Highway engineering

A farmer owns a rectangular field that fronts along a road. State highway engineers surveyed the frontage and found that it measures 138.3 m in length. The farmer, who wants to build a fence around the field, paces off the field s width and estimates it to be 52 m. How many meters of fence will the farmer have to build What mass of fertilizer will the farmer need to fertilize the field with 0.0050 kg of fertilizer for each square meter of field ... 

U. S. Department of Transportation/Federal Highway Administration Report No. EHWA-SA-94-081, Fly ash facts for highway engineers, August 1995. 

Yu Zhifeng Xie Zhengwen. 2007. Improved grey model by exponential smoothing for settlement predication and its application. Central South Highway Engineering (T) 12Q-122. 

Regardless of the way they have been formed, the lack of homogeneity is a feature of soils. Soils appear to vary from loose to very well compacted, with or without cohesion, with continuous or non-continuous particle size distribution. The above heterogeneity appears in both horizontal and vertical levels. The highway engineer has to deal with many kilometres and in most cases has to use the existing soil without any adjustment. This fact makes the determination of its representative mechanical behaviour more difficult and tricky. 

The natural moisture of the soil is a crucial factor for the highway engineer, since the bearing capacity of the pavement s foundation layer depends directly from it. 

The soil fractions as described in Section 1.2 along with the description of natural properties (such as origin, colour, shape, etc.) did not help engineers to easily recognise the soil s suitability for roadworks. As early as 1928, the AASHTO developed a soil classification system for highway engineering. The system has been revised several times, and the 1945 version formed the basis of the existing soil classification system by AASHTO. 

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