Research coordinator, Geosynthetics Engineering Research Laboratory,Louisiana Transportation Research Center, Baton Rouge, LA
Administrator, Geophysical Systems, Louisiana Transportation Research Center (LTRC), Baton Rouge, LA
Pages: 14 Published: Jan 1993
The growing interest in utilizing on-site cohesive soils in reinforced-soil structures raises the need for development of testing procedures to evaluate their interaction properties (i.e. pull-out resistance and shear stress-strain characteristics). In determining the pull-out resistance of geosynthetics in clay, several factors can influence the measured properties. These factors are generally related to the testing equipment, the associated boundary effects, testing procedure, pull-out rate, geosynthetics characteristics, soil properties (e.g. soil density, grain size distribution and moisture content), compaction procedure and confining pressure.
This paper presents a part of the pull-out testing program conducted in the Geosynthetic Engineering Research Laboratory at the Louisiana Transportation Research Center to evaluate the effect of related physical parameters on the pull-out resistance of geogrids. Tests are conducted on HDPE geogrids in two pull-out boxes. The large pull-out box has dimensions of 1.5 m (60 in.) length, 0.9 m (36 in.) width, and 0.76 m (30 in.) height. The small box is 1.22 m (48 in.) long, 0.6 m (24 in.) wide, and 0.45 m (18 in.) high. A compaction procedure is developed in order to control soil density and moisture content. An instrumentation array is implemented to monitor the pull-out load, pull-out rate, normal pressure, and the displacement distribution along the geogrid specimens.
The results of the pull-out tests in both boxes provide an evaluation of the effect of various parameters on the pull-out mechanism and suggest a standardized procedure for control of box boundary effects and other influencing parameters on the pull-out resistance of geogrids.
laboratory testing, pull-out, geosynthetics, geogrids, cohesive soils, granular soils
Paper ID: STP24314S