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Maintaining the functionality of wastewater networks is critical to individual well-being, business continuity, public health, and safety. However, seismic damage and loss assessments of wastewater networks traditionally use fragility functions based on median repair rates without considering relevant sources of uncertainty and correlations of damage when estimating potential damage states and pipe repairs. This study presents a probabilistic methodology to incorporate modeling uncertainty (e.g. model parameter and model class uncertainty) and spatial correlations (e.g. spatial auto- and cross-correlation) of pipe repairs. The methodology was applied to a case study backbone system of a wastewater network in Portland, OR, using the expected hazard intensity maps for multiple deterministic earthquake scenarios, including a moment magnitude M6.8 Portland Hills Fault and M8.1, M8.4, M8.7, and M9.0 Cascadia Subduction Zone (CSZ) events. As spatial-correlation models of pipeline damage were non-existent in the literature and local information on costs to repair the pipes was limited at the time of this study, correlation methods and repair costs were proposed to estimate lower and upper bounds of pipe damage and loss. The results show how the consideration of different levels of uncertainty and spatial correlation for pipe repair rate could lead to different probabilistic estimates of damage and loss at the system level of the wastewater network, even though the point estimates, such as the mean and median, remain essentially unaltered.

This article presents the data collected through an online survey of experts in the field of roadway and bridge inspection and repair, with an aim to understand and characterize post-hazard restoration timelines. Accurate characterization of natural hazard resilience of a community requires a thorough understanding of the restoration process. However, empirical data are lacking to systematically relate damage induced by multiple hazards to functionality for both roadways and bridges. Existing models, relying on survey data which are tailored for seismic damage to bridges, either fail to capture the entire restoration timeline or do not account for intermediate stages of restoration. To address these gaps, an online survey of experts eliciting recommended traffic closures and the estimated time required to remove traffic closures/partial restrictions is presented herein. This article contains a detailed description of the survey methodology with insights into the data collected from a total of 29 respondents to enable its use in the area of transportation infrastructure risk and resilience analysis under natural hazards.

Following the 25 April 2015 Mw7.8 Gorkha, Nepal, earthquake and subsequent aftershocks, field surveys were conducted on medium-to-high rise reinforced concrete (RC) frame buildings with masonry infill located in the Kathmandu Valley. Rapid visual assessment, ambient vibration testing, and ground-based lidar (GBL) showed that these buildings suffered damage ranging from light to severe, where damage occurred in both structural and nonstructural elements, but was most prevalent in nonstructural masonry infills. Finite-element structural analyses of selected buildings corroborate field observations of only modest structural damage. The lack of severe structural damage in this relatively limited class of engineered medium-to-high rise RC infill frame buildings illustrates the impact of modern seismic design standards and stands in stark contrast to the severe damage and collapse observed in low-rise nonengineered RC infill frame buildings. Nonetheless, the nonstructural damage hindered many of these buildings from being occupied for many months following the earthquake and subsequent aftershocks.

This paper documents and analyzes the seismic behavior of unreinforced masonry (URM) buildings that were damaged by the 2015 Gorkha earthquake in Nepal, and reports on the performance of palaces, giving an overview on the failures suffered by significant examples of these monumental buildings. Field reconnaissance was completed through both rapid, in-situ visual assessment and state-of-the-art procedures utilizing light detection and ranging (lidar) and virtual reality (VR) technologies. Both the visual and virtual assessments were compared for 20 structures and were generally consistent; however, the virtual assessment process enabled detection of damage that could not be captured or was difficult to distinguish in the field observations. Further, both in-plane and out-of-plane mechanisms were analyzed and attributed to specific structural deficiencies that usually characterize poorly detailed masonry buildings. Moreover, wall overturning was correlated with the peculiarities of the pseudo-accelerations and rocking response spectra of the earthquake.

This paper presents a novel methodology to combine ambient vibration-based operation modal analysis with three-dimensional ground-based lidar data to study damage on the Nyatapola Temple, which is a Bhaktapur UNESCO World Heritage Site that was damaged during the 2015 Gorkha, Nepal, earthquake. The post-earthquake ambient vibration data, collected via accelerometers placed on various levels of the temple, are used to estimate the vibrational properties via operational modal analysis. These properties are then compared to the pre-earthquake dynamic characteristics collected in 2002. The lidar data provide a geometric assessment of the current condition of the temple, capturing post-earthquake drift as a function of height as well as significant cracks present in the facade. The lidar data also inform the numerical models implemented for the post-earthquake condition assessment of the temple.