Risk Analysis in
Construction Stage of Urban Rail Transit
Mao Tian
Postgraduate Department, China Academy of Railway Sciences, Daliushu road 2, Beijing, China
tmzsh@163.com
Keywords: Urban rail transit, Risk analysis, Analytic hierarchy process, Consistency test.
Abstract: The paper analyses three kinds of packing methods of urban rail transit construction project; Summarizes
the main work of preparation stage, financing stage, construction stage and operation stage in urban rail
transit project ; Concludes the key risk points of each construction unit. At the same time, according to the
analytic hierarchy process model, the paper calculates the weights and importance scores of risk factors in
the construction stage. The main risk sources and risk level of construction phase are identified and
analysed, lastly the consistency of the results is tested.
1 INTRODUCTION
Urban rail transit project risk identification contains
many factors and a variety of response measures,
this article focuses on the urban rail transit
construction phase of risk identification and
response measures. Prerequisites for risk
identification include the packing method of
construction project, main stages and key tasks of
urban rail transit, and the division of organization
among the participating units.
2 RISK PREREQUISITES OF
URBAN RAIL TRANSIT
CONSTRUCTION PHASE
2.1 Packing Method of Urban Rail
Transit Construction Project
The way of packing of the project has great
influence on the management organization and
construction progress. It is one of the prerequisites
for risk identification in the construction phase of
the urban rail transit project.
From the perspective of urban rail transit
construction, there are three types of packing
methods commonly used in the project.
Table 1: The main types of packing methods and typical
applications
Types of packing Typical applications
Non-sunken capital
investment project
model
Beijing Metro Line 4, Beijing Metro
Line 14, Beijing Metro Line 16,
Hangzhou Metro Line 1 and Hangzhou
Metro Line 5
The overall
investment and
financing project
model
Urumqi Line 2, Beijing New Airport
Line, Hohhot Line 1 and Line 2,
Chengdu New Airport Line
Overall construction
+ land development
model
Shenzhen Metro Line 4, Shenzhen
Metro Line 6, Foshan Metro Line 2
The first is the type of non-sunken capital
investment project model, it’s sunk capital part of
the investment is capital investment by the
government, non-sunken part is that the social
capital investment. Belonging to sunk capital part in
Urban rail transit project is civil engineering
construction, and belonging to non-sunken part is
the mechanical and electrical equipment project
(Qingwu, Zhao, 2014). Civil engineering
construction is partly funded by the government and
construction. By means of bidding, the
electromechanical equipment is invested and
constructed by a project company jointly set up by
social capital and the government. After the
completion of the construction, the project company
is responsible for the operation of the project routes
and is rewarded through the revenue during the
210
Tian, M.
Risk Analysis in Construction Stage of Urban Rail Transit.
In 3rd International Conference on Electromechanical Control Technology and Transportation (ICECTT 2018), pages 210-215
ISBN: 978-989-758-312-4
Copyright © 2018 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved
operation period (mainly the ticket revenue and
government subsidies).
The second type is the overall investment and
financing mode of construction projects, that is, the
government selects one social capital company and
the designated government company to set up the
project company by means of bidding. The project
company is responsible for the investment and
construction of the project as a whole (including
civil engineering, mechanical and electrical
equipment) . After the completion of the project, the
project company is responsible for the operation of
the line and is rewarded with revenue during the
operation period (major ticketing revenue and
government subsidies).
Table 2: The main tasks of urban rail transit construction phase and division of responsibilities
Main tasks
The division of responsibilities
Owners of units Design unit Supervision unit Construction unit Supplier unit
Line design Make a demand Implement - - -
Model selection of vehicles Organization Design Consultation - Coordination
Land demolition Organization Coordination Check Implement -
The line and station construction Check Design alteration Supervision Organization -
Equipment procurement Organization Coordination Check - Production
Design contact Organization In charge Check Coordination Coordination
Model machine production Check In charge Supervision - Organization
Leave-factory check and acceptance Check In charge Supervision Coordination Organization
Equipment installation Check Guidance Supervision Implement Coordination
Equipment debugging Organization Guidance Check Implement Coordination
Final acceptance Organization Coordination Implement Coordination Coordination
The third type is to build the overall construction
+ land development model. That is, the government
selects the social capital through competitive
bidding and sets up the project company with the
government appointed company. The project
company is not only responsible for the investment
and construction of the project as a whole , and also
get the development rights along the land line. After
the completion of the project, the project company is
rewarded mainly through the ticketing revenue,
advertising revenue and land development income
during the operation period.
