Highway and Railway Engineering Flashcards

Flashcards about Highway and Railway Engineering Module 4 and 5, including design criteria for both.

AASHTO

American Association of State Highway and Transportation Officials. It represents all five transportation modes: air, highways, public transportation, rail, and water, with the goal to foster the development, operation, and maintenance of an integrated national transportation system.

Highway Design Consistency

Clear information and guidance through road signs, avoiding abrupt changes, suitable for traffic volume, consistent alignment, grade and distance, pleasing to users, complete, simple for builders, low maintenance cost, and safe.

Road Network

Composed of various types of roads, each of which performs a particular service in facilitating vehicular travel between points of trip origin and destination.

Urban Roads

Roads characterized by use in principal arterial, minor arterial, collector, and local streets.

Rural Roads

Roads characterized by use in principal arterial, major arterial, minor arterial, collector, and local streets.

Road Function

Includes freeways for through movement, surface arterials for through movement and access, collectors for traffic movement to higher rank roads, and local roads for access to abutting land and local traffic movement.

Philippine Road System

Classified into national, provincial, city, municipal, barangay, tourism, and farm-to-market roads.

Highway Capacity

Maximum number of vehicles that are reasonably expected to pass a given point over a given number of time, measured in vehicles per hour (veh/hr).

Reaction Time

The period of time that elapsed before a muscular reaction occurs (component of the 2.5 seconds of Perception and Reaction Time).

Perception Time

Interval of time required before reaction begins (component of the 2.5 seconds of Perception and Reaction Time).

Design Hourly Volume (DHV)

Projected hourly volume that is used for design, a percentage of the expected ADT on the highway (the 30th highest hourly volume).

Design Speed

Speed determined for design and correlation of physical features of a highway that influences vehicles operation, maximum speed that can be maintained over a specified section of the highway.

Types of Terrain ; Level

Relatively flat - Horizontal and vertical sight distance are generally long and can be achieved without much construction difficulty or major expenses

Design Vehicle

Selected to represent all vehicles on the highway, used to determine critical design features such as radii at intersections and highway grades.

Principal Elements (Cross Section)

Pavement, travel lanes, shoulders, and median.

Marginal Elements (Cross Section)

Curbs, sidewalks, drainage channels and side slopes, traffic barriers, frontage roads, noise control, roadside control, pedestrian crossings, curb-cut ramps, bicycle facilities, bus turnouts and park and ride facilities.

Traffic Lane

Portion of the pavement allotted for the use of a single line of vehicles.

Cross Slope

Slope of the surface of a pavement measured at right angles to the horizontal alignment.

Crown

Highest point on the pavement.

Shoulder

Provides structural support to pavement, space for pedestrian and bicycle use, space for vehicles with mechanical difficulties, space for motorists to stop, space for evasive maneuvers, improved sight distances and highway capacity.

Median

Section of a divided highway that separates the lanes in opposing directions, to separate opposing traffic streams, prevent U-turns, enhance traffic flow safety, allows smooth turning of vehicles, installs traffic signs.

Grade Line

Longitudinal profile of the highway, showing how the centerline of the highway rises and falls, a series of straight lines connected by parabolic vertical curves.

Curb and Gutter

Raised structures that are used mainly to delineate pavement edges and pedestrian walks, to control drainage, improve aesthetics and reduce right of way.

Sidewalks

Provided where roadside and land development conditions affect regular pedestrian movement along a highway, suitable to the conditions, width depends on setting.

Guard Rails

Longitudinal barriers placed on the outside of sharp curves and at sections with high fills, to prevent vehicles from leaving the roadway.

Drainage Channels

Collect water and convey surface water from the highway right-of-way, should have adequate capacity and provide a smooth transition from the roadway to the back slope.

Side Slopes

Should be designed to enhance roadway stability and provide a reasonable opportunity for recovery for an out-of-control vehicle.

Traffic Barriers

Used to prevent vehicles that leave the traveled way from colliding with objects that have greater crash severity (flexible, semi-rigid, rigid).

Frontage Roads

Roads used to control access to nearby arterial highways, function as a street facility serving adjoining properties and maintaining traffic circulation on each side of the arterial.

Noise Control

Used to minimize the adverse effect that noise can have on people.

Roadside Control

Used by highway authorities to keep the full width of right-of-way unaffected for public highway purposes, used to minimize interference to through traffic movement.

Tunnels

Used in long, narrow terrain ridges, narrow rights of way, large intersection areas, railroad yards, or where right-of-way acquisition costs exceed the cost of tunnel construction.

