In retaining and breast walls weep holes are provided at 100 cm vertical height

In retaining and breast walls weep holes are provided

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In retaining and breast walls, weep holes are provided at 100 cm vertical height and 120 cm center to center horizontally According to Highway Research Board of U.S.A. practical land width, is 3.6m As per recommendations of I.R.C., traffic volume study is carried out for rural roads for 7 days continuously during harvesting and lean season According to the recommendations of Nagpur Conference, the width formation of an ideal National Highway in hard rock cutting, is 7.9 m On the recommendations of Nagpur Conference, the minimum width of a village road may be2.45 m Minimum radius of curvature of National Highways or State highways in hill region free from snow, is kept 50m On the recommendations of Indian Road Congress, the ruling gradient in plains, is 1 in 30 Roadway width for a National highways and State highways (two-lanes) is 12 m The minimum width of the pavement of a National Highway should be 5.7 m 13 | P a g e
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The normal road land width for a major district road in open area, is 25 m The normal road land width for a National or State highway, in open areas should be 45 m Minimum permissible speed on high speed roads, is decided on the basis of 15 percentile cumulative frequency Speed regulations on roads is decided on the basis of 85 percentile cumulative frequency The wall constructed for the stability of an excavated portion of a road on the hill side, is known as breast wall The wall constructed for the stability of a back-filling portion of a road on the downhill side, is known as retaining wall Parapet walls along hill roads, are provided to prevent the wheels of the vehicle from coming on the retaining wall When each particle of aggregates is thinly coated with cement paste, a heterogeneous solid is formed, which is known as concrete When load is applied on concrete pavement on the edges, the maximum stress is parallel to the edge of the slab Design of horizontal and vertical alignments, super-elevation, sight distance and grades, is worst affected by speed of the vehicle Raising of outer edge of a road with respect to inner edge, is known, super elevation, cant and banking If no super elevation is provided on a road along curves, pot holes may develop at outer edge of the road The most commonly adopted method to provide super-elevation on roads, is by pivoting the road surface about inner edge so that outer edge is raised Hill roads are seldom provided a camber In scanty rainfall regions, the camber provided will be flatter On a pavement with parabolic camber, the angle of inclination of the vehicles will be more at the edges 14 | P a g e
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The convexity provided to the carriageway between the crown and edge of the pavement, is known as camber Excessive camber on pavements may cause deterioration of central portion, slip of the speedy vehicles towards the edges and erosion of the berms Before providing super-elevation on roads, the portion of the carriageway between the crown and the outer edge is made to have slope of the camber on the other half of the carriageway
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