Unstable phenomenon including collapse of face is important problem in tunneling works, and give greater influence to safety of works, construction period and cost. In the past 10 years, face stabilization methods such as umbrella-methods and long length facebolting become spread gradually. Therefore safety of tunnel works nearby unstable face including face collapse was improved, and influence to neighboring structures such as ground surface settlement was decreased. In this paper we analyzed construction examples of umbrella-methods and long length facebolting, and considered by 3-D analytical methods (FEM, FDM). As rock mass condition, to examine plastic zone structure in front of face, FEM has normally used unitil now. Also under the rock mass condition where wide plasticization occurs as excavation proceeds, effectiveness of various face stabilization methods were examined by FDM which is easier for forepiling-member modeling and has actual records in plasticity analysis.

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This paper describes simple methods to evaluate the conditions of tunnel face stability in sand strata that contain a clay layers by simulation of the model tests and the practice. As results, the followings were made clear: 1. The simple method (with friction) and the rigid-plastic finite element method can express the actual condition of face stability. 2. Murayama's Method and the simple method (with no friction) show the condition on the fairly safe side. 3. Simple methods can be applied to the practice if used properly.

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In recent years, shotcrete is being applied as the eternal lining. Shotcrete can be placed without using molds shortly after excavation. On the other side, the shotcreting thickness and finishability are largely based on the experience of the nozzle man. Therefore, high technique is needed. In such a background, we developed the fully automatic shotcreting robot, which used sprayed mortar for TBM and then achieved to make practical use. This paper describes the outline of the robot and the way of controlling to get the design thickness and the good finishability.

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Accuracy of the data obtained by model experiments is affected by such many factors as the frictional stress mobilized between the model ground and the experimental device, mechanical characteristics of the model ground, and the geometry of the experimental device. In order to determine the optimum geometry of the experimental device, a method of genetic algorithm, which takes into account the frictional stress and the mechanical characteristics of the ground, has been shown. Firstly, general solutions of stresses, strains and displacement are theoretically derived by considering the existence of the frictional stress. The experimental results conducted support the appropriateness of the general solutions. Parametric study shows that the optimum geometry of the model device can be determined by the method of genetic algorithm.

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Tunnels in poor rock are driven by short bench excavation method. However, in order to limit the deformation of tunnel sidewalls and roof, micro bench excavation method utilizing face bolts as an auxiliary measures will be required. From this view of point, numerical analysis using finite element method was carried out to simulate the support effect of face bolts in poor rock. Analytical results indicate that fully grouted face bolts are available to reduce the deformation of the tunnel face.

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This paper is to clarify the mechanical behavior of tunnels in soft rock masses by using a new three- dimensional numerical method, in which the largedeformation with the plastic flow and the post failure mechanism of rock masses during excavation process can be simulated correctly. Furthermore, the supporting effects of shotcrete, rockblots and concrete lining on controlling the deformations and collapse of rock masses around the tunnel excavation are investigated and discussed. The proposed 3D numerical analysis approach is also verified by comparing with the field measurements.

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In this study, tunneling model tests are performed in the ground with inclined layers. Tunneling is simulated by a trapdoor experiment, in which earth pressure acting on both the upper and the outer parts of the trapdoor can be measured. Aluminum rods and blocks in the shape of rectangules are used as the ground materials for the formation of the inclined layers.
Not only variations in earth pressure but also the surface settlements due to the descending trapdoor are investigated. Moreover tunnel loads equation considered the angle of the inclined layers is induced so that comparisons between tests results and theoretical results are also conducted.

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This paper presents a non-destructive field testing technique for evaluate the depth of crack, whose existence and particularly progress in concrete can be a severe safety hazard to the tunnels (underground structures). Although several testing methods have been developed to measure the concrete crack depth, their performance is not satisfactory. Herein, a new testing technique is proposed to monitor the cracking depth and progress through detecting the propagation of energy flow density of Rayleigh wave. Field experiments have demonstrated that this new method provides more accurate estimation of the depth of concrete crack than those by existing methods.

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At present, the allowable stress design method is usually applied to the design for shield segments. However, most of concrete structures tend to be designed from the limit state design method. The purpose of this paper is to investigate the applicability of the limit state design method to shield segments.
At first, the partial safety factors were determined from contrast between the design results of the limit state design method. Secondary the provisional design was performed and the design results were discussed. As a result of this study, the limit state design method is applicable and useful as the design method for shield segments.

