In transport engineering, subgrade is the native material underneath a constructed road, pavement or railway track (US: railroad track). It is also called...

(sleepers, British English) and ballast (or slab track), plus the underlying subgrade. It enables trains to move by providing a dependable surface for their...

highway engineering, subbase is the layer of aggregate material laid on the subgrade, on which the base course layer is located. It may be omitted when there...

directly above this layer. Otherwise, it is built directly on top of the subgrade. Typical base course thickness ranges from 100 to 150 millimetres (4 to...

30. Hogentogler, C.A.; Terzaghi, K. (May 1929). "Interrelationship of load, road and subgrade". Public Roads: 37–64. Unified Soil Classification System...

The California Bearing Ratio (CBR) is a measure of the strength of the subgrade of a road or other paved area, and of the materials used in its construction...

pavers. The first layer in the construction of such a surface is called the subgrade—this is the layer of native material underneath the intended surface. It...

sub-ballast above a prepared subgrade/formation (see diagram). It is designed primarily to reduce the stress on the subgrade. Other definitions include...

borings are taken to determine the subgrade condition, and based on the relative bearing capacity of the subgrade, the specifications are established...

subgrade. When building a three layer flexible pavement, the subbase layer is not used and the base course is placed directly on the natural subgrade...

the ACR-PCR method is based on layered elastic analysis, uses standard subgrade categories for both flexible and rigid pavement, and eliminates the use...

England, patented "lava stone." This method involved spreading tar on the subgrade, placing a typical macadam layer, and finally sealing the macadam with...

perpendicular to the rails, ties transfer loads to the track ballast and subgrade, hold the rails upright and keep them spaced to the correct gauge. Railroad...

the land surface through which it passes, known to highway engineers as subgrade material.[citation needed] Terms similar to dirt road are dry-weather road...

airplane of a given weight on a pavement structure for a specified standard subgrade strength; The PCN, a number (and series of letters) representing the pavement...

the native subgrade. In areas with very soft or expansive subgrades such as clay or peat, thick gravel bases or stabilization of the subgrade with Portland...

surface layer will follow the crown established by the subgrade layer. Scarification of the subgrade layer prior to application of the surface gravel layer...

than a critical value and to keep the vertical strain at the top of the subgrade less than another critical value. With these two strains kept, respectively...

factors include heat and cold, the presence of water in the subbase or subgrade soil underlying the pavement, and frost heaves. High temperatures soften...

Natural features Topography Vegetation Terrain Topsoil Water table Bedrock Subgrade Subsoil Earthworks Shoring structures Retaining walls Gabion Ground freezing...

Natural features Topography Vegetation Terrain Topsoil Water table Bedrock Subgrade Subsoil Earthworks Shoring structures Retaining walls Gabion Ground freezing...

multi-layer system (e.g. asphalt concrete on top of a base course on top of the subgrade) based on surface deflections is known as "backcalculation", as there is...

Prolovic, Verka (2012). "Waste glass as additive to clayey material in subgrade and embankment of road pavement". Facta universitatis - series: Architecture...

recommended a roadway consisting of three layers of stones laid on a crowned subgrade with side ditches for drainage. The first two layers consisted of angular...

organisms compared to humus-rich topsoil. Ecology portal Soil Soil horizon Subgrade Parent rock Håkansson, Inge; Reeder, Randall C. (March 1994). "Subsoil...

Natural features Topography Vegetation Terrain Topsoil Water table Bedrock Subgrade Subsoil Earthworks Shoring structures Retaining walls Gabion Ground freezing...

Runway 11/29 (elev 91 ft/28m): PCN 45 FBXT (flexible pavement, medium subgrade strength, medium tyre pressure (1,500 kPa (220 psi)), technical evaluation...

Natural features Topography Vegetation Terrain Topsoil Water table Bedrock Subgrade Subsoil Earthworks Shoring structures Retaining walls Gabion Ground freezing...

base course, which is normally placed on the subbase, which rests on the subgrade. There are various different types of flexible pavement wearing course...

lane in each direction and no interchanges. In transport engineering, subgrade is the native material underneath a constructed road. Road construction...