Design standards for railway structures and commentary concrete structures.

2. CONTENTS
I DESCRIPTION OF THE CONCRETE STANDARD .............................................................................. 1
II A BRIEF HISTORY OF REVISIONS OF THE DESIGN STANDARD .................................................. 1
III VERIFICATION PROCEDURE IN THE CONCRETE STANDARD ..................................................... 3
IV SUMMARY OF THE CONCRETE STANDARD .................................................................................... 3
1. General ................................................................................................................................................ 3
2. Basis of Design.................................................................................................................................... 4
3. Required Performance and Performance Verification of Structures....................................................4
4. Actions................................................................................................................................................. 6
5. Materials .............................................................................................................................................. 9
6. Computation of Response Values ...................................................................................................... 11
7. Verification of Safety......................................................................................................................... 12
8. Verification of Serviceability............................................................................................................. 14
9. Verification of Restorability .............................................................................................................. 14
10. Assessment of Durability .................................................................................................................. 16
11. Prerequisite ofVerification ................................................................................................................ 18
12. Construction and Maintenance .......................................................................................................... 18
13. Members ............................................................................................................................................ 18
14. Structures....................:...................................................................................................................... 18
15. Structural Details ............................................................................................................................... 19
16. Bearings............................................................................................................................................. 19
17. Appendices ........................................................................................................................................ 20
V VERIFICATION EXAMPLES, DESIGN GUIDEBOOKS, AND VERIFICATION SOFTWARE........ 20
1. Verification Examples ....................................................................................................................... 20
2. Design Guidebook............................................................................................................................. 20
3. Verification Software......................................................................................................................... 21

