Investigation of geogrid reinforcement in unpaved road applications

土工格栅材料在道路工程中的应用已成为一项重要的岩土工程实践。土工格栅放置在路基和基层之间，或基层内部，改善了未铺设道路的性能。目前土工格栅加筋土工路面的设计都是基于经验方法，不能有效地利用现代较强的土工格栅。本项目的主要目标是了解土工格栅的加固机理，优化土工格栅层的位置，量化其加固效果。这将涉及监测具有不同强度特征的土工格栅层的性能，并在实地研究中放置在不同的位置。测试项目将在伦敦西部大学环境中心（ESWU）进行。ESWU有一条未铺设的道路（入口），由于交通繁忙，这条道路会出现明显的车辙，因此将被视为测试道路。它将被细分为5个部分。四段将用土工格栅材料（Terrafix生产，即tbx1500， TBX2000， TBX2500和TBX3000）进行加固，一段将用作基线（对照）。每个部分将被细分为两个部分。在一段中，土工格栅将放置在地表以下200毫米处。在第二段中，土工格栅将放置在地表以下400mm处。全球土工格栅应变将由四个位置传感器测量。一套土压力传感器将用于监测地基和路基不同位置的应力状态。此外，所有土工格栅层将在不同位置进行应变测量，以监测土工格栅中的应力分布。此外，将定期测量路面，以确定每一百个荷载循环后的高程（车辙）变化

Geogrid materials' use in road projects is becoming an important geotechnical practice. Placed between the subgrade and base course, or within the base course, the geogrid improves the performance of unpaved roads. Currently, the design of geogrid reinforced unpaved roads is based on an empirical method, which doesn't allow efficient utilization of modern stronger geogrids. The main objectives of this project are to understand the reinforcing mechanism of geogrids and optimize the location of the geogrid layer and quantify its reinforcing effect. This will involve monitoring the performance of geogrid layers with different strength chracteristics and placed at different locations in a field study.The testing program will be carried out at the Environmental Site of Western University (ESWU), London. The ESWU has an unpaved road (entrance), which experiences significant rut due to the heavy traffic and will be considered here as the test road. It will be subdivided into 5 segments. Four segments will be reinforced with geogrid material (manufactured by Terrafix, i.e. TBX 1500, TBX2000, TBX2500 and TBX3000) and one segment will be used as base line (control). Each segment will be subdivided into two sections. In one section, the geogrid will be placed at 200 mm below the ground surface. In the second section, the geogrid will be placed at 400 mm below the ground surface. The global geogrid strain will be measured by using four Position Sensors. A set of earth pressure transducers will be used to monitor the stress state at different locations in the base and the subgrade. In addition, all geogrid layers will be strain gauged at various locations to monitor the stress distribution in the geogrid. In addition, the road surface will be surveyed regularly to establish the change in elevation (rut) after each hundred load cycles