The Study On The Physical And Mechanical Properties And Tailings Dam Stability Analysis Under Capillary Action

Tailings pond is an important production facilities of mine, the tailings dam is one of theimportant forms lead to mine disasters. The dam have a big influence on the lives andproperties of human beings surrounding the mines, therefore the studies on the stability of thetailings dam is significant, but the influence of capillary water on the tailings dam was barelyreported at home and abroad. Based on the National Natural Science Foundation of Chinaproject (Stability of capillary water on uranium tailings research (No.51004067)), laboratoryrising test of capillary water was carried out for studying rising law of capillary water in atailings dam of a metal mine in Hunan. The self-designed layered sampling device was usedfor layered sampling and soil testing to research the physical and mechanical properties oftailings sand in capillary water. numerical simulation is used to study the stability of thetailings dam in three different condition which are without consider the capillary water action,tailings in capillary water as a whole to consider and tailings in capillary water layeredconsider.The major works and results of this paper are as follows:(1) The capillary water in tailings rise quickly in the early stages then decreasing withtime increases, the power function fit the tailings capillary water rise well and and thecalculation equations were obtained to describe the law of capillary water rising.(2) The water content and gravity density of the tailings decreased with the height ofcapillary water, gravity density changes with tailings capillary water content changes. Therelationships of cohesion and internal friction angle with the height of capillary waterincreased firstly and then decreased.(3) The internal friction angle with water content increased firstly then decreased andstabled finally, we indicated that is caused by surface properties of the tailings particles andthe action of capillary water. (4) The cohesion with water content increased firstly then decreased, we indicated that iscaused by the interaction of electrostatic attraction and matric suction in the tailings;(5) Numerical analysis of stability in three conditions of a certain tailings dam isconducted. The three conditions include ignoring capillary water, tailings in capillary water asa whole to conside and tailings in capillary water layered consider. The calculation resultsshow that the factor of safety ignoring capillary water is1.17and the other two conditions is1.13, the factor of safety decreased when consider the capillary water. The existence ofcapillary water has some influence on the safety stability of tailings dam.