3. OUTLINE OF DESIGN STANDARDS FOR RAILWAY
STRUCTURES AND COMMENTARY
(CONCRETE STRUCTURES)
DESCRIPTION OF THE CONCRETE STANDARD
The latest edition of the "Design Standards for Railway Structures (Concrete Structures)" was published in
April 2004, hereinafter referred to as the "2004 edition standard." The previous standard was revised to the
2004 edition standard in order to follow the conversion to performance-based regulations of the code
provisions of the national technical norm; "Ministerial ordinance that stipulates technical standards
pertaining to railways." The 2004 edition standard has been used for the design of railway structures
throughout Japan.
The highlights of the revision to the 2004 edition standard are (1) the adoption of a performance-based
design method, (2) the extension of the applicability of high-strength materials, and (3) the adoption of the
latest durability improvement technologies. Some of the latest concrete technologies are also incorporated.
The 2004 edition standard has 16 chapters. The standard also includes several appendices that summarize
the results of the technical studies conducted for the revision. Table 1 shows the table of contents of the
standard.
Chapter No.
1
2
3
4
5
6
7
8
Table 1 Contents of Design for Railway Structures (Concrete Structures)
Title I Chapter No. I Title
General
Basis of Design
Required Performance and its Verification
for Structures
Actions
Materials
Computation of Response Values
Verification of Safety
Verification of Serviceability
9 Verification of Restorability
10 Assessment of Durability
11
12
13
14
15
16
Prerequisite ofVerification
Construction and Maintenance
Members
Structures
Structural Details
Bearings
Appendices
II A BRIEF HISTORY OF REVISIONS OF THE DESIGN STANDARD
Before 1955, the Standard Specifications for Concrete Structures written by the Japan Society of Civil
Engineers had been applied to the design of railway concrete structures. The Design Standards for Civil
Engineering Structure (Plain and Reinforced Concrete) was issued in 1955 from the Japanese National
Railways. The exclusive design standards for railway structures have been used ever since and they have
been revised successively as shown in Table 2.
Some special design standards have been issued and used for the design of the Tokaido Shinkansen's
structures and the design of prestressed concrete bridges. A new Design Standard for Railway Structures
was issued in 1970 incorporating these precursory standards. The design standards were revised several
times by the Japanese National Railways on the basis of the allowable stress design method until 1983.
After the privatization of the Japanese National Railways in 1987, the code provisions (code texts) of the
design standard have been treated as ministerial notifications and published by the government (Railway
Bureau of the Ministry of Transport, currently Ministry of Land, Infrastructure and Transport). Then,
combining the code provisions, commentaries and appendices, the Design Standards for Railway
Structures and Commentary have been published as a technical textbook within six months to one year
after the notice.
Under this new system, the first design standard to use the limit state design method was formulated. It was
published as the "Design Standard for Railway Structures and Commentary (Concrete Structures)" in
October 1992, hereinafter referred to as the"1992 edition standard." This involved a major revision work
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4. from the previous edition of the design standard which had been coded based on the allowable stress
design method. The 1992 edition standard was revised to adopt SI units in 1999 with no other changes.
The 1992 edition standard was applied to all the designs of railway concrete structures (reinforced and
prestressed concrete) in Japan when they were designed based on the ultimate limit state design method.
The 1992 edition standard covered and provided seismic design provisions. These provisions, however,
were superseded by the corresponding provisions specified in the "Design Standards for Railway
Structures and Commentary (Seismic Design)," hereinafter referred to as the "seismic standard," which
incorporated experiences learned from the 1995 Hyogoken-Nanbu Earthquake.
Table 2 History of Revisions of DeSign Standards for Railway Concrete Structures
Revision
Year
1955
1961
1965
1970
1972
Design Standards
Design Standard for Civil Engineering Structures (Plain and Reinforced Concrete)
Design Standard for Shinkansen Structures
Design and Construction Standards for Prestressed Concrete Railway Bridges
Design Standard for Reinforced and Plain Concrete Structures, Design Standard for
Prestressed Concrete Railway Bridges
Design Standard for Shinkansen Network Structures (Joetsu, Tohoku and Narita
Shinkansens)
1974 Design Standard for Railway Structures (Revised)
Design
Method/System
Allowable stress
design method
_____}J..~~ ______R~~~g~ _~t_ap'~,!~~ f9!}3·~i!'Y~Y- ~~~~!t!~~~ {!~,::i~~ftJ __________________________________________________________ _
1991 Design Standard for Railway Structures (Concrete Structures), Notice issued from the
Ministry ofTransport Limit state design
1992 Design Standard for Railway Structures and Commentary (Concrete Structures) method
1999 SI Unit Edition, Design Standard for Railway Structures and Commentary (Concrete (specification-based)
________________~t~9!~~~~1 _______________________________________________________________________________________________ _
2004 Design Standards for Railway Structures (Concrete Structures), Ministry ofLand,
Infrastructure and Transport Notice
Design Standards for Railway Structures and Commentary (Concrete Structures)
Performance-based
design method
The following describes the background to the latest revisions in the 2004 edition standard.
In December 2001, a national technical norm "Ministerial Ordinance that Stipulates Technical Standards
Pertaining to Railways," was converted from the conventional specification-based format to the
performance-based one. It had been almost a decade since the last revision, i.e. the 1992 edition standard.
The Standard Specifications for Concrete Structures of the Japan Society of Civil Engineers, hereinafter
referred to as the "JSCE Specifications," which is the model code of the railway design standard, was
revised adopting the performance-based design method in 2002. The above-mentioned seismic standard,
formulated in 1999, had already adopted the performance-based design scheme that demands to verify the
required seismic performance when the structure is subjected to the design seismic motion. Therefore, the'
2004 edition standard was expected to adopt the performance-based design scheme to ensure conformity
with these associated ordinances and standards.
On the other hand, the research on high-strength concrete and reinforcing bar has advanced and
fundamental technical data has been sufficiently collected to be reflected in the provisions of the design
standard. The necessity of practical prescriptions on the durability improvement technologies for concrete
structures has also been deeply recognized. Therefore, the content of associated provisions of the standard
had to be substantiated with these technical developments and other advanced technologies.
In July 2000, the Ministry of Transport formed the "Committee on Design Standards for Railway Concrete
Structures," appointing the Railway Technical Research Institute as the organizing secretariat. University
professors and railway engineers, specialists in the design of concrete structures, were called together and
three years were spent discussing how to determine the code provisions.
Based on the deliberations of this committee, the Ministry of Land, Infrastructure and Transport noticed
the "Design Standards for Railway Structures (Concrete Structures)" in March 2004. The "Design Standard
for Railway Structures and Commentary (Concrete Structures)" was published in April of the same year
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5. being added commentaries and appendices to the governmental notice.
III VERIFICATION PROCEDURE IN THE CONCRETE STANDARD
Figure 1 shows the schematics of the verification procedure according to the performance-based design
method.
The left side of Figure 1 shows processes up to computation of the design response value IRd• The target
structure is subjected to structural analysis under the design load Fd, that is obtained by multiplying the
load factor Yf with the characteristic value of load Fb to obtain the response value IR of the structure or
member. Then, the design response value IRd can be obtained by multiplying the response value with
structural analysis factor Ya.
On the other hand, the right side of Figure 1 shows processes up to computation of the design limit value
IRd• The design strength of materialfd is obtained by the characteristic value of material strengthfk divided
by the material factor Ym, which is determined according to the material used. In the computation formula
for the limit value, this design strength of material fd is used to obtain the limit value I L , and design limit
value hd can be obtained by dividing the limit value by the member factor Yb.
Verification of performance involves confirming that the result of multiplying this design response value
IRd with the structure factor Yi and then dividing the result by the design limit value hd is less than or equal
to 1.0. Ifthis condition is satisfied, it is assumed that performance is ensured, and this completes design.
Design response value Design limit value
Characteristic value of action Fk
Action [ .-__Yf_a_c_tio_n_f_a_ct_o_r"--_____----,..
Design action Fd=yf • Fk
Characteristic value of material strengthA J
.-"tJ_m_m_a_te_fl_·a_If_a_ct_o_r-.:...______---, Material
Design strength of materialsid=ikIYm
r - - - - - - - - - - - - - - - - Response analysis --- ------------------------,
Response value IR (Fd)
Computation Ya structural analysis factor
of response
value Design response value hd=Ya • IR (Fd)
Limit value h ifd)
Yb member factor
Design limit value ILd=hifd) IYb
Figure 1 Basic Performance Verification Procedure
IV SUMMARY OF THE CONCRETE STANDARD
JLimit value
The following describes an overview of the code provisions and commentaries of each chapter in the 2004
edition standard. The following description makes no particular distinction between the code provisions of
the standard and their commentaries.
1. General
"General" specifies the scope of application, definitions ofterms and notations.
The scope of application is prescribed as "It shall be in accordance with these provisions when verifying
the performance of reinforced concrete and prestressed concrete railway structures."
"Definitions" describes approximately 130 terms that are associated with concrete and that are important in
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6. performance-based design such as the following examples.
Design:
Structural design:
The series of activities up to creation of the form of a structure, that is
planned with the required performance borne in mind, verification of
performance, and drafting of a design drawing.
The determination ofthe actual shape and dimensions of a structure.
Required performance: The performance that is requited of a structure
Verification:
2. Basis of Design
The act of evaluating whether or not a structure, members or materials satisfy
the required performance
"Basis of Design" specifies the fundamental design philosophies. These include the purpose of the design,
construction and maintenance conditions that are the prerequisites of design, and the design life.
(1) The purpose of the design is prescribed as "The railway structure must comply with its purpose, and
must be safe and economical." It is often difficult to repair, strengthen, and improve concrete
structures. So the purpose of design states that sufficient surveys must be performed at the beginning
of the design stages, and those events that may occur during the service period be reliably forecasted.
This makes it possible to design a structure that is durable and easy to maintain.
(2) Conditions of maintenance are prerequisites of design. Therefore, maintenance of structures must be
made to be as easy as possible. In a normal environment, materials degradation must be examined in
the design stage so as not to become conspicuous during the design life. Periodic inspections should
be planned as mainly visual observations.
(3) The design life of a structure is defined as "the specified life time in terms of the design in which the
structure or members upon their use must sufficiently fulfill the target functions," and is prescribed as
"it should be determined taking into consideration not only the service period (which often is not be
prescribed in the design stage) that is required of a structure, but also maintenance methods,
environmental conditions, life cycle costs, etc."
Under normal environmental conditions, 100 years is considered a standard design life. This assumes that
appropriate inspection and maintenance are performed. The design life can be set to 100 years or longer
when materials have high durability. Also a period shorter than 100 years can be set for structures in
corrosive environments, such as environments subject to chloride induced deterioration.
3. Required Performance and Performance Verification of Structures
"Required performance and performance verification of structures" specifies the type of required
performance, performance items and verification indices, principles and methods of performance
verification, and safety factors.
(1) Performance verification of a structure is prescribed as "to verify that required performance is
satisfied by setting the required performance corresponding to the purpose of use, and by using
appropriate verification indices." Performance must be expressed by indices that can be evaluated
quantitatively. The design standard explains computation methods for indices that can be evaluated by
current technology.
The following are advantages of introducing performance-based design methods.
a) Flexible adaptation to new technologies and individual circumstances: The designer has more
freedom to introduce the latest technology and adapt to unique circumstances.
b) Disclosure of performance associated information: The performance of the structure is clearly
indicated, making it easier for the general public to understand whether or not required
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7. performance is satisfied.
c) Evaluation of life cycle costs: Evaluation of life cycle costs can also be predicted by evaluating
performance not only during but also after construction.
(2) The three required performances of safety, serviceability and restorability of structures are defined as
follows.
a) Safety: Performance to prevent any threat to the lives of people using the structure and those
surrounding it under all anticipated loads. Not only the structural safety but also the functional
safety of structures is prescribed.
b) Serviceability: Performance of the structure so that it may be used comfortably by the people,
using the structure and those surrouding it under anticipated loads. Functional performance
required of the structureis also included.
c) Restorability: Performance to allow a structure to be easily restored under anticipated loads when
the structure has been subjected to damage.
"Safety" includes "ultimate limit states" and "fatigue limit states" in conventional limit state design
methods. Likewise, "serviceability" corresponds to "serviceability limit states." "Restorability" is a
required performance that has been incorporated from the seismic design.
(3) Table 3 shows a summary of required performances, perfornlance items, examples of verification
indices, and action to be considered.
Table 3 Required Performances, Performance Items, Examples of Verification Indices, and Action to be Considered
Required Performance
Verification Indices Actions to be Considered
Performance Item
Failure Force, displacement!deformation
Fatigue failure
Force, stress intensity, number of • All actions and their repetitions that occur during
Safety
repeats the design life*2
Running safety Displacement!deformation • Accidental actions having a low frequency of
Public safety*1
Carbonation depth, chloride ion occurrence but a large influence*3
content
Riding comfort Displacement!deformation
Aesthetic
Crack width, stress • Large actions that occur relatively frequently
Serviceability appearance* 1
Watertightness* Crack width, stress intensity
during the design life
Noise/vibration· Nose level, vibration level
Displacement!deformation, force,
• Actions that occur during the design life
Restorability Damage • Accidental actions having a low frequency of
stress
occurrence but a large influence*3
*1: Performance items that are set up as necessary, *2: ActIons that are conSIdered III the venficatIOn of fatIgue failure are
specified separately considering characteristics ofvariation, *3: Actions that are considered as necessary
(4) "Durability" is defined as the "resistance against variations in the performance of structures or
members due to variations in material characteristics (material deterioration) that occur with the
passage of time." This does not include fatigue caused by external forces, such as train loads.
"Durability" is not, however, an independent required performance. It is an item that should be taken
into consideration at all times when evaluating performance, factoring in materials deterioration.
Therefore, it is a basis of verification of all required performances taking the durability into
consideration.
As it is described above, the material degradation must be taken into consideration in every
verification of required performance. However, "methods of performing verification without taking
materials deterioration into consideration in a positive manner" also is prescribed as a realistic method
at the current technical level, presuming that the material deterioration will be kept within a certain
range. In this case, it is assumed that the reinforcing steel will not corrode during the design life.
(5) Five safety factors are used: load factor Yf, structural analysis factor Ya, material factor Ym, member
- 5 -

