www.elsevier.com/locate/enggeo

Engineering Geology 71 (2004) 199–211

A case history of Tunnel Boring Machine jamming in an inter-layer

shear zone at the Yellow River Diversion Project in China

Yanjun Shanga,*, Jihong Xueb, Sijing Wanga, Zhifa Yanga, Jie Yangc

aKey Laboratory of Engineering Geomechanics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, ChinabDeputy Site Agent of CMC for Connecting Works—Lot 5 of Shanxi Wanjiazhai Yellow River Diversion Project,

Chaicun Town, P.O. Box 18, Taiyuan 030023, ChinacDepartment of Civil Engineering, Xi’an University of Science and Technology, Xi’an 710054, China

Received 10 July 2002; accepted 6 March 2003

Abstract

This is a case study of a Tunnel Boring Machine (TBM) jamming in a section of the Connection Works No. 7 tunnel of the

Yellow River Diversion Project (YRDP) in China. Analysis of tunnel lithology, rock convergence by shearing, rock strength and

ground stress, indicates that a high rate of convergence within an inter-layer shear zone in the lower part of an anticline was a

dominant factor in the jamming. In addition, the shield encountered unfavorable tunnelling conditions in the form of wet clay,

groundwater inflow, and cavities, coincident with tensile stresses in the lower part of an adjacent syncline. Based on these

diagnoses, economical and quick measures were adopted, including additional excavation outside of the shield leaving free

space to release the TBM. After 9 days of being jammed, the TBM was totally released and resumed normal excavation. This

example highlights lessons learned from folding and inter-layer shear zone in TBM tunnelling.

D 2003 Elsevier Science B.V. All rights reserved.

Keywords: TBM; Inter-layer shear zone; Fold; Marl

1. Introduction viewed case histories in the Opalinus Clayshale.

Jointed and fractured rock masses, fault zones,

cavities and groundwater inflow are frequently en-

countered and discussed with respect to engineering

geological conditions unfavorable to tunnelling. Most

of them have been included in case studies of TBM

tunnelling. Barton (2000) has modified his well-

known empirical rock mass classification for TBM

case histories, known as QTBM. Einstein (2000) re-

0013-7952/$ - see front matter D 2003 Elsevier Science B.V. All rights re

doi:10.1016/S0013-7952(03)00134-0

* Corresponding author. Fax: +86-10-62040574.

E-mail address: jun94@mail.igcas.ac.cn (Y. Shang).

Alber (2000) evaluated advance rates of hard rock

TBMs and their effects on project economics. Barla

(1999) considered the protection of springs during

excavation of large diameter TBM tunnels. Hamza

et al. (1999) monitored and studied ground move-

ment due to the construction of cut-and-cover struc-

tures and a slurry shield TBM in the Cairo Metro.

Swoboda and Abu-Krisha (1999) used 3D numerical

modeling for analysis of TBM tunnelling in consol-

idated clay.

However, as a feature of geological settings, folds

have not received much attention. In large-scale hydro

projects for transferring water from southern to north-

served.

Y. Shang et al. / Engineering Geology 71 (2004) 199–211200

ern China, problems associated with geological struc-

tures including faulting and folding will be a common

occurrence (Fu, 1998). It has been found difficult to

construct consistent structural geological models for

TBM tunnelling sites, given the linear nature of tunnel

site investigations.

Therefore, detailed site investigation and probe

drilling are necessary in complex geological condi-

tions in order for TBMs to perform to specification

(Pelizza et al., 2001; Barton, 2000). For example, the

approaches to fault zones should integrate field inves-

tigation, bore drilling, probe-drilling, geological radar,

and daily logging (Zhang, 1999; Su et al., 2000, 2001;

Xu et al., 2000; Liu and Cheng, 2000).

Here, it should be noted again that typical case

histories of empirical or actual investigation results

require complete re-evaluation and retrospective study

(Bappler, 2001) for the construction of different

structural geological models. Obviously, these models

are significant in integrating exceptional conditions

encountered in tunnelling. Moreover, they will pro-

mote the advanced development of TBM techniques

(Voerckel and Peters, 2001).

