Krasnov S. Enhancement of pedestrian superstructure under dynamic influence.

The thesis is dedicated to enhancement and research of new type composite reinforced concrete structural systems of pedestrian superstructures with lightweight concrete slab to provide heightened resistance to dynamic influences. Implementation expediency of energy principles and techniques of direct designing (engineering) for improving and regulation dynamic characteristics of pedestrian superstructures structural systems is confirmed based on comparative analysis of literary sources and learned issue status Efficiency of proposed technique regulation of system internal and external parameters a.o. changing of reinforced concrete slab with structural thickness from 10 up to 25 cm wherein saved weight of all construction has been shown. Rational thickness of reinforced concrete slab of the upper zone for superstructures with length 6m, 9m, 12m, 15m, 18m, 21m, 24m, 33m and frequency characteristics have been determined as a result of control. Experimental and theoretical research of eigenfrequencies fluctuations of supposed form superstructure was carried out. Experiment aim and program, object of research, loading and measurement system that were necessary for verification of theoretical preliminaries defining values of eigenfrequencies and natural period construction under the treatment determined on a ground of finite element method modeling in the PC medium "LIRA" (version 9.6) and manual calculations techniques. Thus, research results connected with dynamic of human motion were obtained. Analysis of speed and frequencies of pedestrian movement was treated by the author. Also, experimental eigenfrequencies of forced oscillations estimation of superstructure design of bridge under the treatment with influence on it loading from moving humans (pedestrians) and under microwave loadings from manual tamping or compactors. Efficiency of offered constructive system superstructure of pedestrian bridges improvement method was monitored in full-scale experiment with sample of superstructure under influence of concentrated and dynamic distributed load. However, mathematical analysis of received data for emergence resonances effects was performed and the damping rate value in proposed system was specified. Divergences results not exceed 12%. The implementation of the research results has been carried out via designing and construction thus decisions efficiency was verified.