An Integrated Field-to-Decision Framework for Drilling and Curtain Grouting in Heterogeneous Dam Foundations

Seepage control in complex, heterogeneous rock foundations remains one of the most critical challenges in hydraulic dam engineering. Traditional curtain grouting designs often rely on empirical rules or static, isolated hydraulic conductivity measurements, which fail to capture the dynamic hydro-mechanical response of complex fracture networks under pressure. This paper presents a Field-to-Decision (F2D) framework that links geological logging, hydraulic testing, real-time injection monitoring and quantitative verification protocols. Central to the methodology is the incorporation of A. C. Houlsby's five-stage water pressure test (WPT) interpretation, which classifies non-linear flow regimes (laminar, turbulent, dilation, washout and void filling) to inform grout mix selection and injection pressure limits. Operational protocols are given for drilling method selection, real-time tracking of the Grout Intensity Number (GIN) and apparent Lugeon values, and split-spacing verification sequences (Primary-Secondary-Tertiary-Quaternary). A preliminary field application is presented using project records from the Sidi Khelifa Dam (Algeria).