Predicting reinforced concrete frame response to excavation induced settlement

In many tunneling and excavation projects, free-field vertical ground movements have been used to predict subsidence and empirical limits have been employed to evaluate risk. Validity of such approaches given the reality of two-dimensional ground movements and the influence of adjacent applied loads has been largely unknown. This paper employed analytical and large-scale experimental efforts to quantify these issues, in the case of a reinforced concrete frame structure adjacent to an excavation. Nearly half of all soil and building movements occurred prior to installation of the first tie-back, even when conservative practices were applied. Free-field data generated a trough half the size of that recorded near the building frames. Empirically based relative gradient limits generally matched the extent and distribution of the damage. Application of various structural limits also generally reflected global experimental response but did not fully identify local damage distribution. Fully free-field data or failure to include accurate two-dimensional soil displacements under-predicted building response by as much as 50% for low-rise concrete frames without grade beams.Science Foundation IrelandNDRCNeed to link to publisher version at: http://cedb.asce.org/cgi/WWWdisplay.cgi?170891. DG 02/07/10 ti au SB. 22/7/1

Use of Fenton oxidation to improve the biodegradability of a pharmaceutical wastewater

The applicability of Fenton's oxidation to improve the biodegradability of a pharmaceutical wastewater to be treated biologically was investigated. The wastewater was originated from a factory producing a variety of pharmaceutical chemicals. Treatability studies were conducted under laboratory conditions with all chemicals (having COD varying from 900 to 7000 mg/L) produced in the factory in order to determine the operational conditions to utilize in the full-scale treatment plant. Optimum pH was determined as 3.5 and 7.0 for the first (oxidation) and second stage (coagulation) of the Fenton process, respectively. For all chemicals, COD removal efficiency was highest when the molar ratio of H2O2/Fe2+ was 150-250. At H2O2/Fe2+ ratio of 155, 0.3 M H2O2 and 0.002 M Fe2+, provided 45-65% COD removal