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This paper investigates the characteristics of vertical ground motions obtained by the 1995 Hyogoken-Nanbu Earthquake and at Oharai array observation site in recent several years. After the survey of several design codes concerning the vertical ground motions, observation records treated in this paper are compared to the response acceleration spectra proposed by Building Rresearch Institute in MOC, Japan, and some recommendation are proposed.

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Various seismic design method for underground structures has been proposed. But the applicability of each method has not been discussed thoroughly. In this paper, the accuracy of seismic deformation method (SDM) for the transversal direction of the underground structures is examined focusing on seismic external forces by comparing FEM dynamic analysis. The generating mechanism of seismic external forces, the re-evaluation of modeling and seismic forces of SDM are also discussed. It is made clear that the difference of seismic force obtained by SDM and FEM is caused by the difference of interaction spring and impedance matrix.

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The steel pipe attachment method has been employed as a seismic strengthening technique for RC columns in cut and cover tunnels. In this method, two concrete-filled tubular steel columns are attached to the RC column from both sides, and they will prevent the, tunnel from collapse even if the RC columns undergo shearing failure. In order to appreciate the mechanical properties of the attached column, numerical analyses are accomplished. This paper presents the modeling of the RC and attached columns and then constructs an interaction analysis method. Several discussions are carried out through comparison between the numerical and the experimental results.

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Ome-Tunnel has the maximum excavation cross section of approximately 260m², which is quite large for a tunnel constructed directly under downtown area. Since numerous lifeline facilities are buried above the tunnel, the effects of construction on such facilities or nearby buildings have to be kept as small as possible. In order to meet this requirement, we have applied the horizontal-jetgrouting to minimize the surface settlement above the tunnel. The excavation of second bench of upper half of this tunnel has been finished so far and it has been proved, based on our measurement results, that this method is very effective to reduce the surface settlement. For example, the settlement after the excavation was 10-20mm for the grouted area while it was 20-40mm for the non-grouted area.

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The Shin-Kobe tunnel, which is constructed by the NATM, drives through uncemented soft ground under the condition of the overburden from 4m to 10m. The construction of the tunnel passing beneath a vital trunk line, moreover, is required the prudent controls of the surface settlement, as well as the restraint of the influence on buried lifelines and the surrounding structures. With the aim of restraining the surface settlement, the supplementary excavation methods are examined by carrying out test constructions reflecting the results of 2/3-dimensional FEM analysis. At the comprehensive monitoring in the site, the surface settlement during the tunnel excavation is confirmed less than the anticipated settlement.
This paper mainly describes the verification of the designing and the effect of the applied supplementary methods.

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Presently, the tunnel portal is located on the slope of halfway up the mountain with un-equivalence pressure or at the creak with small overburden.
In many cases in auxiliary methods, AGF method is applied because of the effective forepiling. Additionally, Tunnel-Jumbo of the general type can be used for AGF method.
In this paper, the basic ideas on the design and the construction of AGF-HITM method developed from the current AGF method were mentioned. In addition, economy, site execution and stability at the cutting face were studied based on the measurement data during construction.

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A new finite element analysis procedure is proposed for simulation of deformational behavior around a shallow tunnel. The method incorporates reduction of shear stiffness, as well as strain softening effects of a given material. An illustrative example is shown in which the proposed method is applied to simulate a an excavation process of a tunnel made of aluminum bars. Results obtained indicated that surface settlement, ground reaction curve, minimum supporting pressure, and formation of kinematic collapse are in good agreement with experimental results. The typical deformational mechanism observed in the experiment is also seen in the field, which is hopefully modeled with accuracy by the proposed numerical procedure.

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To grasp the influence on the existed tunnel by exavating a new tunnel closely, 3-dimensional model tests in sandy ground were carried out. The folowing results were acquired.
(1) The ground pressure acting on the existed tunnel increased by 1.2-1.5 times when a new tunnel was exavated at a horizontal deistance of 0-1.0D (D: tunnel diameter).
(2) The ground pressure acting on the existed tunnel increased slightly by excavating a new tunnel under the existed one, while the ground pressure decreased by excavating a new tunnel above the existed one.

