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EXHIBIT A <br />MINIMUM REQUIREMENTS FOR NUMBER AND SPACING <br />' OF PITS AND BORINGS FOR SAMPLING SOILS AND ROCK <br />Number and spacing of Level 2 sampling pits or borings and Leve13 test borings should conform to the following <br />guidelines. For Leve13, the Geotechnical Engineer will select the locations of borings and the type, frequency, and depth <br />of samples and/or field strength tests. <br />Guidelines for Spacing of Borings <br /> Maximum distance between borings, feet <br />prpj~t Horizontal stratification of soil or rock Minimum number of borings <br /> Uniform Average Non-uniform <br />Multi-story buildings 150 100 50 4 per structure <br />One or two-story buildings 200 100 50 3 per lstructure <br />Land divisions, development site <br />4 or less acres 500 200 100 2 per acre <br />Land divisions, development site <br />4 or more acres 500 200 100 Minimum 8 per site with 3 <br />per soil unit <br />`Bridge piers, abutments, <br />television towers, etc. .100 100 25 <br />Roadways, sewers, pipelines 1000 500 200 - 100 <br />Borrow pits <br />(for compacted fill) 500 200 100 - 50 <br />Earth dams, dikes 200 100 50 <br /> <br />New site of wide extent Space preliminary borings 200 to 500 feet apart so that the area between any four <br />borings includes approximately 10% of the total area. In detailed exploration, add <br />borings to establish geological sections at the most useful orientation. <br />Development of site on soft <br />compressible strata Space borings 100 to 200 feet at possible building locations. Add intermediate <br />borings when building site is determined. <br />Low load warehouse building or <br />large area Minimum of 4 borings at comers plus intermediate borings at interior foundations <br />sufficient to define subsoil profile. <br />Slope stability, deep cuts, high <br />embankments provide 3 to 5 borings on line in the critical direction to provide geological section <br />for analysis. Number of geological sections depends on extent of stability <br />roblem. For active slide, lace at least one borin u slo of slidin area. <br />Page t of 2 <br />