Evaluation of the effectiveness of a grout curtain using a physical model

In the past decade, the grouting industry has made significant technological advancements in real-time monitoring, stable grout mix design, and with grout curtain concepts dealing with placement and orientation. While these practices have resulted in a renewed appreciation of the grouting industry, current design guidelines are still predominately based on qualitative measures such as engineering judgment and experience. This project mainly focused on the development of quantitative guidelines to evaluate the effectiveness of a grout curtain design in karst limestone formations using piezometric data. In this study, a physical model was developed to aid in the understanding and development of geotechnical trends that evaluate the effectiveness of a grout curtain. A new performance parameter was developed based on a double normalization scheme. This scheme took into account the distance to the pore pressure transducer and the relative position of the outflow of the physical model. The double normalization scheme, combined with pore pressure and hydraulic conductivity measurements for different grout curtain orientations produced a graphical representation of the grout curtain effectiveness. This study found that pore pressures were strongly affected by grout curtain orientations and the location of the point of pore pressure measurement.