17 research outputs found

    Failure of an Anchored Sheetpile Bulkhead

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    An anchored steel sheetpile bulkhead was constructed in soft organic silt and clay. The bulkhead failed when the anchors ruptured during dredging in front of the bulkhead. The construction and failure of the bulkhead are described. Analyses were performed to investigate the cause of the failure. The major factors which contributed to the failure were: 1) failure to design for the lowest tide condition, 2) use of design soil strengths which were too high, 3) prestressing of the anchor system which resulted in increased anchor loading due to soil arching, and 4) bending stresses induced in the anchors by settlement and equipment loading. Particular emphasis is placed on the effects of soil arching on the anchor loading

    Failure of a Dredged Slope in a Sensitive Clay

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    During construction of a new wharf facility in Portland, Maine, an underwater slope failed during dredging and subsequent driving of piles through the slope. The construction and failure of the slope are described. The major factors which contributed to the failure were: 1) high sensitivity of the silty clay, 2) placement of riprap on the crest of the slope to 4 to 6 ft above the design elevation, 3) method of dredging which caused high shear stresses and probable disturbed zones near the toe of the slope, 4) dredging slope steeper than design slope, 5) pile driving causing localized disturbed zones with low strength around the piles, and 6) sequence of dredging and pile driving

    Vertical Load Tests of Footings on Silt

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    Vertical load tests were performed on two shallow spread footings founded on nonplastic silt. Maximum vertical loads of 500 kips were applied to the test footings which were about 24 x 12 x 4 ft in size. Instrumentation was installed to measure footing displacements, footing contact stresses, and soil displacements below the footings. Results of the load tests have been presented in graphic form. Comparisons have been made between measured settlements of the footings and predicted settlements based on standard penetration test results in the silt deposit

    Utility of echocardiography in predicting mortality in infants with severe bronchopulmonary dysplasia

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    This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Objective: To determine the relationship between interventricular septal position (SP) and right ventricular systolic pressure (RVSP) and mortality in infants with severe BPD (sBPD). Study design: Infants with sBPD in the Children's Hospitals Neonatal Database who had echocardiograms 34-44 weeks' postmenstrual age (PMA) were included. SP and RVSP were categorized normal, abnormal (flattened/bowed SP or RVSP > 40 mmHg) or missing. Results: Of 1157 infants, 115 infants (10%) died. Abnormal SP or RVSP increased mortality (SP 19% vs. 8% normal/missing, RVSP 20% vs. 9% normal/missing, both p < 0.01) in unadjusted and multivariable models, adjusted for significant covariates (SP OR 1.9, 95% CI 1.2-3.0; RVSP OR 2.2, 95% CI 1.1-4.7). Abnormal parameters had high specificity (SP 82%; RVSP 94%), and negative predictive value (SP 94%, NPV 91%) for mortality. Conclusions: Abnormal SP or RVSP is independently associated with mortality in sBPD infants. Negative predictive values distinguish infants most likely to survive

    Top Quark Physics

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    We review the prospects for studies of the top quark at the LHC.We review the prospects for studies of the top quark at the LHC. Members of the working group who have contributed to this document are: A.Ahmadov, G.Azuelos, U.Baur, A.Belyaev, E.L.Berger, W.Bernreuther, E.E.Boos, M.Bosman, A.Brandenburg, R.Brock, M.Buice, N.Cartiglia, F.Cerutti, A.Cheplakov, L.Chikovani, M.Cobal-Grassmann, G.Corcella, F.del Aguila, T.Djobava, J.Dodd, V.Drollinger, A.Dubak, S.Frixione, D.Froidevaux, B.Gonzalez Pineiro, Y.P.Gouz, D.Green, P.Grenier, S.Heinemeyer, W.Hollik, V.Ilyin, C.Kao, A.Kharchilava, R. Kinnunen, V.V.Kukhtin, S.Kunori, L.La Rotonda, A.Lagatta, M.Lefebvre, K.Maeshima, G.Mahlon, S.Mc Grath, G.Medin, R.Mehdiyev, B.Mele, Z.Metreveli, D.O'Neil, L.H.Orr, D.Pallin, S.Parke, J.Parsons, D.Popovic, L.Reina, E.Richter-Was, T.G.Rizzo, D.Salihagic, M.Sapinski, M.H.Seymour, V.Simak, L.Simic, G.Skoro, S.R.Slabospitsky, J.Smolik, L.Sonnenschein, T.Stelzer, N.Stepanov, Z.Sullivan, T.Tait, I.Vichou, R.Vidal, D.Wackeroth, G.Weiglein, S.Willenbrock, W.W

    ATLAS detector and physics performance: Technical Design Report, 1

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    Independent component analysis: fetal signal reconstruction from magnetocardiographic recording

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    Independent component analysis (ICA) was used for the processing of cardiological signals obtained by means of fetal magnetocardiography (fMCG), a technique allowing the non-invasive recording of the weak magnetic field variations associated to the electrical activity of the fetal heart. Purpose of the present work was to verify whether a computational-light ICA algorithm (FastICA), tailored to the characteristics of fMCG, could reconstruct reliable signals of the fetal cardiac activity during the last gestational trimester, when good electrophysiological traces are difficult to obtain although being extremely important for clinical diagnosis of severe fetal dysrhythmias. Several combinations of input recordings and output components were examined in order to assess the best configuration to successfully use FastICA. The reconstructed traces were compared with those obtained with deterministic techniques already used for this purpose, and they showed to be stable and reliable, unaffected by overlapped maternal and fetal beats and suitable for clinical applications
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