HIGHWAY Engineering IRC 2020 draft PPT .pptx

HIGHWAY Engineering IRC 2020 draft PPT .pptx

• 1.
  A presentation on “IRC :73 -2020 Draft” Guided By: Dr. V. Sairam SANJIVANI COLLEGE OF ENGINEERING, KOPARGAON DEPARTMENT OF CIVIL ENGINEERING Group Members : Saurabh Bachkar (24) Pratik Gade (28) Gaurav Gadekar (29) Pramod Gambhire (30)
• 2.
  CONTENT • Introduction • FunctionalClassification of Non-Urban Roads • Factors controlling design of various geometric elements • RIGHT-OF WAY • Building Line Control line • Sight Distance • Setback distance on horizontal curve • Formulae (OSD, SSD, Superelvation) • Definitions and Notations • Dynamics of Motion of a Vehicle on a Curve • Transition curve • Types of Vertical Curves
• 3.
  Introduction  Over theyears, many changes have taken place in the geometric design standards as well as in the design concepts of non-urban highways (Rural Highways).  The revision of IRC: 73-1980 “Geometric Design Standards for Rural (Non- Urban) Highways” was, thus, discussed during the first meeting of Transport Planning & Traffic Engineering (H-1) Committee at IRC Bhawan, R.K. Puram, New Delhi in May, 2018.  The ambitious task of revising IRC: 73-1980 included merging the following codes in unison. • IRC: 73-1980 “Geometric Design Standards for Rural (Non-Urban) Highways” • IRC: 66-1976 “Recommended Practice for Sight Distance on Rural Highways” • IRC: SP: 23-1983 “Vertical Curves for Highways” • IRC: 32-1969 “Standard Vertical & Horizontal clearances of overhead electric power & telecommunication lines as related to roads”
• 4.
  Functional Classification ofNon-Urban Roads • Non-urban roads in India are classified into following five categories based on location and function according to Nagpur road plan:- 1. National Highways (NH) 2. State Highways (SH) 3. Major District Roads (MDR) 4. Other District Roads (ODR) 5. Village Roads (VR)
• 5.
  Classification of Non-UrbanRoads NATIONAL HIGHWAYS • These are the important roads of the country. • They connect state capitals, ports and foreign highways. They also include roads of military importance. • They are financed by the central government. STATE HIGHWAYS • These are the important roads of a state. • They connect important cities and district head quarters in the state , national highways & state highways of neighboring states. • They are financed by state government roads and buildings department of the state government constructs & maintain constructs and maintain these roads.
• 6.
   THE MAJORDISTRICT ROADS They are roads connecting district head quarters, taluka head quarters and other important town in the district production and market centers with each other and with state , national highways & railways. DISTRICT ROADS • These are the roads within a district . • They are financed by zillaparishads with the help of grants given by state government. OTHER DISTRICT ROADS AND VILLAGE ROADS • They are district roads of less importance.  VILLAGE ROADS they connect villages with each other and to the nearest district road. They are financed by panchayats with the help of zilla parishads and state government.
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  Factors controlling designof various geometric elements  Topography • The next important factor that affects the geometric design is the topography. • It is easier to construct roads with required standards for a plain terrain. Table:-Terrain Classification
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  Design Speed • Designspeed is the single most important factor that affects the geometric design. • It directly affects the sight distance, horizontal curve, and the length of vertical curves. Table:- Design Speeds
• 9.
  • Other Factors •Design Vehicles :The dimensions, weight of the axle and operating characteristics of a vehicle influence the design aspects such as width of the pavement, radii of the curve, clearances, parking geometrics etc. • Human: The important human factors that influence geometric design are the physical, mental and psychological characteristics of the driver and pedestrians like the reaction time. • Traffic: It will be uneconomical to design the road for peak traffic flow. Therefore a reasonable value of traffic volume is selected as the design hourly volume which is determined from the various traffic data collected. The geometric design is thus based on this design volume, capacity etc. • Environment: Factors like air pollution, noise pollution etc. should be given due consideration in the geometric design of roads. • Economy: The design adopted should be economical as far as possible. It should match with the funds alloted for capital cost and maintenance cost.
• 10.
  RIGHT-OF WAY Sr. No. Road Classification Maximumright of way 1 2- Lane Highways 30 m 2 4- Lane Highway 60 m 3 6- Lane Highway 60 m 4 2- Lane Highways with Bypasses 45-60 m 5 2- Lane Highways in Open Areas (mountainous & Steep terrain) 24 m (18 m Exceptional) 6 2- Lane Highways in built up areas (mountainous & Steep terrain) 20 m (18 m Exceptional) Right-of-Way : Road land width (also termed the right-of-way) is the land acquired for road construction purposes and provision of utilities along the length of road Fig : Typical Cross Section for 2-Lane Highway (Plain/Rolling Terrain)
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  Fig . RoadLand Boundary, Building Lines and Control Lines for a Typical Roadway Building Line & Control line
• 12.
