Necessity of Geotechnical Data Base and of Reliable Technical Title Committees for the Civil Engineering Projects

Author(s) Adachi, Toshihisa

Proceeding of TC302 Symposium 2011 : International Symposium on Backwards Problem in Geotechnical Citation Engineering and Monitoring of Geo-Construction (2011): 194- 202

Issue Date 2011

URL http://hdl.handle.net/2433/173828

Right

Type Article

Textversion publisher

Kyoto University International Symposium on Backward Problems in Geotechnical Engineering TC302-Osaka 2011

Necessity of Geotechnical Data Base and of Reliable Technical Committees for the Civil Engineering Projects

T. Adachi Geo-Research Institute, Osaka, Japan

ABSTRACT: In order to safely and soundly construct any civil engineering infrastructure and to predict the liquefaction potential as well as the seismic intensity, it is very important to have a reliable geotechnical data base and also to constitute an effective scientific and technical committee. At first, this paper describes the out- line of geotechnical database, “Kansai Geo-Informatics Database (GI-base)”, that was created by a consortium of geotechnical engineers/researchers and their affiliated organizations in Kansai region of Japan; the KG-NET (Kansai Geo-informatics Net work). Then, it emphasizes that the geotechnical engineers must have the knowledge of subsurface structure in addition to that of soil properties. Finally, it introduces the case history of a successfully disbanded technical committee for the railway line (subway) construction project which consisted of members not only from universities, owner and administrative organizations, but also from contractors. The committee greatly contributed to the successful completion of the Nakanoshima line.

1 INTRODUCTON Secondary, it stresses the importance of knowledge of subsurface structure by showing a In this paper, at first, the usefulness of GI-base and case history. Finally, a technical committee, which its historical development are represented. The his- was banded to support the construction of the tory of geo-informatics research in which geology Nakanoshima Railway Line, is discussed. In the and geotechnics have been closely collaborated is history, the railway and ground transportation net- one of the key factors for the successful achieve- works have been taking over the role of the river ment of GI-base. The Kansai region is the second transportation in Osaka. Now, Nakanoshima Island largest area where old capitals of Japan such as is the area of increasing high-density land use, Osaka, Nara, and Kyoto are located. These cities therefore the improvement of the transportation have been developed mainly on low, flat and allu- links is required. Nakanoshima Line is in the sym- vial plains. In addition to Osaka, Kobe and many bolic island of water metropolis of Osaka, and it other cities are developed in the Osaka Plains and will not only contribute to the further economic along the coast of the Osaka Bay where soft development but also provide a direct link with the grounds are widely spread. Thus the development central and northern area of Kyoto city via Keihan of these cities required careful site investigations Main Line. Furthermore, Nakanoshima Line will with a very large number of borehole studies to contribute to improvement of the transportation construct much of needed infrastructures, such as network in Kansai region. highways, railways, lifelines, and airport construc- Since the construction had to be done under tions, as well as to establish disaster prevention very severe conditions, not only geotechnical but countermeasures. also surrounding environmental conditions, it was needed to establish a technical committee, which

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consisted of both academic researchers and practi- geotechnical and geological features of the Osaka cal engineers. The committee greatly contributed Basin by collecting significant amounts of to the successful completion of the Nakanoshima Line. 2005~ KG-NET Kansai Geo-informatics 2. GI-BASE AND ITS HISTORY Network Kansai 2005 (GI-base) 2003~ 2005 2.1 Outline GI-Base Council Kansai Geo-informatics 2000 1998~ 2003 Research Council of The Geo-Information Database in Kansai (GI- Geotechnical Information on OB Osaka Kansai 1995 1995~2003 Geo-Database Information base) was constructed by gathering a very large Bay Inland Committee of Kansai amount of borehole investigation data obtained in 1990 many projects of urban construction in Kansai re- 1989~1994 Research Committee on Utilizing of Underground Space & Research Committee on Structure and Properties of gion, such as the construction of manmade islands, 1985 Deep Underground in Kansai (JGS Kansai Branch) subways, lifeline, etc. 1991~1995 Research Committee on Geotechnical Information of OBSD Fig. 1 shows the locations of more than 48,000 1980 1984~1991 Research Committee on Seabed Deposit of Osaka Bay (JGS boring data, which have been collected and digit- Kansai Branch) ized. Through geological and geotechnical inter- pretations, GI-base has been developed and updat- Fig. 2 Historical developments of GI-base and KG- ed. Cross-section view of the required underground NET can easily be drawn on personal computers togeth- er with various soil properties such as classifica- borehole data, and there have been publications of tion, gradation, the thickness of each layer, ground “Osaka Ground” (a collection of soil boring logs) in 1970, and “A New version of Osaka Ground” in water level, N SPT values and so on. The history of geo-informatics research in which geology and ge- 1987, although no digital borehole database was otechnics have been closely collaborated is one of created. the key factors for the successful achievement of Borehole investigations for the Kansai Interna- GI-base. tional Airport and Phoenix Project (landfills for waste disposals) have started one after another in

