Search

Hurricane and tsunami events can generate extreme water flows in nearshore regions of the United States with catastrophic consequences to coastal structures. Field records have shown that light-frame wood structures exhibit high vulnerability to wave-induced forces due to their light construction characteristics, which feature flexible connections and slender pile foundation systems. Previous research has studied the behavior of these structures under wave action, but most studies used rigid body modeling, which is shown in this study to be insufficient for capturing the force demand on these structures. Using a fluid-structure interaction (FSI) framework, this research investigated the structural and soil flexibility effects in the interaction between elevated light-frame wood structures and water flows. Study variables included the flexibility of timber-to-timber connections, soil type, pile embedment, wavelength, and wave amplitude. The study concluded that structural and soil responses to water flows can introduce strong coupled motions. Neglecting this coupling effect may underestimate the force demand on the light-frame wood structures by more than 40%. Accounting for both structural and soil flexibilities is necessary to accurately quantify the wave force demand of these structures. [ABSTRACT FROM AUTHOR]

This article discusses a combined analytical and experimental study on the nonlinear seismic performance of two Guastavino-style masonry domes located in the United States. The seismic performance of these masonry domes is simulated with nonlinear finite-element (FE) models. To support the assumptions and decisions established during the development of the FE models, the vibration response of the domes is measured on-site and systematically compared against the numerical model predictions. Linear FE models are developed that are in close agreement with the measured natural frequencies and in visual agreement with the measured mode shapes. Next, these linear models are extended into the nonlinear range by incorporating the Drucker-Prager damage criterion. Finally, nonlinear FE models are used to assess the performance of these two domes under seismic loadings obtained from the 1940 El Centro earthquake acceleration records. The predicted displacements and internal tensile stress levels are used to make inferences about the potential behavior of these two buildings under the selected earthquake load. [ABSTRACT FROM AUTHOR]

The foundations contract for replacement of the Woodrow Wilson Bridge near Washington, D.C., presented an opportunity to profit from partnering. This article tells why partnering was necessary, the techniques used, and some payoffs. The contract had disincentive payments, potential for differing site conditions, community constraints, and untested relationships. Regular meetings and a monthly questionnaire facilitated partnering, trends and comments were analyzed monthly to keep on track, and both parties went beyond contract requirements to succeed. Partnering belongs in any major acquisition program’s toolkit. [ABSTRACT FROM AUTHOR]

Describes the damages to the anchor bolt connection between the concrete foundation and the wood sill plate caused by the 1992 earthquake at Big Bear Lake in San Bernardino County, California. Cause of depletion of shear capacity of the connection; Persons who are responsible for installation; Observations about tie-down anchors.