A Field Experimental Study on the Diffusion Behavior of Expanding Polymer Grouting Material in Soil

Abstract

The diffusion behavior of expanding polyurethane foam, which is widely used in soil improvement, foundation remediation, and road maintenance, was investigated. This study is the first step towards the ultimate aim of examining the feasibility of using polyurethane foam for constructing a vertical impervious curtain in soil dams or dikes. Using a hole-sealing grouting method, experimental grout injection tests were performed in situ on a type of foaming polyurethane grout, comprised of two components. The results reveal that sheet fracturing diffusion was evident in the foaming polyurethane grout, eventually forming wedge-shaped segments in the generated cracks. Moreover, the direction along which the grout fractures the soil exhibits some uncertainty due to the unevenness in the soils and the random distribution of stress inside the dam. The test results show that for the purpose of constructing a continuous cut-off wall in the dam by injecting polymer grouts, some effective measures should be taken to guarantee that the polymers fracture the soil in the required direction, or axis of the dam or dike, and that the final solidified segments overlap one other.