High-strength, non-woven geotextile was used as base reinforcement in a test embankment on soft Bangkok clay. Instrumentations for stress-strain measurements consisted of wire extensometers, Glotzl type high accuracy extensometers, special strain gages and dog-bone load cell. Wire extensometers were installed in both geotextile and surrounding soils in order to measure their relative displacements and global strains. Glotzl extensometers were attached in geotextile as redundant measurement to verify the reliability of wire extensometers. Strain in geotextile was also measured by means of strain gages. The comparable results of strain measurements from these different instn1ments have been obtained. Glotzl and wire extensometers gave reasonable data up to the strain larger than 10%. The strain gages yielded good results at strain levels lower than 3 % . All of the strain gages ceased to function at strain levels less than to 5 % both in the field and in the laboratory calibration tests.
Menu