(英文）外文翻譯---日本山嶺隧道的設(shè)計和施工（節(jié)選）

1、<p>　　Tunnelling and Underground Space Technology 18 (2003) 115–126</p><p>　　Design and construction of mountain tunnels in Japan</p><p>　　Katsushi Miura*</p><p>　　Shizuoka Con

2、struction Bureau, Japan Highway Public Corporation, Shizuoka, Japan</p><p>　　Received 10 September 2002; received in revised form 29 January 2003; accepted 4 February 2003</p><p><b>　　Abst

3、ract</b></p><p>　　This paper presents the state of technologies of the mountain tunneling method in Japan. In addition to the review of the design and construction technologies, the paper focuses on th

4、e development of technologies for tunnels with large cross-sections, urban tunnels in non-cemented soil ground, and applications of TBMs, which are technically evolving nowadays.</p><p>　　© 2003 Elsevie

5、r Science Ltd. All rights reserved.</p><p>　　Keywords: Mountain tunneling; Urban tunnel; TBM</p><p>　　Presentstateofdesignandconstruction technologies</p><p>　　Introduction&l

6、t;/p><p>　　In Japan, the mountain tunneling method has become popular since the end of the 19th century. Many tunnels, including those under difficult conditions such as the Seikan Tunnel, have been successfull

7、y constructed with advanced technologies.</p><p>　　Approximately 20 years ago, the Japanese mountain tunneling method was changed when it adopted the use of supports which combine shot crete and rock bolts,

8、or in some cases, steel supports. Since then, design and construction technologies have made more progress. Attempts have been made to create technical develop- ment for high-speed construction, using advanced mech- aniz

9、ation, and challenges to handle technically difficult tunneling construction works, such as tunnels with large cross-section</p><p>　　Initial design and modification of the design</p><p>　　In ge

10、neral, a ‘standard cross-section’, specified by an administrator, is adopted in the initial design stage.</p><p>　　*Tel.: q81-54-272-4881; fax: q81-54-272-4891.</p><p>　　E-mail address: katsu

11、shi.miura@jhnet.go.jp (K. Miura).</p><p>　　The ground can be classified into several general types, and a preliminary design should be made for each ground type.</p><p>　　The initial design meth

12、ods are as follows.</p><p>　　:2(2,6,1)Application of‘ standard designs’.</p><p>　　In Japan, administrators of railways, roadways, etc. maintain a list of ground classifications and corre- spondi

13、ng standard designs based on past experiences. These standard designs are employed for the construc- tion of tunnels under normal conditions.</p><p>　　Application of designs under similar conditions.</p&g

14、t;<p>　　Application of analytical methods.</p><p>　　For tunnels with special cross-sections or special ground conditions, numerical analyses are employed. The most general type of numerical analytsis

15、is the finite element method (FEM).</p><p>　　Observations, measurements and modified designs</p><p>　　Designs are modified during the construction stage by making judgments and evaluations from

16、the view- point of whether or not the ground conditions are the same as those anticipated during the initial design stage. If modifications are required, the following problems must be solved, namely: (1) how to change t

17、he amount of support and yor the installation time; (2) whether or not the stability of the cutting face can be maintained if construction is continued; and (3) if unstable, what rat</p><p>　　0886-7798

18、/03/$ - see front matter © 2003 Elsevier Science Ltd. All rights reserved. PII: S0886-7798 ? 03 . 00038-5 </p><p>　　Evaluation of the ground</p><p>　　It is very important to observe the cu

19、tting face and to evaluate the ground conditions. However, there are many factors which have to be systematically taken into account. An attempt is made to compute the percentage that each factor contributes by analyzing

20、 past records and by expressing the ground conditions in terms of evaluation points.</p><p>　　Probing exploration</p><p>　　In order to speed up the construction time, it is particularly importan

21、t to properly evaluate the ground conditions. To meet this goal, an investigation should be conducted to evaluate the ground conditions ahead of the cutting face. In addition to pilot boring, an estimation method which i

22、nvolves drilling energy or elastic waves is adopted.</p><p>　　Use of measurements</p><p>　　In order to evaluate the present state of the ground conditions with the measurements, the following ma

23、in- tenance targets are often set up.</p><p>　　Evaluation of the stability of the ground; Sakurai (1982) and Sakurai et al. (in press) proposed a method for estimating an allowable value of displace- ment fr

24、om relationship between the limit strain and the uniaxial compressive strength.</p><p>　　Maintaining limits for the soundness of the supports.</p><p>　　Limits not to influence the surrounding st

25、ructures.</p><p>　　Support designs</p><p><b>　　Shotcrete</b></p><p>　　A strength of18 MPa (a curing period of28 days), as high as lining concrete, is used as the standar

