I. PURPOSE AND INTENT
a) The intended purpose of these guidelines is to assist the customer and/or owner to retain the services of a Geotechnical Engineer.
b) It is not ROHN´s purpose or intent to supercede the Geotechnical Engineer´s knowledge, judgement and/or experience. It is the Geotechnical Engineer´s responsibility to add or delete from these items, based on local site conditions and other factors.
c) Additional information is provided in ANSI/TIA-222-G Annex G "Geotechnical Investigations".
a) ROHN will not accept any liability, either expressed or implied, for the use of, and omissions in, these guidelines.
III. EXPLORATORY BORINGS
a) Borings should be taken at tower legs for self-supporting towers and at the base and anchor points for guyed towers. For small self-supporting towers, two borings may suffice. For large self-supporting towers, one boring should be taken at each tower leg. A "small" self-supporting tower is assumed to have a face width less than 20 feet and a compression load less than 50 kips per leg. For pole structures, one boring may suffice.
b) The minimum boring depth should be 30 feet for pole structures, self-supporting towers and guyed tower bases. For guyed tower anchors, the minimum depth should be 15 feet. The actual depth of boring must be determined by the Geotechnical Engineer based on reactions, soil conditions and the type of foundation recommended.
c) If borings cannot be advanced to the desired depth, rock corings should be taken. Rock Quality Designation (RQD) values and compressive strengths should be determined.
IV. GEOTECHNICAL REPORT
a) The following properties, for each soil layer encountered, should be determined by field or laboratory testing and summarized in the geotechnical report:1. Soil classification and elevations
b) The following items should be discussed in the geotechnical report:1. Geological description of site