In folding section with high ground stress, the

inter-layer shear zones are categorized as either being

under-developed or well developed according to the

shearing displacement being dominant and apparent

or not. Only the latter category affects the stability of

rock engineering works (Qu and Xu, 1979; Xiao et al.,

2000). Laboratory studies indicate that the two types

of inter-layer shear zone are differentiated from the

shearing function which the inter-layer zone experi-

enced (Morgensten and Tchaleko, 1967). We know

little about how the fold geometry adjustment affects

location of the inter-layer shear zone, except about the

evaluations of the effects of lithological properties on

fold geometry according to mechanical analysis and

modeling (Ramsay and Huber, 1987).

With an increase in the imposed stress, a large

displacement due to shearing will occur, which must

involve the movement of the heavy rock layers

overburden, in addition to localized stress concentra-

tion, as indicated by field evidences (Qu, 1985; Xiao

et al., 2000). This kind of phenomenon is widely

known in Daqing Petroleum Field, Northeast China,

where the convergence often results in borehole

failure during drilling to a large depth because of

secondary inter-layer shearing (Prof. Jiamo Xu, per-

sonal communications, 2001). When inter-layer shear

appears in the middle of a coal seam, it is traditionally

known as a bedding shear zone, or soft-coal band (Li,

2001). To perform analyses of shear zones and joints,

a simple contact–friction interface element for 2D

models is applied (Lei et al., 1995).

The contact zone (esp. inter-layer shearing zone)

between two beds (incompetent and competent) with

distinctive mechanical features generally deformed

and failed due to secondary shearing (Ramsay,

1967). The shearing displacement resulted from sim-

ple shearing usually occurs in the soft rocks or layers

adjacent to the contact zone (Qu, 1985). This move-

ment not only induces the disintegration of intact rock

masses, but also disturbs the original distribution of

ground stresses and results in convergence (Hudson

and Harrison, 1992). According to numerous case

examples of underground engineering in soft rocks,

when a project requires a depth of more than 200 m

and especially more than 300 m, the convergence

values are often large.

Pelizza et al. (2001) have discussed the instability

of the tunnel excavation faces and walls, fault zones,

and squeezing/swelling ground as typical limiting

ground conditions affecting the performance of

Tunnel Boring Machine (TBM). They noted that

‘‘jamming of rock TBMs for long periods of time

due to convergence problems has not been heard of, at

least recently’’. This case study of TBM jamming,

which occurred on 18 June 2001, in the Connection

Works No. 7 tunnel of Yellow River Diversion Project

(YRDP) (Fig. 1) provides an example of this kind of

problem.

With a total length of 13.52 km, the No. 7 tunnel

excavation of the YRDP (Fig. 1) started in December

2000. The final breakthrough to the TBM exit shaft

was achieved by the end of September 2001. A 1994

Robbins Double Shield TBM model 155-274 with a

4.8-m external diameter was used, together with a

complete backup system. It has a unit square cutting

power of 52 kW/m2 with two-speed motors. The

modified length of the backup line was 330 m; its

production rate was 2.4 m/cycle. Although four Rob-

bins Double Shield TBMs had been previously used

in the YRDP with great success (Martinis, 1995; Liu

et al., 2000; Cao et al., 2001), severe jamming initially

occurred in No. 7 tunnel. The lessons learned from

this are discussed below.

Fig. 1. Sketch map showing the alignment of No. 7 tunnel of the Yellow River Diversion Project (A–B cross-section shown in Fig. 3).

Y.Shanget

al./Engineerin

gGeology71(2004)199–211

201

Y. Shang et al. / Engineering Geology 71 (2004) 199–211202

Within one 1130-m section of No. 7 tunnel of the

YRDP, TBM encountered cavities and groundwater

inflow from 22 May to 3 June. After that, boring

advanced at a slow rate under unfavorable geological

conditions before jamming occurred. After jamming

took place on 18 June, it took 9 days to free the

machine. Then, the TBM was again advanced at a

normal rate. Backfilling with pea-gravel and grouting

for fractured rocks and cavities, enlargement excava-

tion outside of the shield with a jackhammer, were

carried out accordingly.