the Osaka Bay around 1980. Extensive investiga- tions of the Osaka Bay seabed were necessary for the waterfront development, and archiving of data in digital form by GRI became routine with the de- velopment of computers. The Research Committee Kyoto Shiga on Seabed Deposit of Osaka Bay (1984-1991, Chairperson, Prof. K. Akai) was established first by the Kansai Branch of JGS. This activity was succeeded to the Research Committee on Osaka Kobe Bay Geo-Informatics and Utilization (1991-1995, Osaka Nara Prof. T. Matsui), and the Research Council of Osa- ka Bay Geo-Informatics (1995-2003). Through Osaka Bay these research activities, “Geo-Informatics Data- bases in Osaka Bay Area” (GI-base OB) was con- structed. On the other hand, the Research Committee on Wakayama Underground Space Utilization (1989-1994, Chairperson, Prof. T. Adachi) was established, and Fig. 1 Distribution of boreholes in GI-base this committee dealt mainly with public sector’s infrastructure to utilize deep underground spaces in 2.2 Historical Developments of KG-NET the large cities (Osaka, Kobe, and Kyoto). This committee worked together with the Research Fig. 2 shows the chronology of how the KG-NET Committee on Structure and Properties of Deep was developed from the starting organization of Underground in Kansai Branch of JGS (1989- the Research Committee on Sea-bed Deposit of 1992). This activity was succeeded to the Geo- Osaka Bay (1984-1991). Before the geotechnical Informatics Committee of Kansai (1995-2003). researches by this committee, there have been sev- During these research activities, “Geo-Informatics eral research groups under the Kansai Branch of Databases in Kansai Inland” (GI-base K) was con- Japanese Geotechnical Society (JGS) studying the structed.

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These two databases were integrated into a sin- cene clay in this region is well known as sensitive gle system in 2003, and the whole data was man- clay. aged under an organization of the Council of Kan- In the practice of earthquake disaster prevention sai Geo-informatics (2003-2005). Further in 2005, and mitigation for a wide area, estimate of the it is recognized to form “Kansai Geo-Informatics damage that will be caused by the earthquake of Network (KG-NET Chaired by )”. target area is generally performed. And then, local governments draw up the regional plan for disaster 2.3 Geotechnical Fragility Mapping in Terms of prevention based on the information of volume and Seismic Intensity Due to Expected Uemachi Earth- locations of damages due to earthquake. The pre- quake diction of earthquake behavior, such as seismic in- tensity, liquefaction occurrence, and others, is very A representative cross-sectional view of subsurface vital, as its results become the basis of evaluating ground for Osaka Plain is shown in Fig. 3. The se- earthquake damages. lected line is the one along the subway Chuo Line As previously mentioned, GI-base could be a from the coast of Osaka Bay to Ikoma Mountain. versatile tool to provide necessary input of under- Uemachi Upland is located in the heart of Osaka ground geometry as well as dynamic properties of where all strata are tilting by the prevalence of the strata. In the practical sense, the regional distri- flexure structure developed by the tectonic move- bution of hazardous area against high seismic in- ment of the Uemachi Fault. tensity and liquefaction due to earthquake can

W E

do E Yo v . Re W Osaka Plain Osaka Bay

Fig. 3 Cross-sectional view of subsurface ground for Osaka Plain

On the west side of Osaka, the thick Holocene ma- provide very important and useful information for rine clay (Ma 13) layer exists underlain by the disaster mitigation. Pleistocene gravel layer and the alternating Pleis- Let us pay attention to the distribution of the up- tocene deposits. The strata are rather stable and per Holocene sand and clay layers in Osaka Plain horizontal deposited. On the eastern part of Osaka, and the surrounding area because those layers in- the basin structure can be seen between the Uema- tensify seismic intensity and can be fragile for liq- chi Upland and the Ikoma Mountains. The Holo- uefaction. Distribution of the thickness of the up-

