<p><p><strong>Reference(s):</strong></p><p><em>Dawson and Little (1990)<br>Fannin and Sigurdsson (1996)<br>Hufenus et al. (2006)<br>Kim et al. (2005)<br>Yong et al. (1990)</em></p><p><strong>Method Summary </strong></p><p>This QC/QA method evaluates performance of test sections for rut depth and base course layer thickness in the channelized wheel path, deformation of geosynthetics, strains in the aggregate and geosynthetics with a cumulative number of vehicle passes, and lateral and vertical subgrade deformations.</p><p>Dawson and Little (1990) used strain coils, pressure cells, thermocouples, piezometers, horizontal extensometers, and various sets of vertical inspection tubes to measure the strains in aggregate, subgrade and geotextile pressure distributions, temperature of geotextile, pore water pressure, and lateral and vertical subgrade deformations, respectively. Strain in the geosynthetic was obtained from displacements of an array of marker studs fixed across the fabric beneath the wheel path and outside the wheel path (Fannin and Sigurdsson 1996). A similar approach was used to measure the strains in the geogrids by recording the spacing between selected nodal junctions.</p><p>The condition of the track and the geosynthetics from installation to removal was monitored by instruments, using CBR measurements (CBR penetrometer), vane shear measurements (Pilcon), specific gravity measurements, static and dynamic plate load tests, a dynamic Falling Weight Deflectometer (FWD), the overall dynamic compaction control and the profile measurements (ruts) and strain gauges on the geogrids (Hufenus et al. 2006). Trafficking tests were also carried. A falling weight deflectometer and resistance type strain gauges were used for measurements of deflection and geosynthetics strains respectively (Kim et al. 2005). Settlement induced by numerous passes of a 225-ton American Hoist Crane after a heavy rainfall was monitored over a period of time (Yong et al. 1990).</p><p><strong>Accuracy and Precision</strong></p><p>Instrumentation and evaluation of a test section are typically considered to be representative of the performance of the final construction platform. Hence, this method provides somewhat accurate and precise assessment of construction quality for this technology.</p><p><strong> </strong><strong>Adequacy of Coverage</strong></p><p>This method provides an adequate assessment of the inclusions and the entire quantity of improved soil, using reasonable number of tests.</p><p><strong> </strong><strong>Implementation Requirements </strong></p><p>Implementation requirements are somewhat greater than desired.</p><p><strong> </strong><strong>General Comments</strong></p><p>The method is more likely applicable to the performance-based application and somewhat applicable to the method approach specification. Geosynthetic stabilizes the soft subgrade, reinforces the road section, reduces settlement, and increases the bearing capacity. Working platforms reinforced with geosynthetics have smaller elastic deformation. Hence, geosynthetics enhance service life by reducing rut depth and deformation of the road section.</p></p>