Rock Grouting

1 Introduction.- 2 Remarks on the Methodology of Preparation.- 3 Analysis of Completed Grouting Programmes.- 3.1 Preliminary Remarks.- 3.2 Description and Evaluation of the Programmes.- 3.3 Microscopical Studies.- 3.4 Generally Valid Conclusions from the Analysis of the Grouting Programmes.- 4 Discussion of the Conventional Investigation Methods for Determining Rock Permeability.- 4.1 Introduction.- 4.2 On the Execution, Evaluation and Interpretation of Water Pressure Tests.- 4.3 Assessment of Current Investigation Methods for Rock Permeability.- 4.4 Conclusions.- 5 On Hydraulic Routing in Rock.- 5.1 Introduction.- 5.2 Methods of Researching the Hydraulic Routing in Rock.- 5.3 Influential Factors in the Development of Water Paths in Rock.- 5.4 Discontinuities as Prescribed Water Paths and Their Behaviour During Grouting.- 5.5 The Results of Field Investigations of the Hydraulic Routing.- 5.6 Synopsis of the Percolation Behaviour in Rock.- 5.7 Remarks on Percolation Models and Calculation Methods in Rock Mechanics.- 6 Studies of the Relationship Between the Type of Hydraulic Routing, the Course of the Water Pressure Tests and Grouting Behaviour.- 6.1 Introduction.- 6.2 Tests Using Geologically Defined Models for the Hydraulic Routes Around the Boreholes.- 6.3 Interpretation of Simulated Water Pressure Tests and Conclusions.- 6.4 Interpretation of Simulated Grouting Tests and Conclusions.- 7 Practical Field Investigations on Permeability by Means of Water Pressure Tests.- 7.1 Introduction.- 7.2 Rock Fracturing Contingent upon Injection Pressure.- 7.3 Appropriate Maximum Pressures for Water Pressure Tests.- 7.4 The Factor "Time" in Conducting the Water Pressure Tests.- 7.5 Characteristic Water Pressure Tests for Determining the Permeability Behaviour of Different RockTypes.- 7.6 Comparison of Rock Permeabilities Under the Conditions of Injection and Operation.- 7.7 Water Pressure Tests in Grouted Rocks for Controlling its Success.- 7.8 On the Definition of "Reference" Pressure.- 8 Practical Criteria for Determining Grouting Methods Considering Rock-Type-Specific Groutability.- 8.1 Introduction.- 8.2 Selection of Grouting Pressures in View of the Fracturing Behaviour.- 8.3 Assessing the Rock-Type-Specific Groutability.- 8.4 Penetration or Displacement Grouting?.- 8.5 Comments on Setting W/C Ratios.- 8.6 Spacing of Grout Holes, Grouting in Series.- 8.7 Downstage or Upstage Grouting, Schematic or Adapted Execution, Accompanying Water Pressure Tests.- 8.8 Relationship Between the Type of Hydraulic Routing and the Remaining Permeability.- 8.9 Test Grouting.- 9 Practical Criteria for Determining the Tolerable Permeability.- 9.1 Introduction, Hydraulic Fundamentals, Depth of the Curtain, "Tolerable Permeability".- 9.2 Estimating the Mean Permeability of the Rock for Determining Seepage Losses.- 9.3 Erodibility.- 9.4 Examples of the Possible Differences Between Groutable and Tolerable Permeabilities.- 9.5 Changes in Permeability and Groutability Due to Comparatively High Storage Levels.- 9.6 The Expenditures for Grouting Programmes Compared with the Degree of Impermeabilization.- 9.7 Summarizing Assessment of the Tolerable Permeability.- 9.8 The Expediency of a Control Gallery Considering Geological Setting and Rock-Type-Specific Groutability.- 9.9 Lateral Extension of the Grout Curtain, Systematic Groundwater Measurements Prior to the Construction of the Dam.- 9.10 Influence of the Type of the Project on the Tolerable Permeability.- 10 The Influence of the Local Geological Setting and the Grouting Measures on the Reduction ofUplift.- 10.1 Introduction.- 10.2 Example: Aabach Dam.- 10.3 Example: Antrift Dam.- 10.4 Example: Tavera Dam.- 10.5 Example: Twiste Dam.- 10.6 Conclusions Concerning the Reduction of the Uplift.- 11 Final Remarks: an Attempt at Guide-Lines.- 11.1 Hydrogeological Scope.- 11.2 Site Investigations by Geological Mapping, Core Drilling, Testing of Both Permeability and Groutability.- 11.3 Control Measures During Impoundment.