Study On Seismic Response Of Long-span Cylindrical Reticulated Shell Under Complex Conditions

Long-span reticulated shells are used more and more widely and its span becomes longer and longer. In our country, most of areas are located in the seismic region, so multiple-support excitation should be considered. Thus, there are important theory and practicality signification to study reticulated shell's seismic behavior. In this dissertation, based on the FEM, seismic response of cylindrical reticulated shell under multiple-support excitations and uniform excitations is discussed. Some main achievements of the dissertation are described as follows:1. The dynamic response mechanism of single layer cylindrical reticulated shell under horizontal harmonic excitations was investigated. The results indicate that it is great different between dynamic response of reticulated shell under wave-passage excitations and that of under uniform excitations, and dynamic response under wave-passage excitations can even exceed that of under uniform excitations. Thus, it is essential to consider wave-passage effect of the ground motion..2. Based on linearity model and nonlinearity model of steel, seismic response of single layer and double layer cylindrical reticulated shell under multiple-support excitations and uniform excitations are studied and compared for understanding the rule of seismic response. And the effect of apparent wave velocity is considered.3. Seismic responses of double layer cylindrical reticulated shell under vertical wave-passage excitations and uniform excitations are investigated, and the seismic responses are compared with that of under horizontal seismic excitations. The rules of seismic response under vertical wave-passage excitations are obtained.4. The reticulated shell and the column-support subsystem are separated in the computation for simplified calculation at present, but this is not appropriate. So based on both geometrical nonlinearity and material nonlinearity, seismic responses of long-span double layers cylindrical reticulated shell with column-support subsystem under multiple-support excitations are analyzed deeply, and comparison is made. The column-support subsystem has important effect on seismic response of double layer cylindrical reticulated shell under multiple-support excitation.5. With DMAP language, the equivalent linearization method is added to MSC.Nastran finite element software. Nonlinearity seismic responses of double layer cylindrical reticulated shell under multiple-support excitations are studied considering soil-structure interaction, and the results are compared with that of under uniform excitations. The effect on the seismic response of reticulated shell under multiple-support excitations considering soil-structure interaction are analyzed as well as the effect of apparent wave velocity is discussed.6. Based on equivalent linearization method, the dynamic analysis of the effective stress method was realized by DMAP language considering seismic pore water pressure. Seismic response of double layer cylindrical reticulated shell is computed, and the result is compared with former result. The effect of soil liquefaction on seismic response of reticulated shell was analyzed.