Shallow underground structures used for public transportation are a key component of sustainable cities. In dense urban environments, underground structures are often built near tall buildings. Although such buildings have the potential to alter ground motions in their vicinity and transmit significant forces to adjacent underground structures, the impact of these forces remains uncertain. This project will study the seismic response of temporary and permanent cut-and-cover box structures near mid- to high-rise buildings using a combination of centrifuge testing and numerical simulations. The NEES centrifuge facility at UC Davis will be used for these tests. The data from the tests will serve two purposes: first, to understand seismic soil-structure-underground structure-interaction (SSUSI), and second, to calibrate and improve numerical models. Nonlinear numerical simulations of centrifuge tests will help assess and improve the capabilities of existing numerical tools in capturing SSUSI and key loading mechanisms. Parametric studies using calibrated models will be conducted to make design recommendations. Data from this project will be archived and made available to the public through the NEES Project Warehouse/data repository.
This endeavor will provide engineers with well-calibrated predictive tools to more reliably characterize interactions between soil, foundation, structure, and shallow underground structure during earthquakes. A better understanding of these interactions will also advance research and practice for a range of underground facilities and critical lifelines including tunnels, pipelines, and utilities. As such, the findings of this project are an important step toward improving the resilience of our urban centers to earthquakes. This research project is a collaborative effort between the University of Colorado at Boulder, the University of Illinois at Urbana-Champaign, and ARUP San Francisco. This study will also benefit from collaboration between researchers at NEES and Japan's E-Defense. In its outreach program, the project will recruit outstanding students from underrepresented groups in engineering in collaboration with NSF funded Colorado Alliance for Graduate Education and the Professoriate (AGEP) and the Center for Broadening Opportunity through Leadership and Diversity (BOLD) at CU Boulder. This award is part of the National Earthquake Hazards Reduction Program (NEHRP).