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NATM is used for excavation of department tunnel between stations in construction of subway line No.3 by Fukuoka-city traffic bureau.
There is a section of cross change from large tunnel to small twin tunnel. That section (at twin tunnel side) there are not many intervals in each tunnel. And grounds are easy to destroy caused by the impact of KEGO fracture.
It is weighty the grasping behaviors of ground. Especially NATM in urban site adapt the observation construction reasons of safety.

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SHINMINATOGAWA TUNNEL is the large section tunnel planned in uncompacted ground which consists of water and loose sand. A railroad runs right on the tunnel entrance and the surface settlement soused by tunnel excavation was a big problem. Therefore, construction method was reconsidered and finally advancing side drift and piperoof method were accepted to drift minimize the surface settlement. During excavation, the deformation of the piperoof and ground were measured at the same time. Based on the measuring data, we predicted precisely each settlement of next excavation step and consequently finished construction safety.

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The secondary lining of Hakamagoshi-Johana evacuation tunnel is designed to execute with the dry mix shotcrete. To reduce the rebound and dust, the low-rebound and low-dust type proportion admixing silica fume and limestone powder are selected. Test execution were performed to determine optimal proportion by measuring rebound and dust quantity. As a result, the rebound rate of decided proportion became about 20% or less, was similar to the value of a usual wet mix method. It was confirmed that this type of proportion has a substantial effect on reducing rebound compared with the conventional proportion of the dry mix method.

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Japan Railway Construction Public Corporation applies the new shotcrete to many tunnels, whitch is using limestone powder and silica fume with two-stage mixing.The authors investigated the material, efficiency, and strength etc. of the new shotcrete at the construction site. This report describes the properties of hardened materiales in new shotcrete based on efficiency and strength of new shotcrete at the construction site.

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This paper proposes the results of questionnaires about the stiffness of tunnel supports. We sent two questionnaires to 209 engineers who were employed at the Japan Highway Public Corporation, consulting, and construction companies. The first was about ranking of already reported methods which estimate the stiffness ofsupports by numerical analyses or experiential methods, and the second was onthevalue which the answers regarded as valid. The results was interpreted as follows: the engineers thought that the difference of the stiffness between support patterns was not equable, but the effect of supports was depended only on the quantity of the material regardless of rock type around the tunnel. It was near for the experientially deducing value that the engineer regarded as the most valid value for the stiffness of tunnel supports.

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It is important to understand the geological condition beforehand and to reflectthe plan and the design of the mountain tunnels in construction.
However, itis difficult to understand the geological condition before the tunnel is constructed for a limit of the investigation technology and economical reasons. Therefore, the support of the tunnel might be largely different in the step of the design and construction.
Then, we considered the check system of the tunnel design by two or more engineers.

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In this paper, we evaluated the sensitivity of each support members for displacement control by using FEM analysis. Furthermore, we measured the support member stresses and examined a limit of displacement capacity. The following things arefound out as the result. 1) Shotcrete linings have effect on displacement control after complete closing of linings. 2) Rock bolts have effect on displacement control without closing of linings. 3) The reduction of support can be attempted when about displacement is permitted setting up the displacement capacity which makes 150mm a limit.

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In Japan, we have only constructed a limited number of twin tunnels with center pillar. So the design and construction manuals have not been established.
The discussions were concentrated in the number of heading tunnels, the shape and scale of the center pillar and connecting system between secondary lining and invert concrete.
The Authors collected papers and reports concerning the projects and reported the state of the art of this type of tunnels.

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In jointed rockmass, it is important to understand the effect of reinforcement of shearing joint by cablebolting. We tried to performed laboratory shear test under the several conditions like strength of rock, characterization of joint roughness and some kind of bolts. The experimental results indicate that the reinforcement by cablebolt give effects of confining the joint almost equally in comparison with PS anchor method.
In addition, we tried to evaluate the result of laboratory shear test by numerical analysis using shear joint model we suggested from the data of these test.

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Shin-Toyohama Tunnel will become a longsingle tunnel by connecting existing Toyohama Tunnel with its adjacent Setakamui Tunnel by a bypass tunnel. At each junction of the new and old tunnels, two-lane tunnels merge at a small angle, resulting in a large cross section with a low oblateness. Traffic on the existing tunnels will not be restricted during the construction work. To conduct the tunnelingwork under such difficult conditions each junction area was divided into four blocks based on the sectional shape, and the processes of tunnel face division andexcavation were design for each block to minimize rockmass loosening.