8. factor Yb, and structure factor Yi. These safety factors are defined as follows. The safety factors shown
in Table 4 are used as standard values.
Action factor, Yf: Safety factor considering unfavorable deviations from the characteristic value of,
uncertainty in evaluation of action, changes in actions during the design life, influence
of nature of actions on limit states, and variations of environmental actions.
Structural analysis factor, Ya: Safety factor considering uncertainty in structural analysis.
Material factor, Ym: Safety factor considering unfavorable deviations of material strengths from the
characteristic values, differences of material properties between test specimens and
actual structures, influence of material properties on specific limit states, and time
dependent variations ofmaterial properties.
Member factor, Yb: Safety factor considering uncertainty in computation of limit values of member
performance, effect of scatter of dimensional error of members, the importance of
members which reflects the influence on the overall structure when the member
reaches a certain limit state.
Structure factor, Yi: Safety factor considering relative importance of the structure, as determined by the
social impact when the structure reaches the limit state.
Table 4 Standard Values for Safety Factors
~
Structural
Material factor, Ym
Required
Action factor,
analysis
for
for steel
Yf concrete
Performance factor, Ya
Yc
Ys
Safety (failure, running
1.0'"'-'1.2 1.0
safety)
(0.8'"'-' 1.0)*1
1.0 1.3 (1.05)*2
for other than seismic design
Safety (failure, running
safety) 1.0 1.0 1.3 1.0
for seismic design
Safety (fatigue failure) 1.0 1.0 1.3 1.05
Serviceability (aesthetic
1.0 1.0 1.0 1.0
appearance, riding comfort)
Restorability (damage) 1.0 1.0 1.3 1.0
*1 Values III parentheses ( ) are applIed when the smaller is dIsadvantageous.
*2 Values in parentheses ( ) are applied to steel materials used for stoppers.
Member factor, Structure factor,
Yb Yi
1.1
1.0*4'"'-'1.2
(1.2'"'-'1.3)*3
1.0
(1.1 '"'-'1.3)*5
1.0
1.0'"'-' 1.1
1.0'"'-'1.1
(1.3)*3
1.0 1.0
1.0
1.0*4'"'-'1.2
(1.1 '"'-'1.3)*5
*3 Values in parentheses ( ) are applied to computation of the shear and torsion capacities depending on the concrete strength.
*4 In the case of a "permanent action + primary variable action + secondary variable action," it is generally recommended to set
this value to 1.1 or lager.
*5 Values in parentheses ( ) are applied to computation ofthe shear capacity.
4. Actions
"Actions" specifies kinds of actions, characteristic values, action factors, the basic philosophy on the
combinations of design actions, and practical design values of actions.
Basically, action is the equivalent of "load" specified in the previous edition standard which adopted
conventional limit state design methods. The characteristic values of actions are a) dead load, b) train load,
c) impact load, d) centrifugal load, e) train lateral load and wheel lateral force, t) breaking force· and
traction force, g) track-work vehicle load, h) sidewalk live load, i) continuous welded rail normal force, j)
prestressing force, k) effect of shrinkage of concrete and creep, 1) effect of temperature changes, m) soil
pressure, n) hydrostatic water pressure, fluid stream force and wave force, 0) wind load, p) snow load, q)
effect of earthquakes, r) ground displacement and effect of support drift, s) construction stage loads, t)
automobile collision loads, u) effect of environment, and v) other actions.
The following describes the changed contents and characteristic points of"actions."
- 6 -

