A Basic study on geological risk reductionin Japan public works
Daisaku Tachibana and Tsunemi Watanabe
Kochi University of Technology

ABSTRACT:In recent years, as the finance of the national and local governments becomes severe in Japan. The
government construction investment has been decreasing, and now it is reduced by 48.9 percent from its
peak. People’s cost consciousness is also rising due to cut in the construction investment. The public works
project in Japan is under severe conditions due to the budgetary cutback. Responding to this situationalchange, the government has started implementing the cost structural reform of public works” used for thewhole government in 2003. This reform describes reconsideration of all processes of the public works projectfrom cost viewpoints. However, “the viewpoints from the geological feature” are not specifically described.
Geological conditions influence effectiveness and/or efficiency at any stage of life cycles of public works,conception, design, construction, and maintenance. In this study, thus, setting "reduction of the geologicalrisk in public works" as the ultimate goal, an attempt is made to study a possibility of lowering the geologicalrisk by introducing geological engineering advisor and concept of GBR (Geotechnical Baseline Report),
developed and applied in a large-scaled underground construction project in the U.S. Here, geological risk isdefined as a possibility of cost increase and/or project delay caused by poor or insufficient treatment ofgeological conditions. It is observed that the public client and the contractor have her/his own worry about
payment associated with design document change: “Paying too much” and “Paid enough?,” respectively. It isconcluded that introduction of geological engineering advisor is expected to reduce the public client’s worry
and that concept of GBR is expected to reduce the contractor’s worry.
KEYWORDS: geologic risk management, geological engineering adviser, geotechnical baseline report

1. RESEARCH BACKGROUND

decreasing. Now, it is reduced by 48.9 percent fromthe peak. People’s cost consciousness is also rising

In recent years, as the finance of the national anddue to cut in the construction investment. The public

local governments becomes severe. As shown inworks project in Japan is under severe conditionsFigure 1, the government construction investment indue to the budgetary cutback.

Japan was in the peak in 1995 with an increase fromaround 1985. Since 1996, however, it has been

Responding to this situational change, thegovernment developed a wide range of programs to1

（unit : trillion ¥）40
35
30
25
20
15
10
50

construction in the U.S. to clarify risk share between
the owner and the contractor.
We define geological risk as a possibility of cost
increase and/or project delay caused by poor orinsufficient treatment of geological conditions.

19831987

1991

1995

1999

20032007 （year）

3.

PRACTICESGEOLOGICAL
Figure 1: The change of the government

OFRISKCONVENTIOANLMANAGEMENT

IN

JAPANESE PUBLIC WORKS

construction
We conducted literature reviews and interviewed
cut cost of the public works. The government

practitioners

tounderstandactualpracticesofdevelops guidelines and tackles the reduction of thegeological risk management and their consequences.

and the efficiency improvement actively. A

It is found that the conventional geological risk

representative guideline is “the cost structural reformmanagement is usually based on the “minimum”

of public works” used for the whole government ingeological survey. Therefore, contract conditions have2003.

to be changed very often. Thus, many requests forcost

This reform describes reconsideration of allchange are submitted from the contractor. Design

processes of the public works project from cost

document changes are done by negotiation between

viewpoints. However, “the viewpoints from thethe owner and the contractor.
Thus, projects are started from an optimistic

geological feature” are not specifically described.
Geological conditions influence effectivenessrecognition of geological risk. The difference between

and/or efficiency at any stage of life cycles of public

the assumed conditions and the actual conditions areworks,

dealt with through the design document changes.

conception,design,construction,andmaintenance.

The Japan Geotechnical Consultant Association

At construction stage, poor geological risk

(JGCA) has been studying improvement of practices

management can cause cost increase or project delay.

of geological risk management. The JGCA raises theIn Japanese public works, not a few risks occur

following five reasons for the current practicerelated to geology are occurring.

starting from optimistic risk recognition and taking
reactive measures after problems are found:

2. RESEARCH OBJECTIVES

1) Unclear concept of body of knowledge ofgeological risk,

First, we set "the reduction of the geological2) Insufficient data on geological risk,

feature risk in public works" as the ultimate goal of

3) Undeveloped quantification method of geological

the research. As this study objective, then, we willrisk,

try to "study a possibility of lowering the geological4) Unclear status of a person in charge of geologicalrisk by introducing geological engineering advisorrisk, andand GBR."

5) Undeveloped profession of geological engineer toGBR is the abbreviation of geotechnical baseline support the public client.
reports, and it has been used for a large-scale tunnel
2Watanabe pointed out that Japanese public client

The contractor is always worried if the owner pays

had been required to implement a huge amount ofenough at the end of project. In overseas construction

public works “perfectly,” that is, to execute the given

market, contractors are required to submit claims

budget neither too much nor too little, to completewith strict quantitative accounts. In Japanese public

the works within the fiscal year, and to deal with theworks, increase in contract value is often dealt withauditing “safely” so that no controversy is generated.

through budgeting for other construction works; thus,

In Japanese public works percentage of completion

the strict quantitative account is not necessarilyof design documents is generally low. Unspecified

required. Moreover, “flexible” payment method iscustomer’s requirement can be interpreted as asometimes

means to implement a huge amount of works withindocument change. That is, the contractor does not

the fiscal year.

obtain sufficient payment in the case of tight budget

The current practice starting from optimistic risk
recognition and taking reactive measures after
problems is considered a means to satisfy theperfectionism required for the public client.

employedassociatedwithdesign

and recover the shortage in the case of sufficientbudget.
The owner feels if they are paying too much. This isbecause they often do not have a sufficient level ofengineering knowledge to judge contractor’s request

4. PROBLEMS OF THE CONVENTIONAL

for increase in contract value. It is considered that these

PRACTICES

two worries have been reduced by designated

OFGEOLOGICALRISKMANAGEMENT IN JAPAN

competitive bidding and Dango, a method of deciding
the winner by negotiation among contractors.

