Grouting and Quality Control for Micropiles and Anchors in Karst Geology

This paper presents the grouting methods used to successfully complete micropile installations in Karst geology and the quality controls and testing used to avoid failures. The techniques described in this paper were assembled from 15 years of design-build micropile experience working in Karst geology. This paper captures lessons learned for installation of micropiles and rock anchors installed in Karst geology including the use of modern, stable grouts with thixotropic additives, stage grouting of piles, and field quality controls used during the pile drilling and grouting process to minimize the risk of failures. The authors offer the perspectives of both the contractor and the design engineer regarding the design-build process, field and laboratory testing, grout mix designs, drilling and grouting methods, and field quality control for projects in Karst geology.