infrastructure

MARCH 2015 Research, Planning & Coordination Department 2

RAILWAY TRACK

CROSS SECTION OF TRACK


CROSS SECTION OF TRACK

POOR SOIL

IDEAL SOIL AND POOR SOIL


IDEAL SOIL

IDEAL SOIL AND POOR SOIL IDEAL SOIL

MARCH 2015 Research, Planning & Coordination Department

The characteristics of the ideal soil;

Strong against static loading and crashes must be less,

Differences in grains, high structural strength and well

compacted; strong aganist dinamic loading,

Elastic,

Resistant to erosion,

Permeable for water,

Solid, and serve like filter to track bed and ground,

Delivery and construction should not be expensive.

Ideal soil can be seen very rare in nature.

5

IDEAL SOIL AND POOR SOIL POOR SOIL


The characteristics of the poor soil;

Flowing and loose,

Mixed ground with cohesive, soft or semi-soft

sand, mud, clay,

Has too much boulders.

6

COARSE-GRAINED SOILS

PROPORTIONS

SOIL TYPES


FINE-GRAINED SOILS

ORGANIC SOILS

SOIL TYPES COARSE-GRAINED SOILS


The particles can be

distinguished by the naked

eye :

Boulders (have diameter

greater than 300 mm)

Cobbles (have diameter

between 75 mm and 300

mm)

Gravel (has diameter

between 4.75 mm and 75

mm)

Sand (has diameter

between 0.075 mm and 4.75

mm)

8


Corrupt mud, silt or clay are examples for fine-grained

soils. Fine-grained soils are identified with elasticy,

structure and color. Elasticy is determined by the clay

content in them.

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SOIL TYPES FINE-GRAINED SOILS


SOIL TYPES PROPORTIONS

Proportion of fine material Below %5 Coarse-grained soil

Proportion of fine material Between %5 and %40 Mixed-grained soil

Fine material has diameter below 0.075 mm

Proportion of fine material Over %40 Fine-grained soil


These are the swamps and peat soil. Organic layers in the

ground can be animal or vegetable origin.

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SOIL TYPES ORGANIC SOILS

SOIL TESTS


PROCTOR COMPACTION TEST

BEARING CAPACİTY TEST

SOIL TESTS


CALIFORNIA BEARING RATIO (CBR)

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SHAPE INEQUALITY DEGREE (U)

WATER CONTENT AND DRY DENSITY

PLASTIC PROPERTIES

PLATE LOAD TEST

SOIL TESTS SHAPE INEQUALITY DEGREE (U)


U is ratio between weights of grains have size 0-60 mm

and 0-10 mm. It shows slope of grain distiribution. If this

ratio is low (U is lower than 6 ) slope is vertical. This means

ground has almost same grain size. If this ratio is high (U is

higher than 6) ground has different grain sizes.

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SOIL TESTS PROCTOR COMPACTION TEST


This test establish relation between

water ratio and dry unit weight of

ground. Using this relation we have a

proctor density that is a value using to

estimate compress density of adhesive

grounds. When water ratio below

optimal water ratio, proctor density can

be 100% with an additional

compressing. If water ratio above

optimal water ratio, proctor density can

not be calculated with an additional

compressing.

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SOIL TESTS PROCTOR COMPACTION TEST


The proctor test is a compression test. In this experiment, the material

is put into a container and is compressed by using a mallet release.

This test is done in cases where the materials contain various amounts

of water.

Dry volume weight ratios record on water ratio which they belong. A

curve is formed from results and top of this curve shows dry volume

density.

Dry volume density is called simple proctor density and water ratio that

is belong this density called optimal amount of water.

Proctor curve gives information about acceptable water content to

reach the required compression values.

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SOIL TESTS PLATE LOAD TEST


Beside dry density, this test gives us a value that specifes

quality of loadbearing or protective material and bearing

capasity. At plate load test a circle plate has 30 cm

diameter makes loading and discharge with different

weights. Circle makes a mark is measured to calculate

depth.

