This paper presents a numerical simulation to assess lateral-torsional buckling (LTB) behavior of steel H-beams exposed to localized fire. The nonlinear buckling analysis was conducted using a finite element program, ABAQUS, to assess LTB of the beams. The steel beams were subjected to pure bending and localized fire. The location of the localized fire was applied below at a one-eighth point, a quarter-point and a half of the beam from the support. The combined effects of initial geometric imperfection and residual stress were also considered. The buckling strength of the beam under localized fire and ISO-834 standard fire were generated and compared. The results showed that the LTB strength degradation of the beam under localized fire was slower than that in ISO-834 standard fire. The fire source location and the length-to-height ratio of the beam have a significant effect on the LTB strength of the beam. The LTB capacity of beams using Eurocode 3 with the uniform heating assumption can give over-conservative results when the real fire scenario is localized fire. The buckling strength of steel beams using Eurocode 3 can give unconservative results when the fire scenario is ISO-834 standard fire.

The water quality of a waterbody influenced by stormwater runoff was tested in a lab-scale setting by filtration. The filtration bed was packed with two or three types of media, sand, bottom ash (BA), and woodchips (WC), and tested with three hydraulic conductivities (HCs). Five pollutants—namely, total suspended solids (TSS): BOD, COD, T-N, and T-P, were analyzed and compared. The application of sand-bottom ash (S-BA) and bottom ash-sand (BA-S) media types showed the highest removal efficiencies for TSS, BOD, COD, T-N, and T-P, respectively. Among the five pollutants, TSS achieved the highest removal efficiency for any of the filter media, which was up to 93% for the S-BA and decreased to 72% with an increase in HC, followed by T-P > BOD > COD = T-N. The maximum removal efficiency values of BOD and COD were obtained at 67% and 52%, respectively, indicating that BOD removal was always higher than COD removal. Due to the low C:N and high HC, biodegradation was disregarded during filtration. Based on the different removal forms of T-P compared with TSS, adsorption would be involved in the removal of dissolved T-P by BA.

This paper reports the results of parametric analyses for the lateral torsional buckling strengths of singly symmetric stepped Ibeams with constant depth subjected to general loading conditions. Simply supported beams with varying monosymmetric ratios from 0.1 to 0.9 were analyzed using a finite element program ABAQUS and a regression program MINITAB. Stepped length ratios, flange width ratios and flange thickness ratios were taken from the geometry of real bridges. The beams were first subjected to pure bending to take account for the effect of steps in beams. And then ten-different loading conditions were applied to the beams to study the effect of varied moment along the unbraced span. Design solutions were suggested based on the results of the parametric analyses. The use of equations for beams with inflection point of zero and one is recommended for stepped beams with monosymmetric ratios between 0.1 and 0.9. In specialty, the use of new equation for beams with inflection point of two is recommended for doubly stepped beams with monosymmetric ratios between 0.1 and 0.9 and for singly stepped beams with monosymmetric ratios between 0.1 and 0.7.

Variable Message Signs (VMS) have become a new trend in roadway signs. These signs offer an increase in traffic safety by their ability to relay messages to motorists for warning of hazards ahead such as fog, traffic congestion, accidents, and lane closings. the geometry of these signs sometimes results in significant cyclic loading of the support structure due to wind gusts. This studypresents analytical and experimental investigations of bridge-type VMS structures. GTSTRUDL (2003) is used to perform space frame structural analyses of these welded tubular structures. This paper includes measurements from a static filed test and compariso ns between the measurements and the structural analyses results. Fatigue evaluations are performed based on the stress ranges fromfield measurements and structural analyses. According to this comparative study, the fatigue design loadings derived from AASHTOSpecifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals (2001) can be conservatively used to evaluate the fatigue life of the bridge-type VMS structures.