Natural hazards engineering plays an important role in minimizing the effects of natural hazards 9 on society through the design of resilient and sustainable infrastructure. The DesignSafe 10 cyberinfrastructure has been developed to enable and facilitate transformative research in natural 11 hazards engineering, which necessarily spans across multiple disciplines and can take advantage 12 of advancements in computation, experimentation, and data analysis. DesignSafe allows researchers to more effectively share and find data using cloud services, perform numerical 14 simulations using high performance computing, and integrate diverse datasets such that researchers can make discoveries that were previously unattainable. This paper describes the design principles used in the cyberinfrastructure development process, introduces the main components of the DesignSafe cyberinfrastructure, and illustrates the use of the DesignSafe cyberinfrastructure in research in natural hazards engineering through various examples.

Eight dynamic model tests were performed on a 9-m-radius centrifuge to study the behavior of single piles and pile groups in liquefiable and laterally spreading ground. Pile diameters ranged from 0.36 m to 1.45 m for single piles, and from 0.73 m to 1.17 m for pile groups. The soil profile consisted of a gently sloping nonliquefied crust over liquefiable loose sand over dense sand. Each model was tested with a series of realistic earthquake motions with peak base accelerations ranging from 0.13 g to 1.00 g. Representative data that characterize the important aspects of soil-pile interaction in liquefiable ground are presented. Dynamic soil-pile and soil-pile cap forces are back calculated. Directions of lateral loading from the different soil layers are shown to depend on the mode of pile deflection relative to the soil, which depends on the deformed shape of the soil profile, the pile foundation stiffness, and the magnitude of loads imposed by the nonliquefied crust. Procedures for estimating the total horizontal loads on embedded piles and pile caps (i.e., passive loads plus friction along the base and sides) are evaluated. Due to liquefaction of the sand layer beneath the crust, the relative displacement between the pile cap and free-field crust required to mobilize the peak horizontal loads is much larger than expected based on static pile cap load tests in nonliquefied soils.

During earthquake ground shaking earth pressures on retaining structures can cyclically increase and decrease as a result of inertial forces applied to the walls and kinematic interactions between the stiff wall elements and surrounding soil. The application, based on limit equilibrium analysis, of a pseudo-static inertial force to a soil wedge behind the wall (the mechanism behind the widely-used Mononobe-Okabe method) is a poor analogy for either inertial or kinematic wall-soil interaction. This paper demonstrates that the kinematic component of interaction varies strongly with the ratio of wavelength to wall height (/H), asymptotically approaching zero for large /H, and oscillating between the peak value and zero for /H < 2.3. Base compliance, represented in the form of translational and rotational stiffness, reduces seismic earth pressure by permitting the walls to conform more closely to the free-field soil displacement profile. This framework can explain both relatively low seismic pressures observed in recent experiments with /H > ~10, and relatively high seismic earth pressures from numerical analyses in the literature with /H = 4.

We characterize the seismic fragility of levees along the Shinano River system in Japan using field performance data from two M 6.6 shallow crustal earthquakes. Levee damage is quantified based on crack depth, crack width, and crest subsidence for 3318 levee segments each 50 m long. Variables considered for possible correlation to damage include peak ground velocity (PGV), geomorphology, groundwater elevation, and levee geometry. Seismic levee fragility is expressed as the probability of exceeding a damage level conditioned on PGV alone and PGV in combination with other predictive variables. The probability of damage (at any level) monotonically increases from effectively zero for PGV < 14 cm/s to approximately 0.5 for PGV ≈ 80 cm/s. Of the additional parameters considered, groundwater elevation relative to levee base most significantly affects fragility functions, increasing and decreasing failure probabilities (relative to the PGV-only function) for shallow and deep groundwater conditions, respectively.

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