Recently, however, the conventional approach isThus, reducing the two worries by designatedfacing a difficulty. Especially in local governments,competitive bidding and Dango will be more difficult.

request for increase in contract value by the change

Thus, a new method has to be developed. One ofof design is becoming difficult to be accepted by thethem is to improve owner’s capability of geologicaldiet.

risk management. We believe that introduction of

Furthermore, this approach has inherent problem. geological engineering advisor to the public owner isThe both public client and contactor have worries an effective solution.
about payment associated with these design documentchanges (Figure 2).

5. WEAKNESS OF DANGO SYSTEMS
Watanabe pointed out the weakness of the dango
systems (Watanabe 2006). There is no alternative
system to them which can achieve virtuous circle ofcertainties when competition among contractorsbecomes hard.
When the dango is not agreed, the structuralindeterminacy is actualized. Since the uncertainty of

Figure 2: Inherent problem in conventional geological contractor’s business increases, the contractor would
risk management

have to take measures to reduce the businessuncertainty. The actualized structural indeterminacy
3expected to do timely and appropriate advice.
Of course, the advisor is also expected to judge if
the request for change submitted from the contractor isjustified or not and to do proper management promptly,
too.
Public owner’s worry is expected to reduce byintroducing the geological engineering advisor.
7. GEOTECHNICAL BASELINE REPORT
However, the contractor’s worry may not be
Figure 3 Structure and performance of dango

reduced without improving the relationship between

systemsthe owner and the contractor even if the geologicalengineering advisor is introduced.

and the existing artificial indeterminacy induces andenables contractors to take “easy” measures such as

Therefore,

wewilldiscuss

effectivenessofintroducing concept of the GBR.
GBR is to establish a contractual statement of thesacrificing quality of works or cutting labor wage.
If such easy measures are frequently taken,
speculative nature of contractor business rapidly

geotechnical conditions anticipated to be encounteredduring underground and subsurface construction.

increases. As a result, there is a possibility that theUsing this contractual document, the owner side

quality of works is lowered and construction labor

provides detailed geological related information to theaccidents frequently occur. In another word, users

contractor.

and construction workers would have to accept theabove-mentioned“unsound”

risk.

Increase

It makes risk share between the owner and theincontractor specific and clear and makes the both

speculative nature of contractor business andparties understand importance of geological risk

unsound risk sharing is fragility of the dango

management.

systems under hard competition among contractors.

In the U.S., the following idea is historically

The two environmental changes of enhancement

understood: “if all bidders can base on their estimatesof taxpayers’ consciousness and loss of sufficient

on a well defined set of site conditions with assurance

budget are now possibly exposing the fragility of thethat equitable reimbursement will be made when

dango systems.

changed conditions are encountered, the Owner will
receive the lowest reasonable bids with a minimum of6.

INTRODUCTIONOFGEOLOGICALENGINEERING ADVISOR

contingency unknowns.”
The following observation is also made: “thegreater

theinvestment

Conventionally, the geological survey only provides communicating,andinexploring,

disclosing

theclearlysubsurface

the data for the design. Actually, problems incurred conditions, the lower the final cost of the project.”from poor geological risk management can occur at
any stage of the project.
Thus, a good geological engineering advisor is4

8.

INTRODUCTIONOFCONCEPTOF

GEOTECHNICAL BASELINE REPORT

conducting the entire business in the equal footing.
These two measures are expected to lower
geological risk, cost increase and project delay.

GBR should be introduced consistently with thecontractual document between the public owner
employer and the contractor. It is expected that the 10. REFERENCES
risk which each should be taken becomes clear.
Thus, the contractor’s worry is expected to reduce ・Randall J. Written by Essex, 2007, "geotechnicalbecause the contractor also can know who should take baseline reports for construction" American Society
what type of risk.

of Civil Engineers (ASCE) The publishingIn other words, the owner and the contractor dobusiness on an equal foot. Introduction of GBR would ・Watanabe Tsunemi and Sabase Yoshihito " ground
be expected to lead to more efficient geological risk information
management.

"JACICinformation

86

number,pp58-63, doing 2007 July 10th published・"Geological survey", the social law person national
geological survey committee to learn from the case,doing September, 2003 published learn・ The

nationalgeologicalsurvey

industry

cooperation joint association, http://www.zenchiren.or.jp
・The Ministry of Land, Infrastructure and Transport
Figure 4 New geological risk management with GBR

The statistical basic data The change of the scale ofthe public investment
http://www.mlit.go.jp/toukeijouhou/chojou/index.ht

9. CONCLUSIONSml

By clarifying the position of geological engineer ・The Nihon Kensetsu information synthetic center,dealing with project risks related to geology and http://www.jacic.or.jp
creating and introducing the profession of engineering
advisor, the owner’s worries about not being able to ・The investigation and the study ( the provisional
judge requests for change submitted from the version ), Japan Geotechnical Consultant Association,
contractor and about too much payment towards them 2007.3 about the geological feature risk
are expected to reduce.
Introduction of the GBR of clarifying the risk ・Tsunemi Watanabe, “Past, Present, and Future of
sharing between the owner and the contractor is Bidding and Contracting Systems of Japanese Public
expected to reduce the contractor’s worry about Works,” Proceedings of The Tenth East Asia-Pacificinsufficient payment and to increase a possibility of Conferenceon

StructuralEngineering&5

Construction (EASEC-10), Vol. 5, pp. 245-250, 2006

6