Earthquake resilience of urban underground structures: State ofthe art

Abstract

<p indent="0mm">Earthquake-resilient underground structures can reduce earthquake-induced damage, protect life and property, and maintain their functions with minor or no repair after an earthquake. As earthquake-resilient cities are increasingly developed, improving the seismic resilience of underground structures has become a popular topic in research on underground structure earthquake engineering. This paper systematically summarizes research progress on the improved seismic resilience of urban underground structures. The principle of earthquake-resilient underground structures is first introduced. Then, the latest achievements in these structures are summarized from two aspects, namely, improvements in the seismic performance of underground structures during earthquakes and restoration of the function of underground structures after earthquakes. Finally, the research trend of earthquake-resilient underground structures is discussed. Most of the technologies proposed to improve the seismic resilience of underground structures focus on reducing earthquake-induced damage. Research on restoring the function of underground structures after earthquakes is generally insufficient. Future work should focus on restoring the function of underground structures after earthquakes, especially the restoration degree and speed. Moreover, new structural systems and larger-scale model tests, which form the basis of assessments of the seismic behavior of underground structures, should be further developed. The seismic design standards and codes of earthquake-resilient underground structures should be put forward, and the popularization and further applications of earthquake-resilient underground structures should be conducted.