9. (1) The term "action" has been commonly used in place of the term "load." This is for a number of
reasons as follows. In dynamic analysis and non-linear analysis used in design, there is an increase in
the number of cases where modeling to equivalent weight and force is skipped and instead their effect
is directly computed in the analysis to obtain response values. In durability checks, it is necessary to
place the effect of environment as one of the actions on a structure. The word "action" was adopted
after the IS02394: 1998 (General principles on reliability for structures) and the "Basis of Design
Associated with Civil Engineering Structures and Architectures" issued by the Ministry of Land,
Infrastructure and Transport that were published to lead international standardization of associated
technology. "Action" and "load" are defined in the 2004 edition standard as follows:
Action: Overall operation to make the stress, the fluctuation of deformation, and aging associated
with changes in material properties of structures and members.
Load: Of the various actions, those that are modeled as weight or force in order to be taken into
consideration in design
Figure 2 shows the relationship between action and load. The term "load" is used in the "effects of
gravity," such as "dead load" and "train load" that are usually modeled and substituted as weight and force,
as well as the "effect oftrain running," such as "impact load" and "centrifugal load."
___- - - Loads __--......
Actions that are turned into
weight and force models:
-Dead load -Train load
-Impact load -Centrifugal
load
-Continuous welded rail
normal force
-Prestress force -Earth
pressure
Actions
- Effect of concrete shrinkage
- Effect of concrete creep
- Effect of temperature changes
- Effect of earthquakes
- Effect of environment
Figure 2 Relationship between Action and Load
(2) In a combination of actions, there are two kinds of variable actions, "primary" and "secondary," that
are used in combination with permanent action.
The characteristic value of primary variable action is defined as the expected value of the maximum value.
Appropriate value must be determined for the characteristic value of the secondary variable action
depending on the combination with the primary variable action or the accidental action.
An accidental action is an action that occurs rarely during the design life, but has serious consequences
once it occurs. When the accidental action is combined with a variable action, the variable action should be,
in general, taken as a secondary variable action.
The performance item that the variable action needs not be distinguished between "primary" and
"secondary" is simply treated and expressed as "variable action."
Table 5 shows the basic combinations of design actions.
- 7 -

10. Table 5 Basic Combinations of Design Actions
Required Performance
Combinations ofActions
Performance Item
Failure
Permanent action + primary variable action + secondary variable action
Permanent action + primary variable action + secondary variable action
Safety Fatigue failure Permanent action + variable action
Running safety
Permanent action + variable action
Permanent action + primary variable action + secondary variable action
Riding comfort
Serviceability Aesthetic Permanent action + variable action
appearance
Restorability Damage
Permanent action + variable action
Permanent action + primary variable action + secondary variable action
(3) The following describes a standard train load that was newly stipulated and an impact load that was
revised in characteristic values of action.
a) The H-load that conforms to the axial length and train length of an actual Shinkansen train was
newly added as a standard train load (see Figure 3). The quantity of the wheel load used in the
H-load, which alternates depending on the type of railway vehicle, is chosen taking also into
consideration the passenger capacity and the passenger load factor that depend on the future
transport demand, and characteristics ofthe line.
l-__~-~__---~-~:l--~~----___---~~-_J[--~_~.
Im4 15.0 .!~4 5.0 Jl·5.14 15.0 .IJJJ~lm
14 25.0m .14 25.0m .1
Figure 3 H-Ioad
b) The running of a train induces dynamic response to structures. The ratio between dynamic
response to the increase in static response of stress or deflection caused by dynamic response is
called the "impact factor." In design, the design impact factor i configured as shown in equation
(1) is multiplied by the train load.
i=(1+ia)(1+ic) - 1 (Eq. 1)
where, ia= impact factor of speed effect, ic= impact factor of vehicle motion
In the 2004 edition standard, the impact factor of the speed effect ia is presented using numerical table, that
was computed using the speed parameter a (=V/(7.2nLb)) and Lb/Lv (V= maximum velocity oftrain (km/h),
n= fundamental natural frequency of members, Lb= span of members, and Lv= length of a vehicle), to deal
with the higher speed of trains and the lower rigidity of structures (see Figure 4).
- 8 -

11. .,li .,li
i:i i:i<U <U
'G 'G
S S<U <U
0 0
() ()
t) t)
o:l o:l
0.. 0..
.§ .§
0.1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Velocity parameter a
(a)Lb/Lv=O.02-0.16
Velocity parameter a
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Velocity parameter a Velocity parameter a
(b)Lb/Lv=O.2-0.5
1.0
---L')4=0.6 --L,)Lv=0.6
0.9
-------- L,)Lv=0.7
- - - - - - L,)Lv=0.8
- - - - - - - - L,)Lv=0.7
- - - - - - L,)Lv=0.8
- - - - L,)Lv=0.9 - - - - L,)Lv=0.9
0.8 --- --- L,)Lv=I.O --- --- L,)Lv=I.O
.,li 0.7
i:i<U 0.6
'G
S<U 0.50
()
t)
0.4o:l
0..
.§
0.3
0.2
0.1
0·8.0 0.1 0.2 0.3 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Velocity parameter a Velocity parameter a
(c)Lb/Lv=O.6-1.0
Figure 4 Impact Factor of the Speed Effect ia (for bogie type vehicle)
5. Materials
"Materials" specifies the quality of materials that are prerequisite in design, and the characteristic values
and design values of these materials.
The following are specified as characteristic values of concrete materials: a) characteristic values of
strength (tensile strength, bond strength, bearing strength, flexural cracking strength), b) fatigue strength,
c) stress-strain curve, d) tension softening properties, e) modulus of elasticity, f) Poisson's ratio, g) thermal
characteristics, h) shrinkage characteristics, and i) creep characteristics. Also, the following are specified as
characteristic values of steel: a) characteristic values of strength (tensile yielding strength, compressive
yielding strength, and shear yielding strength), b) fatigue strength, c) stress-strain curve, d) Young's
- 9 -

12. modulus, e) Poisson's ratio, f) coefficient of heat expansion, and g) relaxation ratio ofprestressing steel.
The following are additions made to high-strength concrete and high-strength steel, and revisions to the
design fatigue strength of steel.
(1) Concrete
a) The applicable range of the characteristic value of the compressive strength of concrete f'ck has
been extended from the conventional strength of 60N/mm
2
to 80N/mm
2
.
b) Following the revision of the JSCE Specifications, the formula to compute the flexural strength
of concrete was abolished. A new formula to compute the flexural cracking strength has been
adopted. This formula takes into consideration the influence of the tension softening properties,
drying, hydration, and other factors associated with concrete.
c) The method of computing the shrinkage strain and creep of concrete also has been changed to
those specified in the JSCE Specifications.
(2) Steel
No special examination of the usage of reinforcements that comply with JIS G 3112 "Steel Bars for
Concrete Reinforcement" is required except when using SD490.
When using the SD490 reinforcing bar, the 2004 edition standard requires its mechanical properties,
weldability, joint performances, fatigue, cracking of members, deformation performance of members are
fully examined. Then, the characteristic values of strength and its usage have to be determined. In JIS G
3112, seven types of reinforcement are stipulated: SR235, SR295, SD295A, SD295B, SD345, SD390 and
SD490. (Note: JIS stands for Japanese Industrial Standards, SD stands for the deformed reinforcing bar,
and SR stands for the plain bar.)
Before using high-strength reinforcements (SD685, SD785, SD1275, etc. or equivalents) that are not
compliant with JIS G 3112, various characteristics including mechanical properties must be fully examined
taking their locations and purpose ofuse into consideration.
Generally, wire compliant with JIS G 3536 "Uncoated Stress-relieved Steel Wires and Strands for
Prestressed Concrete" should be used as prestressing steel wire and prestressing steel strand. Other types of
wire that do not meet this standard must be fully examined to determine if they are suitable to be used or
not.
The 2004 edition standard specifies that the round bar type A No.2, round bar type B Nos.l and 2, and
deformed bar type B No.1, which are compliant with JIS G 3109 "Steel Bars for Prestressed Concrete" and
JIS G 3137 "Small Size-Deformed Steel Bars for Prestressed Concrete" should be generally used.
High-strength prestressed steel bar, such as types C and D, demonstrate a relatively large drop in static
strength and fatigue strength when they are subjected to bending, stress concentration, corrosion, or other
factors. Therefore, it is also specified that they must be fully checked before a high-strength prestressed
steel bar is used.
(3) Fatigue strength ofreinforcements
The fatigue strength of deformed reinforcing bar was revised taking into consideration the fatigue test
conducted to obtain the fatigue life in the region longer than 2.0x 106cycles. As the result, the gradient of
the S-N line k for the deformed reinforcing bar was changed from 0.12 to 0.06 in the region where the
fatigue life is longer than 2.0xl06 cycles (see Figure 5).
- 10 -

