Seismic response of an elevated aqueduct considering hydrodynamic and soil-structure interactions

Abstract

In conventional design of an elevated aqueduct, apart from considering the weight of water inside the channels, hydrodynamic forces are generally neglected. In a few special cases involving high seismic zones, hydrodynamic forces have been modeled considering equivalent lumped-mass type idealization or other models. For support conditions, either the base is considered as fixed or in a few cases, equivalent spring-dashpot system is considered. However, during an intense seismic event, nonlinear soilstructure interactions (SSI) may alter the response of the aqueduct significantly. This paper investigates the effect of hydrodynamic forces and SSI on seismic response of a representative elevated aqueduct model. Different modeling concepts of SSI has been adopted and the responses are compared. Frequency domain stochastic response analysis as well as time-history analysis with a series of ground motions of varying hazard levels have been performed. Demand parameters such as base shear and drift ratio are studied for varying heights of water in channels and different site conditions. From the frequency domain analysis, the effect of convective masses is found to be significant. From the time history analysis, the overall effect of increase in height of water is found to be negligible for nonlinear base case unlike the fixed and elastic base cases. For the nonlinear base condition, the base shear demand is found to decrease and the drift ratio is found to increase when compared to the results of linear base condition. The results of this study provide a better understanding of seismic behavior of an elevated aqueduct under various modeling assumptions and input excitations.

Seismic Response of Cable-Stayed Spanning Pipeline Considering Medium-Pipeline Fluid–Solid Coupling Dynamic Effect

“…This indicates that heat-fluid-solid coupling should be added to the seismic response of oil pipelines, which provides technical and theoretical support for the design and seismic resistance of oil and gas pipelines in cold regions. Bhavana [26] presented a model with a combination of equivalent mass and other types of hydrodynamic models because the effect of hydrodynamic forces in themselves is often neglected in elevated ferries, and the seismic response analysis of the model considering hydrodynamic and soil-structure interactions indicated that the effect of fluid mass on the ferry was significant in the frequency domain. However, this study did not take into account the hydrodynamic effects that occur when the bridge structure is completely submerged in water, thus only providing theoretical insights for the modeling and seismic response of an elevated aqueduct.…”

Stable parameters identification for rational approximation of Single degree of freedom frequency response function of semi‐infinite medium

“…Meng et al 11 calculated and obtained the analytical solution of the longitudinal complex impedance of large‐diameter floating pipe piles. Luan et al, 12 Zheng et al 13 and Cai et al 14 studied the method for calculating the frequency response function of the dynamic stiffness of pile foundations in different soil conditions; Valeti et al, 15 Li et al 16 and Bencharif et al 17 proposed numerical methods for calculating the dynamic stiffness of raft, strip, and piled raft foundations; and Lian et al, 18 Ostlund et al 19 and Latini et al 20 studied the influence of different soil conditions and physical parameters on the dynamic stiffness of foundations. Scholars have also studied the frequency response function for semi‐infinite water; Medina et al, 21 for example, calculated the dynamic stiffness frequency response functions for dams and columns in water.…”

Seismic Fragility Evaluation of Simply Supported Aqueduct Accounting for Water Stop’s Leakage Risk

“…Aqueducts and bridges have similar super-and substructures. However, compared with a bridge, the coupling effect of fluid in an aqueduct should be considered [4]. Therefore, fluid-structure interaction (FSI) should be taken into account.…”

“…Moreover, there have been a large number of studies on the seismic fragility of liquid storage tanks, industrial storage pipes, and silos [17][18][19][20][21][22]. In terms of aqueducts, Valeti et al [4] studied the seismic response of an elevated aqueduct with a hydrodynamic force and the nonlinear interaction of soil-structure, and the effect of convective masses was found to be significant. Prashar [23] conducted an aqueduct earthquake disaster assessment.…”