In this paper, the lithology, structural geology, and

ground stress behavior in the section with a distance

of 1130 m are analyzed. The approaches adopted

include site investigation, laboratory test and logging

data analysis, and conveyor-taken muck observations.

2. Engineering geological setting

The No. 7 tunnel, which is the subject of this case

history, is located in the southern flank of an anticline

(Fig. 2), in the western mountainous area of the

Meso–Cenozoic sedimentary basin of Taiyuan on

the North China Craton (Shanxi Bureau of Geology,

1989). In the section where the TBM became jammed,

the axis of a small-scale anticline trends about 50jNE,whereas the orientation of the tunnel is 71.7jNE(Fig. 2). The included angle, therefore, is about

20j. The dip angles of the southern and northern

limbs of the anticline are 20j and 16j, respectively,in the researched section (Fig. 2). To a larger area,

there are two dominant sets of folds. The first one

was formed earlier with an orientation of SN at the

eastern part of this area. The second set was formed

later with an orientation of NE at the western part of

this area.

Rocks surrounding the tunnel mainly include thick-

ly bedded dolomitic limestone (O2s2), marl with

breccia and marl intercalated with argillaceous lime-

stone, and gypsiferous limestone (O2s1), of Upper

Majiagou Group, Middle Ordovician System.

3. Exceptional events in No. 7 tunnel

As shown in Fig. 3, TBM excavation encountered

very bad geological conditions from May 21 to June

18, 2001, along a total length of 1130 m (chainages 49

km+ 321.21 m to 48 km+ 190.48 m). First, cavities,

wet clay and then groundwater inflow appeared in

sequence. Then on 18 June, the TBM was totally

jammed in squeezing ground.

From 21 to 27 May, TBM tunnelling advanced

slowly through strongly fractured rock masses in a

zone between O2s1 and O2s

2, soft rocks (marls) and

hard rocks (dolomitic limestone) appeared alternately

with high frequencies, together with the presence of

large fissures and karst cavities of various sizes. The

location with karst cavities is just 200 m deep from a

valley bed surface (Fig. 3). Surrounding rock masses

were very unstable and fallen stalactite in various size

of karst cavities were at chainage 49 km+ 167.06 m.

From 29 to 31 May, a karst cavity was encountered at

the upper-left side of the tunnel section. It was about

0.8–2.0 m wide and 2–4 m long along the perimeter

of tunnel, and it extended about 10–15 m along the

tunnel alignment (Fig. 3). This cavity was situated

partially in marl and partially in limestone. Rock

fragments of up to 1–2 m3 fell into the excavation

chamber.

About five wagons of muck comprising of marly

clay with high moisture content were taken from the

TBM excavation face and sent out on the last train of

the night shift of 2 June (at chainage 48 km+ 895.41).

From then until 5 June (reaching to chainage 48

km+ 829.64 m), groundwater seeping occurred local-

ly. After 6 June, the TBM slowly advanced more than

600 m forward through both dry and wet plastic marl

soils, but without encountering seeping water. How-

ever, at midnight of 17–18 June, the TBM became

totally jammed in squeezing ground. The total free

space between the shield of the TBM and surrounding

rocks with a width of 5–8 cm (Fig. 4) was closed in

about 2 h. Thus, the rate of convergence was about

20–40 mm/h.

The particular geological problems encountered as

wet clay, underground water, cavities and squeezing

ground are all in the upper part of the O2s1 formation

overlay by O2s2. Geographically, The former three

accidents occurred in a depth of 200 m beneath a

valley bed, the latter one happened at a depth of 300

m from the peak crest. In geology, the former three are

in the lower part of a syncline core, while the latter

one is near the limb and in the lower part of an

anticline core (Fig. 3). Therefore, the folding played a

Fig. 2. Geological map of the tunnel site in the western mountainous area of Taiyuan (A–B cross-section shown in Fig. 3) (according to Shanxi Bureau of Geology, 1979, 1989). (1)