13. 500
400
~ 300
....
-e k=-0.12(N~ x 106V
"0
e=;::l
.£l ~ 200
OJ) == 0
15 .~
IZl = "-V ~ <I>=32mm
51 OJ)
100..... =~ '.0
~ i)l
S
0...
10
5
10
6 2XlO-6
10
7
10
8
Fatigue life N
Figure 5 Fatigue Strength under Pulsating Tension of Deformed Reinforcing Bar
6. Computation of Response Values
"Computation of response values" prescribes the following four items: a) principles of computation of
response values, b) modeling of structures, c) structural analysis methods corresponding to verification of
the respective required performances of safety, serviceability and restorability, and d) how to compute
design response values. In the section about the method for computing design response values,
computation formulas for a) design stress and design flexural cracking strength in a reinforced concrete
structures, and for b) design stress in prestressed concrete structures, are prescribed.
"Response values" are a generic term describing the section force, displacement, stress, strain and other
factors that are induced by actions.
(1) Modeling of members
Members are modeled as linear members or planar members subjected to in-plane forces depending on the
member dimensions and the directions of forces acting on the member.
As for the non-linear models of reinforced concrete members, the model beyond the flexural yielding is
made compatible with the seismic standard as shown in Figure 6.
M
~--~----------~----~----~B
Be By Bm ~
Mer: flexural moment when flexural cracking occurs
My: flexural moment at yield
Mm: maximum flexural moment
Be: member angle at occurrence of flexural cracking
By: member angle at yield
Bm: maximum member angle that can sustain Mm
Bn: maximum member angle that can sustain My
Figure 6 Relationship between Flexural Moment of Member End and Member Angle
(2) Computation of flexural crack width
The properties of flexural cracks that occur in reinforced concrete and prestressed concrete are influenced
by many factors. The computation formula for flexural crack width Wd shown in Equation 2 is used to
obtain flexural crack width in accordance with the JSCE Specifications, which take into consideration the
- 11 -

14. quality of concrete and the influence of multiple layer of tensile reinforcement arrangements.
w, = 1.1 kl k, k3 k4 {4c +O.7(c, - IP)} [ ~~ lor~')+&'",l (Eq.2)
where, k1: constant to take into consideration the effect of surface geometry of reinforcement on crack
width. It may be taken to be 1.0 for deformed reinforcing bars, and 1.3 for plain bars and prestressing steel.
k2: constant to take into consideration the effect of concrete quality on crack width
k2= 15 +0.7
f' e+20
f'e: compressive strength of concrete (N/mm2
). In general, it may be taken to be equal to the design
compressive strengthf'ed .
k3: constant to take into consideration the effect of the multiple layers of tensile reinforcement on
crack width.
k3= 5(n +2)
7n+8
n: number ofthe layers of tensile reinforcement
k4 : constant to take into consideration the fluctuation of flexural cracking
Cs: center-to-center distance of tensile reinforcement (mm)
c: concrete cover to tensile reinforcement (mm)
cp: diameter oftensile reinforcement (mm)
c: 'esd: compressive strain for evaluation of increment of crack width due to shrinkage and creep of
concrete
O"se: increment of stress of reinforcement from the state in which concrete stress at the portion of
reinforcement is zero (N/mm2
)
O"pe: increment of stress of prestressing steel from the state in which concrete stress at the portion of
reinforcement is zero (N/mm2
)
7. Verification of Safety
"Verification of safety" prescribes the standard methods for verifying the safety of structures.
Verification of the safety of structures refers to both "verification to confirm that structure will not reach to
the limit states against all design actions and their repetition that occur during the design life" and
"verification shall be performed for failure, fatigue failure, travel safety, and public safety, and by setting
proper limit values that take structural safety into consideration."
(1) Verification of safety associated with failure
Verification of safety associated with failure involves verification of the following: a) flexural moment and
axial forces, b) shear force, c) torsion, and d) displacement/deformation.
The limit state of failure is prescribed as a "state in which the structure can no longer sustain bearing
capacity due to excessive action." Generally, structures are made up of multiple structural elements such as
members, and the relationship between structure failure and structural element failure differs from
structure to structure. However, in this design standard, structures where even one of the members that
make up the structure reaches the failure limit state are presumed to be a structural failure. Therefore,
verification of the limit state of the members on failure must be represented as verification ofthe limit state
ofthe structure.
Appropriate verification indices must be used since the verification indices used in verification of member
failure differ according to the type of structure, the failure mode of the member, and the response value
- 12 -

15. computation method. The following shows examples of verification indices.
a) Flexural moment and axial forces
The limit values, which are taken as the verification indices of member forces caused by the flexural
moment and the axial force, are computed by the M-N interaction curve according to design flexural
capacity Mud and design axial compressive capacity N'ud. When the effect of axial compressive force
is large, members that are subjected to the design flexural moment Md and design axial compressive
force N'ud are verified by confirming that the point (Yi· Md, Yi· N'd) falls inside ofthe Mud - N'ud curve.
N'
o
Figure 7 Verification of Bending Capacity when the Effect of Axial Compressive Force is Large
The design capacity of members is computed based on the following assumptions: a) the fiber strain is
proportional to the distance from the neutral axis of the member section, b) the tensile stress of concrete is
ignored, and c) the stress-strain curve of concrete and steel is dependent on the items indicated in the
section "5. Materials."
b) Shear force
When member forces are taken as the verification indices at failure of a member (linear member with
shear reinforcement) subjected to shear force, verification is performed using the design limit values
that are derived from the yield of the shear reinforcement and from the diagonal compressive failure
of web concrete.
In accordance with the JSCE Specifications, the design shear capacity of linear member Vyd is
expressed as the sum of the design shear capacity of linear members without shear reinforcement Vcd
and the design shear capacity of shear reinforcement in linear member resistance Vsd .
Besides this, the verification methods are also prescribed for the punching shear of planar members,
shear force in planar members subjected to in-plane forces, and the failure due to shear transfer.
(2) Verification of safety associated with fatigue failure
The 2004 edition standard stated that it is preferable to determine an appropriate limit state for the
structural system in the verification of fatigue failure, because the fatigue failure at the material level,
member level and structure level are not necessarily the same.
On the other hand, structural safety is ensured unless fatigue failure occurs at the material or member level.
Therefore, verification of structural fatigue failure may be replaced with verification of material fatigue
failure or member fatigue failure. This means that the fatigue failure of beams and slabs is verified based
on the fracture of reinforcement that is subjected to repeated tensile stress.
In a regular service state, the verification of fatigue failure of prestressed concrete structures is generally
- 13 -

