Seismic Researchn The Combined Structure-Equipment System Of Coal Preparation Plant

This research investigated systematically the seismic performance of combined structure-equipment systems in the coal preparation plant, and analyzed the effects of considering the dynamic interaction or not. Three frame constructions (FR1, FR2, FR3) are chosen as research examples according to the true state of coal preparation plant. FR1 and FR2 are typical systems with equipments supported on frame. FR3 is the typical complicated system. The primary and secondary systems are analyzed separately for FR3. Elastic and inelastic time history analyses are conducted on the three frames, and different strong motion records are iuput according to the field types. The main contents including:1. On the basis of summarization of current researches, the problems in this area are discussed.2. Conclusions are summarized for FR1 and FR2:(1) .It's beneficial for seismic resistant of the system with single-degree-of-freedom equipment to consider interaction in elastic stage, responses of the system is reduced .In inelastic stage, the responses are same, but with the increase of seismic intensity, the benefit is impaired. Even in the case of interaction considered under lager amplitude acceleration, the system will enter inelastic stage earlier. So interaction will cause responses increased and disadvantage factors in inelastic stage.(2) .It's unbeneficial for seismic resistant of the system with two-degree-of-freedom equipment to consider interaction in elastic stage, responses of the system is increased . In inelastic stage, the response of top displacement and the maximum interstory drift ratio are same as in elastic stage, but the bottom shear force is reduced simultaneously when considering interaction. After comprehension analysis, it's believed that interaction is disadvantage in inelastic state.3. Single-equipment and multi-equipment are considered in the analysis of FR3. According to the existence of main equipment, the multi-equipment situation is divided into different type. Through analysis, the conclusions are as follows:(1) .For the complex compound system, interaction benefit to seismic resistance of primary structure in elastic stage .When main equipment is on the floor, it's response is the main component of systematic response. When the mass ratio of primary equipment is 30% of the mass of the floor and the period ratio is between 0.8~1.0, interaction is obviously effective to reduce seismic response for the primary structure. The reduction ratio of displacement and bottom shear force are up to 25% and 15% respectively. When there are more equipments on the floor, seismic performance of the system will vary with the different position of the primary and secondary equipments.-II-Abstract(2). In inelastic range, though dynamic interaction reduces top displacement and the maximum interstory drift ratio, however it increases the bottom shear simultaneously. The bottom shear amplification factor is assumed to be 1.25 after comparison and analysis.4. For the secondary structure, interaction is considered to reduce the seismic response after concrete analysis.5. At last, suggestion on structure design of coal preparation plant are presented.