Twenty-one years of heave monitoring in London Clay at Horseferry Road Basement

An 11 m-deep basement structure in London SW1 was left vacant from 1968 to 1989. The basement heaved significantly during this period due to the lack of a superstructure, providing a unique opportunity to study the development of long-term heave in London Clay. May (1975) presented the monitoring results from 1968-73 and excerpts of site data collected after 1973 have also been circulating informally in the industry since the 1990s. However, the full set of monitoring data remains hitherto unpublished. This paper was initially drafted in the early 1990s when three of the authors (Nicholson, Chapman, and Solera) were working together with Arup. The paper somehow never got published as people and circumstances changed. More recently, the first author (Chan) started postgraduate research on heave and pressure beneath slabs in excavations in over-consolidated clays, using the heave monitoring data from the draft paper to complement centrifuge test results. For this reason, it was decided that the draft paper should be revised and published for the benefit of the wider industry. This paper provides a comprehensive case history of the site, publishing further heave data to June 1989, giving a total of 21 years of heave monitoring. Further site investigation data and calculations are included for comparison. The data show that the presence of a basement did not significantly reduce the shear strength of the clay beneath it. The coefficient of consolidation of the clay was 38 – 52 m²/year and long-term heave was still ongoing 21 years after the end of excavation.EPSRC grant reference number EP/L016095/

Research data supporting "Twenty-one years of heave monitoring in London Clay at Horseferry Road Basement".

This dataset provides details on the heave monitoring data, the site investigation data, and the calculations presented in the paper "Twenty-one years of heave monitoring in London Clay at Horseferry Road Basement". The dataset contains 13 files described as follows: "A1 - Site investigation cross-sections" contain cross-section drawings of the Horseferry Road Basement as of 1989 and form the basis of Fig. 2 of the paper. "A2 - Graphs of soil test results" present the results of laboratory tests of soil samples from Horseferry Road site in 1989. "A3 - Undrained shear strength data and calculations" combine undrained shear strength data from the 1962 and 1989 site investigations; the XLSX version of this file also includes the calculations producing Fig. 5 and Table 2 of the paper. "A4 - Piezometric profile with interpreted trendline" gives groundwater level data from the 1989 site investigation (Fig. 4 of paper). "A5 - Standard penetration test data and calculations" gives soil strength results from the 1989 site investigation. "B - Heave monitoring data 1967-89 and calculations" provides all survey data of settlement and heave of the Horseferry Road Basement during the 21 years of monitoring. The XLSX version includes calculations of theoretical best-fit and coefficients of consolidation, as presented in Fig. 6. "C - VDISP back-analysis of heave monitoring data at Horseferry Road, 1993" presents the calculations of drained stiffness and strength profile from an analysis produced in 1993 for use in the reconstruction of the site, as discussed in the "Analysis of heave" section of the paper; the computational results date from 1993 and the abridged summary was written by the editor of the dataset. "D - Site investigation factual report, 1989" contains borehole logs from the 1989 site investigation. The original data and scans are provided by the courtesy of Arup Geotechnics and Laing O'Rourke who kindly agreed to make this set of data publicly available for the benefit of industry and society.EPSRC Centre for Doctoral Training in Future Infrastructure and Built Environment at Cambridge University (EPSRC grant reference number EP/L016095/1

Experimental study of structural movements and swelling pressures on deep basements caused by long-term heave in over-consolidated clay

Urban growth has necessitated the construction of many large, deep basements in city centres. In many places, most notably London and South East England, these basements are founded upon stiff, over-consolidated clay strata. These clays exhibit long-term heave over many years after the construction of the basement structure, producing additional heave-induced soil stresses and movements. However, scarcity of site monitoring data has led to much conservatism in the design of basements subjected to long-term heave loading. This paper presents the results of a series of geotechnical centrifuge tests, which model the three-dimensional heave behaviour of a rectangular deep basement structure underlain by over-consolidated clay. The tests are carried out at a centrifuge acceleration of 100 times Earth’s gravity. A heavy fluid of the same density as the soil is drained from the basement cavity, to model the excavation process in the field. An actuator subsequently applies a vertical load on the structure’s walls to simulate the construction of an over-site development. The model structure is instrumented to monitor the evolution of vertical displacement at various points on the base slab, structural bending strains in the basement slab and in the walls, and the contact pressures between the structure and the soil. The results show good agreement with monitoring data from a site in London where a basement slab was allowed to heave without any building on top for over 20 years. These findings aim to provide guidance on heave magnitude for future construction projects.Mott MacDonal

