HRE terms Flashcards
The cross section of a typical highway has latitude of variables to consider such as:
- The volume of traffic.
- Character of the traffic.
- Speed of the traffic.
- Characteristics of motor vehicles and of the driver
A cross section design generally offers the expected level of service for safety and a recent study showed that:
- A 7.20 meters wide pavement has l8% less accident compared with pavement narrower than 5.50 m. wide.
- A 7.20 meters wide pavement has 4% fewer accidents than the 6.00 meters wide roadway.
- Accident records showed no difference between the 6.60 meters and the 7.20 meters wide pavement.
- For the 6.00 m., 6.60 m. and,7.20 meters wide pavement with 2.70 to 3.00 m. wide shoulder, recorded accident decreases by
30% compared to 0 to .60 m. wide shoulder. And 20% compared with a .90 to 1.20 meters wide shoulder.
is needed in estimating the amount of cut or fill needed for a given strip of roadway.
Cross-sectional data
distance at which a driver of a vehicle can see an object of specified height on ht e road ahead, assuming adequate sight and visual acuity and clear atmospheric conditions.
sight distance
types of sight distances
- Stopping or absoulte minimum sight distance (SSD)
- safe overtaking (OSD) or passing sight distance (PSD)
- Safe sight distance for entering an intersection, Intersection Sight Distance
Minimum sight distance available on a highway at any spot should be of sufficient length to stop a vehicle traveling at design speed, safely without collision with any other obstruction.
It depends on
a. Feature of road ahead
b. Height of driver’s eye above the road surface (1.2m)
c. Height of the object above the road surface (0.15m)
Criteria for measurement
a. Height of driver’s eye above road surface (H)
b. Height of object above road surface (h)
Stopping or absolute minimum sight distance (SSD)
Factors affecting SSD
- Total reaction time of driver
- Speed of vehicle
- Efficiency of brakes
- Frictional resistance between road and tire
- Gradient of road
It is the time taken from the instant the object is visible to the driver to the instant the brake is effectively applied.
total reaction time of driver
It is the time from the instant the object comes on the line of sight of the driver to the instant he realizes that the vehicle needs to be stopped.
perception time
The brake reaction also depends on several
factor including the skill of the driver, the type of the problems and various other environment factor. Total reaction time of driver can be calculated by “PIEV” theory.
brake reaction time
PIEV theory
P - perception
I - intellection
E - emotion
V - volition
is the sum of lag distance and the braking distance
SSD
The distance the vehicle travelled during the reaction time
lag distance
Distance travelled by the vehicle after the application of brake.
breaking distance
The minimum distance open to the vision of the driver of a vehicle intending to overtake slow vehicle ahead with safety against the traffic of opposite direction
minimum overtaking sight distance (OSD)
or the safe passing sight distance
analysis of SSD
lag distance
breaking distance
Clear sight triangle must be free of sight obstructions such as
- buildings
- parked or turning vehicles
- trees
- hedges
- fences
- retaining walls
- actual ground line.
in 1824, he carried out the pioneering work developing steam energy
Nicolas Carnot
in 1804, he designed and constructed a steam locomotive
Richard Trevithick
in 1814, he produced the first steam locomotive used for traction in railways
George Stephenson
in 1825, Recorded first public railway in the world was opened to public, between
Stockholm and Darlington
in 1833, First railway line in USA between
Mohawk and Hudson
in 1835, First railway in Germany was opened
from Nuremberg to Furth
in 1875, he promulgated a Royal Decree directing the Office of the Inspector of Public Works of the Philippines to submit a general plan for railroads on Luzon
King Alfonso XII of Spain
What was the plan King Alfonso XII proposed?
Memoria Sobre el Plan General de Ferrocarriles en la Isla de Luzón.
When was the first tracks laid?
1891
1892 –Openned for commercial use, from
Ferrocarril de Manila to Dagupan
how may were operational after the war.
only 452 km
In 2021, how many route kilometers remain operational?
only 129 km
Ongoing rail projects
- LRT 1 cavite extension
- LRT 2 east extension
- MRT 7
- Metro Manila Subway Projects
- North South Commuter Rail Project
- Mindanao Railway System
it is expected to reduce the travel time between Baclaran and Bacoor to around 20 minutes from the usual one hour.
