عنوان مقاله [English]
The heterogeneous materials behavior of municipal solid waste is affected by two main parts of inert materials and combustible materials of waste. The purpose of this study was to investigate the effect of inert materials behavior on shear strength of solid waste in the Kahrizak burial center of Tehran. These studies were carried out by evaluating the behavior of the Recycled Solid Waste Samples in large scale triaxial apparatus in consolidated - undrained samples of fresh municipal solid waste and older (9 years old) under the conditions of the burial center. Initially, the behavior and strength parameters of the samples were examined in the present situation without adding additional inert materials and then, in order to evaluate the effect of inert materials on the shear strength of the waste, we used the concrete aggregates as an additional inert material section in the samples. These aggregates were used as a inert material part in modeling with different levels of roughness and fracture percentages of 15%, 40%, 60% and 15% in weight. The results of the studies show that the presence of a inert materials section causes significant changes in the shear strength of the samples and increases the deviator stresses, so that the inert materials increases the shear strength of the waste mass up to three times the initial value, and as these materials have more roughness and more rigid surfaces, shear strength increases further. The impact of the inert materials section on new samples is due to the nature of the waste components is more than the elderly samples, the shear strength of old samples in the same conditions is determined 50% higher than fresh samples. Also, due to the creation of a larger lock and fastener between aggregates in larger all-round tensions, the effect of the inert materials performance increases with increasing levels of tension in the test. In addition, the inert materials have a greater effect on the increase of the internal friction angle parameter (Φ) and can increase this parameter up to three times the initial value.