Applications of geofoam for buried culverts/pipes keep increasing; however, the design of such applications is still challenging due to lack of full-scale studies. Considering practice needs, a full-scale field study was carried out to investigate the effectiveness of different geofoams with different layouts to reduce overburden stresses on deeply buried, large-size culverts. Among the eight test sections, five were installed with two different of geofoams (7.5 and 15 kg/m³) in thicknesses of 300 and 600 mm and the remaining three were built with loose sand, lightly and normally compacted clay, respectively. The acquired data indicated that the geofoam can greatly reduce the overburden stress over the culvert. In general, higher compressibility of geofoam resulted in greater stress transfer but did not cause excessive settlement at the surface due to significant burial depth. However, due to its large span and dome shape, a secondary soil arching formed when the soil over shoulder settled more than that over the crown, which readjusted the stress and resulted in further reduction in the stress at the culvert shoulder but partially compromised the stress reduction at the crown. Such phenomenon shall be appropriately addressed to avoid unexpected damage to buried culverts or pipes.

土工泡沫在埋地涵洞/管道中的应用不断增加；然而，由于缺乏全面的研究，此类应用程序的设计仍然具有挑战性。考虑到实践需要，进行了全面的实地研究，以研究不同布局的不同土工泡沫对降低深埋大型涵洞上覆应力的有效性。在八个测试部分中，五个安装了两种不同的土工泡沫（7.5 和 15 kg/m ³) 的厚度分别为 300 和 600 毫米，其余三个分别用松散的沙子、轻度和正常压实的粘土建造。获得的数据表明，土工泡沫可以大大降低涵洞的上覆应力。一般来说，土工泡沫的可压缩性越高，应力传递越大，但不会因埋藏深度大而导致地表过度沉降。然而，由于其大跨度和圆顶形状，当肩部土壤沉降大于冠部土壤时，会形成二次土拱，重新调整应力，导致涵洞肩部应力进一步降低，但部分地损害了应力在冠部减少。应妥善处理此类现象，以免对埋地涵洞或管道造成意外损坏。