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It is important to evaluate the ground condition correctry in advance for rational tunnel design. Many kind of methods for ground investigation have been developed, and electrical prospecting has been widely used recently. In this paper theevaluation of rock resistivity obtained by electrical prospecting method and theapplication of this method to pre-investigation before excavation was examined. It was found that the change of ground condition could be evaluated by examiningthe relative change of resistivity.

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Three tunnel had constructed in shale and sandstone area of the Shimanto formations in Wakayama Prefecture.
Tunnel support patterns of these tunnels were decided by the new rock mass classification of J. H. at cutting face. The crown settle and convergence at part of DI pattern which was decided based on slickensideand fall of rocks at face were 15 or less mm. In these of case, it needs to consider some geological factors for design tunnel support pattern. We study the monitoring and observation method at cutting face for design tunnel support pattern.

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TSP method which is one of the elastic waves reflection method has been applied in many tunneling fields. However, it is known that the prediction accuracy depends on the structure of the geology. Authors developed the analysis code which simulated wave propagation phenomenon of elastic wave using simple input parameter. In addition, evaluation program which estimated the reflecting surface ahead of face was developed. We examined the survey method in order to improve the accuracy of the reflection survey method.

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Inaccessibility for making the direct inspection of the cut face in TBM excavation and a possible Inaccurate assessment of the ground conditions during the excavation may bring about various problems Including a suspension of excavation with eventual impossibility of speedy excavation aimed for the TBM excavation. In order to grasp the ground conditions in real time and to obtain date for establishing a judgment method for support patterns, excavation energy analysis system is introduced. The ground stabilization can be achieved by expeditious erection of supports after excavation.

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The Koi tunnel (Hiroshima No.4 High Way: HIROSHIMA-SEIFUUSINTO line, about 4, 900m length) has some shallow overburden sections. The Koigami area is the one of those sections and its depth is from the surface to the tunnel roof about 50m. This area consists of Masa-soil, hard weathered granite, and the Koi-active is running beside the Hachiman river. The Koi-double way tunnel is planned to be located across the Koi-fault, developed in the Koigami area. Therefore, we needed to carry out a lot of boring survey, geophysical exploration, hydrological survey. The results of these survey and the numeral hyodro-simulation are following. Koigami's shallow overburden area consists of the hard weathered and weak rock, which was fractured by the event displacement of Koi-active fault, and has the hugegroundwater of the different water head between the front and the back of Koi-fault.
This paper describes the estimation of the hydoro-geological condition of this Koigami area and the countermeasure for the huge groundwater around the active fault by using the deep re-injection well method. This method was carriedout from the surface before the tunnel excavating. Consequently, the tunnel faceunder construction keep on so dry condition, but consists of weak rock. So, thismethod will be considered the economical and safety countermeasure.

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Discharge of groundwater due to excavation of a drift and the drilling of a borehole possibly induces water desaturation of the surrounding rock, i.e. air intrusion into the surrounding rock. This phenomenon may cause the change of chemicalcondition of groundwater around the drift. The authors conducted Excavation Disturbed Zone (EDZ) experiment with new drift excavation in crystalline rock at the Kamaishi mine in Japan from 1995 to 1998. As a part of the experiment, the waterpressure in the EDZ experiment site was monitored for three years and the large water pressure changes were observed due to the excavation of new drifts and thedrilling of the boreholes from the drift wall. The major factors of the changes were derived from the results of the fracture mapping around the experiment site. The conclusions are; 1) the fractures with reddish alteration are major water conductive fractures in the experiment site, 2) the water pressure change during the drift excavation and the borehole drilling is caused by the dischage from major water conductive fractures and its displacement in this experiment site.

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If booster is set not so far from the entrance of tunnel to ventilate smoke at the fire in the tunnel, there may be some influence in the booster power because of the contracted flow and the length of boosting pressure. Some of the representative way to investigate those subjects are the spot and the model experiments. But there are some problem in those way.
In recent years, the simulation tends to be adopted from these reasons. However, the technique of the condition setting isn't sometimes established, there are not so many case studies. This report shows the examination results about the air behavior in the immerset tunnel, which is set booster at the 90 m position from the portal, and modeling with setting conditions for simulation.

