series of fire tests were conducted to verify their fireproof performance. This paper mainly reports on the results of fire tests.

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Composite segment is the steel structure, which is filled with high flowability concrete. The cross section of segment can be made small because its stiffness is bigger than that of RC structure and others. Steel shell and concrete are combined by the stud bolts welded on the inner surface of the shell. Some loading tests were carried out to verify the structural advantages of the segment and examine the propriety of reinforced concrete theory and three dimentional finite element method. This paper shows the rational design method of composite segment.

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Shield tunneling method, one of the excavation methods, expands of demand in underground space at great depth. In underground space at great depth, the ground is stable, and axial force generated in shield tunnel excels. Therefore, in case of using steel segments at great depth shield tunnel, we must take local buckling at main girder into consideration. In this study, we prove local buckling at main girder of steel segment in great depth shield tunnel by experiment and Finite Element Method.

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In shield tunnelling, the frictional resistance of ground against the shield skinplate is a major factor of jack thrust. However, there are few laboratory test results on the dynamic friction characteristics concerned with shield. Therefore, this research investigates the above dynamic friction characteristics by the ring shear test, where the surface roughness, the soil type, the inclusion, the shear speed and the confining pressure are taken as test parameters. Furthermore, the influence of those test parameters on the dynamic friction characteristics are discussed.

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As well known, after the infrastructure construction during the past years, it is very difficult to keep enough space to construct new infrastructure in shallow underground. The new water pipelines have to be built in deep underground. To make water pipelines construction more economy and rationalization, the separate-typed segment structure scheme was proposed and studied, which can be simultaneously build outer tunnel and inner pipe, but will leave little gap between the outer RC segment and the inner pipe. In case that great underground water pressure directly acts to pipeline, the pipeline is easily destroyed due to buckling. In this paper, we will study the buckling of water pipeline subjected to the great underground water pressure, and the design method of pipeline bucking built by separate-typed segment structure.

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If a large fire break out in a traffic tunnel, the temperature in the tunnel will be over 1, 000 degrees centigrade. The high temperature causes the loss of mechanical propertires of structural materials and often spiting of concrete. Due to the changes in mechanical properties of materials, it is possible the tunnel structure deforms and influences to the infrastructure on the tunnel. Taking above as a background, the structural fire resistance of the cut and cover tunnel was investigated experimentally and analytically. As the results of the investigation, it is confirmed the application of concrete mixed with polypropyren fibers can improve the fire resistance of reinforced concrete sturucture.

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As a number of cut and cover tunnels with reinforcing bars are deformed and cracked by earth pressure, the assessment methods of their crack width and growth have been researched. On the other hand, there have been no well-established evaluation methods for the movement of cut and cover tunnels, which are safe against earth pressure. Then, the inspection and numerical calculation concerning tunnels are carried out to investigate the mechanical properties of them. It is confirmed that the simulation for results of inspection is required the stress path from the installation of propped wall to the completion of structure and their movements can be grasped by using the numerical calculation described in this paper.

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The method of arch culvert, by using the pre-cast reinforced concrete arch, has been adopted at a two-level crossing in embankment of a road. That is for shortening of a period and improvement of construction. The statically determinate 2 hinge arch structure has a good stability toward earth pressure and an ability to reduce the bending moment. But investigation of seismic is required on introducing into Japan, happened earthquake frequently. We carried out the model vibration experiment and FEM analysis. This study describes dynamic characteristic and proposes practical analysis model of the structure longitudinal direction.

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The method of arch culvert, by using the pre-cast reinforced concrete arch, has been adopted at a two-level crossing in embankment of a road. That is for shortening of a period and improvement of construction. The statically determinate 2 hinge arch structure has a good stability toward earth pressure and an ability to reduce the bending moment. But investigation of seismic is required on introducing into Japan, happened earthquake frequently.
We carried out the model vibration experiment and FEM analysis. This study describes dynamic characteristic and proposes practical analysis model of the structure cross direction.

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In cold region at Hokkaido, due to cold winter climate shows the experience of frost into tunnels, it is necessary to prevent or reduce the opportunity of frost in tunnels. But, amount of the frost information of all northern part of Japanese municipalities is not published. Therefore, this paper presents a pair of interpolation and identification procedures, to estimate of temperature at the portal and inside tunnel. The former study, the tunnel portal temperature is interpolated by Semi-Variogrm which stochastic method using to the temperatures from Automated Meteorological Data Acquisition System (AMEDAS) in Japan, and the others, the inside tunnel temperature is identified by actual observation data. Finally, numerical examples are worked out to demonstrate the usefulness of these methods.

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In this paper, the mechanical behavior of the trap door test is estimated from stress changes and displacement in the ground. In order to measure the stress in the model ground, the author developed a new device of measuring stress. On the other hand, a simple formula is proposed to calculate the distribution of the earth pressure around the trap door by following Terzaghi's theory on the loosened earth pressure. The formula is considered slip line which is estimated by the vertical stress changes in the model ground. It is compared and examined through the data obtained by the trap door experiment as well as the DEM analysis. It is considered that the proposed formula gives an important idea about the earth pressure around the cavity.

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