To prevent spontaneous failure due to liquefaction in existing upstream tailings dams, one of the three critical conditions (loose soils / presence of water / stimulation by vibration or load change) must be eliminated in a deﬁned manner. Soil improvement measures in the subsurface, such as immobilization by a deep mixing method (DSM) and drainage, can signiﬁcantly reduce the risk of failure. In addition, installation of a rigid grid of interconnected DSM elements can help stop the ﬂow of liqueﬁed material toward a critical tailings dam.
It is recommended to install a monitoring system that can be used before, during and after the subsurface improvement methods. This would be particularly useful for sensitive structures, to establish the necessary controls required ensuring their safety and integrity. Online-monitoring systems are available. Bauer has the know-how and technologies for such instrumentation and monitoring installation.