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Tunnel lining is designed and constructed mainly based on the past experience. Considering mechanical characteristic and the introduction of new materials to lining lead to a proper structure, and it can reduce the cost of construction. In this study, full-scale loading experiment for tunnel lining was carried out to achieve the upper purposes, and the analysis was done on the basis of the results. It was found that SFRC used for tunnel lining was effective to prevent the falling of debris, and had little connection with the improving the structural strength under certain loading condition.

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When high-speed trains are running and passing each other in tunnels, comparative large air pressure transients are generated in the tunnels. Therefore, the airpressure transient may have fatigue effect on tunnel lining concrete.
First, we measured pressure transient on tunnel lining during the Shinkansen trains arerunning and passing each other in Fukuoka tunnel. Then, we performed bending tests of plane concrete specimens and their simulation analysis in order to elucidate the fatigue effect on tunnel lining concrete. As a result, we came to a conclusion that there is no problem if tunnel lining concrete is sound.

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FFC lining method is tunnelling method which places the lining concrete in the permeable bag, does the pressurizing dewatering, and assumes the lining of the tunnel.
In this report, it has been understood that the experiment of the coefficient of roughness on the surface of the lining can be first done and FFC lining method reduce the section compared with the tunnel of the shotcrete.
The early age compression test turned to the early removal is done, and in addition, in case of a tunnel having about 14m² sectional area, the mix proportion and pressurizing strength for form removal were able to be going to clarify in about three hours after pressurizing dewatering and propose the method by which the construction cycle can be shortened so far compared with the existing method.

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Behavior to which the tunnel is pushed out internally is occasionally shown at Fault part of Mesozoic-Paleozonic layer, Fault part of addition body at mesozoic and Argillaceous rock at Neogene period in mountain tunnel. Such a natural groundis called a so-called expansive ground. A lot of researches on the generation mechanism are performed for an expansive ground. There is a hypothesis that the swelling property is caused so that underground water may flow in the expanding opening and a big transformation is brought.
This thesis is lucky and discusses the technique by which load which acts for the long term is assumed when we encounter expansive natural ground, and secondary lining which has dynamic function designs reasonably.

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Mito tunnel on Naka Water Transmission Canal under the Kasumigaura Water-Conveyance Project was carried out by using the NATM for excavation work, steel pipe of4.5 meter inside diameter was installed, and grouting was plugged between excavated tunnel and steel pipe. The Buckling deformation was caused to the wide range of steel lining, of which length is 180 meter.
In connection to the tunnel deformation, investigation on site, geology and construction record in order to identify the cause of deformation and study for the protection of buckling, investigation of property of grouting material by laboratory test, and verification on yield strength by numeric analysis were executed.
This paper reports the results of the analysis on yield strength of steel pipe through the buckling calculation by using theoretical formula and the elastic FEM analysis, on which model consists of steel pipe as beam member and grouting material as retaining spring.

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In cold region, a newly constructed road tunnel lining, in which a heat insulator was sandwiched between an outer lining and an inner one. It was developed for prevention work against frost heave in ground. This paper proposes an approximate estimation of yearly periodic changes of atmospheric temperature in road tunnel. In this study, periodic changes of atmospheric temperature can be transformedto a moving mean value and narrowing amplitude due to distance from the entrance. Finally, numerical examples using some observational data are worked out to demonstrate the reasonableness of this approximate estimation, which is determinedthe input temperature for heat insulator design at load tunnel lining.

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In this study, load acting on shield tunneling in gravel ground was examined with frame analysis using the in-situ measurement data obtained in shield tunnelingconstruction site to establish the more rational shield lining design method. The handling of own-load of segment in design was also examined. As a result, the amount of load obtained from in-situ measurement in gravel ground was smaller than that of load used in design. Furthermore, design of segment could be more rational with adaptation of beam-spring model, which segment was supported by ground spring, concerning own load of segment.

