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This is the third edition of the NSF Science Plan for the Natural Hazards Engineering Research Infrastructure (NHERI). It was developed to focus natural hazards research on some of the major challenges communities face as they work to enhance their resilience to natural hazard events. It provides information for researchers, funding agencies, practitioners, students, and the public on the critical research needs and the process of conducting multi-hazard research to advance hazards engineering practice and community resilience. The Science Plan provides Grand Challenges and Key Research Questions. 

This is the second edition of the five-year Science Plan for the Natural Hazards Engineering Research Infrastructure (NHERI). It provides information for constituents, including practitioners, as well as guidance for members of the research community.This report is an overview of the research needed to support the Grand Challenges described by the report. It covers both the scope and the process of conducting multi-hazard research for improving civil infrastructure. 

contain conspicuous acknowledgement of where and by whom the paper was presented. ABSTRACT: Shear strength along discontinuities plays a crucial role in the stability of rock structures. The development of geophysical methods to remotely monitor and assess changes in shear strength is essential to the identification of rock hazards that can lead to the loss of life and failure of civilian infrastructure. In this study, compressional and shear ultrasonic waves were used to monitor slip along discontinuities (with different surface profiles) during shearing. A series of laboratory direct shear experiments were performed on two gypsum blocks separated by a frictional discontinuity. The gypsum blocks had perfectly matched contact surfaces with a half-cycle sine wave profile that spanned the central third of the discontinuity, surrounded by planar surfaces. The amplitude of the half-cycle sine wave was varied and ranged between 2 to 10 times the height of the asperities. Compressional, P, and shear, S, ultrasonic waves were continuously transmitted and recorded throughout the shearing process, while Digital Image Correlation (DIC) was used to capture surface displacements. At low normal stresses, distinct maxima in the normalized P and S wave transmitted amplitudes occurred before shear failure in regions where dilation was observed. Where dilation was not detected, an increase in transmitted wave amplitude was observed, even after the peak shear stress was achieved. At high normal stresses, dilation was suppressed, which was associated with an increase in wave amplitude with shear stress until the peak, and then a decrease in amplitude. Monitoring changes in transmitted wave amplitude is a potential method for the detection of dilation along rock discontinuities.