Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Study > CEE 412 > Flashcards

CEE 412 Flashcards

1
Q

What is railway track engineering?

A 
Engineering discipline engaged in planning, design, 
construction,
inspection,
Maintenance,
Advancement of track structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Evolution of track structure

A 
Has evolved over past 200 years
Changes often to increase train loads and speed
Trial and error approach
Analytical approach began end 1800s
Modern: mechanistic design
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Primary function of track

A 
Support and distribute train loads
Guide the vehicle
Provide adhesion at wheel-rail interface
Provide smooth running surface
Facilitate drainage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Secondary function of track

A

Transmission of signal circuit
Broken rail detection
Path of ground return for traction power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Track engineering fundamental

A

Providing adequate drainage

Where does the water go

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Track components

A 
Welded rail
Crosstie
Fastener
Tie plates
Spikes
Rail anchors

Rail pads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where is track gauge measured

A

distance between heads

5/8“ (15.875mm) below the top of the rail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Track gauge examples

A 
Spain, India 1767
Russia 1524
UIC 1435
South Africa, japan 1067
Switzerland, india 1000
Russia 750
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Klingel Motion

Amplitude/Cycle length

A

Lk=2Pi sqrt(rs/2gamma)

y=y0sin(2pix/L)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Truck hunting

A

Lateral, side to side steering motion

Influenced by speed, carbody resonance, wheel conicity, rail head geometry, suspension

Can lead to excessive rail wear, wheel wear, wider gauge, derailment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Quasi static Forces acting on the track

A

Groß tare
Centrifugal
Wind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Dynamic forces acting on the track

A

Track irregularities
Discontinuities
Irregular running surface
Vehicle defects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Vertical forces acting on track

Similar for lateral

A

P total =

P static +
P centering (curvature,cant) +
P wind +
P dynamic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Longitudinal Force on track

A

Thermal force
Traction force
Braking force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Calculating dynamic wheel load

A

Dynamic load> static load

Pd = Ps + thetaPs

Impact factor theta:
33V[MPH]/(D[inches]100)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Size of a contact patch

A

1/2 sq. In.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Track performance requirements

A 
Stiffness
Resilience
Resistance to permanent deformation
Stability
Alignment and adjustability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Criteria for success

A

Safety

Cost:
Reliability, availability, maintainability

Comfort

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Components of track superstructure

A

Rail
Ties (sleeper)
Fastening system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Components of track substructure

A 
Top Ballast
Bottom ballast
Subballast
Placed foil (fill)
Natural ground
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Importance of the wheel-rail Interface

A

Low friction for efficiency

Strength to resist vertical forces

Wear and fatigue resistance for cost effective operation

22
Q

Key aspects of rail metallurgy

A 
Chemical composition 
Cleanliness of steel
Microstructure 
Hardness and wear resistance
Tensile properties
23
Q

Additional Chemicals in rail steel

Wanted or unwanted

A 
C
Mn
Si
S
P
Cr
V
24
Q

Definition: Hardness

A

The ability of a material to resist penetration, scratching, wear, abrasion and cutting

25
Definition: ductility
The ability of a material to undergo relatively large plastic deformations before fracture
26
Definition: toughness
The ability of a material containing a crack to resist fracture
27
Key rail dimension
Head shaped to meet wheel contour Broad base to resist overturning Base shaped to facilitate fastening to ties Web connects head and base
28
Standard rail sections
136 RE. 136 lb/yd UIC 60. 60 kg/m
29
Typical hardness of rails
Measured in brinnel hardness: 200-240 ... 350-390
30
Continous welded rail
Welded to eliminate joints Length > 400 feet (200-800m) Needs control of thermal stresses Must be anchored
31
Crosstie fundamentals
Maintain gauge Distribute wheel loads from rails to ballast Anchor track against lateral, longitudinal, vertical movement Spacing: 18-30“
32
Function of fasteners
Longitudinal resistance Torsion resistance Lateral, vertical flexibility
33
11 Functions of ballast
Transmit and reduce tie pressure to subgrade Anchor rail-tie structure Absorb dynamic impact Facilitate drainage Provide dry support medium to prolong service life of ties Facilitate maintenance Reduce occurrence of track frost heave Prevent vegetation growth Provide voids for „storage“ of fouling material Absorb noise and vibrations Provide electrical resistance between rails
34
Important ballast properties
Particle size, gradation, shape Resistance to weathering, fragmentation, degradation Compressive strength Clean and cleanable Workability for alignment adjustments
35
Ballast material suitable for HSR
Crushed stone - granite - quartzite - basalt - traprock (Hard, durable, good repeated load behavior)
36
Sources of fouling
Ballast breakdown - handling - thermal stress - freezing water - tamping damage - Traffic damage Infiltration from ballast surface Tie (sleeper) wear Infiltration from underlying Granulat layers
37
Drainage requirements
Keep the ballast clean enough for water to drain as fast as it enters Have the surface of the subballast and subgrade slopes away from the center of the Track Provide a means for water coming out of the substructure to drain away from the track
38
Design principle of slab track systems
Enough strength and stability: high safety Reasonable design scheme of manufacturing, laying and fine-adjusting of track structure: smooth Reasonable structure types and durable engineering material: low maintenance
39
Classification of loads | Slab track
Dead load - structure weight - shrinkage - creep of concrete Live load - vertical, lateral, temperature force - flexure of support Additional loads - braking, traction force - uneven settlement of support layers Special loads - temporary construction forces
40
Dynamic evaluation of slab track
Safety index - derailment coefficient - rate of wheel load reduction Comfort index - carbody acceleration Dynamic response index - vertical, lateral force - acceleration - vibration, noise
41
Typical uses for continous/discrete concrete bed structure
Cobtinous: - subgrade - tunnel sections Discrete: - bridges
42
Technical features of pre-cast slab track
High concrete structure quality Environmental and weather influence reduced Allows scheduling efficiencies
43
Advantages of ballasted tracks
Low initial construction cost High elasticity Simple maintenance at low cost High noise absorption Easier to renew on existing lines Less complex drainage systems Advanced maintenance techniques
44
Advantages of slab track
Higher level of track stability More precise control of alignment Improved ride comfort Longer life cycle Minimal maintenance requirement Higher availability Reduced structural height
45
Disadvantages of ballast track
Rate of geometry deterioration Lower lateral track resistance Fouled ballast inhibits drainage Weight increases cost on bridges Increased structural height Ballast flight st high speed
46
Disadvantages of slab track
Higher initial construction cost Complexity of construction Sensitivity to construction defects Less long-term experience More susceptible to settlement Less sound & vibration absorption
47
Decision between ballast/slab: | Operational concept
Availability for operations Business case Ride comfort requirements
48
Decision between ballast/slab: | Production & maintenance concept
Maintainability Possibility of making adjustments Replacement investment requirement Availability of component supplies
49
Decision between ballast/slab: | Risks/ malfunctions
Safety Pattern of damage & repair following derailment Remediation of defects
50
Decision between ballast/slab: | Miscellaneous requirements
Drainage Structure-borne noise Airborne noise Effects on the subsoil Clearance gauge
51
What are the current types of slab track on the market?
Cast in site concrete Precast concrete elements

Study (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions