MECHANICAL PROPERTIES OF DEWATERED SEWAGE SLUDGE AND ITS INFLUENCE ON THE STORAGE BIN

Because of the lack of the research of the mechanical properties of the dewatered sewage sludge, this paper carried out geotechnical experiments, to study the relationship among the void ratio, the compressibility coefficient, the stress-strain relation, the shearing strength and the vertical pressure, and to analyze the inffiuence of the properties of the sludge on the storage bin. Results show that the water ratio and the void ratio of the sludge are much higher than those of the average mucky sludge. For the solid sludge, the shearing strength and the cohesion are much higher than those of the loose sludge. The loose sludge has a high compression, with a minimum compression coefficient under a vertical pressure around 62.5~100 kPa, and the particle structure of the sludge is relatively stable. When the vertical pressure exceeds 60 kPa, the sludge is apparently over- consolidated, the internal friction angle is close to that of the solid sludge. Before putting the sludge into the bunker, it should be crushed to avoid to be over-consolidated.