Typical applications about three types of packing
methods are shown in table 1.
2.2 Urban rail transit construction
phase division and key work
No matter what type of urban rail transit
construction mode, the construction generally can be
divided into four stages: the preparation stage,
financing stage, the construction phase and the
operation phase (General Administration of Quality
Supervision, 2013). To grasp the division of these
phases and the key tasks they include is of great
significance to the identification of urban rail transit
construction phase risks. The main work of each
phase is shown in figure 1.
Figure 1: The V diagram of the main works about four
stages in the urban rail transit projects
2.3 The Main Work of Urban Rail
Transit Construction and Division
of Responsibilities
Many articles have been written on the risk analysis
during the preparation stage and the financing stage
of urban rail transit projects, which will not be
repeated here. This article focuses on the analysis of
the major risks in the construction phase. One of the
important prerequisites for risk identification is to
analyse the main tasks in the construction phase
Risk Analysis in Construction Stage of Urban Rail Transit
211
(Yanjun, Xiao, 2014) and the division of
responsibilities between the participating units, as
shown in table 2.
3 IDENTIFICATION OF MAIN
RISKS IN URBAN RAIL
TRANSIT CONSTRUCTION
STAGE
The risks of urban rail transit construction stage
mainly include construction conventional risk,
technology risk, management risk, interface risk,
political risk, financial risk and legal risk (Hetai,
Sheng, 2015). See table 3 for details.
Table 3: Risk identification in construction stage of urban
rail transit
Risk
classification
Risk factor
Construction
conventional
risk
The land demolition and
compensation(m
1
), The increase in
finance costs(m
2
), Protection of the
archaeological relics, Construction
force ma
j
eure
Technology
risk
Improper design(m
3
), Improper
construction technology(m
4
),
Improper protective measures,
Improper product protection, Harsh
construction environment
Management
risk
The construction time delay(m
5
),
The risk of quality control, Safety
risk control, Cost overruns
Interface
risk
Imported equipment control(m
6
),
Transfer of existing complex
facilities(m
7
), No cooperation
between departments, System
interface mismatch
Political risk The negative behaviour of
government(m
10
), The local partner
unreliability, The government
non
p
a
y
ment
Financial
ris
k
Inflation(m
11
); interest rate(m
12
),
Rate of forei
g
n exchan
g
e
legal risk Default of contractor(m
8
), Standard
Specification update(m
9
), The
bankruptcy of item company, The
contract dispute, arbitration,
ambi
g
uit
y
4 THE RISK LEVEL
CALCULATION OF
CONSTRUCTION RISK
FACTORS
The risk level of risk factors can be calculated using
analytic hierarchy process (AHP) model. Firstly,
experts were invited to score the weight and the
importance of the risk factors separately. Then, the
weight and the importance of the risk factors were
normalized according to the AHP model, and the
consistency of the results was verified. Finally,
according to the results of the example to determine
the level of risk factors.
