Laserfiche WebLink
<br /> <br />• <br />H5.0 Summary of Selected Monitoring Information <br />This section is an update of Section 5.0 of the "1997/98 Landslide Corrective Measures Report". This <br />section provides new results on landslide monitoring gathered to June 30, 1999. <br />H5.1 Surface Monitoring Points <br />Complete historic cumulative movement of landslide movement monitoring points is provided in <br />Appendix H2. Locations of all landslide movement monitoring points aze shown on Figure H I . Figure H6 <br />shows a few selected monitoring points, illustrating the trend in movements during the spring and surnmer <br />seasons. Increased rates of movement can be seen to occur during spring seasons. <br />Landslide movement can be classified in accordance with the Landslide Velocity Classification presented <br />in Appendix A, of the 1997/98 report. From a period between February of 1998 to June of 1999, the <br />current average rate of movement was approximately 23 mm/year (0.9 inches per year) at the toe, and 306 <br />mm/year (12 inches/year) at the head. It should be noted that this period covers two typical landslide <br />seasons; the Spring of 1998 and the Spring of 1999. This classifies the landslide at the lower end of <br />Landslide Velocity Class 2 (low LVC-2) at the toe and alower-middle LVC-2 at the head. This compared <br />to values reported in 1998 for movement to April 1998, when an average rate of movement of 56 mm/yeaz <br />(2.2 inches/yeaz, low LVC -2) at the toe and 1112 mm/year (44 inches/yeaz, high LVC-2) at the head was <br />measured. Overall, the movement can be described as very slow to extremely slow, with permanent <br />structures likely to remain undamaged. The values also indicate that 1998/99 landslide movements have <br />decelerated dramatically from the previous 1997/98 movements. <br />Future movement is predicted using the log-log plot of historic movement, and extrapolating the movement <br />to the future is shown on Figure H11. Figure Hl I shows that [he all portions of the landslide are <br />stabilizing. <br />Bart Engineering Company <br />PCDOCS1208220/CAK <br />July 37, 1999 <br />16 Appends: H <br />1999 Addendum to <br />7997199 Landslide Corrective Measures Report <br />