Holocene alluvia; (2) Upper Pleistocene pluvial-talus series; (3) Middle Pleistocene pluvia; (4) Pliocene sediment series; (5) Sandy shale, sandstone of Upper Permian system; (6)

Sandstone, sandy shale, shale intercalated with coal seam of Lower Permian; (7) Sandstone, sandy shale, shale intercalated with coal seam, Shanxi Group of Upper Carboniferous

system; (8) Sandstone, sandy shale, shale, limestone with coal seam, Taiyuan Group of Upper Carboniferous system; (9) Allite, shale, limestone and iron deposit, Benxi Group of

Middle Carboniferous system; (10) Dolomitic marl with breccia, Limestone, gypsum, Fengfeng group of Middle Ordovician system; (11) Dolomitic limestone, marl with breccia,

limestone, Upper Majiagou Group of Middle Ordovician system; (12) Marl with breccia, dolomitic limestone, argillaceous dolomite, Lower Majiagou Group of Middle Ordovician

system; (13) Argillaceous dolomite, dolomite intercalated with shale, Lower Ordovician system; (14) Reversed fault; (15) Normal fault; (16) River; (17) Tunnel and researched

section (A–B).

Y.Shanget

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gGeology71(2004)199–211

203

Fig. 3. Engineering geological problems encountered when the TBM excavated through the fold (including geological section and occurrence sequence of the accidents) (note that the

vertical scale is larger than the horizontal scale of the tunnel, which gives a false appearance of steeply dipping layers in the tunnel than the overlaying strata).

Y.Shanget

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gGeology71(2004)199–211

204

Fig. 4. Free space left between shield of TBM and surrounding rocks before TBM jamming with orientation of principal ground stresses.

Y. Shang et al. / Engineering Geology 71 (2004) 199–211 205

major role in engineering geological conditions in this

case history.

4. Analysis of engineering geological conditions

4.1. Ground stresses and rock strength

The rock mass is generally in a dry state since the

groundwater table in this site is 40–80 m deeper than

the bottom of the tunnel. The limestone and dolomitic

limestone (O2s2) were in the form ofmassive thick beds

with high strength as hard rocks. For dolmitic lime-

stone with a natural moisture content, the uniaxial

compression strength (UCS) was about 60 MPa, and

the deformation modulus, between 300 and 1000 MPa.

In contrast, the marl (O2s1) was soft rock with lower

strength: its UCS was about 5 MPa (much lower when

saturated), and its deformation modulus, generally

about 300MPa in a dry condition (SHIDI, 1996). From

Fig. 3, it can be seen that in this section the rock mass

quality is Grade V (similar to those with a quality index

of rock mass by Barton Q < 0.1) (Li, 1999, Table 9-2).

From the results of hydraulic fracture tests aimed to

determine ground stresses, it was known that the

horizontal component comprising the major principal

stress increased with depth (Fig. 5). At a depth of

about 300 m, where the TBM jamming occurred, the

maximum horizontal major principal stress was larger

than the vertical major principal stress. The horizontal

deviatoric stress was about 5 MPa, which was similar

to the UCS value of the marl.

4.2. Fold and inter-layer shear zone

The exceptional events occurred at a position be-

tween two boreholes (Fig. 3). So, the initial geological

conditions had been inferred from the drill logging and

site investigation. On the lower part of the adjacent

syncline, extensive joints and small-scale fissures had

developed (Fig. 3), which were favorable for rock

fracture and groundwater movement. Dolomitic lime-

stone, the major part of O2s2, acts as a permeable

aquifer, whereas marl, the dominant part of O2s1,

constitutes impermeable strata. Thus, karst cavities in

various sizes and residual wet clay mainly from disso-

lution of limestone formed along the contact zone

between the two beds as illustrated in Fig. 3. As a

result, perched groundwater actively accumulated

there. After a long-term dissolution, stalactites formed

on the roof of karst cavities and wet clay accumulated

on the floor. Karst cavities, wet and plastic clay, and

groundwater inflow developed not only because of

lithology, but also because the tensile stress in the

lower part of the syncline affected the formation of

these unfavorable geological conditions (Engineering

Geomechanics Lab., Institute of Geology, CAS, 1976).