LRT 1 cavite extension
to add new stations: Marikina-Pasig and Antipolo
LRT 2 East Extension
elevated railway from North Ave. to SJDM, Bulacan. Expected to serve 350,000 daily commuters.
MRT 7
expected to serve 370,000 daily passengers.
Metro Manila Subway Project
Clark-Calamba Railway, expected to be full operational by 2025
North South Commuter Rail Project
–Phase 1 construction expected to begin Q4 in 2021
Mindanao Railway System
The gradients of railways tracks are ____________, and curves are _______
- flatter (normally not more than 1 in 100)
- limited up to only 10° on broad gauge.
are constructed normally with steeper gradients of up to 1 in 30 and relatively much sharper curves.
Roads
are best suited for carrying heavy goods and large numbers of passengers overlong distances.
railways
is best suited for carrying lighter goods and smaller numbers of passengers over shorter distances.
road transport
are the members of the track laid in two parallel lines to provide an unchanging, continuous, and level surface for the movement of trains.
rails
Functions of Rail
- Rails are similar to steel girders. These are provided to perform the following functions in a track.
- Rails provide a continuous and level surface for the movement of trains.
- Rails provide a pathway which is smooth and has very little friction.
- Rails serve as a lateral guide for the wheels.
- Rails bear the stresses developed due to vertical loads transmitted to them through axles and wheels of rolling stock as well as due to braking and thermal forces.
- Rails carry out the function of transmitting the load to a large area of the formation through sleepers and the ballast.
is defined as the minimum distance between two rails.
gauge
is measured as the clear minimum distance
between the running faces of the two rails
rail gauge
are the transverse ties that are laid to support the rails.
sleepers
They have an important role in the track as they transmit the wheel load from the rails to the ballast.
sleepers
Functions of Sleepers
- Holding the rails in their correct gauge and alignment
- Giving a firm and even support to the rails
- Transferring the load evenly from the rails to a wider area of the ballast
- Acting as an elastic medium between the rails and the ballast to absorb the blows and vibrations caused by moving loads
- Providing longitudinal and lateral stability to the permanent way
- Providing the means to rectify the track geometry during their service life.
is the number of sleepers per rail length.
sleeper density
-It normally used as the initial ballast in new constructions and as sub-ballast.
moorum ballast
– used primarily for cast iron rails.
coarse and ballast
normally used in yards as initial ballast in new constructions since it is very cheap
coal ash cinder
made from hard stones, normally used for high- speed tracks.
broken stone ballast
functions of ballast
- Provides a level and hard bed for the sleepers to rest on.
- Holds the sleepers in position during the passage of trains.
- Transfers and distributes load from the sleepers to a large area of the formation.
- Provides elasticity and resilience to the track for proper riding comfort.
- Provides the necessary resistance to the track for longitudinal and lateral stability.
- Provides effective drainage to the track.
- Provides an effective means of maintaining the level and alignment of the track.
Fish plates, combination fish plates, bolts, and nuts
for joining rail to rail
Cast-iron bearing screws, plate screws, pandrol clifts, rubber pads
for joining rails to sleepers
Track fittings and fastenings
- for joining rail to rail
- for joining rails to sleepers
Track components
- ballast
- sleepers
- rails
are foundational structures and systems for transporting people and goods.
transportation infrastructures
Common Types of Transportation
Infrastructures
➢ Roads
➢ Railways
➢ Bridges and Tunnels
➢ Ship Canals
➢ Ports
➢ Airports Runways
Roads Failure Causes
➢ Rutting due to high variation in ambient temperature
➢ Uncontrolled heavy axle loads
➢ Inadequate Stability
➢ Loss of binding action
➢ Poor Design and Fabrication
➢ Congestion
➢ Environmental Hazard (Flood, Earthquake etc.)