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SOIL TESTS BEARING CAPACİTY TEST


Short time pulsed loadings are made to track bed. This

way track bed has softened vibration. If sinking and

vibration is bigger, track bed has low bearing capacity. This

test has shorter needed time. Results are nearer to real

load effects than plate load test and also results is ready to

use directly.

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SOIL TESTS PLASTIC PROPERTIES


If fine-grained soil is added water, ground loses

stiffness slowly. First ground passes to half solid,

then plastic form and final liquid form.

Increasing water ratio causes to grains adhesion

force to decrease. Adhesion disappears step by

step, and ground gets a liquid form.

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SOIL TESTS CALIFORNIA BEARING RATIO (CBR)


CBR ıs resistant that ground shows to 20 cm2 cylinder

compress ground with a steady speed that 1.25 mm in a

minute. Resistant curve is compared to a standart curve.

Result is percentage of force that do equal going into best

loadbearing material.

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SOIL TESTS WATER CONTENT AND DRY DENSITY


Water content is determined with drying process in oven.

Water content ratio is current water content over dry

weight. Dry density is t/m3 or kg/m3 . Optimal dry density is

maximum dry density that ground can be concentrated.

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GROUND INSPECTION


SEISMIC METHOD

CONE PENETRATION TEST

GROUND INSPECTION


BORING

TRACK BED SEISMIC METHOD


TRACK BED SEISMIC METHOD


Seismic method is used in the examination of major

grounds. When appliying this examination speed of waves,

size of amplitude and decrease of amplitude is measured.

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TRACK BED BORING


Boring machine will bring to the

surface, soils that will be tested.

With these tests we get soil

proporties.

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TRACK BED CONE PENETRATION TEST


TRACK BED CONE PENETRATION TEST


With this method rigidity, strength and thickness can be

detected directly. There is a force required to pass different

layers. This force is a measure to bearing capacity. 28

GROUND STABILIZATION AND

GROUND IMPROVEMENT


GROUND IMPROVEMENT

GROUND STABILIZATION AND GROUND IMPROVEMENT


GROUND STABILIZATION

GROUND STABILIZATION AND GROUND IMPROVEMENT GROUND STABILIZATION


At the ground stabilization process, increasing the bearing

capacity of the ground must be provided by the addition of

binding materials.

Lime and cement can be used as a binding material.

If lime is used as binder, at least 40 cm thick layer of lime

should be used.

Above the lime layer, at least 20 cm protective layer must be

placed.

If cement is used as binder, cement layer must have thickness

at least 20 cm.

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GROUND STABILIZATION AND GROUND IMPROVEMENT GROUND IMPROVEMENT


At ground improvement process, suitability for

construction of ground and compressibility are improved.

Mechanical ground improvement is possible, when track

bed grain mix can be fixed with grains that have

appropriate size are added. This way ground should be

compressed better and should have better bearing

capacity.

Also ground improvement can be done with lime.

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CHEMICAL GROUND IMPROVEMENT


GROUND STABILIZATION WITH CEMENT

CHEMICAL GROUND IMPROVEMENT


GROUND IMPROVEMENT WİTH LİME

CHEMICAL GROUND IMPROVEMENT GROUND IMPROVEMENT WİTH LİME


Bearing capacity of clay is highly dependent on the water

content. When lime mixed to clay, clay will be drained.

Drained clay is hard and have high bearing capacity.

Ground improvement with lime is short term improvement.

Improvement of ground should be economic to be

meaningful. Lime must apply only with sandy gravel

protection layer and must have at least 20 cm thickness.

Adding lime to coarse-grained ground do not provide

improvement.

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CHEMICAL GROUND IMPROVEMENT GROUND STABILIZATION WITH CEMENT


Coarse-grained ground stabilization and

increasing bearing capacity of coarse-grained

ground can be done with adding cement. Cement

must be added to sandy or muddy ground for at

least 15 cm.

Before stabilization with cement at clay, lime must

be mixed to ground.

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TRACK BED


TRACK BED LAYERS

LAYER REQUIREMENTS

TRACK BED


CAUSES AND CONSEQUENSES OF TRACK BED FAILURES

38

TRACK BED

USAGE OF GEOTEXTİLE PRODUCTS

TRACK BED DRAINAGE

TRACK BED FAILURES

TRACK BED TRACK BED


Composed of ballast and ballast blanket and subbase.

