Study On Technique Of Reinforcement Of Dry Heap Tailings Dam With Anchor Plate

With the acceleration of the country's industrialization process,the demand for various mineral resources increases,leading to a large number of tailings ponds in use,tailings emissions are also increasing,tailings pond safety accidents also occur from time to time,resulting in huge loss of life and property;At the same time,due to the avoidance of accidents,the slope ratio of tailings dam established in recent years is too small,the area is too large,and the reservoir capacity is too small.Compared with wet heap,dry heap tailings dam has better stability and can increase slope ratio appropriately.However,the design of dry heap tailings dam has not been clearly regulated in China.Therefore,it is of great practical significance to determine the reasonable slope ratio of dry heap tailings dam and to study the corresponding reinforcement measures.In this paper,the stability of a tailings dam under different working conditions is analyzed based on the engineering background of a tailings pond in Jilin that needs to be expanded with variable slope and the use of anchor plate for subgrade engineering reinforcement.The following results have been achieved:(1)According to the geological exploration data and the field test data,to determine the soil mechanical parameters,using strength subtraction to improve the slope ratio of tailings dam stability analysis,combined with the specifications to determine when the slope ratio of 1:2 to the limit of tailings fill dam slope ratio.Compared with the original scheme,the reservoir capacity can be increased by13.5%.(2)In view of the problem of insufficient safety reserve of tailings dam after the slope ratio is improved,the method of anchoring plate strengthening dry heap tailings dam is designed.By comparing the safety factor,stress,displacement and maximum shear strain of tailings dam,the optimal laying spacing of 1m×1m×0.2m anchoring plate structure is determined by 2.5m.The safety factor increased from 1.31 to 1.54,an increase of 17.6%.(3)Combined with local meteorological data of precipitation intensity grade division standard issued by the national weather service and rainfall parameters,with stress and seepage coupling method for strengthening tailings dam seepage characteristics under different rainfall conditions and stability analysis.The results show that the dry heap tailings dam after reinforcement is stable under different rainfall conditions,but special attention should be paid to the influence of prolonged rainfall on the stability of the tailings dam and the erosion damage of the surface of the heap dam caused by heavy rainfall.(4)Using different seismic waves and adjusting its peak value to the local designed seismic basic acceleration,the acceleration response characteristics at the key position of the strengthened tailings dam,the deformation after earthquake,the development characteristics of the sliding surface during earthquake and the stability after earthquake are analyzed.The results show that the strengthened tailings dam is still stable after the earthquake.