4.1 Calculation of risk factor weight
value ω
i
4.1.1 Construct a comparison matrix
Suppose n risk factors in the construction phase are
C
1
, C
2
,…, C
n
and weight of every factor importance
is ω
1
,ω
2
…, ω
n
. For any two factors C
i
and C
j
, let a
ij
denote the ratio of C
i
to C
j
(Zhonggeng, Han, 2009),
get:
a(,1,2,,)
i
ij
j
ij n
(1)
Construct a comparison matrix
ij
A=( )
nn
a
，
get:
11 12 1
21 22 2
12
A=
n
n
ij
nn nn
aa a
aa a
a
aa a
(2)
And:
11 1
12
22 2
12 2
12
A=
n
nn n
n
(3)
Obviously the matrix is a positive reciprocal
matrix, get:
ICECTT 2018 - 3rd International Conference on Electromechanical Control Technology and Transportation
212
ij ij ij
ij
1
01ij12naa a
a
＞， ， （， ，，， ）
(4)
4.1.2 Determination of relative weight vector
ω
i
Assume the weight vector is ω
i
， According to
formula 3，get
T
1
12
2
n
11 1
A= ) (ω,ω, , , , )ω
n
（，
(5)
TT T
1
12 n 12 n 12
2
n
11 1
A)=)(ω,ω, ω ω,ω, ω ω,)ω,,, , ω)
n
，，（，（（
n
T
12
ω,ω ,Anω) = W，（
(6)
This shows that (ω
1
,ω
2
…, ω
n
)
T
is the
eigenvector of matrix A, and n is the eigenvalue.
According to formula 3, A is a positive
reciprocal matrix, the knowledge of linear algebra
shows that the positive reciprocal matrix has a
property λ
max
=n，so：
TT
max12 n 12 n
ω,ω, ω ω,ω,A) )ω
，（，（
(7)
(ω
1
,ω
2
…, ω
n
)
T
is the eigenvector corresponding
to λ
max
.
4.2 Calculation of importance value y
i
of risk factors
According to the five Likert Scale (Weiya, Hao,
2012), the importance of risk factors is scored, and
the importance of the risk factors given by the
experts is k, as shown in table 4.
Table 4: K scores and their meanings
k Likert scale score meaning
1 “Very unimportant”
2 “ Unimportant”
3 “Generally important”
4 “Important”
5 “Very important”
Then，use weighted average method to calculate
the y
i
values about importance of the risk factor , the
formula is as follows:
5
1
5
kk
i
kn
y
（8）
Where y
i
is the average of the i number risk
factor importance; n
k
is the number of experts with
the marking score of k.
4.3 Calculation of risk factor value s
i
Based on the results of the previous two steps, the
weight vector ω
i
and the importance vector y
i
are
multiplied together to obtain the risk factor risk
degree s
i
, the formula is as follows:
iii
s
y
（9）
4.4 Consistency test of the result
calculation
Under normal circumstances, the judgment matrix
obtained may not be the same. However, in practice,
it is not absolutely necessary that the coherence be
absolutely established, and only require a general
agreement. This can be judged by the consistency
indicator.
(1) Consistency Indicator CI
max
CI
1
n
n
(10)
(2) Random Consistency Indicator RI.
Generally use the table 5 given value
Table 5: Relationship values between n and RI
n 1 2 3 4 5 6 7
RI 0 0 0.58 0.90 1.12 1.24 1.32
（3）Consistency Ratio Indicator CR
CR
CI
RI
(11)
When CR <0.1, it is acceptable to consider the
consistency of the matrix. And get:
ij
max 1
1kj
1
(i 1, 2, , )
n
k
n
k
a
n
na
(12)
5 CASE ANALYSIS OF RISK
FACTORS
(1) From table 3, 12 risk factors(m
1
~m
12
) are
initially selected as samples, 6 experts give the
weight value of risk factors (ω
1
~ω
6
) , and calculate
its average value
, the results in table 6.
