Large-scale model testing of high-pressure grouting reinforcement for bedding slope with rapid-setting polyurethane

Abstract

Bedding slope is a typical heterogeneous slope consisting of different soil/rock layers and is likely to slide along the weakest interface. Conventional slope protection methods for bedding slopes, such as retaining walls, stabilizing piles, and anchors, are time-consuming and labor- and energy-intensive. This study proposes an innovative polymer grout method to improve the bearing capacity and reduce the displacement of bedding slopes. A series of large-scale model tests were carried out to verify the effectiveness of polymer grout in protecting bedding slopes. Specifically, load-displacement relationships and failure patterns were analyzed for different testing slopes with various dosages of polymer. Results show the great potential of polymer grout in improving bearing capacity, reducing settlement, and protecting slopes from being crushed under shearing. The polymer-treated slopes remained structurally intact, while the untreated slope exhibited considerable damage when subjected to loads surpassing the bearing capacity. It is also found that polymer-cemented soils concentrate around the injection pipe, forming a fan-shaped sheet-like structure. This study proves the improvement of polymer grouting for bedding slope treatment and will contribute to the development of a fast method to protect bedding slopes from landslides.