Laserfiche WebLink
3.0 Slope Monitoring Instrumentation <br />Visual observation, which is anticipated to be performed approximately monthly, will be used to <br />document the presence of and changes in possible tension cracks within the slope. In addition to the <br />visual observation, instrumentation has been installed as part of the observational approach to slope <br />stability design and monitoring being used for the haul road slide repair and the RPEE facility. This <br />section provides information on instrumentation planned for each area. <br />3.1 Haul Road HR -1 Area <br />This section summarizes instrumentation installed to monitor the repaired slopes along Haul Road <br />HR -1. Slope monitoring will be conducted in the vicinity of the repaired haul road slide area through <br />the measurement of survey mirrors, inclinometers, and piezometers. These instrumentation types are <br />described in more detail below. <br />3.1.1. Survey Mirrors <br />Fifteen (15) survey mirrors have been installed along the repaired slope to monitor slope movement <br />as shown in Figure 14. Mirrors are advantageous because they can provide extensive monitoring <br />coverage along the slope and they can provide data for very large displacements without being <br />damaged. The disadvantage is that there is a significant amount of "noise" in the readings due to <br />temperature and other effects, and they can be impacted by animals, equipment, and other elements. <br />Most of these mirrors were installed within the original slide mass area, but a few of them were <br />located outside this area to determine if possible movement is contained within the original slide <br />mass or if it extends outside this area. <br />3.1.2. Inclinometers <br />Two (2) inclinometers have been installed along the north edge of haul road HR -1 as shown in Figure <br />15. Inclinometers are advantageous because they can accurately measure very small displacements <br />and they are less susceptible to disturbance at the ground surface. They also help to identify the depth <br />of the shear surface should movement occur. Disadvantages of inclinometers include the length of <br />time needed to monitor and they can shear off with sufficient subsurface movement, and might <br />become inoperable after several inches of displacement. <br />These inclinometers are 85 mm (3.34 inches) in diameter. These are the largest diameter <br />inclinometers commonly manufactured. These are recommended because they can remain functional <br />P:\Mpls\06 CO\26\06261003 Haul Road Slide Repair\WorkFiles\Report\MCC_Slump_Repair-Instrumentation-Drain Rev 2012-12-12.docx 12 <br />