➢ Accidents
➢ Poor Maintenance
four major types of pavement failure
- cracking
- Surface deforming
- disintegration
- surface defects
Cracking
➢ Fatigue Cracking
➢ Longitudinal Cracking
➢ Transverse Cracking
➢ Block Cracking
➢ Slippage Cracking
➢ Reflective Cracking
➢ Edge Cracking
Surface Deformation
➢ Rutting
➢ Corrugations
➢ Shoving
➢ Depressions
➢ Swell
Disintegration
➢ Pot Holes
➢ Patches
Surface Defects
➢ Ravelling
➢ Bleeding
➢ Polishing
➢ Delamination
Types of Road Maintenance
- Surface maintenance
- Roadside and drainage maintenance
- Shoulder and approaches maintenance
- Snow and ice control
- Traffic service
Includes restoring or betterment of roadway such as resurfacing.
rehabilitation
Including painting pavement markings, removing snow ice and litter
traffic service activities
Activities such as sealing, patching, filling joints etc.
physical maintenance
Railways Failure Causes
➢ Impact of moving loads
➢ Effect of acceleration and deceleration
➢ Constant reversal of stresses
➢ Defects in manufacture
➢ Braking of wheels
➢ Fatigue caused by shearing stresses
➢ Effect of weather and Temperature
➢ Maintenance of rail joints
➢ Axle load of locomotive
➢ Design of rail joints
➢ Frequency of rail renewal
➢ Corrosion
➢ Poor Maintenance
Type of Railway Failures
- Crushed Head
- Transverse and Compound Fissure
- Split Head
- Horizontal Fissure
- Square of Angular Breaks
- Rail Misalignment
Railway Maintenance and Rehabilitation Includes
- Ballast Checking
- Lubricating Places such as curves on the side
of the head of the rails - Tightening of joints and Fittings
- Use of special alloy rails where wear is more
- Renewal of Rails
is a structure to cross an open space or gap.
bridges
are mostly made for crossing rivers, valleys, or roads.
bridges
is an underground passageway, dug through the surrounding soil/earth/rock and enclosed except for entrance and exit, commonly at each end.
tunnel
Bridge and tunnels failure causes
➢ High variation in ambient temperature
➢Uncontrolled heavy axle loads.
➢ Inadequate Stability
➢ Effect of seawater/water especially to the bridge columns
➢Inadequate ground Investigation
➢ Poor Design and Fabrication
➢ Congestion of Vehicles
➢ Environmental Hazard ( Flood, Earthquake, Tsunami etc.)
➢ Accidents (Car crash, Boat Crash, Train Crash etc.)
➢ Inadequate Support method of excavation
Type of Bridge and Tunnel Failures
- steel materials
- Concrete material
- expansion joint
- drainpipe
expansion joint
✓ Abnormal Spacing
✓ Difference in Level
✓ Rupture
✓ Drainage Blocked
concrete material
✓ Collapse
✓ Spalling
✓ Wear/Abrasion
✓ Material Deterioration
✓ Surface Defect
✓ Delamination
✓ Water Leak at Deck
steel materials
✓ Corrosion of Steel
✓ Paint Deterioration
✓ Loose Connections
bridge and tunnel maintenance and rehabilitation includes
❖ Exposed steel work must be cleaned and repainted
❖ Cleaning and resealing of Deck joint
❖ Damage to guard rail, must be repaired and strengthened
❖ Resurfacing of deck
❖ Scour around and under piers and abutments should be removed
❖ Sealing, patching, filling joints and such.
❖ Checking of steel cables for corrosion.
❖ Checking of supports
is a maritime facility which may comprise one or more wharves where ships may dock to load and discharge passengers and cargo.
port
is a canal especially intended to
accommodate ships used on the oceans, seas or lakes to which it is connected, as opposed to a barge canal intended to carry barges and other vessels specifically designed for river and/or canal navigation.
ship canal
Ports and Ship Canal Failure Causes
➢ Poor Design and Fabrication
➢ High variation in ambient temperature
➢ Effect of seawater to the construction materials
➢ Severe Corrosion
➢ Congestion of Ships
➢ Environmental Hazard (Flood, Earthquake, Tsunami etc.)
➢ Accidents (Boat Crash)
➢ Poor Maintenance
types of ports and ship canal failures
- material deterioration
- damage of components
- scouring
- sedimentation
- collapsing of wharf or settlement of foundation
Ports and Ship Canal Maintenance and Rehabilitation includes
➢ Steel repair and painting
➢ Implementation of coatings for corrosion protection
➢ Epoxy injection into small Cracks on deck and supported beams
➢ Removal of plastered concrete and cleaning of surface
➢ Subject rebars replacement and re-concreting of damage section
➢ Placement of anti scouring devices.