In a plane map, the TBM jammed section is on the

axis of the anticline (Fig. 2), and the anticlinal axis

plunges to the NE. In a cross-section, this part is in the

Fig. 5. Measured and computed ground stress components at different depth of two boreholes near No. 7 tunnel.

Y. Shang et al. / Engineering Geology 71 (2004) 199–211206

lower part of the anticline where compressional shear-

ing stress is dominant (Engineering Geomechanics

Lab., Institute of Geology, CAS, 1976). Stresses

concentration occurred at interface between the dolo-

mitic limestone and marls, known as an inter-layer

shear zone. Then shear convergence, taking the marls

as its dominant, took place (Figs. 3 and 6).

The TBM excavation at a depth of 300 m in soft

surrounding rocks with high ground stress concen-

trations caused the flow of marl at a rate of 20–40

mm/h in the inter-layer shear zone. The excavation of

TBM further disturbed the ground stress distribution,

Fig. 6. Plates taken outside of the shield windows showing geological cond

see Fig. 4). (A) Inter-layer shear zone between limestone and marl with sh

with breccia; (C) tensive longitudinal fissure in the tunnel roof; (D) local

scratches in marls.

and caused the TBM jamming. Observations outside

of the TBM opened windows (a square with side

length 80� 80 cm) on the two sides of the rear shield

(for their locations, see Fig. 4) in the jammed section,

provided the following information.

� The inter-layer shear zone between greyish black

limestone and greyish yellow marl, with a thickness

of 12f13 cm, and at 30jB20j, could be found on

the northern side. The intercalated shear zone

materials had geometries indicating levorotary shear

(Fig. 6A).

itions in TBM jammed location (for standpoint and view orientation,

eared and crept rock mass, small-scale fold developed in it; (B) marl

scratches implies secondary compressive shearing (E) old grouped

Y. Shang et al. / Engineering Geology 71 (2004) 199–211 207

Y. Shang et al. / Engineering Geology 71 (2004) 199–211208

� On the northern side of the front shield, marl with

breccia with a higher strength (UCS = 13 MPa in

saturation) (SHIDI, 1996) was dominant (Fig. 6B).

It belongs to O2s1 and comprises the soft rocks.

� From the window on the roof of the front shield, a

longitudinal fissure was seen (Fig. 6C), which

implied differential shear stress on the walls and

roof, respectively. Mostly, it is parallel with the

axis of the anticline.� Outside of the window on the southern side of the

rear shield, both newly formed scratches from the

shearing and crushing action of marls could be

seen (Fig. 6D). Back of it is also soft marls with

early-formed scratches surrounding and tightly

crushing on the shield (Fig. 6E). These soft marls

presented more pushing force on the southern side

of the shield, and acted as a major part jamming the

TBM.

It should be noted here that the gypsum content in

O2s1 varies, although such gypsum could not be found

in the field profile. Its existence, however, obviously

affects groundwater discharge by reducing porosity

and permeability (Fig. 3). Certainly as a waterproof-

ing agent, gypsum prevents or hinders groundwater

seepage. The dissolution of gypsum, on the other

hand, produces cavities in the gypsiferous limestones.

But after observation at the tunnel site, it could be

seen that most of the gypsum has not been dissolved.

Thus, its effect on unfavorable geological conditions

at the TBM jamming site was not so important as that

of the ground stresses concentration and the low

strength of the marl at the inter-layer shear zone.

In brief, from site investigation and laboratory

tests, it is known that the combination of the following

four factors resulted in TBM jamming:

� Fold: The fractured rocks and karst cavities exist in

the lower part of the syncline, while the TBM

jamming site was in the lower part of the anticline.

The stress states are very different at these two

locations of the fold.� Inter-layer shear zone: It has soft marl and over-

laying hard dolomitic limestone as its two compo-

nents. The marl, mainly presenting in surrounding

rocks as soft rock layers, could not withstand the

shearing force compared with the limestone and

marl with breccia because of its lower strength.