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per Holocene sand and clay layers is illustrated in The latest action plan of Osaka local government Fig.4. The Holocene layers can be seen at almost for Earthquake-induced disaster mitigation has ac- whole area of Osaka Plain. Along the coastal line tually been established on the basis of the present and the rivers, the thickness of the Holocene layers outputs of the liquefaction fragility. tends to be larger (more than 30 m). 0 10 km Seismic Thickness (m) Intensity 0~0 0~4 7 4~8 6 upper 8~12 6 lower 12~16 16~20 5 upper 20~25 5 lower 25~30 4 or less 30~

Fig. 4 Thickness distribution of Holocene Deposits based on the GI-base for Osaka Plain Fig. 5 Estimation of seismic intensity during The distribution of strong ground motion, that is, Uemachi Faults Earthquake the seismic intensity in Japanese Scale, due to the expected Uemachi earthquake motion, which is es- 2.4 Required Knowledge of Subsurface Structure timated based on GI-base, is shown in Fig.5. Gen- erally speaking, the high seismic intensity zone is Although there exists the reliable GI-base, some- corresponding to the area having thick Holocene times completely different ground formation would layer, however, it is very important to realize that be drawn when having not enough knowledge of the highest seismic intensity zone is estimated to specific geological structures in the concerning re- be along the Uemachi Fault. gion. Such a case will be introduced as follows. In In this paper, the results of liquefaction estima- 2003, the construction of the Hanshin Namba Line, tion are not presented. However, as already made which extends Nishikujyo to Namba, was started clear, it is ascertained that GI-base can give an ac- as shown in Fig. 6. ademic knowledge to understand the local under- ground conditions as well as the primary inputs to Hanshin evaluate the expected geo-hazard such as liquefac- Main Line Amagasaki Osaka tion due to earthquake. The liquefaction fragility JR Loop for Osaka basin area is evaluated with the simpli- Kobe Line Nishi- fied method on the basis of GI-base. The calculat- Kujyo ed results clearly exhibit the local characteristics, Nanba Nara i.e. liquefaction will widely take place and induce Kintetu Hanshin Line serious geo-hazard in Osaka Plains, and along the Namba Line coast of Kobe and the adjacent area. It is also found that the distribution of the previous locations of liquefaction occurrence in Osaka basin area val- Fig. 6 Hanshin Namba Line directly connecting idates the present performance based on GI-base. Kobe to Nara

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U

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(b) Corrected geological profile while the former water transportation system was in force. Nakanoshima Island area has been a very Fig. 7 Geological profile around the Sakuragawa valuable place for the activities in Osaka till now Station because of its location, in the middle of Okawa River (the tributary of Yodo River, used to be the In order to support the construction works, the main stream from Kyoto). In the history, the rail- technical advisory committee was established. At a way and ground transportation networks have been meeting when the construction of the Sakuragawa taking over the role of the river transportation in Station was discussed, the geological profile illus- Osaka. Now, Nakanoshima Island is the area of in- trated in Fig. 7(a) was submitted. Immediately, one creasing high-density land use, therefore the im- of the members made an observation that the geo- provement of the transportation links is required. logical profile was doubtful, since the Sakuragawa Nakanoshima Line is in the symbolic island of wa- Flexure should intersect the new line around this ter metropolis of Osaka, and it will not only con- region as shown in Fig. 8. Then committee re- tribute to the further economic development but al- quested to carry out additional couple deep bor- so provide a direct link with the central Osaka and ings. The corrected geological profile based on the northern area of Kyoto city via . results clarified by the additional borings is illus- Namely, the line was made a branch line from the trated in Fig. 7(b). From the view point of the con- Tenmabashi Station of the main Keihan Line. struction by cut and cover method, this finding is Therefore, Nakanoshima Line will contribute to very important to determine the appropriate selec- improvement of the transportation network in Kan- tions of the embedded depth of earth retaining wall sai region. and cutoff method. Good use of right method, the When this new line project was being put into construction of the station was completed success- operation, a vertically separated structure is adopt- fully. On March 20, 2009, the line opened from ed, which consists of the railway assets holder Nishikujyo Station to Nanba station (Nakanoshima Rapid Railway Co., Ltd.) and the train operators ( Co., Ltd.). 3. NECESSITY Of RERIABLE TECHNICAL However, the construction was taken care by Kei- COMMITTEE AND INTEGRATED DATA han Electric Railway Co., Ltd., as the site man- & INFORMATION COLLECTING SYS- agement organization, since it had much construc- TEM tion experiences. Fig. 9 shows the organizational chart for the Nakanoshima Line construction. 3.1 Nakanoshima Line Fig. 10 illustrates the alignment of Nakanoshima Line and newly constructed 4 stations. The con- Over countless years, Osaka has been devel- struction was performed by dividing the total con- oped historically around the rivers and canals, struction section into seven sections and each sec- tion was constructed by different contractor.