Airport runways failure causes
➢ Poor Design and Fabrication
➢ High variation in ambient temperature
➢ Poor Maintenance
➢ Degradation
➢ Congestion of Aircrafts
➢ Environmental Hazard (Flood, Earthquake, Tsunami, Bird Strikes etc.)
➢ Accidents
types of Airport Runways Failures
- cracking
- surface deformation
- disintegration
- surface defects
- rubber deposits
means any work carried out to keep airports runways excellent condition, keep their operations running smoothly and meet the high safety standards
airport maintenance
Maintenance of Unpaved Areas
➢ Maintenance of green areas within strips
➢ Maintenance of grass on unpaved runways and taxiways
➢ Maintenance of green areas outside strips
➢ Treatment of cut grass
Maintenance of Visual Aids
➢ Airport Light maintenance
➢ Basic maintenance programme for approach, runway and
taxi way lighting systems
➢ Special types of lights
➢ Cleaning procedures for lights
➢ Light measurement
➢ Lamp replacement
signs
➢ Markings
Maintenance of Airport Electrical Systems
➢ Power cables and distributors in field
➢ Transformers and regulators (including standby units)
➢ Transformer stations for electric power supply
➢ Relay and switch cabinets (including switch cabinets in
sub-stations)
➢ Control cables, monitoring units, control desk
➢ Secondary power supplies (generators)
➢ Fixed 400 Hz ground power supplies
➢ Apron floodlighting
Maintenance of Pavements
➢ Surface repair
➢ Repair of cracks
➢ Portland cement concrete pavements
➢ Bituminous pavements
➢ Repair of joints and cracks
➢ Joints in concrete pavements
➢ Concrete joint maintenance
➢ Joints in bituminous pavements
➢ Repair of pavement edge damage
➢ Edge repair
➢ Corner repair
➢ Repair of other pavement
surface deficiencies
Airport Runways Maintenance and Rehabilitation Includes
- Maintenance of Visual Aids
- Signs
- Maintenance of airport electrical systems
- maintenance of pavements
- sweeping
- removal of snow and ice
- drainage
- Maintenance of unpaved areas
Sweeping
➢ Purpose of sweeping
➢ Surface monitoring
➢ Cleaning of surfaces
➢ Purpose of cleaning pavements
➢ Removal of rubber deposits
➢ Fuel and oil removal
Removal of snow and ice
➢ Procedures for snow removal
➢ Surface de-icing
➢ Surface anti-icing
drainage
➢ Cleaning of slot drains
➢ Drain pipes or culverts between surfaces and collector basins
➢ Oil and fuel separators
➢ Water hydrants
provides basis in measuring the operating performance of the highway
traffic analysis
Various dimensions used in traffic analysis
- Number of vehicle per unit time (traffic volume)
- Vehicle types and speeds
- Variation in traffic volumes over time (e.g., Peak Hour)
Other dimensions that influenced
traffic operations
- Traffic control device (i.e., traffic
signals, signs and markings) - Types of pavement and geometric
design - Selection of the number of lanes
Most used numerical dimensions of traffic flow
- Speed (km/hr)
- Flow/flowrate/volume (veh/hr)
- Density (veh/km)
is defined as the number of vehicles passing a point during a specified period of time.
flow rate
is defined as rate of motion in distance per unit time.
speed
two types of speed
- time mean speed
- space mean speed
is simply the arithmetic mean of the speeds of vehicles passing a point within a given interval of time.
Time Mean Speed / Spot Speed
is used to describe the rate of movement of a traffic stream within a given section of road. It is the speed based on the average travel time of vehicles in the stream within the section.
