OPTIMIZATION DESIGN OF THE LANDSLIDE MONITORING IN SPECIAL CONDITIONS

Landslide is one of the common geological hazards. So it is becoming more and more important to monitor and forecast it. However, the design of monitoring net is always confined by topography and poor visibility especially. in mountainous areas. Therefore, it is necessary to analyze the qualify the index of the monitoring net in those conditions and optimize it.By considering the economic index, the traditional design method of monitoring net and base net for their mature operation are usually adopted. However, for the poor condition mentioned above, the monitoring net with angle observation can not satisfy the minimum angle in surveying criterion. On the other hand, considering that the total station has high precise on line surveying, we adopted to survey the lines, analyzed and calculated internal and external reliabilities and sensitivities of the two typical points which precisions is lowest. We analyzed the reason why the line is poor reliable according to the result calculated. And we bring out the way to design an optimized method according to the economic and quality index. This method is to observe an angle related to this line with 2.5" precision additionally. It is proved that the reliability has been increased greatly So, it is necessary and effective to optimize the monitoring net.