16. skipped because the stress of reinforcement induced by variable action is small owing to the reason that the
occurrence of cracking is not allowed.
On the other hand, as for the partially prestressed concrete structures, the stress of reinforcement induced
by the variable action becomes relatively large because the occurrence of cracking is allowed. Therefore,
the fatigue failure of reinforcement and prestressing steel must be verified.
(3) Verification ofrunning safety
It is described that the verification of the running safety of trains should be performed according to
"Design Standards for Railway Structures and Commentary (Displacement Limits)" (issued in February
2006), hereinafter referred to as the "displacement limit standard".
(4) Verification ofpublic safety
The 2004 edition standard also describes the verification of safety hazards for third parties (public) which
might be caused by concrete spalling or peeling and falling on a person.
It is quite difficult, at present, to verify quantitatively the relationship between the influence of the
environment and concrete cover spalling or falling, that is very much influenced by the construction quality.
However, if it satisfies the "checks on durability" owing to appropriate construction, it can be regarded that
steel corrosion or concrete deterioration induced by the intrusion of deterioration factors is limited. This is
considered capable ofpreventing the spalling or falling of concrete in most cases, and this verification may
be replaced by the check on durability.
8. Verification of Serviceability
"Verification of serviceability" prescribes to conduct verification on the necessary performance items
chosen from riding comfort, aesthetic appearance, watertightness, noise/vibration and so on.
(1) Verification of riding comfort
The 2004 edition standard prescribes verifying riding comfort according to the displacement limit standard.
(2) Verification of serviceability associated with aesthetic appearance
Railway structures have to preserve the performance to avoid surface cracks, dirt, and other things, in order
not to make the surrounding people uneasy or obstruction in using the structure. The 2004 edition standard
prescribes how to verify without compromising the aesthetic appearance caused by cracking as follows.
Crack width or stress of reinforcement is used as the performance index in the verification of external
cracks associated with the aesthetic appearance of structure. The crack covered in this verification is
formed by mechanical actions such as flexural moment, shear force and torsion. The verification will be
conducted using the load in regular service condition.
The verification of flexural crack width of prestressed concrete structures, in which the crack forming is
not allowed under regular service conditions, can be omitted not only when a) fiber stress of concrete due
to permanent actions does not become tensile stress, but also when b) fiber stress of concrete induced by a
combination ofpermanent and variable actions is smaller than the design flexural cracking strength and the
specified tensile reinforcement is arranged at these locations.
9. Verification of Restorability
"Verification of restorability" prescribes to verify that a) damage caused by variable actions (e.g. train load
and wind load) and accidental actions (e.g. effect of earthquakes) and b) damage caused by materials
deterioration due to the effect of the environment, will not reach to the performance level limit state which
take into consideration the difficulty of sustaining and recovering function of the structure.
- 14 -

17. The following two levels are set as the performance levels of restorability:
Performance level 1: Functions are sound and can be used without making repairs.
Performance level 2: Functions can be recovered within a short time but repair is necessary.
(1) Verification ofrestorability associated with damage
The 2004 edition standard requires determining the damage states for structural elements so that the
restorability ofthe structure is preserved. The classified damage level of members is defined as follows:
Damage level 1: Repair is not needed
Damage level 2: Repair is needed occasionally
Damage level 3: Repair is needed
Damage level 4: Repair is needed or replacement of members is needed occasionally.
Table 6 and Figure 8 show an example of the relationship between the damage level of structural elements
and the performance level of structures in a rigid frame structure.
The fundamental idea shown in Table 6 is as follows: Damage level 1 is set for each of the members as the
restorability performance level 1 for a structure that should avoid damage requiring repair. For the
restorability performance level 2, it is assumed that the structure will be reused, so the member damage
levels are set for each of the members in consideration of the difficulty of repair. This means that damage
up to level 3 is allowed except for foundations that are difficult to repair and members that are important
for ensuring that functions are recovered in a short time.
Table 6 Restorability of a Structure and Damage Levels of Structural Elements (reinforced concrete rigid frame viaduct)
Restorability of Structure I Performance level 1: I Performance level 2:
Bearings 1 2
Slabs 1 2
Damage level of
Cap beam 1 2
structural elements
Other beams 1 2'""'"'3
Columns 1 2'""'"'3
Foundation
1 2
members
~ Damage areas
Figure 8 Schematics of Critical Sections of Rigid Frame Viaduct.
Figure 9 shows the limit value or critical points for a linear member corresponding to the damage level
with respect to the failure mode (bending, shear or torsion). The critical points associated with damage
levels beyond the flexural yielding point of a member follows the definitions prescribed in the seismic
standard.
Then, for the damage level of reinforced concrete linear members with respect to flexure or shear failure
modes, design limit values are determined in correlation with the limit states induced by the maximum
response displacement, as shown in Figures 9 (a) and (b), respectively.
- 15 -

18. Damage level 4
:: :::
Damage level 2 Damage level 3
Damage level I
CID@@
Flexure failure
o Displacement
Damage level 4
~
Damage level I
@
Shear failure
Displacement
(a) When the failure mode is flexural
CD Point where first crack forms
(b) When the failure mode is shear
CID Point where concrete reaches compressive strength
® Point where reinforcement reaches yield point or
member reaches yielding
@ Point where shear failure occurs before flexural
yielding
@ Point where buckling of longitudinal reinforcement or
buckling related deformation start
(J) Point where concrete cover spalls
® Point where yield capacity is sustained
Figure 9 Relationship between Damage Level and the Load-Displacement
Envelope Curve with Respect to Each Linear Member Failure Mode
(2) Verification of stability
It is prescribed that the verification of residual displacement should be conducted if necessary. In cases
where the performance level 2 is satisfied, it can be omitted because the residual displacement is small in
general.
10. Assessment of Durability
"Assessment of durability" prescribes requirements to restrict the material deterioration caused by the
effect of the environment within a certain level through out the design life.
By satisfying these requirements, it is possible to adopt verification methods that ignore aging
deteriorations in the structure due to the effect of the environment. The assessment is conducted to confirm,
in principle, that the corrosion of reinforcement does not occur.
Cracking, carbonization, chloride ions, freezing/thawing, chemical attack, and alkali-aggregate reaction are
considered, in general, as deterioration factors that initiate the corrosion of reinforcement in concrete
structures (see Figure 10). These influences are verified in the "assessment of durability" using appropriate
indices.
Assessment of
Durability
Corrosion of
reinforcement
Deterioration of
concrete
t
Cracking
Carbonization
Chloride ion
t
Freezing/thawing
Chemical attack
Alkali-aggregate
reaction
u.u •• u •••• Effect of
mechanical action
Effect of environment
Figure 10 Example of Typical Deterioration Factors Requiring Assessment of Durability
(1) Assessment of corrosion ofreinforcement
The assessment of corrosion of reinforcement is prescribed to be conducted by confirming that corrosion
does not occur due to deterioration factors such as cracking, carbonization, and chloride ions.
- 16 -

