Local Stiffness Assessment of Geogrid-Stabilized Unbound Aggregates in a Large-Scale Testbed
This paper integrates and extends an earlier article presented at the 20th International Conference on Soil Mechanics and Geotechnical Engineering. The generation of a stiffened zone in the proximity of a geogrid is one of the primary mechanisms of mechanical stabilization of pavement unbound aggreg...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-12-01
|
| Series: | Applied Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3417/14/1/352 |
| _version_ | 1797359111382237184 |
|---|---|
| author | Mingu Kang Han Wang Issam I. A. Qamhia Erol Tutumluer Jeb S. Tingle |
| author_facet | Mingu Kang Han Wang Issam I. A. Qamhia Erol Tutumluer Jeb S. Tingle |
| author_sort | Mingu Kang |
| collection | DOAJ |
| description | This paper integrates and extends an earlier article presented at the 20th International Conference on Soil Mechanics and Geotechnical Engineering. The generation of a stiffened zone in the proximity of a geogrid is one of the primary mechanisms of mechanical stabilization of pavement unbound aggregate layers using geogrids. This paper focuses on the quantification of the stiffened zone through a local stiffness assessment using bender element (BE) sensors. Unbound aggregate base layers were constructed in a large-scale laboratory testbed. Geogrid-stabilized layers had geogrids with different-sized triangular apertures contributing to the geogrid-stiffened zone. Shear wave velocities were measured at three different heights using BE sensors, and the vertical stiffness profiles of the mechanically stabilized aggregate layers were evaluated. In addition, the conversion method between small-strain stiffness and large-strain stiffness was established from the repeated load triaxial tests with BE pairs to transform the vertical stiffness profile into that of the resilient modulus. Furthermore, dynamic cone penetration (DCP) and light-weight deflectometer (LWD) tests were performed at multiple locations into the stabilized and unstabilized unbound aggregates. From the large-scale experimental study, the local stiffness improvement owing to the geogrid enhancement was up to 16.2% in the vicinity of the geogrid location, and the extent of the local stiffened zone evaluated through various test methods was between 15.2 cm (6 in.) and 25.4 cm (10 in.) above the geogrid. |
| first_indexed | 2024-03-08T15:11:58Z |
| format | Article |
| id | doaj.art-f908ddc25db94fc9bb35fa45cd2a374b |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-08T15:11:58Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-f908ddc25db94fc9bb35fa45cd2a374b2024-01-10T14:51:50ZengMDPI AGApplied Sciences2076-34172023-12-0114135210.3390/app14010352Local Stiffness Assessment of Geogrid-Stabilized Unbound Aggregates in a Large-Scale TestbedMingu Kang0Han Wang1Issam I. A. Qamhia2Erol Tutumluer3Jeb S. Tingle4Department of Civil Engineering, University of St. Thomas, 2115 Summit Ave., St. Paul, MN 55105, USADepartment of Civil and Environmental Engineering, University of Illinois Urbana-Champaign, 205 N. Mathews Ave., Urbana, IL 61801, USADepartment of Civil and Environmental Engineering, University of Illinois Urbana-Champaign, 205 N. Mathews Ave., Urbana, IL 61801, USADepartment of Civil and Environmental Engineering, University of Illinois Urbana-Champaign, 205 N. Mathews Ave., Urbana, IL 61801, USAU.S. Army Engineer Research and Development Center, Vicksburg, MS 39180, USAThis paper integrates and extends an earlier article presented at the 20th International Conference on Soil Mechanics and Geotechnical Engineering. The generation of a stiffened zone in the proximity of a geogrid is one of the primary mechanisms of mechanical stabilization of pavement unbound aggregate layers using geogrids. This paper focuses on the quantification of the stiffened zone through a local stiffness assessment using bender element (BE) sensors. Unbound aggregate base layers were constructed in a large-scale laboratory testbed. Geogrid-stabilized layers had geogrids with different-sized triangular apertures contributing to the geogrid-stiffened zone. Shear wave velocities were measured at three different heights using BE sensors, and the vertical stiffness profiles of the mechanically stabilized aggregate layers were evaluated. In addition, the conversion method between small-strain stiffness and large-strain stiffness was established from the repeated load triaxial tests with BE pairs to transform the vertical stiffness profile into that of the resilient modulus. Furthermore, dynamic cone penetration (DCP) and light-weight deflectometer (LWD) tests were performed at multiple locations into the stabilized and unstabilized unbound aggregates. From the large-scale experimental study, the local stiffness improvement owing to the geogrid enhancement was up to 16.2% in the vicinity of the geogrid location, and the extent of the local stiffened zone evaluated through various test methods was between 15.2 cm (6 in.) and 25.4 cm (10 in.) above the geogrid.https://www.mdpi.com/2076-3417/14/1/352mechanical stabilizationunbound aggregatesgeogridbender elementsshear wave velocity |
| spellingShingle | Mingu Kang Han Wang Issam I. A. Qamhia Erol Tutumluer Jeb S. Tingle Local Stiffness Assessment of Geogrid-Stabilized Unbound Aggregates in a Large-Scale Testbed Applied Sciences mechanical stabilization unbound aggregates geogrid bender elements shear wave velocity |
| title | Local Stiffness Assessment of Geogrid-Stabilized Unbound Aggregates in a Large-Scale Testbed |
| title_full | Local Stiffness Assessment of Geogrid-Stabilized Unbound Aggregates in a Large-Scale Testbed |
| title_fullStr | Local Stiffness Assessment of Geogrid-Stabilized Unbound Aggregates in a Large-Scale Testbed |
| title_full_unstemmed | Local Stiffness Assessment of Geogrid-Stabilized Unbound Aggregates in a Large-Scale Testbed |
| title_short | Local Stiffness Assessment of Geogrid-Stabilized Unbound Aggregates in a Large-Scale Testbed |
| title_sort | local stiffness assessment of geogrid stabilized unbound aggregates in a large scale testbed |
| topic | mechanical stabilization unbound aggregates geogrid bender elements shear wave velocity |
| url | https://www.mdpi.com/2076-3417/14/1/352 |
| work_keys_str_mv | AT mingukang localstiffnessassessmentofgeogridstabilizedunboundaggregatesinalargescaletestbed AT hanwang localstiffnessassessmentofgeogridstabilizedunboundaggregatesinalargescaletestbed AT issamiaqamhia localstiffnessassessmentofgeogridstabilizedunboundaggregatesinalargescaletestbed AT eroltutumluer localstiffnessassessmentofgeogridstabilizedunboundaggregatesinalargescaletestbed AT jebstingle localstiffnessassessmentofgeogridstabilizedunboundaggregatesinalargescaletestbed |