Synthesis, structure and reactivity of new late transition metal complexes bearing diphosphane ligands derived from bis(pyrazol-1-yl)methane

Modification of the multistep synthesis of the previously described bis[5-(diphenylphosphanyl)pyrazol-1-yl)]methane (bppzm, 1) produces the novel diphosphane (diphenylphosphanyl)-[5-(diphenylphosphanyl)pyrazol-1-yl](pyrazol-1-yl)methane (p4m, 2). Treatment of this ligand with [MCl2(PhCN)2] (M = Pd, Pt) or [M(COD)(THF)2]BF4 (M = Rh, Ir) produces [MCl2(p4m)] (M = Pd 3, Pt 4) or [M(COD)(p4m)]BF4 (M = Rh 5, Ir 6) complexes, which chelate in a P,P-bidentate fashion. Sulfidation of bppzm and p4m produces the disulfidophosphanes bppzmS2 (7) and p4mS2 (8). Treatment of 7 and 8 with [PdCl2(PhCN)2] produces [PdCl2(bppzmS2)] (9) and [PdCl2(pmS2)] (10), respectively, in which ligands 7 and 8 act in an N,N-bidentate chelate fashion. In contrast, ligand 8 reacts with [Rh(COD)(THF)2]BF4 to produce [Rh(COD)(p4mS2)]BF4, where ligand 7 acts in a dynamic S,S-chelate fashion. The activity of some of these complexes in the catalytic hydrogenation of olefins is reported and the single-crystal X-ray structures of 4, 8, and 9 have been obtained.We gratefully acknowledge financial support from the Dirección General de Enseñanza Superior e Investigación Científica (Ministerio de Educación y Cultura), Spain (Grant. No. 1FD97−0176)

Prediction of long-term outcomes of HIV-infected patients developing non-AIDS events using a multistate approach

Outcomes of people living with HIV (PLWH) developing non-AIDS events (NAEs) remain poorly defined. We aimed to classify NAEs according to severity, and to describe clinical outcomes and prognostic factors after NAE occurrence using data from CoRIS, a large Spanish HIV cohort from 2004 to 2013. Prospective multicenter cohort study. Using a multistate approach we estimated 3 transition probabilities: from alive and NAE-free to alive and NAE-experienced ("NAE development"); from alive and NAE-experienced to death ("Death after NAE"); and from alive and NAE-free to death ("Death without NAE"). We analyzed the effect of different covariates, including demographic, immunologic and virologic data, on death or NAE development, based on estimates of hazard ratios (HR). We focused on the transition "Death after NAE". 8,789 PLWH were followed-up until death, cohort censoring or loss to follow-up. 792 first incident NAEs occurred in 9.01% PLWH (incidence rate 28.76; 95% confidence interval [CI], 26.80-30.84, per 1000 patient-years). 112 (14.14%) NAE-experienced PLWH and 240 (2.73%) NAE-free PLWH died. Adjusted HR for the transition "Death after NAE" was 12.1 (95%CI, 4.90-29.89). There was a graded increase in the adjusted HRs for mortality according to NAE severity category: HR (95%CI), 4.02 (2.45-6.57) for intermediate-severity; and 9.85 (5.45-17.81) for serious NAEs compared to low-severity NAEs. Male sex (HR 2.04; 95% CI, 1.11-3.84), ag

Impact of late presentation of HIV infection on short-, mid- and long-term mortality and causes of death in a multicenter national cohort : 2004-2013

