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Due to all the variables that enter into a predictive slope stability analyses, CNI recommended a <br /> monitoring program for the mines in the Report. The recommendations are listed below: <br /> 6.0 MONITORING SCHEDULE <br /> A definite monitoring schedule should be established. If shooting in the monitoring <br /> points is left to the mine surveyor to do when he "gets time, " the results will be erratic at best. <br /> The frequency of monitoring is a function of the precision of the system, the rate of <br /> movement, and how critical the area is. Table I provides a suggested schedule. In the event of <br /> heavy rain or a large blast in the area, additional measurements should be taken. <br /> Cooperation between operations and engineering is important. Equipment operators <br /> often have an intuitive feel for ground conditions. Any changes in the condition of an area <br /> observed by operators should be reported to engineering for follow-up. <br /> 7.0 DATA REDUCTION AND REPORTING <br /> The following measurement or calculations should be made for each survey reading: <br /> 1. Date of reading, time, incremental days between readings, and total number of <br /> days the survey point has been established <br /> 2. Coordinates and elevation <br /> 3. Magnitude and direction of horizontal displacement <br /> 4. Magnitude and plunge of vertical displacement <br /> 5. Magnitude, bearing, and plunge of resultant displacement vector <br /> 6. Rates (velocities) of horizontal, vertical, and resultant(total) displacements <br /> Both incremental and cumulative displacement values should be determined. Calculating <br /> the cumulative displacement from initial values rather than from summing incremental <br /> displacements minimizes the effect of occasional survey aberrations. Table 2 is an example <br /> of reduced monitoring data. <br /> Slope displacements are best understood and analyzed when the monitoring data are <br /> graphically displayed. For engineering purposes, the most useful plots are: <br /> 1. Horizontal position <br /> 2. Vertical position (elevation versus change in horizontal position,plotted on a <br /> section oriented in the mean direction of horizontal displacement) <br /> 3. Displacement vectors <br /> 4. Cumulative total displacement versus time <br /> 5. Incremental total displacement rate (velocity, usually in meters per day) <br /> versus time. All graphics should be kept up-to-date and should be easily reproducible (for ease <br /> of distribution). By studying several graphics simultaneously, the movement history of a <br /> particular slope can be determined. <br /> The velocity-versus-time plot is usually constructed on semi-log paper rather than on a <br /> linear scale. This allows a greater range of displacements to be plotted without losing the <br /> precision required for small measurements. Also, this type ofgraph is compatible with current <br /> monitoring techniques and analyses of slope movement kinematics. <br /> Precipitation data should also be recorded to evaluate possible correlations with slope <br /> displacement. A gauge (or gauges) located at the mine site can be used to measure occurrences <br /> and amounts of precipitation. In addition, measurement of the average daily temperatures will <br /> provide some indication of freeze and thaw periods. <br /> The location of mining areas, the number of tons mined, and blasting patterns in the area <br /> 30 <br />