Investigation of geogrid reinforcement in unpaved road applications

土工格栅材料在道路工程中的应用正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，或在基层内，改善了未铺砌道路的性能。目前，土工格栅加固未铺路面的设计是基于经验的方法，这不允许有效利用现代更强的土工格栅。本计画的主要目的是了解土工格栅的补强机制，并优化土工格栅层的位置与量化其补强效果。这将涉及监测不同强度特性的土工格栅层的性能，并在现场研究中放置在不同的位置。测试计划将在伦敦西部大学（ESWU）的环境网站进行。ESWU有一条未铺路面的道路（入口），由于交通繁忙，该道路会出现严重的车辙，此处将其视为试验道路。它将被细分为5个部分。四个区段将用土工格栅材料（由Terrafix制造，即TBX 1500、TBX 2000、TBX 2500和TBX 3000）加固，一个区段将用作基线（对照）。每个部分将再分为两个部分。在一个部分中，土工格栅将放置在地面以下200 mm处。在第二部分中，土工格栅将放置在地面以下400 mm处。将使用四个位置传感器测量全球土工格栅应变。将使用一套土压力传感器来监测基底和路基中不同位置的应力状态。此外，将在不同位置对所有土工格栅层进行应变测量，以监测土工格栅中的应力分布。此外，将定期测量路面，以确定每一百次荷载循环后的高程变化（车辙

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