Space Mean Speed / Harmonic Mean Speed
is defined as the number of vehicles in a given length of road at an instant point in time.
density
is defined as the time interval between passage of consecutive vehicles at a specified point on the road with a unit of time per vehicles.
time headway
is the distance between two vehicles measure from the front bumper of a vehicle to that of another.
spacing
It can only be measure, however, if a detector is installed at a specific point on the carriageway. It is defined as the total time of a detector is occupied divided by the total time of observation.
time occupancy
is the most difficult variable to measure. It can be obtained indirectly using this relation.
density
three most importanat traffic variables
flowrate
space mean speed
density
a model that accounts for the non-uniformity of flow by assuming that the pattern of arrivals corresponds to some random process
poisson distribution
limitation poisson distribution model
- only applicable for lightly congested traffic conditions
- not appropriate for heavy traffic conditions particularly in urban areas where traffic signals cause cyclical stream distrubances
are conducted to establish a complete understanding of the travel patterns within the study area.
travel surveys
asks questions about each trip that is made on a specific day—such as where the trip begins and ends, the purpose of the trip, the time of day, and the vehicle involved (auto or transit)—and about the person making the trip—age,
sex, income, vehicle owner, and so on.
origin destination survey or O-D survey
used to determine the demand for and the supply of parking facilities in an area, the projection of the demand, and the views of various interest groups on how best to solve the problem.
parking studies
types of parking facilities
on-street parking facilities
off-street parking facilities
spaces along the side of public roads or streets
on-street parking facilities
These are also known as curb facilities.
on-street parking facilities
are provided alongside the curb on one or both sides of the street.
parking bays
These facilities may be privately or publicly owned; they include surface lots and garages.
off-street facilities
require that drivers park their own automobiles;
self-parking garages
maintain personnel to park the automobiles
attendant-parking garages
is a unit of parking that defines the use of a single parking space for a period of 1 hour.
space-hour
is the total number of vehicles that park in a study area during a specific length of time, usually a day.
parking volume
is the number of parked vehicles in a study area at any specified time. These data can be plotted as a curve of parking accumulation against time, which shows the variation of the parking accumulation during the day.
parking accumulation
is the area under the accumulation curve between two specific times. It is usually given as the number of space-hours used during the specified period of time.
parking load
is the length of time a vehicle is parked at a parking bay.
parking duration
is the rate of use of a parking space. It is obtained by dividing the parking volume for a specified period by the number of parking spaces.
parking turnover
comprehensive parking study usually involves
(1) inventory of existing parking facilities
(2) collection of data on parking accumulation, parking turnover and parking duration
(3) identification of parking generators
(4) collection of information on parking demand.
is a detailed listing of the location and all other relevant characteristics of each legal parking facility, private and public, in the study area.
inventory of existing parking facilities
collection of parking data
- accumulation
- turnover and duration
are obtained by checking the amount of parking during regular intervals on different days of the week. The checks are usually carried out on an hourly or 2-hour basis between 6:00 a.m. and 12 midnight.
accumulation data
This is done by recording the license plate of the vehicle parked on each parking space in the sample at the ends of fixed intervals during the study period.
turnover and duration
is used to correct for time lost in each turnover. It is determined on the basis of the best performance a parking facility is expected to produce.
effiiciency factor, f
Efficiency factors for curb parking, during
highest demand, vary from _____; for surface lots and garages, from _______
78 percent to 96 percent
75 percent to 92 percent.
Average values of f are ______ for curb parking, _______ for garages, and _______ for surface lots.
90 percent
80 percent
85 percent
may be categorized according to shape, type of structure, and type of operation.
intersections
This refers to the configuration of the intersection and would depend largely on the number of legs.
shape
Most of the intersections are either designed as _____________ such as flyovers or interchanges.
at-grade intersection or grade separation
type of structure
at-grade intersection
grade separation
type of operation
unchannelized
channelized
unsignalized
signalized
maximum number of legs
4
an angle of ___ must be considered as the minimum
60 degrees
turning geometry
direct
indirect
semidirect
trumpet
cloverleaf
design elements of an intersection approach
- left run storage bay
- through lanes
- exclusive right turn lane
- corner lane
- turning roadway
- median
- nose treatment
types of conflict
diverging
merging
crossing
(three leg)
diverging - 3
merging - 3
crossing - 3
(four leg)
diverging - 8
merging - 8
crossing - 16
methods of control of intersections
unsignalized
signalized
grade separation
grade separation or interchanges
trumpet
diamond
double trumpet
cloverleaf
used to describe the minimum gaps needed by drivers of minor road vehicles.
critical gap
is a layer of broken stones, gravel, or any other granular material placed and packed below and around sleepers for distributing load from the sleepers to the formation.
ballast