� ground stress: The principal horizontal stress

components were high and locally concentrated at

the interface in the lower part of the anticline. It

induced the shearing stress playing roles in the inter-

layer shear zone and resulted in the movement of the

soft marls, and finally caused the TBM jamming.

While in the lower part of the synclinal core, the

ground stress transformed to tension state and

provided space for development of karst cavities.� TBM excavation: The TBM excavation unloaded

the stress confining the layered rocks, and made the

shearing stress activated in the jamming site. Thus,

it could be said that the TBM excavation was a

triggering force for the convergence at the inter-

layer shear zone.

Therefore, the inter-layer shearing directly caused

the lateral flow toward the free space around the TBM

shield, which finally induced the TBM jamming. That

is, the high rate of convergence is mostly due to the

concentration of ground stresses locally controlled by

the inter-layer shear zone in the lower part of the

anticline.

5. Treatment measures and the results

For the purpose of freeing the TBM from squeez-

ing ground, manual excavation with a jackhammer

was used to cut and remove the converged rock mass

behind the shield from the windows of the telescopic

shield. Meanwhile, two windows were opened on the

rear shields (for their locations, see Fig. 4), in order to

provide entrances for manual excavation. The space

left by removing squeezing soft rock via a jackham-

mer was just outside the shield of the TBM with a

width of about 1.0 m (Fig. 6).

In the unfavorable geological conditions with dif-

ferent kinds of exceptional events, some other meas-

ures were also adopted. These can be summarized

under four headings.

(1) Measures which were feasible and effective in

boring through small-size karst cavities:� slow down the TBM advance rate and drive

the TBM very carefully;� observe carefully any abnormal phenomena

seen during the excavation;

Y. Shang et al. / Engineering Geology 71 (2004) 199–211 209

� use grouting to backfill the gap between

segment extrados and the surrounding rock

as quickly and as completely as possible;� keep the cutterhead against the front face in

order to avoid any collapse or over-excavation.

(2) In order to minimize the bending of the telescopic

shield on the TBM, the extended length of the

thrust cylinders was reduced from 0.6 to 0.1 m.

Because the support from the surrounding rock

masses was insufficient and the segment joints

were not able to be closed, the installed segments in

the area of the karst cavity were bolted together

with steel plates. Meanwhile, the cavity was

backfilled with pea-gravel as soon as possible.

(3) In order not to interfere with or stop TBM

excavation because of the presence of big

fissures, fractures, karst cavities, and the unstable

surrounding rock masses, grouting was carried

out in two stages.� The first stage was completed during TBM

excavation to backfill the lower part of tunnel

with grouting;� The second stage grouting was performed after

TBM completion of the whole length of No. 7

tunnel, with some special treatment to fissures

and cavities before that time.

(4) In sections where the clay was sticking and

squeezing, the buckets, the hoppers and the

conveyor belt were manually cleaned. At the

same time, some cutters were removed in order to

increase the incoming crushed rocks. Water was

sprayed on the conveyor belt so as to reduce the

sticking clay.

Following the adoption of these measures, the

TBM advanced at a rate of 42 m/day under these

unfavorable geological conditions before the jam-

ming. After jamming, it took 9 days to release the

machine. After that, the TBM continued to advance at

an average rate of 60 m/day.

6. Discussion

(1) Rock loads as predicted by conventional empirical

methods are not applicable to TBM tunnelling in

squeezing ground, especially at large depths of

folds with ground stresses concentration where

high rate of convergence is mostly likely to be

triggered.

(2) The potential for rapid squeezing ground of marl

in areas of folding indicates that TBM excavation

may not be economic in these portions of the

tunnel. Difficult ground conditions can be

handled using various alternative tunnelling

techniques. It may be possible, for example, to

mine these difficult zones by drill and blast or

hand mining methods. With good quality geo-

logical information at the head of the tunnel face,

the need for such non-TBM techniques can be

anticipated in advance and preparations can be

made accordingly.

(3) In TBM tunnelling, substantial attention should

be given to prior engineering geological and

hydrogeological investigations and analyses,

especially as to the suitability of TBM excavation

under unexpected geological conditions in order

to assist the flexible design of TBM tunnelling.

