Interpretation of monitored behavior of slopes for early warning of failure

摘要

Monitoring and early warning is one of the most promising ways toward reduction of disastersrninduced by landslides and slope instabilities. Although less costly than construction of retaining walls and otherrnmechanical measures, early warning has several problems to be overcome. First, it is often the case that the exactrnlocation of an unstable soil mass is not defined and hence the location of monitoring sensors cannot be decided.rnThis problem can be solved by installing many low-cost sensors within a possibly unstable slope. The secondrnproblem concerns what slope information should be monitored. The present study has developed a low-cost MEMrnsensor that can monitor slope deformation by means of tilting angle of the sensor during heavy rainfall. A wirelessrnnetwork collects signals from the sensors periodically and helps local governmental issues through cellular phonesrnan alert signal or emergency evacuation order, depending upon the progress of tilting of sensors. It is furtherrnimportant that the low cost of the sensors allow individuals to purchase personally and installs them in order tornprotect themselves from slope disasters. The developed equipments have been deployed in several slopes in thernrecent times for validation of field performance. The present text reviews the obtained records and discusses theirrnuse for practice.