The Amenability Theory: Applied in Rock and Soil to Maximize Productivity
Ward Naudts, ECO Grouting Specialists Inc.; Eric Landry, ECO Grouting Specialists
The amenability theory was developed by Alex Naudts, and considers grouting operations as continuous permeability tests where Newtonian test fluid water, is replaced by a cementitious or solution grout. It utilizes hydraulic conductivity and grouting data to establish the amenability coefficient of a particular grout zone. The amenability coefficient reflects the quantity of apertures or voids accessible to the selected grout, divided by the amount of apertures accessible to water, in the zone intersected by the grout hole. By calculating in real time the effectiveness of a particular grout at the start of a grouting operation, the most appropriate grout to match design criteria can be targeted. By incorporating the amenability theory in every grouting operation schedule savings and an increase in productivity are typically achieved. Three short case studies illustrate different enhancements in productivity: At an underground mine during the construction of declines, a cement based suspension grouting program was highly ineffective and did not appear to affect the inflow into the mine workings. The amenability theory was utilized to evaluate the grouting program and based on this evaluation, changes to the grouting program were made which allowed the grouting to meet the project’s objectives. A pre-excavation grouting program implemented during shaft sinking operations utilized the amenability theory to select the most suitable grout for the program. Schedule constraints also influenced the selection of the grout. In a highly heterogeneous ‘soil’ formation in a tunnel/shaft project in Miami, the amenability theory was used to select the grouting sequence of every individual grout hole. The amenability theory was developed by Alex Naudts, and considers grouting operations as continuous permeability tests where Newtonian test fluid water, is replaced by a cementitious or solution grout. It utilizes hydraulic conductivity and grouting data to establish the amenability coefficient of a particular grout zone. The amenability coefficient reflects the quantity of apertures or voids accessible to the selected grout, divided by the amount of apertures accessible to water, in the zone intersected by the grout hole. By calculating in real time the effectiveness of a particular grout at the start of a grouting operation, the most appropriate grout to match design criteria can be targeted. By incorporating the amenability theory in every grouting operation schedule savings and an increase in productivity are typically achieved. Three short case studies illustrate different enhancements in productivity: At an underground mine during the construction of declines, a cement based suspension grouting program was highly ineffective and did not appear to affect the inflow into the mine workings. The amenability theory was utilized to evaluate the grouting program and based on this evaluation, changes to the grouting program were made which allowed the grouting to meet the project’s objectives. A pre-excavation grouting program implemented during shaft sinking operations utilized the amenability theory to select the most suitable grout for the program. Schedule constraints also influenced the selection of the grout. In a highly heterogeneous ‘soil’ formation in a tunnel/shaft project in Miami, the amenability theory was used to select the grouting sequence of every individual grout hole.
Keywords:
Amenability, Grouting, Shaft
