Guanzhou Jie

Bio: Guanzhou Jie is an academic researcher from University of California, Davis. The author has contributed to research in topics: Earthquake engineering & Seismic loading. The author has an hindex of 2, co-authored 4 publications receiving 94 citations.

Time domain simulation of soil-foundation-structure interaction in non-uniform soils

Abstract: Presented here is a numerical investigation of the influence of non-uniform soil conditions on a prototype concrete bridge with three bents (four span) where soil beneath bridge bents are varied between stiff sands and soft clay. A series of high-fidelity models of the soil-foundation-structure system were developed and described in some details. Development of a series of high-fidelity models was required to properly simulate seismic wave propagation (frequency Lip to 10Hz) through highly nonlinear, elastic plastic soil, piles and bridge structure. Eight specific cases representing combinations of different soil conditions beneath each Of the bents are simulated. It is shown that variability of soil beneath bridge bents has significant influence on bridge system (soil-foundation-structure) seismic behavior. Results also indicate that free field motions differ quite a bit from what is observed (simulated) under at the base of the bridge columns indicating that use of free field motions as input for only structural models might not be appropriate. In addition to that, it is also shown that usually assumed beneficial effect Of Stiff soils underneath a Structure (bridge) cannot be,generalized and that such stiff soils do not necessarily help seismic performance of structures. Moreover, it is shown that dynamic characteristics of all three components of a triad made Lip of earthquake, soil and structure play crucial role in determining the seismic performance of the infrastructure (bridge) system. Copyright (C) 2009 John Wiley & Sons, Ltd.

Benefits and Detriments of Soil Foundation Structure Interaction

Abstract: Current design practice for structures subject to earthquake loading regards dy- namic Soil-foundation-Structure Interaction (SFSI) to be beneficial to the behavior of structures. Including the flexibility of the foundation and soil reduces the overall stiffness of a SFS system and can therefore reduce peak loads caused by a given ground motion. This might be true in (some) many cases. However, there is the possibility of SFS system going into resonance with the exciting earthquake motions as a result of a shift of the natural frequencies of the SFS-system. This can lead to much larger inertial forces acting on a structure. In that case, the SFSI is not beneficial, but rather detrimental to the seismic response of the structures (and of the SFS system). In this paper we present methodology and an analysis of beneficial and detrimental effects SFSI can have on seismic response. It will be shown that an interaction between SFS system and the seismic motions plays crucial role in determining if SFSI will be beneficial or detrimental. In other words, SFSI can be both beneficial and detrimental for a particular SFS system, depending on the characteristics of the seismic motions exciting the system.

Numerical Modeling and Simulations of A Complete Earthquake-Soil-Pile-Bridge Seismic Performance

Abstract: Presented is the development of a complete Soil-Pile-Bridge (soil-foundation-structure, SFS) system model (three bents, four spans) in three dimensions subjected to seismic loading. In addition to that, presented also are illustrative and interesting results describing varying performance of the SFS system depending on the local soil conditions, beneath each bent. Seismic shaking results for varying soil conditions beneath bents indicate that local soil conditions (can) have significant effects on dynamics of SFS system. Among other findings, it is noted that free field motions are quite different from motions observed (simulated) at the base of bridge bents, hence SFS interaction plays significant role in dynamics of a SFS system. In addition to that, dynamic characteristics of earthquake also plays significant role in seismic response of SFS system. Presented work constitutes another step in our effort to develop high fidelity models and simulation tools for use in performance based design of infrastructure objects.

OpenSees: A Framework for Earthquake Engineering Simulation

Abstract: Structural engineers face many challenges in attempting to analyze and design structures that can withstand the devastating effects of earthquakes. The OpenSees software framework seeks to aid in this challenging task by letting earthquake engineers develop finite-element and finite-element-reliability applications for use in sequential, high-performance, and distributed processing environments.

Coupled Soil-Structure Interaction Effects of Building Clusters during Earthquakes

Abstract: This study addresses the responses of idealized building clusters during earthquakes, their effects on ground motion, and the ways individual buildings interact with the soil and with each other. W...