Pedestrian Crossings

Safe access to all destinations, typical pedestrian generators and destinations include residential neighborhoods, schools, parks, shopping areas and public transit stops.

Island

Area between traffic lanes for control of vehicle movement or pedestrian refuge.

Curb-Cut Ramps

Needed to accommodate persons of disabilities, necessary to provide access between the sidewalk and the street at pedestrian crossings.

Bicycle Facilities

Vary, including bike paths or trails, bike lanes and shared roadways or bike routes.

Bus Turnouts

Minimum length of 60 m and maximum of 185 m, minimum width shall be 3.6 m, proximity to pedestrian concentration, offset stagger for turnouts on opposite sides of the road.

At-Grade Intersection

An intersection in which traffic is directed into definite paths is called a channelized intersection.

Interchange

A system of interconnecting roadways providing for the interchange of traffic between two or more intersecting highways, usually without at-grade crossings.

Technical Standards (Railway)

Classified as Compulsory Standards (Concrete, Steel, Earth, etc.) and Optional Standards (International, Regional, National, Group).

Main Line (Railway)

Track constantly used for train operation.

Siding (Railway)

Track other than a main line.

Station

Place used by passengers to get in and out of trains or for the loading and unloading of cargo.

Shunting Yard

Place mainly used for the shunting of rolling stock or the composition of a train.

Train

A group of rolling stock composed for operation on track outside a station, etc.

Signals

Objects indicating the operating conditions of a train, etc. to railway staff.

Cant

The shortest distance between the inner side surfaces of two rail heads of a track is measured.

Track And Civil Engineering Structures

Shall be determined to ensure the safety and security of the rolling stock and the railway facilities.

Vertical Curve (Railway)

Shall be introduced to prevent the derailing of rolling stock and prevent any unpleasant feeling on the part of passengers.

Contact Line

Part of the components of railway power facilities

Transportation Development Process

Includes nationwide systems planning, transportation programming, project evaluation, preliminary development phase and detail design phase.

Highway Plans

Contains engineering drawings of the project.

Highway Specifications

Written instructions and conditions considered as integral part of the contract between the contractor and highway agency classified as legal documents.

Engineering (Route) Survey

Stages consist of locating the center line, determining elevations, plotting the profile and cross sections, computing earthwork volumes and staking out cuts and fills.

Sub-grade

Supporting structure on which the pavement surface and its special under-courses rest; the earth beneath the road.

Sub-base

Layer of granular material provided above sub-grade generally natural gravel.

Base Course

Layer on top of the sub-grade consists of crushed stone or gravel, sometimes mixed with asphalt binders.

Pavement / Surface

Also called Wearing Course. Material laid over the base course consisting of Asphalt Concrete or Portland Cement Concrete, in direct contact with the wheels of vehicles.

Granular Base Course

Road surface of untreated soil mixture – Gravel Road, consisting of soil particles ranging in size from coarse to fine.

Treated Base Course

Compose of mineral aggregate and additive to make them strong or more resistant to moisture, using Bitumen/Asphalt, Cement, or Lime as binders.

AASHTO standard specifications

Requires maximum Liquid Limit of 35 and a Plastic Index of 4 to 9 and a maximum 8% passing the No. 200 sieve.

Soil Cement

Stabilized cement mixture, subdivided into sandy and gravelly soil, sand, and silty and clayey soils.

Sequence Of Improvement

1. Earth Road Surface,
   2. Untreated Gravel Road,
   3. Application of Asphalt over the Gravel,
   4. Use of Stone type Pavement with Gravel (Base).

DPWH 200 Aggregate Sub-base Course

Consists of furnishing, placing, and compacting aggregate sub-base course on a prepared sub-grade (Item 200).

Concrete Quality Control Plan

The contractor shall furnish the engineer a Quality Control Plan detailing the production control procedures and the type and frequency of sampling and testing to insure that the concrete produced complies with the specifications

DPWH 201 Aggregate Base Course

Materials passing the 20mm shall have a soaked CBR value of not less than 80% (Item 201).

DPWH 202 Crushed Aggregate Base Course

The portion passing the 0.075 mm sieve shall not be greater than 0.66 of the portion passing the 0.425 mm sieve (Item 202).

DPWH 203 Lime Stabilized Road Mix Base

Consists of foundation for a surface course composed of soil aggregate, lime and water mixed on the site and constructed on a prepared sub-grade (Item 203).