To analyze the impact of late presentation (LP) on overall mortality and causes of death and describe LP trends and risk factors (2004-2013). Cox models and logistic regression were used to analyze data from a nation-wide cohort in Spain. LP is defined as being diagnosed when CD4 < 350 cells/ml or AIDS. Of 7165 new HIV diagnoses, 46.9% (CI:45.7-48.0) were LP, 240 patients died.First-year mortality was the highest (aHR = 10.3[CI:5.5-19.3]); between 1 and 4 years post-diagnosis, aHR = 1.9(1.2-3.0); an

Contemporary use of cefazolin for MSSA infective endocarditis: analysis of a national prospective cohort

Objectives: This study aimed to assess the real use of cefazolin for methicillin-susceptible Staphylococcus aureus (MSSA) infective endocarditis (IE) in the Spanish National Endocarditis Database (GAMES) and to compare it with antistaphylococcal penicillin (ASP). Methods: Prospective cohort study with retrospective analysis of a cohort of MSSA IE treated with cloxacillin and/or cefazolin. Outcomes assessed were relapse; intra-hospital, overall, and endocarditis-related mortality; and adverse events. Risk of renal toxicity with each treatment was evaluated separately. Results: We included 631 IE episodes caused by MSSA treated with cloxacillin and/or cefazolin. Antibiotic treatment was cloxacillin, cefazolin, or both in 537 (85%), 57 (9%), and 37 (6%) episodes, respectively. Patients treated with cefazolin had significantly higher rates of comorbidities (median Charlson Index 7, P <0.01) and previous renal failure (57.9%, P <0.01). Patients treated with cloxacillin presented higher rates of septic shock (25%, P = 0.033) and new-onset or worsening renal failure (47.3%, P = 0.024) with significantly higher rates of in-hospital mortality (38.5%, P = 0.017). One-year IE-related mortality and rate of relapses were similar between treatment groups. None of the treatments were identified as risk or protective factors. Conclusion: Our results suggest that cefazolin is a valuable option for the treatment of MSSA IE, without differences in 1-year mortality or relapses compared with cloxacillin, and might be considered equally effective

Epidemiology of intra-abdominal infection and sepsis in critically ill patients: "AbSeS", a multinational observational cohort study and ESICM Trials Group Project

PURPOSE: To describe the epidemiology of intra-abdominal infection in an international cohort of ICU patients according to a new system that classifies cases according to setting of infection acquisition (community-acquired, early onset hospital-acquired, and late-onset hospital-acquired), anatomical disruption (absent or present with localized or diffuse peritonitis), and severity of disease expression (infection, sepsis, and septic shock). METHODS: We performed a multicenter (n = 309), observational, epidemiological study including adult ICU patients diagnosed with intra-abdominal infection. Risk factors for mortality were assessed by logistic regression analysis. RESULTS: The cohort included 2621 patients. Setting of infection acquisition was community-acquired in 31.6%, early onset hospital-acquired in 25%, and late-onset hospital-acquired in 43.4% of patients. Overall prevalence of antimicrobial resistance was 26.3% and difficult-to-treat resistant Gram-negative bacteria 4.3%, with great variation according to geographic region. No difference in prevalence of antimicrobial resistance was observed according to setting of infection acquisition. Overall mortality was 29.1%. Independent risk factors for mortality included late-onset hospital-acquired infection, diffuse peritonitis, sepsis, septic shock, older age, malnutrition, liver failure, congestive heart failure, antimicrobial resistance (either methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Gram-negative bacteria, or carbapenem-resistant Gram-negative bacteria) and source control failure evidenced by either the need for surgical revision or persistent inflammation. CONCLUSION: This multinational, heterogeneous cohort of ICU patients with intra-abdominal infection revealed that setting of infection acquisition, anatomical disruption, and severity of disease expression are disease-specific phenotypic characteristics associated with outcome, irrespective of the type of infection. Antimicrobial resistance is equally common in community-acquired as in hospital-acquired infection.status: publishe