(4) When facing exceptional events, the design

schedule may require modification to fit the

new conditions.

(5) The high rate of tunnel wall convergence should

be further researched in detail, which influences

the TBM excavation more directly than the total

convergence value in soft rock masses to a large

extent.

(6) A general structural geological model is required

before tunnel boring begins, in order to system-

atically tackle complicated geological conditions

at different depth of folds without the benefits of

detailed site investigation and logging data.

7. Conclusions

The existence of an inter-layer shear zone in the

lower part of the anticlinal core, together with local

concentration of ground stresses caused a high rate of

convergence of marls in the tunnel wall, which

directly brought about TBM jamming.

The trough of the syncline under tension stresses

controls the development of fractured and jointed

rocks and cavities. Differential dissolution between

marl and limestone at this location made the formation

of karst cavities and wet clay and groundwater inflows

possible.

Y. Shang et al. / Engineering Geology 71 (2004) 199–211210

Enlargement excavation with a jackhammer out-

side of the shield is both feasible and economical to

free the blocked TBM in time.

Acknowledgements

The authors would like to thank Prof. Bingjun Fu,

the former General Secretary of Chinese ISRM, and

Prof. Jiamo Xu, for their constructive advice on

revision of this paper. Field investigation was assisted

by the staffs of the Shanxi Wanjiazhai Yellow River

Diversion Project, CMC Company, Italy. Language

(English) correction was provided by Prof. Gregory

Davis, Department of Earth Sciences, University of

Southern California. Thanks should also be extended to

the two anonymous reviewers for their helpful

suggestions and comments. The authors would like to

acknowledge the financial support by the National

Natural Science Foundation of China (Project No.:

40102024).

References

Alber, M., 2000. Advance rate of hard rock TBMs and their effects

on project economics. Tunnelling and Underground Space Tech-

nology 15 (1), 55–64.

Bappler, D.I.K., 2001. Learning from experience. Tunnels and Tun-

nelling International 33 (10), 25–27.

Barla, G., 1999. Larger diameter TBM tunnel excavation in weak

environmental conditions. News Journal, International Society

for Rock Mechanics 5 (3), 48–54.

Barton, N., 2000. TBM Tunnelling in jointed and faulted rock.

Balkema, the Netherlands, pp. 3–104, 147–149.

Cao, C.C., Meng, J.Z., Fan, A.S., Guo, Y.F., 2001. Development of

TBM at home and abroad and application in YRDP. Water Re-

sources and Hydropower Engineering 32 (4), 27–30 (in

Chinese).

Einstein, H.H., 2000. Tunnels in Opalinus Clayshale—a review of

case histories and new developments. Tunnelling and Under-

ground Space Technology 15 (1), 13–29.

Engineering Geomechanics Lab., Institute of Geology, Chinese

Academy of Sciences, 1976. Basement and approaches for re-

searches on the engineering geomechanics of rock masses. In:

Institute of Geology (Ed.), Problems of the Engineering Geo-

mechanics of Rock Masses. Science Press, Beijing, pp. 1–45

(in Chinese).

Fu, B.J., 1998. Mega Hydro Projects for transferring water from

Southern to Northern China. News Journal, International Soci-

ety for Rock Mechanics 5 (2), 25–30.

Hamza, M., Ata, A., Roussin, A., 1999. Ground movements due to

the construction of cut-and-cover structures and slurry shield

tunnel of the Cairo Metro. Tunnelling and Underground Space

Technology 14 (3), 281–289.

Hudson, J.A., Harrison, J.P., 1992. A new approach to studying

complete rock engineering problems. Quarterly Journal of En-

gineering Geology 25, 93–105.

Lei, X.Y., Swoboda, G., Zenz, G., 1995. Application of contact–

friction interface element to tunnel excavation in faulted rock.

Computers and Geotechnics 17, 349–370.

Li, S.H., 1999. A new concept of tunnel support design—applica-

tion and theory of precedent type analysis. Science Press,

Beijing, pp. 312–318 (in Chinese).