Pavement

Portion of a road or highway, placed above the subgrade, specifically for the support of and to provide a running surface for vehicular traffic.

Bitumen

A black viscous mixture of hydrocarbons obtained naturally or as a residue from petroleum distillation

Functions of Pavement

Provide reasonable riding surface, durable and dust-free surface, visual definition of road ahead, skid resistance, prevent water ingress, distribute wheel loads.

Flexible (asphalt) Pavement

Pavement structure bends or deflects due to traffic loads, generally composed of several layers of materials which can accommodate this flexing.

Rigid (concrete) Pavement

Composed of a PCC surface course, substantially stiffer than flexible pavements due to the high modulus of elasticity of the PCC material. Can have reinforcing steel.

Gravel Pavement

Presents a smooth riding surface, resists wearing, raveling and corrugation, possesses adequate tire / soil friction.

Bituminous Surface Course

Mixture of mineral aggregates and bituminous materials, placed as an upper course and usually constructed on a base course.

Bituminous Prime Coat

Application of low-viscosity cutback bituminous asphalt to an absorbent surface to bind the granular base to the asphalt layer.

Bituminous Tack Coat

Very light application of bituminous asphalt, usually asphalt diluted with water, to ensure a bond between the surface being paved and the overlying course.

Sub-base Course

Granular Material that prevents intrusion to the sub base, prevents a working platform, accumulation of fine grain.

Pavement Slab

May be constructed with or without reinforcement, may be designed as continuous or jointed structural elements.

Materials Used In ITEM301 Bituminous Prime Coat

Rapid Curing (RC) or Medium Curing (MC) Cutback asphalt, applied only to dry or slightly moist surface, during a non foggy or rainy day (DPWH Item 301).

Materials Used In ITEM302: Bituminous Tack Coat

Rapid Curing Cutback or Emulsified Asphalt within the range of 0.2 to 0.7 liters per m2 applied to the surface course to permit it to dry (DPWH Item 302).

Factors of Asphalt Binder For Base Course

Type of load, traffic volume, climate conditions, and road materials can be used for base course

Bituminous Treatment

single application of bituminous material followed by a single spreading of aggregate or two applications.

ITEM305: Bituminous Penetration Macadam Pavement

Consists of one or more courses of graded aggregate and one or more application of bituminous materials, followed by Seal Coat cover aggregate constructed on a prepared base DPWH (Item 305).

ITEM306: Bituminous Surface Course (Equipment and Prep)

Use a bituminous distributor, heating equipment, scarifier, mixer, and compactor. Existing base is scarified lightly and bladed to a uniform grade and cross-section, and may includes salvaged aggregates. DPWH Item 306

New Road Performance Factors

Traffic, subgrade Strength, quality of Construction, Material, and water

Stages in Designing New Roads

Assess Loading, Support and Design (Thickness, structure)

Geoplastic Fabrics

Used to reinforce soil of pavement; provide drainage; and erosion control for highway and railroads, made of Polypropylene and Polyester.

Functions of geoplastic Fabric

Filter Drainage Separator Reinforcement

Drainage. Provide channels for carrying water away from the soil to the drain

Separator Prevent different materials from mixing

Reinforcement. Adds mechanical strength to the soil of the pavement structure

Armor. Protects the soil from surface erosion or the attractive force

Types Of Cements

Could be used in combo with Portland Concrete, Hydraulic, and Polymer.

ASTM C150 - Type 1 Portland

General construction, making of precast and prestressed concrete that isn't in contact with groundwater and or soils.

ASTM C150 - Type 2 Portland

Has Moderate Sulfate Resistance, suitable for construction projects that have the cement being exposed to groundwater (pavement and drainage systems)

ASTM C150 - Type 3 Portland

High Early Strength Cement, used when the forms are to be removed right away or if it needs to be of service directly

ASTM C150 - Type A Portland

greater thaws and freeze resistance to cement as it will prevent cracking with large variances in temp.

ASTM C150 - Type 4 Portland

Low heat of hydration, releases heat slow during setting, used in large structure projects (dams).

EN 197 1

Portland Cement Contains cement and up to 5% of minor additional constituents

Deterioration

The changes the concrete went through brought about stress.

Distortion Deterioration

Vertical Displacement of concrete slab, related to failure or weakness of concrete.

Cracking Deterioration

Resulted as applied load, or temperature, or moisture changes, or corner cracks.

Disintegration Deterioration

Scaling Spalling from related to the mix or construction problem.