Shaking Table Test And Aseismic Capacity Assessment Of Utility Tunnel System

The utility or common tunnel is popularly regarded as the symbol of urban modernization, particularly in scientific management and programming of infrastructures in urban area. Owning to many virtues, such as avoiding high-frequency road cutting and low maintenance fees for safety and function of infrastructure system, as the economy rapidly development, utility tunnel in China is gradually increasing. As one of the important lifeline systems, utility tunnel plays an important role in keeping the healthy economy and harmonious social order, its malfunction or interruption will result in the economic losses. Although China faces a high seismic risk, there is still not a special aseismic design standard for shallow underground structure like utility tunnel, experimental study aiming to utility tunnel in this thesis will be a great practical significance for aseismic design and constructing this kind of underground structure.Firstly, based on elaborating the advantages of utility tunnel, reviewing its development history, comparing structural parameters and construction method of utility tunnel in China with that abroad, and analyzing earthquake damage characteristics of utility tunnel system, the author discusses to develop aseismic design method for utility tunnel system, suggests that the shaking table test is an ideal platform to explore seismic response mechanism of utility tunnel system, and highlights the problems which should be paid great attention in the test process.Secondly, considering the ditch form, size, buried depth and structural characteristics of utility tunnel constructed or being constructed in China and seismic design requirements of shallow underground structure,two utility tunnel models--branch utility tunnel and main utility tunnel--for shaking table test are designed. The thesis describes the details how to set up shaking table test, including structural model design and making, sensors selection and layout of monitored points, the preparation of model soil and selection of earthquake waves input, and so on.Thirdly, based on the results got by shaking table test, basic dynamic characteristics of model systems, acceleration time history and strain of utility tunnels and soil pressure are analyzed using Spectrum Analysis Method, and some valuable conclusions are got. A series of numerical simulation to study seismic response of model system under different earthquake waves input is done. Compared results from numerical analysis with that from the test, such as the acceleration time history, strain of utility tunnel and soil pressure, conclusions have been obtained.Lastly, this thesis summarizes the achievement in this shaking table test, some useful conclusions for aseismic design of utility tunnel system, which is significant for formulating aseismic design standard.