26、d design strength. In cases where the thickness needs to be increased, attempts are sometimes made to either apply reinforcements using steel fiber or to increase the stan- dard design strength, just like the tunnels for

27、 the New Tomei and the New Meishin Expressways or tunnels with thick overburdens (Miura et al., in press).</p><p>　　Shotcrete is sometimes reinforced by the insertion of wire nets. Steel fiber reinforced con

28、crete is used when complicated stress or large deformation develops.</p><p>　　A new support is under development along with new construction methods, namely, shot mortar, extruded concrete lining (ECL), prel

29、ining, and so on.</p><p>　　Rock bolts</p><p>　　Rock bolts are used as primary support materials just like shotcrete. The main anchorage method for rock bolts is a full-faced anchorage. For cases

30、 in which a rock bolt hole cannot stand alone, a self-boring type of rock bolt may be employed. When rock bolts are</p><p>　　anchored to the ground, the friction is increasing. The bolts are not only

31、 effective immediately after installa- tion, but also work even when water inflow is encountered.</p><p>　　Steel supports</p><p>　　Steel supports are considered to have positive effects such as

32、early stabilization of the crown face, reinforce- ment of shotcrete, supporting points of fore-piling, etc., and they are generally used in Japan when ground conditions are poor.</p><p>　　Design of the linin

33、g</p><p>　　At general sites and under normal ground conditions, the purpose of a lining is to increase the safety of the supports. Thus, no particular considerration is given to the mechanical functions. It

34、is conventional practice to apply a standard design.</p><p>　　Mechanical consideration does need to be given to the design of the lining in some cases; for example, the earth pressure or the water pressure a

35、cts after the completion of the tunnel. Some engineers refer to past similar cases, and then conduct a structure analysis or a finite element analysis.</p><p>　　Auxiliary methods</p><p>　　In mou

36、ntain tunneling, the auxiliary methods can be used in order to stabilize an unstable cutting face, to control the preceding displacement ahead ofthe cutting face, to improve the ground conditions so as to obtain the full

37、 effect of the supports, and so on.</p><p>　　Stabilizing the crown</p><p>　　The crown is stabilized in order to prevent its collapse before the shotocrete has been applied and has hardened. Fore

38、-poling, in which rock bolts are driven into the ground around the excavated face, is easy to conduct without changing the arrangement of the construction machines used at conventional construction sites.</p><

39、p>　　Pipe roof protection, horizontal jet grouting (Fig. 1), long-span steel pipe fore-piling, prelining (Fig. 2), etc., are likely to yield highly effective results. Since special construction equipments are required,

40、 however, these methods are adopted only in cases where extremely poor ground conditions continue over a long working section or the settlement of the surface ground is severely restricted.</p><p>　　Among t

41、he long-span steel pipe fore-piling methods, a method which uses a conventional drilling jumbo has been developed. It is often used at the portal or at fractured zones due to its simplicity in application (Fig. 3).</p

42、><p>　　Fig. 1. Ground stabilization method by high-pressure jet grout fore- piling (Koizumi et al., 1990).</p><p>　　Stabilizing the cutting face</p><p>　　There is a method which forces

43、 the cutting face to stand alone by subdividing the face. However, since such poor ground conditions require long-span rock bolts or the early closure of the cross-section, a large</p><p>　　cutting face is

44、necessary. Thus, stabilization by means of auxiliary methods has become popular in recent years.</p><p>　　Face shot crete and face bolts can be added during a conventional working cycle and are easily employ

45、ed. Injection methods are used to improve the mechanical properties of the ground; cement or urethane is being applied nowadays. In some cases, a long bolt or a cable bolt is first inserted ahead of the cutting face; the

46、 bolt is then cut down while the excavation is being carried out.</p><p>　　Methods to counteract water inflow</p><p>　　Drainage methods such as drainage boring and drain- age tunnels are applied

47、 as countermeasures. For non- cemented soil grounds in particular, underground water may cause the ground to liquefy, leading to a difficult construction. For this reason, well-point drainage and deep wells are often con

48、structed.</p><p>　　In cases where there is an exhaustible amount of</p><p>　　underground water, like in undersea tunnels, wherein if drained, the surrounding ground may settle, a cut-off

49、 method is applied. Grouting is the main method, how- ever, and its technology has been developed through</p><p>　　Fig. 2. Prelining (new-PLS method) (Fujishita et al., 1998).</p><p>　　Fig. 3. L

50、ong span fore-piling (Geofront Research Group, 1997).</p><p>　　Fig. 4. Transition ofdriving methods (Satou and Tanaka, 1998).</p><p>　　past experiences such as with the Seikan Tunnel. Pneu- mati