  SIGHT DISTANCE  Typesof sight distance • Stopping Sight Distance : It is the clear distance ahead needed by a driver to stop his vehicle before meeting a stationary object in his path on the road or any obstruction for which the driver may need to stop the vehicle. • Overtaking Sight Distance : The overtaking sight distance is the minimum distance on a highway open to the vision of the driver of a vehicle to overtake slow moving vehicles ahead that are travelling in the same direction safely against opposing traffic in opposite direction. • Intermediate Sight Distance : Intermediate sight distance (ISD) is defined as twice SSD
• 13.
  Setback distance onhorizontal curve Setback distance : Setback distance m or the clearance distance is the distance required from the centerline of a horizontal curve to an obstruction on the inner side of the curve to provide adequate sight distance at a horizontal curve. (a) When length of curve > Stopping Sight Distance (SSD) 𝑚 = − ( − ) cos 𝑅 𝑅 𝑛 𝜃 (b) When length of curve < Stopping Sight Distance (SSD) ′ 𝑚 = − ( − ) cos 𝜃 ′ + 𝑅 𝑅 𝑛 − 𝑆 𝐿𝑐 sin 𝜃 ′ 2
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  FORMULAE • Overtaking sightdistance(OSD) OSD=d1+d2+d3 i) d1=VB*t ii)d2=VB.T+2S iii)d3=VA*T • Stopping Site distance(SSD) S.D in M = lag dist. + braking dist. = Vt + V^2 /2gf S.D = [0.278 Vt + ( V^2 /254f) ] • Superelevation e + f =(V^2 / 127R)
• 15.
  Definitions and Notations Tangent Point (T.P. or P.T.) - The point where the straight alignment ceases and curvature begins. Also the point of reversal of curvature Draft-IRC: 73-2020 62  Horizontal Intersection Point (H.I.P.) - The point of intersection of the two straights tangents connected by curve.  Total Deviation Angle (Δ) - The external angle at the intersection between the tangents at the ends of a curve. This measures the total change of direction in the alignment of the route. This is also the central angle of the complete curve.  Apex Distance (ES) - The shortest distance from the apex to the curve.  Length of Transition (LS) - The full length of the transition curve connecting a straight length of road with a curve which may be circular or transitional.  Tangent Distance (TS) - The length of the straight between the apex (P.I.) and the tangent point of the curve (P.T. or T.P.)  Shift (s) - The displacement of a circular curve from the straight to provide room to introduce a transition curve between it and the straight.
• 16.
   Deviation Angleof Transition Curve (θS) – The tangent deflection angle for the end of the transition curve, i.e. the external angle between the straight and the tangent to the curve at the end of the transition.  Radius of Circular Curve (RC) –The radius of a transitional curve at the point where maximum designed super-elevation is reached.  Deviation and Central Angle of Circular Arc (ΔC) – Deviation angle or central angle of the circular part of a curve with a transition at either end. Fig. Elements of a Combined Circular and Transition Curve
• 17.
  Dynamics of Motionof a Vehicle on a Curve When a vehicle travels around a curve of constant radius at constant speed, it exerts radially an outward force known as the ‘Centrifugal force’. This centrifugal force (P) can be represented by 𝑃 = 𝑊𝑣2 / …(1) 𝑔𝑅 𝑃 = 𝑊𝑉2 /127 …(2) 𝑅 𝑃 𝑊 = 𝑣2 / …(3) 𝑔𝑅 Where, W = Weight of the vehicle v = Speed of vehicle, m/sec g = acceleration due to gravity = 9.8 m/sec Mathematically, it can be shown that the centrifugal ratio is equal to sum of super elevation and friction and hence the basic equation for this condition of equilibrium is 𝑒 + = 𝑓 𝑉2 /127 … (4) 𝑅 Where, V = Vehicle speed in kmph e = Super-elevation in meter per meter f = Coefficient of side friction between vehicle tyres and pavement R = Radius in meter
• 18.
  Design value ofSuper-Elevation Super- elevation required on horizontal curves should be calculated from the following formula. This assumes that centrifugal force corresponding to three fourth the design speed (by neglecting the lateral friction developed) is balanced by super-elevation. 𝑒 = 2 /225 𝑉 𝑅 Where, e = super-elevation V = speed in km/hr R = Radius in meter fig:-Super-elevated Pavement Section
• 19.
  TRANSITION CURVE  DefineTransition curve:-A track transition curve, or spiral easement, is a mathematically- calculated curve on a section of highway, or railroad track, in which a straight section changes into a curve.  Functions of transition curve in the horizontal alignment of highway:- a) To introduce gradually the centrifugal force between the tangent point and the beginning of the circular curve, avoiding sudden jerk on the vehicle b) To enable driver turn the steering gradually for his own comfort and security c) To enable gradual introduction of the designed super-elevation and extra widening of pavement (if any) at the start of the circular curve d) To improve the aesthetic appearance of the road.  Types of Transition Curves:- 1.Spiral (also called Clothoid) 2. Lemniscate 3. Cubic Parabol
• 20.
  TYPES OF VERTICALCURVES a) Summit curves:-Summit curves are identified by its convex shape. There are different combinations of grade lines which will result in a summit curve. fig:-Different Combinations of Grades Resulting in A Summit Curve b) Valley curves:-A vertical curve concave upwards is known as a valley curve.Combination of different grade lines (upward or downward) will result in different orientations of the valley curve. fig:-Types of Configurations of Valley Curve Based on Grade Line
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  THANK YOU