Its purpose is to support the sleepers and dissipate the

forces applied by vehicles passing over the sleepers, and

to provide an elastic and uniform base.

Track bed and drainage infrastructure are required to

keep the ballast clean.

No build-up of water or mud in the ballast.

Layers have multiple layers with different materials and

properties.

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TRACK BED TRACK BED


Under the sleepers are known collectively as ‘Track

bed’.

This consists of the ballast, the ballast blanket and the

sub-grade.

The interfaces between the ballast and ballast blanket,

and between the blanket and sub-grade must be

inclined at 1/20 to allow water to flow towards the

nearest drainage line.

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TRACK BED TRACK BED LAYERS


TRACK BED TRACK BED DRAINAGE


In order to prevent accumulation of water on track bed;

Grass growth must be prevented,

Ballast should be cleaned and a cross slope should be

created,

Side slopes and drainage channels should be cleaned,

At sides, drainages should be done and drainages should

have control and ventilation funnels.

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TRACK BED LAYER REQUIREMENTS


Subballast, geosynthetic materials, subbase prevent fine

materials in infrastructure move up to inside ballast and

accumulation water in infrastructure.

Balast layer have slope with 1/20 rate to nearest drainage

channel.

In case of ballast layer or filler contains sand, average

pressure should not exceed 0.05 MN/m2 at layer contains

sand. Other granular materials can be rated for higher

pressures and geosynthetic layers (e.g. geotextile, geogrid,

geomembrane, geocomposite ) can be used. 43

TRACK BED LAYER REQUIREMENTS


In case ground movement is possible (seasonal

changes or changes in ground from quakes), in a

way that allow ground movements ( e.g. using

terracing layer ) should be designed.

Appropriate drainage systems, during the design

phase should be integrated into the track bed.

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USAGE OF GEOTEXTILE PRODUCT




Drainage lines should be sufficient and

clean.

Ballast should not be contaminated;

contaminated regions should be cleaned.

If subgrade stiffness is too low, a 3 m

wide geogrid should be placed below the

ballast.

• If the existing ballast blanket is functional < 50 mm thick in places

The blanket should be re-applied with a thickness ≥ 100 mm

and a ‘Separating Geotextile’ laid over; this should extend ≥ 0.70

m beyond the sleeper ends, and a crossfall of 1:20.

• If the existing ballast blanket is functional, < 100 mm thick in places

A ‘Separating Geotextile’ laid over; this should extend ≥ 0.70 m

beyond the sleeper ends, and a crossfall of 1:20



The function of geotextile material,

help to reduce tension and deformation,

increase bearing capacity

extend life of added layers.

Geosynthetic materials used between track bed and

ground.

Geotextile materials are placed on compressed and

improved track bed, and covered with a protective

material.

TRACK BED TRACK BED FAILURES


Soils formed of same material, as sand, sand move to

surface of travers from inside ballast result of vibration.

At nonadhesive or less adhesive grounds result of

dinamic loading track bed and ground become loose

and this causes cracks and crack regions.

Muddy grounds, when weather rainy track bed

fluctuates and during muddy ground be subjected to

load changes, move to surface of ballast, it causes

water accumulation and under sleepers ballast subside.

Line immediately decomposes at rainy weather and at

dry weather line stabilizes again quickly.

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TRACK BED TRACK BED FAILURES


At very adhessive grounds and grounds become tight due

to load changes, pitting occurs under sleepers, ground

swells under and between sleepers in direction of side

road. On this grounds when weather is rainy mud is

pumped to surface of ballast from sides of sleepers. This

shape changes in ground occur both in rainy and dry

weather, and it occurs very slowly.

At grounds with equal size of sand, losses can occur with

wind erosion. At very adhesive grounds at drought times

cracks occur due to become dry and shrinking, specially

warm climates at rainy times, swells can occur due to

wetting.