51、c and freezing methods are also used on rare occasions.</p><p>　　Construction method</p><p>　　Excavation</p><p>　　Excavation methods are divided into two types, name- ly, excavation

52、 by drilling and blasting, and excavation by machines. Fig. 4 shows the percentages for the usage of each method. For soft rock and weathered rock, mechanical excavation using a boom type of excavation machine are conduc

53、ted. However, high capacity exca- vation machines are coming into wide use and for ground with uniaxial compressive strength up to 40 MPa. Some machines can complete the excavation faster than by drilling and blas</p&

54、gt;<p>　　Noise and the vibrations associated with blasting have an influence on both human beings and buildings. A promising excavation method, based on the prediction equation of the transmission of vibrations an

55、d test blasting, is under consideration. In some cases, the use of explosives is not allowed. For a boom type of excavation machine, a model machine which can deal with rock that has a uniaxial compressive strength of 80

56、–100 MPa has been developed. For harder rock, the rock-split method and the </p><p>　　Excavation methods</p><p>　　The area of the cross-section, excavated at one time, is determined by stability

57、 of the cutting face. The capacity of excavation machines should be taken into</p><p>　　account. But the method should be planned according to which method is suited for most of the ground in question and th

58、at the local instability ofthe cutting face can be reinforced by auxiliary methods. As shown in Fig. 5, the bench cut method is presently the most popular method. However, the full-faced excavation method with benching i

59、s approaching half the number.</p><p>　　Development of high efficient excavation methods For large-scale construction works, there are some cases in which special purpose machines are employed to improve

60、 the efficiency. With the blasting method, a gantry jumbo is sometimes utilized for this reason. For soft rock, a specially mechanized excavation system which named TWS was developed and adopted to the San-nou Tunn

61、el. New technologies such as quick-hard- ening mortar and spherical cutting face for full-faced</p><p>　　excavation, were employed.</p><p>　　Muck transport method</p><p>　　The work

62、of carrying the muck soil out of the tunnel is generally done with a tractor shovel and dump truck system. In order to shorten the work time and to reduce the ventilation, a large-scale dump truck or the tempo- rary plac

63、ement of container is adopted. For tunnels which have small cross-sections or are long, a rail type is adopted.</p><p>　　A belt conveyor type has been developed in which it is easy to extend the belt as the

64、cutting face advances; it is adopted when using a TBM. In some construction sites of the Shinkansen tunnels, the belt conveyor type was combined with a movable crusher.</p><p>　　Fig. 5. Transition of excavat

65、ion methods (Satou and Tanaka, 1998).</p><p>　　Fig. 6. Example of support pattern for swelling ground (the Orizume Tunnel) (Karasawa and Suda, 1984).</p><p>　　Special ground conditions</p>

66、<p>　　Grounds with swelling</p><p>　　It is often the case that when a tunnel excavation is conducted, rocks exhibiting swelling are encountered, such as relatively new sedimentary rocks like mudstone

67、and tuff, and hydro-thermally altered rocks.</p><p>　　In the early stage of applying the support system to a swelling ground in Japan, using shotcrete and rock bolts, a contractible mechanism was designed on

68、 some occasions with a large number of long rock bolts. From research conducted afterwards, importance should be placed on the early closure of the cross-section of the tunnel by electing a highly stiff support system wh

69、ich can minimize the loosening of the ground and reinforce the cutting face in the case of a swelling ground, since the stabili</p><p>　　An example is shown in Fig. 6. This approach is applied for heading an

70、d temporary upper bench inverts for reinforcement of the cutting face and the early closure, to tunnel in ground of very large swelling.</p><p>　　High water pressure and a large amount of water inflow</p&

71、gt;<p>　　Predictions should be made before the situations get too serious and it becomes necessary to adjust the conditions so that the tunnel can be constructed by employing auxiliary methods such as drainage or

72、cut- off.</p><p>　　Non-cemented soil ground</p><p>　　In the case of a sandy ground, it can be liquefied or the cutting face becomes unstable due to water inflow. When the content of clay and sil

73、t is low, less than 10%, and the uniformity coefficient is low, less than 5%, the ground is possible to become liquefied.</p><p>　　In the case of a clayey ground, an increase in the water content tends to de

74、crease the strength. Since the bearing capacity is generally not large and it deteriorates especially when affected by water, caution should be taken.</p><p>　　High earth temperature, hot springs and toxic g

75、as Many parts of Japan are located in volcanic belts, and tunnels sometimes encounter high temperature and hot</p><p><b>　　springs.</b></p><p>　　Toxic gases, such as inflammable gase

76、s like methane gas, oxygen-deficient air, etc., are sometimes encoutered.</p><p>　　Rock bursts</p><p>　　Rock bursts occurred in the Shimizu Tunnel and in some other tunnels. There is a case in w

