Full-Scale Model Test Study of Trenchless Low-Exothermic Polymer Grouting for Maintenance of Subgrade in Permafrost Region

Abstract

In this study, a refrigeration system was used to freeze subgrade soil, and a full-scale model test study of grouting repair using a new low-exothermic polymer material was conducted. A DHDAS signal acquisition and analysis system was used to monitor the mechanical response characteristics of the frozen soil subgrade before and after grouting using a low-exothermic polymer. GPR and FWD detection equipment were used to detect the repair effect of the frozen soil subgrade after the low-exothermic polymer grouting. The results indicated that the new low-exothermic polymer material could fill the voids of the frozen soil subgrade well at low temperatures. The low-exothermic polymer grouting reinforcement reduced the surface deflection and structural layer strain of the frozen soil subgrade, improved the bearing capacity of the frozen soil subgrade, and delayed the permanent deformation of the frozen soil subgrade under load. The filling layer formed by the low-exothermic polymer grouting reinforcement absorbed part of the additional stress, which reduced the stress transferred to the soil foundation compared to the intact subgrade, thus improving the stability of the frozen soil subgrade. The research results showed that the new low-exothermic polymer grouting material can be used to repair damage to frozen soil roadbeds.

Keywords: New low-exothermic polymer material, Grouting, Permafrost subgrade, Full-scale model test