49

TRACK BED CAUSES AND CONSEQUENSES OF TRACK BED FAILURES


Causes of track bed failures;

A bad ground, in other words a ground composed with

unsuitable ground types,

In case ground is remained under static and dynamic over

load,

Compressing track bed is not sufficient or track bed losses

volume,

When it rains or line remaines under flow drainage is not

sufficient,

High water level,

Cracks are formed dry fill with rain,

Using rail that has not sufficient carrying capacity

Using sleepers with over weight, and using sleepers with

over distance between.

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TRACK BED CAUSES AND CONSEQUENSES OF TRACK BED FAILURES


Consequenses of track bed failures;

Extra line works, regions should be passed slow

or repair works can be necessary

Nonrigid grounds are over loaded under traffic

load, rail steel fatigues early and rail’s working life

shortens.

51

DRAINAGE SYSTEMS


SURFACE DRAİNAGE SYSTEMS

MAİNTENANCE OF DRAİNAGE COMPONENTS

DRAINAGE SYSTEMS


SUBSURFACE DRAİNAGE SYSTEMS

DRAINAGE SYSTEMS SURFACE DRAİNAGE SYSTEMS


• Cess drainage systems

Cess drains are surface drainage systems located at formation level at

the side of tracks, to remove water that has percolated through the

ballast and is flowing along the capping layer towards the outside of

the track formation. They are most frequently found in line sections

where water running off the trackbed cannot freely drain away. Cess

drainage systems are constructed with a slope of at least 1/200. This is

to facilitate cleaning of sediment that may deposit in drains.

DRAINAGE SYSTEMS SURFACE DRAİNAGE SYSTEMS


• Catch drainage systems

These drainage systems

are also named top

drainage systems or surface

drainage systems. The

purpose of such drainage

systems is to intercept water

flow by means of

embankments or obstacles

in order to stop it before it

reaches the track.

These drainage systems can be lined with geosynthetic materials or

instead of geosynthetic materials, pipes with semilunar holes or

trapeze-section ducts can be used, depending on the condition of local

soil. This type of drainage system may also be used on the uphill side of

embankments, and remove water and prevent ponding at the base of

embankments.

DRAINAGE SYSTEMS SUBSURFACE DRAİNAGE SYSTEMS


• Functions of subsurface drainage systems

Collection of infiltration water that seeps into the platform

Lowering underground water level



• Functions of subsurface drainage systems

Collection of water leakages at an impermeable boundary



• Types of subsurface drainage systems

Transverse drainage systems

Drainage blankets

DRAINAGE SYSTEMS MAİNTENANCE OF DRAİNAGE COMPONENTS


Channel Drains and Ditches: common problems and their remedies

Problem Cause Remedy

Blockage Stone fall Clean out, line and reprofile.

Vegetation Overgrowth

Collapse

Collapsing drainage channel

Scour

Improve the channel:

preserve cross-section

reduce maintenance

Protect against bank erosion on

slopes by using 500 mm wide grass

strips.

On steep slopes, reduce the flow

velocity using baffles.

Burrowing animals Control vermin and fill burrows.



Catchpits and Manholes: common problems and remedies


Silting Normal operation

Clean out by

a. hand excavation

b. mechanical jetting or vacuuming

Blockage

Balast

girmesi

Chambers

filled or buried

Damaged or missing

covers

Poor ballasting

practices

Increase frequency of cleaning or

remove ballast in sump and replace

damaged or missing covers to keep ballast

out

raise Catchpits before ballast drops

and/or clean chambers on completion of

track work

Collapse

Damage by ground

movement or on-track

plant

Rebuild Catchpit/Manhole



• Maintenance and cleaning of drainage pipes

The cleaning of pipes should always start from the lower end or

outfall. This is because flooding can occur if pipes at a higher level

are cleaned first. Cleaning can be undertaken by pressure jetting,

rodding or by winching a drain cleaning device (commonly known

as a ‘badger’) through the pipe. The removal of silt through drains

can result in the pipe collars or holes of drainage pipes becoming

blocked. The roots of hedges and/or trees growing in close

proximity to a drain can penetrate pipes in search of moisture. It

might be necessary to use pressurized water or air equipment to

remove roots.