19. a) Of the many kinds of cracks that form in concrete, mechanically formed cracks due to flexural
moment, axial forces, shear force and torsion, which are induced by normal service condition,
are covered in this assessment. It is desirable that cracks, which form due to material and
construction problems, also be taken into consideration as -much as possible at the design stage.
It is prescribed as a practical assessment method that either the crack width, stress of
reinforcement or section force be limited. When setting the limit values in this case, the standard
prescribes the environmental conditions (see Table 7) of the site of the structure and the
corresponding limit values.
Table 7 Classification of Environmental Conditions for Corrosion of Reinforcement
Environmental categories
Normal environment
Corrosive environment
Severely corrosive
environment
Environmental conditions
• Normal outdoor environment where drying and wetting are not repeated much,
or in soil.
• Environment with more frequent cyclic drying and wetting, and underground
environment below the level of underground water containing especially
corrosive (or detrimental) substances.
• Environment of structures submerged in seawater or near the coast.
• Environment in which reinforcement has the risk of being subjected to the
influence of detrimental chemicals such as sooty smoke, acid, oil, and salt.
• Environment of structures subjected to tides, splash, or exposed to severe
ocean winds.
Table 8 shows a specific example of limit values for flexural crack width. The formula for computing the
crack width is prescribed in "Computation of Response Values."
Table 8 Limit Values for Wlim Concrete Crack Width Associated with Corrosion of Reinforcement
Environmental conditions on corrosion of reinforcement
Type of reinforcement Normal Corrosive Severely corrosive
environment environment environment
Deformed reinforcing bar
0.005 c 0.004 c 0.0035 c
and plain bar
Prestressing steel 0.004 c 0.0035 c -
Note) c: Cover oftenstle remforcement. The standard value IS 100 mm or less.
b) Carbonization is assessed by using the estimated carbonization depth value Yg and the
carbonization depth limit value Ylim to confirm the relationship Yg::;;Ylim; where, Ylim is obtained by
Ylim=C - Ce - Ck, C is the design cover thickness (mm), Ce the construction error of the cover (mm),
and Ck the remaining non-carbonated cover thickness (mm), which is taken as 10 mm for
structures in a normal environment and between 10 to 25 mm for structures contain chloride ions
in concrete.
The estimated value of carbonization depth is computed as being proportional to the square root
of design life t.
An appendix of the 2004 edition standard shows an example of design cover thickness
corresponding to the design life of 100 years. Assessment of carbonization can be omitted by
adopting a design cover thickness that is equal to or larger than the value shown in the example.
c) In the assessment of chloride ions, the 2004 edition standard prescribes how to assess structures
that exist in a "corrosive environment" and a "severely corrosive environment," where there is a
risk that the corrosion of reinforcement might occur due to the penetration of chloride ions.
On the chloride ion penetration phenomenon, it is necessary to take into consideration the
chronological variation of chloride ion density on the concrete surface. The 2004 edition
standard proposes an equation to estimate chloride ion density at the position of reinforcement,
- 17 -

20. which is formulated based on the evaluated data of concrete test pieces for chloride ion content
survey taken from railway structures nationwide in Japan and assuming the hypothesis that the
chloride ion density at the position of reinforcement increases proportionally to Ji (where, t:
elapsed years).
Examples of design that indicate the design concrete cover necessary to endure the design life of 100 years
are shown in an appendix of the standard. Assessment of chloride ions can be omitted by adopting a design
concrete cover thicker than the values shown in the appendix.
(2) Assessment of concrete deterioration
Concrete deterioration is assessed by confirming that harmful concrete damage will not occur due to the
penetration of deterioration factors. The 2004 edition standard prescribes the assessment of freezing and
thawing, chemical attack, and alkali-aggregate reaction. However, required conditions to omit assessments
are prescribed for all ofthese items.
11. Prerequisite of Verification
"Prerequisite of verification" prescribes the general prerequisites ofverification for reinforced concrete and
prestress concrete structures. The prerequisites include a) concrete cover, b) diameter of reinforcements, c)
minimum and maximum reinforcement, d) stress limits, e) spacing of reinforcement, f) arrangement of
reinforcement, g) bend configurations of reinforcement, h) development of reinforcement, i) bond of
reinforcement, j) splices of reinforcement, and k) anchorage and connection of prestressing steel, and
reinforcement for concrete of anchorage zone.
12. Construction and Maintenance
"Construction and maintenance" prescribes the conditions for construction and maintenance that are
prerequisites for the verification of the performance of structures. The prerequisites include a) fabrication
of reinforcement, b) construction of prestressed concrete structures, c) timing of loading on structures, d)
camber for girder construction, e) construction of bearings, and f) maintenance utilities. For example,
several remarks associated with kind and required number of spacers, and welding of reinforcements are
described in "fabrication of reinforcement" in order to ensure to have precise concrete cover thickness.
Stress limits for concrete and prestressing steel in the construction stage of prestressed concrete structures
are prescribed in the chapter of "timing of loading on structures."
13. Members
"Members" prescribes details associated with the modeling of slabs, beams, columns, walls, footings, and
precast members. The verification methods of members are also prescribed.
14. Structures
"Structures" prescribes special items corresponding to the kinds of structures that are mandatory in the
verification ofthe performance of structures. This chapter also describes how to combine member elements
to model a structure.
The types of structures include a) slab type girders, b) T-section girders, c) box-section girders, d)
V-section girders, e) skew girders, f) continuous girders, g) straight girders supporting curved tracks, h)
curved girders, i) piers, j) abutments, k) rigid frame structures, 1) flat slab structures, m) box culverts, n)
arch bridges, 0) cable-stayed bridges, p) precast concrete structures, q) bridge sidewalks, and r) parapets
(handrails).
- 18 -