77、hich a rock burst even took place with an overburden of approxi- mately 300 m. Rock bursts are not easy to predict, but investigation using acoustic emission is sometimes recommended.</p><p>　　1.9. Neighbori

78、ng tunnels</p><p>　　Generally speaking, a neighboring tunnel is designed by considering the mechanical influence through an</p><p>　　Fig. 7. Twin-tube tunnels (the Kozukayama Tunnel).</

79、p><p>　　analysis. Since the ground is also affected by both tunnels, plastic zones may have to be expanded. Thus, proper countermeasures need to be taken through the adoption of auxiliary methods. An example of

80、 twin-tube tunnels is shown in Fig. 7.</p><p>　　Tunnels with large cross-sections</p><p>　　Plan and design of the New Tomei-Meishin Express- way tunnels</p><p>　　In Japan, the numbe

81、r of tunnels with large cross- sections of approximately 130 m2, is increasing due to the increasing demand for three-lane road tunnels.</p><p>　　The New Tomei-Meishin Expressway is the second expressway con

82、necting three major cities in Japan, as shown in Fig. 8. They are high-standard roads with six lanes and a speed limit of140 km/h. Since there are many sections along the route which pass through mountains, tunnels accou

83、nt for 25% of the total length</p><p>　　Of the route. Taking into account a balance between the stability of the tunnels and the economic issues, in addition to accommodating the building limits of having a

84、three-lane road and sufficient shoulders, a tunnel with a large, flat cross-section and an excavated area of approximately 190 m2 is planned, as shown in Fig. 9. The first work section of370 km, out of a total length of5

85、02 km, is under construction. There are 167 tunnels in this work section which account for a total tunnel length </p><p>　　Design of the supports and the lining</p><p>　　A new standard pattern o

86、f supports was set, as shown in Table 1, by feeding back the measurement data taken during the test construction.</p><p>　　Since the settlement of the crown has a flat cross- section, it surpasses the other

87、s, and the horizontal convergence is small. The ground displacement runs deep at the crown, while it occurs near the surface at the side wall. For this reason, the supports are mainly used to help prevent a drop in the g

88、round at the crown.</p><p>　　In order to provide early supports to prevent ground deformation, high-strength shotcrete was adopted. The strength of the high-strength shotcrete was set at double the strength

89、of the standard shotcrete, and the design thickness of the shotcrete was made thin. The strength at an early stage of curing was also important, so it was specified.</p><p>　　In addition to thinning out the

90、shotcrete, a high- standard steel, which was light and easy to handle,</p><p>　　was used for the supports.</p><p>　　Fig. 8. Location ofthe New Tomei-Meishin Expressways.</p><p>　　Fi

91、g. 9. Tunnel cross-section.</p><p>　　For the grounds with a classification of Class B, in which the arched section was relatively self support- ing, steel fiber reinforced concrete was adopted as the shotcre

92、te in the upper-halfsection and steel supports were omitted.</p><p>　　Since a large number of long rock bolts were required for the arched section, high-strength rock bolts were adopted.</p><p>

93、　　The designated standard strength of the lining concrete was increased and its thickness was reduced.</p><p>　　Consideration of the construction method</p><p>　　Based on the results of the pilo

94、t construction, the TBM drift method was adopted for long tunnels. For the other tunnels, the central top heading method was</p><p><b>　　Table 1</b></p><p>　　Standard design patterns

95、</p><p>　　GroundCut perRock boltSteel arch</p><p>　　Thickness ofThickness of lining</p><p>　　classadvance</p><p>　　(top heading)</p><p><b>　　sup

96、port</b></p><p>　　Length (m)PeripheralLongitudinalUpperBench</p><p><b>　　shotcrete</b></p><p><b>　　(cm)</b></p><p><b>　　(cm)<

97、/b></p><p>　　ArchysideInvert</p><p>　　( ) means without TBM pilot advance. Shotcrete is the high strength type, *upper section uses SFRS (steel fiber reinforced shotcrete. Rock bolt: ** has

98、strength of2901, others have strength of 180 kN. Steel arch support is high grade type.</p><p>　　Fig. 10. Advanced reinforcement by cable bolts at the TBM pilot.</p><p>　　adopted, depending on t

99、he stability of the cutting face and the crown.</p><p>　　A TBM, with a diameter of5 m in the upper-half section, was adopted as the drift. The results of the pilot construction led to the following outcome:

100、</p><p>　　The cutting face was stabilized and the geology ahead of the cutting face was confirmed; thus, an efficient construction was possible. Judging that the excavation length could be lengthened, compar

101、ed with the top head method, it was adopted as the standard design.</p><p>　　For poor ground, reinforcements using cable bolts were adopted from the inside of the tunnel preceding the enlargement excavation