Table 3: Piped Collector Drains: common problems and their remedies


Blockage of filter

media

Wet Beds

Ballast attrition Dig out and replace filter surround

Hydraulic

Uneven pipe

gradient from

disturbance of formation Upgrade/relay drainage before renewing

Track Support System

Replace filter surround to improve

drawdown from Track Support System and

prevent formation of Wet Beds Inadequate capacity

for Catchment runoff



Carrier Drains: common problems and their remedies

Problem Cause Remedy (depending upon severity)

Blockage

Capacity reduced by ingress of ballast or silt,

crushed pipes, poor pipe alignment

Rodding: by hand for clearing of small local

blockages and locating larger obstructions

Open excavation: dig up pip, clean out/ repair/

replace

Water jetting: on-track plant ranging from road-

railers to drain trains

Winching: relies on ability to pass cable through

pipe

Root intrusion

Vegetation management to restrict spread of trees

and:

Cutting and cleaning roots

Pipe replacement

Partial collapse Major pipe cracking or deformation

Holes and collapses of less than one pipe length Local open cut repair and/or replacement

Complete collapse Structural failure of more than one pipe length Renew by open cut

Hydraulic insufficiency

Poor fall or pipe alignment

Replace filter surround to improve drawdown from

track and prevent formation of Wet Beds

Relay drains

Inadequate pipe capacity

Relay by open cut or increase diameter of pipe;

size is a compromise between flow capacity and self-

cleansing velocity



Culverts: common problems and remedies Problem Cause Remedy (depending upon severity)

Blockage

Debris Check/ clear Trash Screen

Silt

Clear non-man entry Culverts by

rodding, drag scraping, or water jetting

Clear non-man entry Culverts by water

jetting, hand excavation, drag scraping or,

if sufficient headroom, by mini digger

Remove obstructions from downstream

body of water

Rubbish or trash Fit Trash Screens

Structural

General deterioration

Local repairs; replace missing bricks/

repoint mortar joints

Fill voids/ repair lining

Scour voids

Reline conduct

Extend headwall or training walls,

flumes and connection channels

Collapse Reconstruct

Insufficient flow

capacity

Change in upstream Catchment

Outlet smaller than inlet Remediation to increase capacity



Siphons: particular problem and its remedy

Problem Cause Remedy (depending upon severity)

Blockage

Dry weather flow

velocity insufficient for

self-cleansing

Seek advice from the appointed engineer

before commencing any work on siphons

Common problems and remedies

Problem Cause Remedy (depending upon

severity)

Structural

General deterioration Local repairs: replace missing

bricks/ repoint mortar joints

Wear, tear

Extend headwall or training

walls, flumes and connection

channel

Blockage Seized flap valve Repair or replace valve

TUNNEL GAUGE


TUNNEL GAUGE

LOADİNG GAUGE

TUNNEL GAUGE


CONSTRUCTION GAUGE

TUNNEL GAUGE TUNNEL GAUGE


TUNNEL GAUGE CONSTRUCTION GAUGE


TUNNEL GAUGE LOADİNG GAUGE


BRIDGES, CULVERTS, VIADUCTS


BRIDGES

VIADUCTS

BRIDGES, CULVERTS, VIADUCTS


CULVERTS

BRIDGES, CULVERTS, VIADUCTS BRIDGES


It is called bridge that built to cross rivers, roads, railway or

similar barriers, not under fill, and the total length of 8 m. or

larger structures.

Clear Span : The remaining horizontal distance between bridge

piers.

Total Length : The horizontal distance between starting point

and endpoint of bridge.

BRIDGES, CULVERTS, VIADUCTS BRIDGES


BRIDGES, CULVERTS, VIADUCTS CULVERTS


Bridges that have total length under 8 m and regardless of

total length structures under fill.

75

BRIDGES, CULVERTS, VIADUCTS VIADUCTS


Bridges are made to pass deep valleys or lands have very

high filling cost, and avoid risks that are produces by high

filling.

76

BRIDGES, CULVERTS, VIADUCTS VIADUCTS


infrastructure

Documents

ideal soil ideal soil

poor soil poor soil

peat soil

ideal soil strong

soils proportions soil

soils organic soils

finegrained soils

water ratio