21. 15. Structural Details
"Structural details" prescribes general structural details of reinforced concrete and prestressed concrete
structures. In other words, this chapter prescribes structural details necessary to compensate structural
weaknesses that are not directly associated with verification. Structural details required and intimately
associated with "members," "structures" and "bearings" are prescribed in the respective section.
Structural details include a) additional reinforcement for exposed surfaces, b) reinforcement for stress
concentrated zone, c) reinforcement for openings, d) haunches, e) beveling, f) construction joints, g) joints,
h) drainage and water proofing, and i) protection of concrete surface.
16. Bearings
"Bearings" prescribes verification methods associated with the bearing itself, restrainers, bridge sliding-off
failure preventers, and girder endlbearing seat.
Bearings include elastomeric and steel bearings. Restrainers include the steel plain bar stopper, the steel
square pipe stopper, and the stopper with dampers. Bridge sliding-off failure preventers include stoppers
and bearing seat extension.
Each apparatus of bearing has respective expected functions. Their design limit values must be determined
so as to preserve the expected performance ofthe entire structure.
The 2004 edition standard prescribes the verification formulas and limit values of each type of bearings
with respect to the required performance. The limit values are determined based on the conventional limit
values used in the limit state design method.
Table 9 shows the relationship between the required performance (performance items) of a structure and
the verification indices ofbearings.
Table 9 Example of Required Performance of a Structure and Verification Indices of Each Bearing Apparatus
Required
Verification Indices
Performance Bearings
Performance
Item (Elastomeric Restrainers
Bridge sliding-off Girder end/bearing
of Structure
bearings)
failure preventer seat
Capacity, girder
Safety
Failure - Capacity* sliding-off Capacity, Stress
displacement
Fatigue failure - - - Stress
Serviceability Appearance - - -
Crack width,
Stress
Deformation,
Restorability Damage
Stress
Capacity
Replacement of
- -
bearings
..
*FaIlure IS also venfied when the stopper IS used as the restramer and also as a shdmg-offfmlure preventer.
An appropriate value must be set as the limit value in the determination of the performance level of
structure subjected to the effects of earthquakes because the restorability is greatly affected by the grade of
determined bearing damage states.
Tables 10 to 12 show the relationship between the performance level of structures and the damage level of
each part of the bearing, the damage level of the bearings themselves (elastomeric bearings), and the
damage level of movement limiting apparatus, respectively.
- 19 -

22. Table 10 Restorability of Structures and Damage Level of Each Bearing Part
Restorability of Structure I Performance Levell: I Performance Level 2:
Damage level of bearings 1 2
Bearings
Sl S2
Damage level of (elastomeric bearings)
each apparatus Restrainers Sl S2
Bearing seat/girder end 1 2
Table 11 Damage Level of Bearings (elastomeric bearings)
Damage States and Extent ofRepair I Shear Deformation ofRubber
Exceptearthquakes:70~
Damage level S1 No-damage, no-repair General bearings during earthquakes: 200~ or less
Horizontal force distributing bearings: 250~ or less
Damage level S2
Damage level S1
Damage level S2
17. Appendices
Replacement required because of significant
damage or failure
Table 12 Damage Level of Restrainers
Damage States and Extent ofRepair I
No-damage, no-repair
Failure has not yet occurred though damage requires
repair in some cases.
When above is exceeded
Action Force and Deformation Amount
Yield strength or less
Yield strength to maximum capacity
"Appendices" provide technical information such as the background and the concepts of code provisions
and commentaries prescribed in the design standards. The items contained in the appendices are as follows:
a) Fundamental ideas behind performance verification, b) basis of design actions and their combinations, c)
track skeleton weight and track weight, d) design impact factor for railway concrete bridges, e) train lateral
load, f) verification methods for flexural cracks on reinforced concrete rigid structure viaducts, g) quality
specifications for steel, h) fatigue strength of SD685 and equivalent reinforcement, i) tensile fatigue
strength of reinforcement subjected to the standard train loads of Japan Railways, j) approximate
expression of equivalent number of cycles, k) background of verification of cracks, 1) surface chloride ion
concentration coefficient S, m) design concrete cover thickness required from the point of view of
durability, n) construction error of concrete covers, 0) basic development length of reinforcement, p)
cautions on high-strength reinforcement usage, q) design methods for flexural moments of two-way slabs,
r) displacement limit values associated with train runability
V VERIFICATION EXAMPLES, DESIGN GUIDEBOOKS, AND VERIFICATION
SOFTWARE
The following are provided for the convenience of the structural designers: verification examples that
cover several structures in accordance with the provisions of the design standard, design guidebooks to
explain several design know-how that could not be incorporated in design standard, and a software
program for conducting verification in accordance with the design standard.
1. Verification Examples
Verification examples covering "simply supported slab girder," "simply supported T girder" and
"reinforced concrete rigid frame viaduct" have been published. These publications describe the design
procedures from the setting of required performance through to the verification ofperformance.
2. Design Guidebook
(1) Reinforcement arrangement guidebook
A guidebook to provide appropriate drawings of reinforcement that describe the arrangement of
- 20-

23. reinforcements and their configurations, have been published.
These also describe examples of design concrete cover thickness that satisfy assessment of durability.
Descriptions in these guidebooks also include lists of the required design concrete cover thickness for each
of the water-cement ratios, cement types and member types in carbonization assessment, and for each of
the water-cement ratios, regions and distances from the coastline, and member types in chloride ion
assessment.
(2) Performance verification guidebook
The guidebook describes supplementary items and application methods of the design standard, to be
applied on actual structures. The guidebook is mainly comprised of how to make computation models for
various shaped members and detailed methods for setting limit values in performance verification.
It also presents examples of design condition list tables, combinations of design actions and design output
summaries.
3. Verification Software
"Performance Verification Support Software Program (VePP-RC)" is currently used to improve the
efficiency ofperformance verification in accordance with the new standard.
The VePP-RC adopts the spread sheet format for input and output, and can provide output results in CSV
file format.
- 21 -

24. II
I I
I I
I I

25. Outline of Design Standards for Railway Structures and Commentary (Concrete Structures)
The English edition ofthe outline of the "Design Standards for Railway Structures and Commentary
(Concrete Structures)" was produced by the Railway Technical Research Institute (RTRI) to
introduce one ofthe advanced railway technologies established in Japan.
The provisions of the original standard, written in Japanese, are the fruits ofdiscussions in the
working committees composed of academics and engineering specialists from railway companies.
They are based on the investigation and research ofRTRI, as directed by Japan's Ministry ofLand,
Infrastructure and Transport as a part of ministerial policy to establish railway technical standards.
This document is an English translation summarizing the original standard.
It is our hope that this document helps overseas railway engineers to understand the railway
technologies currently being used in Japan.
Note: Copyright © 2007 by the Railway Technical Research Institute. All rights reserved.
The text was translated by the Railway Technical Research Institute.
March 2007
Railway Technical Research Institute disclaims any and all liability for any loss or damage arising from the use of
these materials.
The original standards were edited by RTRI and published by Maruzen Co., Ltd.
Contact directory
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2-8-38 Hikari-cho, Kokubunji-shi, Tokyo 185-8540 Japan
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