Li, H.Y., 2001. Major and minor structural features of a bedding

shear zone along a coal seam and related gas outburst, Pingding-

shan coal field, Northern China. International Journal of Coal

Geology 47, 101–113.

Liu, L.P., Cheng, B.C., 2000. Harm of defects in TBM construction

to hydraulic tunnel. Shanxi Hydrotechnics (3), 27–29 (in

Chinese).

Liu, L.P., Jin, Z.Y., Sun, W.N., 2000. Wide application of full-faced

TBM, probable problems in tunnelling. Shanxi Hydrotechnics

(2), 30–32 (in Chinese).

Martinis, A., 1995. Yellow River Diversion. World Tunnelling Oct.,

299–302.

Morgensten, N.R., Tchaleko, J.S., 1967. Microscopic structure in

kaolin subject to direct shear. Geotechnique 17 (4), 307–328.

Pelizza, S., Grasso, P., Xu, S.L., 2001. Tunnelling by TBM—an

overview of international issues relevant to China. Workshop

‘‘Tunnel Boring Machines and Related Engineering Practice’’,

Beijing, Sept. Unpublished.

Qu, Y.X., 1985. Engineering geological prediction of inter-layer

shear zones. Institute of Geology, Chinese Academy of Scien-

ces, Research on Engineering Geomechanics. Geological Pub-

lishing House, Beijing, pp. 87–97 (in Chinese).

Qu, Y.X., Xu, R.C., 1979. Study on the inter-layer shear zone at the

Gezhouba Dam site in the Yangtze River. Institute of Geology,

Chinese Academy of Sciences, Problems in Research of Rock

Engineering Geomechanics, 1–10 (in Chinese).

Ramsay, J.G., 1967. Folding and fracturing of rocks. McGraw-Hill,

London, pp. 266–288.

Ramsay, J.G., Huber, M.I., 1987. The techniques of modern struc-

tural geology, Vol. 2: Folds and Faults. Academic Press, H.B.

Jovanovich, London, pp. 106–174.

Shanxi Bureau of Geology, 1979. Regional geological investigation

report (1:200,000): Yuci Section (J-49-XXIII) (Geology Part).

Shanxi Bureau of Geology, Taiyuan (in Chinese).

Shanxi Bureau of Geology, 1989. Shanxi regional geology. Geo-

logical Publishing House, Beijing (in Chinese).

SHIDI, 1996. Engineering investigation report on the South Main

Exit to Taiyuan of the YRDP. Shanxi Hydroelectric Investiga-

tion and Design Institute of MWRC, Taiyuan, Shanxi Province

(in Chinese).

Su, S., Zan, Z.B., He, J.P., 2000. TBM construction in fault zone.

Shanxi Hydrotechnics (4), 31–32 (in Chinese).

Su, S., Du, C.Q., Cheng, X.M., 2001. Geological problems and

construction measures of the tunnels constructed by TBM in

Y. Shang et al. / Engineering Geology 71 (2004) 199–211 211

YRDP. Water Resources and Hydropower Engineering 32 (4),

15–17 (in Chinese).

Swoboda, G., Abu-Krisha, A., 1999. Three-dimensional numerical

modelling for TBM tunnelling in consolidated clay. Tunnelling

and Underground Space Technology 14 (3), 327–333.

Voerckel, M., Peters, M., 2001. Tunnelling with TBM-state of the

art and future development. Workshop ‘‘Tunnel Boring Ma-

chines and Related Engineering Practice’’, Beijing, Sept. Un-

published.

Xiao, Y.X., Lee, C.F., Wang, S.J., 2000. Spatial distribution of inter-

layer shear zones at Gaobazhou dam site, Qingjiang River, Chi-

na. Engineering Geology 55, 227–239.

Xu, J.Y., Liang, J.P., Jin, Y.J., Wang, W.B., 2000. Geological doc-

umentation during TBM tunnel construction. Hydrogeology and

Engineering Geology (6), 35–38 (in Chinese).

Zhang, J.J., 1999. The application and some problems of TBM and

its prospects. Chinese Journal of Rock Mechanics and Engineer-

ing 18 (3), 363–367 (in Chinese).