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St t hi - i -S a as sh im eb ba 3.2 Establishment of Technical Committee and the sh ab a no an iw ka t at an Uemachi Na -S W N Construction Works Fault

Since the construction had to be done under very severe conditions, not only geotechnical but also surrounding environmental conditions, it was Soft clay needed to establish a technical advisory committee, Hard gravel which consisted of members not only from univer- sities, owner and administrative organizations, but also from contractors. Furthermore, when the meetings were held, even the directors of 7 con- tractor’s offices also had to attend and if necessary Fig. 11 Geological profile and vertical alignment they should present the problems at sites and ex- of Nakanoshima Line plain how to overcome. To construct the underground station, the cut and cover method was applied. Especially, since Technical Committee the earth retaining wall is an important step in cut Inspection Meeting and cover method, we decided to select the reliable Owner: Report/Consultation requiredAttendance earth retaining wall for each stations based on the Inspection Nakanoshima Administrative Rapid Railway Co. Offices ground and environmental conditions around the Report Report construction site. For the purpose, trial construc- Inspection Integrated Site management tions to find out the reliable earth retaining wall monitoring Keihan Railway Co. Reference Report Instruction/Presentation data system were carried out. Based on the trial test results, in Use Contractors (7 sections) the construction of the Nakanoshima, Watanabeba- SectionVII SectionIII SectionIV SectionVI SectionII SectionV SectionI shi, and Oebashi Stations the SMW method was,

Up dated on the other hand the Naniwabashi Station the dia- phragm wall was applied as the earth retaining walls. Fig. 9 Organizational chart for the Nakanoshima Observational method was applied by cooperat- Line construction, the technical advisory commit- ing with all seven construction sections. The moni- tee, and the integrated monitoring data system toring items in the cut and cover construction sites were as follows; (1) Temporary works: Horizontal displacement, Stresses in wall, Axial forces in strut, etc., Ｎ (2) Bottom ground: Pore water pressure, Rebound, Plane Oe bash Section 3 i S (3) Surrounding ground: Horizontal displacement, n c t i o n 2 t. tio S e S e N uc c t an tr 1 io n b Pore water pressure, Ground surface settle- ns n 4 S a o tio e c ba C ec t i sh S o n i ment, etc. S 5 S Watanabebashi e c t. t i o (4) Neighboring structures: Displacement, Settle- t n S S St. 6 p

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y were constructed by shield tunneling method. Two N single-line shield tunnels (one going east, the other going west) were opened between each pair of sta- Fig. 10 Nakanoshima Line, 4 new stations, and tions. A single shield machine opened two tunnels construction sections in a U-turn fashion between the station pairs of Nakanoshima and Watanabebashi, Watanabebashi Fig. 11 shows the geological profile along the and Oebashi, and Oebashi and Naniwabashi. How- Nakanoshima Line. As seen in the figure, the ever, two machines were used between Naniwa- ground consists of soft clay layers and complicated bashi and Tenmabashi because the distance be- subsurface structures. Namely, in western side, al- tween the stations is long and the slope is rather ternation of layers of soft clay and hard gravel pre- steep. Both launched from the shaft at the edge of vails, while in eastern side the sudden change of Naniwabashi Station and proceeded toward layers due to the Uemachi Fault can be seen. Tenmabashi Station. The shield tunnels were constructed also un- der very severe conditions. First of all, they had to cross under the three municipal subways with very