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Conventionally, shield tunnels mainly have been circular section in form becauseof superior workability and safety. Recently, however, different forms of shieldtunnel sections, such as ellipsoidal tunnels, etc., have come to be constructed.In such cases, special design conditions due to the tunnel section shape apply. In particular, it is necessary to understand the effects of loads, such as grouting pressure, which temporarily act on the lining structure during construction.
This paper evaluates the effects of loads during construction on tunnel lining sections for elliptical tunnels and considers the safety of construction of ellipsoidal shield linings

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On-going metropolitan area discharge channel is proposed to construct a underground river, which is 6.3 km length, and 60 meter depth under National Highway Route No.16, by underground pressure pipe method, for the purpose to flow flood river water of 200 m³/s to Edo river as the flood control of Naka river basin in Saitama Prefecture.
This facility consists of vertical shaft, whichis 36 meter inside diameter and it's excavation up to 70 meter depth, and shielddriven tunnel, which is 10.6 meter inside diameter and 50 meter earth cover, second lining neglected and pressure tunnel type tunnel and also very large-scale construction work.
We carry out measuring of deformation of shield tunnel segment due to large scale structure, of which experience is few in construction, and verify design method on large scale deep underground structure based on measured data.
This paper explains the results, of which design method on large scale vertical shaft was verified through measured data on shaft, and earth pressure charged to segment of tunnel for the short term period.

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In order to evaluate the load acting on segments based on in-situ measurements, it is necessary to understand the relation between the deformation of segments, the deformation of ground, the measured earth pressure and the geometry of the segments.
In this paper, the relation between the observed load and ground deformation is examined based on the data measured at a site (clay ground of alluvium).

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The Teito Rapid Transit Authority has developed a removable three-centered slurry shield method for station that uses a shield machine for the double track tunnels between stations as part of a three-centered shield machine for station tunnels.
This paper describes the load acting on and stress condition of the tunnel lining to ensure safety during work. Field measurement was made on the lining with the aim of collecting fundamental data to verify the adequacy of the design method. Based on the measurement results, the discussion deals with the effects of load and the sectional force generated in the tunnel circumferential directionduring the work

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Recently, rapid assembling of segments and elimination of secondary tunnel lining are recommended. To satisfy these requirements, we have developed a new type reinforced concrete segment called “QB segment” which is bolt less type and flat shape inner section.
The longitudinal joints of QB segment are not connected. The joints are simply butted; therefore erection time can be reduced.
We intended to adapt the design method of segment using beam-spring model tosimplify the calculation. The studies are executed by comparing tests results, theories and analyses, based on axial force parameter, using a full-scale flat segment.
The study reached to the proposal that beam-spring model functions inaccordance with axial compression stress, reducing the rotation spring ratio calculated by Betongelenke formula.

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In recent years, various tunnel projects such as underground storage pipeline projects and stormwater drain pipeline projects to counter against urban type flooding have been planed. In most cases, consideration and adaptability against internal water pressure is in need.
The authors have developed a type of reinforced concrete segment system using two types of mortise and tenon connection to joint the segments. This type of segment is most suitable for secondary lining free construction as well as adaptable against internal water pressure. Experimental works were carried out and satisfactory results were confirmed both in execution and quality.

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At present, there aren't any clear regulations about verifying the earthquake resistance of the shield segment. Especially in case of earthquake at level2, we're supposed to examine the cross section plan with some criterions, but we have'nt so far. That's why we tried to examine in this report the earthquake resistance of tenoned segment and the ductile cast iron one, which have been adopted asthe plan, by using the allowable stress design method at level1 earthquake and limit state one at level2. As a result, we could find out some problems about these methods.
In this report, we'll make these problems clear and bring forwardthe coming study in the shield segment, especially girder type one.

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Real time shield simulator, called as 3DSS/PC, was developed to visualize the simulation results of shield behavior, such as, the shield trace, the normal ground displacement, and the normal earth pressure around the shield periphery based on the kinematics shield model. The shield operation also can be done, observingthe response of the shield by the operation. Real time shield simulator is helpful to understand the shield behavior.

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For development of a theoretical model on shield behavior, not only the theoretical approach, but also the verification of the model by using actual shield behavior are necessary. The measurement system of the shield behavior with high accuracy has been developed. This system was previously applied in a round shield. And based on the obtained data, the shield behavior had been examined.
Then, the 4-centered shield behavior was measured by using this system. As a result, the followings were made clear: 1) the behavior of the 4-centered shield in the horizontal plane was similar to that of a round shield; 2) the shield behavior was influenced by the excavating area with the articulate mechanism and the copy cutter.

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