Risk Analysis in Construction Stage of Urban Rail Transit
213
Table 6: Expert scoring table of weights of risk factors
Risk
factor
11.9 10 12.5 15 10 10.5 13
9.3 8.3 10 12.5 6.7 10 8.3
9.9 12.5 11.7 10 7.5 10 7.5
11.3 12.5 10 10 9.2 9.2 16.7
7.5 6.7 6.7 10 8.3 6.7 6.7
7.2 6.7 6.7 8.3 6.7 8.3 6.7
7.4 8.3 5.8 8.3 6.7 6.7 8.3
6.6 5 9.2 4.2 8.3 6.7 6
9 10 10 5.8 10 8.3 10
7.7 10 7.5 5.8 6.7 9.2 6.7
6.5 8.3 5 5 8.3 7.5 5
5.6 1.7 5 5 9.2 7.5 5
According to formula 3, using the average value
of the weights given in table 6, a comparison
matrix is constructed:
11 1
12
22 2
12 2
12
11.9 11.9 11.9
11.9 9.3 5.6
9.3 9.3 9.3
A=
11.9 9.3 5.6
5.6 5.6
11.9 9.3
n
nn n
n
5.6
5.6
The largest eigenvalue of A is （according to
MATLAB software calculation）：
max
12.0000000000000002
and get the corresponding eigenvector is：
(ω
1
,ω
2
,…,ω
12
)
T
=（0.12,0.09,…,0.06)
T
,
Detailed ω
i
in (ω
1
,ω
2
,…,ω
12
)
T
is show in table
8.
(2) 6 experts give the importance value of risk
factors (y
1
~y
6
), and calculate its average value
y
,
the results in table 7.
(3) According to formula 9, ω
i
multiplies
i
y
to
obtain the level of the risk factor s
i
. The calculation
results are shown in table 8, and the level of the risk
factor can be seen in figure 2.
As show in figure2, these factors have very high
risk level, they are the land demolition and
compensation (m
1
), improper construction
technology (m
4
), improper design (m
3
), the
construction time delay (m
5
), transfer of existing
complex facilities (m
7
) , which are the need to focus
on prevention and control in construction stage.
Table 7: Expert scoring table on the importance of risk
factors
Risk
facto
r
i
y
4 1 5 5 5 5 3
1.67 1 2 1 2 2 2
2.17 4 1 3 2 1 2
3.33 4 2 3 3 3 5
2.33 5 2 1 2 2 2
1.17 1 1 1 1 1 2
2.67 3 3 3 2 2 3
2.17 5 3 1 1 2 1
1.83 1 2 1 3 1 3
2.17 5 3 2 1 1 1
1.17 2 1 1 1 1 1
1.17 2 1 1 1 1 1
Table 8: The level of risk factor value
Risk
facto
r
ω
i
The level of Risk
factor value
0.12 4 0.48 Very high
0.09 1.67 0.15 Low
0.10 2.17 0.22 High
0.11 3.33 0.37 Very high
0.08 2.33 0.19 High
0.07 1.17 0.09 Low
0.07 2.67 0.19 High
0.07 2.17 0.16
General
0.09 1.83 0.16
General
0.08 2.17 0.18
General
0.07 1.17 0.09 Low
0.06 1.17 0.07 Low
1
m
8
m
7
m
6
m
5
m
4
m
3
m
2
m
12
m
11
m
10
m
9
m
Figure 2: Risk level of risk factor in construction stage
(4) According to the formula 11, do the
consistency test, have:
max
CI
CR 0.1
RI RI(n 1)
n
among them:
ICECTT 2018 - 3rd International Conference on Electromechanical Control Technology and Transportation
214
max
12.00RI 1.24, 0000000n12 0002,000
Because CR<0.1, the result of this judgment is
acceptable.
6 CONCLUSION
(1) The paper analyzes the preconditions of risk
analysis in urban rail transit and points out the main
work and division of responsibilities between
preparation stage, financing stage, construction stage
and operation stage.
(2) This paper analyzes various risks of urban
rail transit construction, including construction
conventional risk, management risk, technology risk,
interface risk, political risk, financial risk and legal
risk.
(3) This paper adopts AHP model to calculate the
degree of risk of each risk factor in the construction
stage and points out that the most important risk
factors are the land demolition and compensation,
improper construction technology, improper design,
the construction time delay, transfer of existing
complex facilities. Finally, the consistency of the
calculated data is tested to ensure the reliability of
calculation.
ACKNOWLEDGEMENTS
Thanks for the support:
Foundation project of China Academy of Railway
Sciences（2017F011）
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215