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small isolation distance, secondary to run above the other construction section by his own personal the active Uemachi Fault and finally to across un- computer as shown in Fig. 9. der the riverbed of the River Tosabori with very thin cover as 4 meter as shown Figs. 10 ,11, and 12 3.4 Counter Measure against Fault Displacement as well as Photo. 1. The monitoring items in the for Nakanoshima Line 2) shield tunneling construction sites were as follows; (1) (Shield machine: Face pressure, Thrust, Cutter As shown in Figs. 5 and 8, a reverse fault, so called torque, Backfill grouting pressure, Pitching, the Uemachi Fault, runs in the very heart of Osaka Rolling, and Yawing, etc. City in North-South direction. Among various (2) (Surrounding ground: Horizontal and vertical problems, the adopted counter rmeasure in the displacements, Surface settlement, Pore water shield tunnel construction against the flexture de- pressure, Temperature, etc. formation due to the Uemachi Fault displacement (3) Neighboring structures: Displacement, Settle- ment, Slanting, etc. was discussed in the committee. The Uemachi Fault was identified under a flat surface ground condition, which is called hidden fault, as shown in Fig. 13.

Naniwabashi-St. West East Uemachi Elevation (m) Flexure Alluvial 0 Ma 6 Ma 9 Upper Osaka- group Ma 3 Ma 1 Ma 6 Osaka- group Ma 3 marine deposit Ma 1

-1000 1 Lower Osaka- group Bed rock, Granite Photo. 1 Shield tunnel under the River Tosabori -1500 Bed rock, Granite 0 500m Uemachi Fault The River Tosabori Fig.13 Hidden Uemachi Fault and above flexure

Deep boring Outer diameter of MinimumThe minimum cover: West Deep boring 300m East 0000 shield: 6.95 m 4 m cover: 4.4m Ma13Ma13Ma13 Ma12Ma12Ma12 MaMa7Ma7Ma7 7 m MaMa6Ma6Ma6 6 Ma1Ma1Ma1 111 Fig. 12 Minimum cover above shield tunnels 100100100100 Ma10Ma10Ma10 Ma9Ma9Ma9 Elevation gap Ma8Ma8Ma8 Difference in height 3.3 Integrated Data & Information Collecting Sys- Ma7 =256m =256m Ma7Ma7Ma7 200200200200 tem =272m Ma6Ma6Ma6 MaMa7Ma7Ma7 7 Ma 6=272m

Ma6Ma6Ma6 Ma 6 In order to carry out the constructions safely and to mmm Sakura tuff 300300300300 minimize the effects on the surrounding area, it was decided to establish the overall integrated in- 700600m600m600m600m m formation and data collecting system not only for one construction section but for all construction Fig. 14 Uemachi Flexure based on boring studies sections. Namely, the central office integrated the information of monitored data from each construc- Based upon the previous study in the area includ- tion section, and then it evaluated the quality of ing the seismic survey, geological borings outside over all construction progress, the construction of the flexure structure were planned. The western safety, and the effect to neighboring region based side boring was long boring of about 300m to on the integrated information. Furthermore, the in- reach Ma 6. As shown in Fig.14, the upper most tegrated data from all construction sections were layer in the eastern side was Ma7 of Osaka Group disclosed for any engineer at each construction and the same marine clay formation in the western sections and he could see the real time data even of

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part was expected to be at about GL-300m. Fig. 14 way, the vertical alignment had to be designed us shows the Uemachi Flexure based on boring ing steep inclination of 4% so as to run under the studies riverbed with enough cover to keep the safe tunnel The rate of the vertical fault displacement of construction. The inclination value 4% is the al- throw was estimated from the difference in the lowable maximum value for train operation in Ja- depths between 256m for Ma7 and 272m for Ma6 pan 4) . Whenever the next Unemachi fault dis- and the time periods after the depositions of these placement will cause the same amount of layers. The results are shown in Table-1. deformation for the Uemachi flexure as in the past earthquake, the maximum inclination of the sub- Table 1 Estimation of Displacement Rate of way exceeds the critical value of 4% and the rail- Uemachi Fault at Nakanoshima way operation is forced to terminate. Base of Sediment Difference However, if the fault displacement is some value Soil Rate of Deposit era West side East side in Height layer throw less than 4m, say 1 m, the railway vertical align- boring boring (Throw) ment can be adjusted to keep the inclination less x10 3year from BP 3 GL -m GL -m m m/10 year than 4% if tunnel inner cross-section has set up Ma7 577 267.11 11.52 255.59 0.443 some room. For instance, if tunnel inner cross sec- Ma6621 301.40 29.47 271.93 0.438 tion is widened about 10cm vertically and the fault displacement is less than 1m, it can adjust the in- Namely, the average displacement is estimated 3 3) clination within the allowable value as shown in as 0.44m/10 year. Sugiyma (2003) reported the Fig.17 and the railway to continue its service even last event along the Uemachi Fault is estimated after the earthquake. about 9,000 years before and estimated the possi- ble release of the vertical displacement is 3 0.44m/10 year x 9,000years = 4m. The fault dis- Max. slope section placement for the design of Nakanoshima line was The case of 4 m of maximum 4.26 % based upon the displacement of 4m. displacement of the fault After quake The subway tunnel section that is constructed in Slope Gap: 6.40 m the Uemachi Flexure with the 700m in width is ex- pected to behave differently according to the mag- Elevation Before quake Slope nitude of the fault displacement. That is, the max- After quake imum displacement will be expected to be 4m, but Vertical Alignment it is not necessarily to reach to the maximum level Before quake in every event. Introducing the pattern of flexure Tenmabashi St. deformation given in Fig. 15 in the beam theory on Shin-Kitahama St. elastic foundation, the longitudinal behavior of the DC-segment RC-segment DC-segment Original design shield tunnel was investigated. DC-segment Shortage of strength

