Research On The Physical And Mechanical Characteristics Of Coal Waste For Dam Building

China is a major coal producer whose production of coal waste, the associated product of coal, keeps increasing with the rise of coal production. Coal waste covers large quantities of land and causes environmental pollution, therefore seriously affects and harms people's health and life. The environmental management of coal waste has become an impending problem. The utilization of coal waste in civil engineering not only alleviates the material shortage at the coal mines but also consumes large quantities of stored-up coal waste, therefore could produce great economic and environmental benefits. Currently the engineering utilization of coal waste in China mainly focuses on building roadbeds and backfilling groundwork. There is not yet any precedent which massively utilizes coal waste in building dams. In order to make coal waste meet projects'requirements, pertinent tests and researches must be done on the engineering characteristics of all kinds of coal wastes, so as to provide necessary basis and reference to the design and construction of the dam.Based on systematic physical and mechanical tests on the coal waste in Guye District in Tangshan, this paper makes research and demonstration on the features of the coal waste's storage, constitution, grain crush, spontaneous combustion and water-related quality; by performing triaxial tests, the paper discusses the influencing elements of the shear strength formula and the shear strength parameters of the coal waste; by performing direct shear tests and triaxial tests to the coal wastes of draft designed gradation and dry density, the paper gets the shear strength parameters and constitutive model, and on this basis by using flac software the paper makes a numerical simulation on the draft designed dam, and makes analysis on the stress and displacement of the dam.With the physical and mechanical characteristics of the coal waste meeting the requirements of the dam building project, the coal waste could be used in building the dam of the gangue storeroom. The grain crush feature of the coal waste has overcome its disadvantage of having too many big grains, therefore it better fits on-site rolling; its osmosis characteristic of being notably influenced by the grain composition and degree of compaction is propitious to the water-infiltration design of the dam; the strength properties of the coal waste show clear linearity character therefore could be shown via Coulomb's equation, and the constitutive model is shown by Duncan-Chang's hyperbola mathematic model. The whole dam undertakes the largest stress with most displacement at the dam toes, therefore appropriate measures and reinforcement should be performed in the design and the construction.