Drip Injection of Chemical Grouts: A New Apparatus

Abstract

Abstract The tip structure of conventionally used drip injection apparatus for chemical grouting has the defect that the chemical grouts flow upwards to the ground surface frequently, which reduces the accuracy and efficiency of injection significantly. Normally, cement and bentonite are used for sealing the gap between injection tube and drill hole, the performance of which is not satisfactory. In this study, a balloon cover injection tip (called BCIT) has been developed. The special tip structure of the injection tube prohibits the chemical grout flowing upward to the ground surface. In particular, BCIT can implement down-to-up chemical grouting due to its soft and tight attachment with the drill hole sides. The main advantage of the BCIT is its simplicity, portability, adaptability, and accurate injection quantity management. Further, this can be used effectively for small-scale strengthening and preservation of historical remains with complicated geographic features without spoiling their appearance. In the laboratory, the feasibility of BCIT apparatus has been verified by chemical grouting in model ground, which simulates the practical condition of Funasako kiln sites. A soil hardness tester was used to evaluate the strength of the solidified body.