Radius of Curvature(m) Radius of Curvature (m) Fig. 16 Vertical alignment before and after fault 5 10 MinimumMinimun Radius Radius of Curvature of Curvature=14,600m = 14,600 m displacement of 4 m

4 10 700 m Max. slope section

3 The case of 1 m of maximum 10 displacement of the fault 2.0 -350 -300 -250 -200 -150 -100 -50 0 50 100 150 200 250 300 350 After quake After quake 4.07 % 1.0

4.0 m HorizontalHorizontal Distance Distance(m) (m) Elevation Gap 6.11m 0.0 Before quake Slope -350 -300 -250 -200 -150 -100 -50 0 50 100 150 200 250 300 350 Slope -1.0 RefernceReference Width=300m Width = 300 m

VerticalDisplacement(m) After quake -2.0

Vertical Displacement (m) Vertical Alignment Before quake

Tenmabashi St. Fig. 15 Deformation Curve Shin-Kitahama St. DC-segment RC-segment DC-segment Original design DC-segment Based upon the study of several cases with dif- Shortage of strength ferent fault displacements and their effect, it was concluded that two types of emergency plan for the Fig. 17 Vertical alignment before and after fault countermeasure should be prepared against two displacement of 1 m different magnitudes of fault displacements. As shown in Fig. 16, in one of the section of the sub-

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At any rate, the section of the shield tunnel of 700 m was assigned as affected by the fault dis- placement. Among various considerable counter- measures to avoid damage of the shield tunnel, it was decided to adapt the ring segments made by ductile steel (DC) rather than precast reinforced concrete (RC) as given in Figs.16 and 17. The moment strength of DC is about 2.5 times larger than that of RC.

CONCLUSIONS

1. Kansai Geo-information Database (GI-base) has been developed by using more than 48,000 boring data mainly collected from urban area, such as Osaka, Kobe, and Kyoto. 2. It is ascertained that GI-base can give an aca- demic knowledge to understand the local un- derground conditions as well as the primary inputs to evaluate the geo-hazard such as the seismic intensity and the liquefaction potential due to earthquake. 3. In addition to the knowledge of soil properties, the knowledge of subsurface structure is re- quired to geotechnical engineers. 4. A reliable technical committee and integrated data & information collecting system are re- quired for the successful completion of any important construction projects. The proper counter measure was taken into account in the Nakanoshima Line construction against the Uemachi Fault displacement by supervision of the technical committee

REFERENCE

1) Kansai Geo-informatics Research Committee (2007): Shin Kansai Jiban-Osaka Plain, 450p (in Japanese). 2) Adachi, et al. Hidden fault and counter measure against fault displacement for Nakanoshima subway in Osaka, Proc. Symp. in Honor of Professor Lee Seng Lip, PP. 49-58, 2011. 3.

3) Sugiyama et al. Complementary study of the Uemachi fault system in the Osaka Basin (2)- Evaluation of the fault activity based on sup- plementary boring and re-interpretation of S- wave seismic reflection data-, Active Faults and Ancient Earthquakes, No. 3, p. 117-143, 2003 (in Japanese). 4) Design Standards and manuals for Railway and related Structures, Shield tunnel, Railway Re- search Institute, 1997.

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