Numerical models for the design and construction of new underground structures at CERN (HL-LHC), Point 5

The Large Hadron Collider (LHC) is the latest, most powerful, world’s largest underground particle accelerator realized on the CERN site. High-Luminosity LHC (HL-LHC) is a new project aimed to upgrade the LHC, at Point 1 (ATLAS in Switzerland) and Point 5 (CMS in France) in order to enhance scientific progress. This paper describes the design and construction issues developed at the Point 5 for the new underground structures, located near the existing LHC tunnel. The project requires new technical infrastructure: an additional shaft with a 12 m-diameter and 60 m-height, cavern with 270 m2 cross-section, approximately 500 meters of tunnels connected to the LHC tunnel, vertical linkage cores and additional technical buildings at the surface. The geological ground model of this site lies in an area covered by Quaternary moraine with two independent aquifers. The bedrock of Molasse comprises sub-horizontal lenses of heterogeneous sedimentary rock, that is known to locally retain hydrocarbons and to have a swelling behaviour. In order to investigate the heterogeneous behaviour of the rock mass composed of several layers with different strengths, numerical calculations have been performed, under a 2D plane strain condition with RS2 9.0 FEM-software.. The purpose of using the software was to design both the rock-supports and the concrete inner lining for the tunnels and the shaft. Data from a comprehensive monitoring system with pre-defined threshold values was compared to the 2D FEM results, confirming the importance of the observational method to verify the assumptions used in the numerical modelling. The execution of the underground works started in April 2018. The excavation of the main un-derground works has been successfully completed without any critical impact on the nearby ex-isting underground structures. The completion of the works is scheduled for September 2022

PRELIMINARY STUDY FOR SEISMIC ASSESSMENT OF THE UNDERGROUND FACILITIES AT POINT 5 OF THE LARGE HADRON COLLIDER (LHC) AT CERN

The European Organisation for Nuclear Research (CERN) is continuously upgrading its extensive underground facilities to cope with the need for new and more complex experiments. The Large Hadron Collider (LHC) houses the Compact Muon Solenoid (CMS) detector at its Point 5, where there are two large shafts, two 100 m deep major parallel caverns, with a total span of 50 m, separated by a 7 m wide and 28 m high concrete pillar, and a system of secondary tunnels and caverns. Such a complex underground infrastructure lies in a sedimentary rock formation (red molasse) of the Geneva basin, with a low rock cover of about 20 m to the overlying 50 m thick layer of water bearing moraine. The site is classified as a zone of moderate seismicity and the underground structures were designed against a “standard” seismic risk, that corresponds to the importance category II according to Eurocode 8. To study the dynamic response of the caverns to seismic waves, a series of Finite Element (FE) full dynamic analyses have been carried out, where the non-linear behavior of the underground layers has been carefully modelled. A suite of input signals that comply with the design spectrum has been applied to the model. The preliminary results are commented in the paper to define the seismic safety requirement for the sensitive infrastructures and installations located inside the tunnels and caverns.</p

PRELIMINARY STUDY FOR SEISMIC ASSESSMENT OF THE UNDERGROUND FACILITIES AT POINT 5 OF THE LARGE HADRON COLLIDER (LHC) AT CERN

The European Organisation for Nuclear Research (CERN) is continuously upgrading its extensive underground facilities to cope with the need for new and more complex experiments. The Large Hadron Collider (LHC) houses the Compact Muon Solenoid (CMS) detector at its Point 5, where there are two large shafts, two 100 m deep major parallel caverns, with a total span of 50 m, separated by a 7 m wide and 28 m high concrete pillar, and a system of secondary tunnels and caverns. Such a complex underground infrastructure lies in a sedimentary rock formation (red molasse) of the Geneva basin, with a low rock cover of about 20 m to the overlying 50 m thick layer of water bearing moraine. The site is classified as a zone of moderate seismicity and the underground structures were designed against a “standard” seismic risk, that corresponds to the importance category II according to Eurocode 8. To study the dynamic response of the caverns to seismic waves, a series of Finite Element (FE) full dynamic analyses have been carried out, where the non-linear behavior of the underground layers has been carefully modelled. A suite of input signals that comply with the design spectrum has been applied to the model. The preliminary results are commented in the paper to define the seismic safety requirement for the sensitive infrastructures and installations located inside the tunnels and caverns.</p

CERN, HL-LHC Project: numerical modelling and design challenges for the new underground facilities at Point 5

The most powerful underground particle accelerator, known as Large Hadron Collider (LHC), is located at CERN on the border between Switzerland and France. The High-Luminosity (HL-LHC) Project will increase existing facilities with new underground and shallow structures at Point 1 (ATLAS, Switzerland) and Point 5 (CMS, France). The new underground structures include a shaft, a wide cavern, 500 meters of galleries and some vertical linkage cores. This paper presents the main challenges of the Project at Point 5 describing the design and construction issues encountered for the underground structures, together with the key role of the numerical modelling in the design. The main challenges of the construction were related to the following: i) meeting the tight schedule of design and construction ii) defining design criteria i.e. calculating expected excavation-induced vibrations and minimizing the disturbance effects on the LHC where experiments were in progress; iii) excavating within a complex rock mass with several known challenging characteristics; iv) assessing the potential impact of the excavation works on the nearby existing underground structures. The excavation of the main underground works was successfully completed without any critical impact on the nearby existing underground structures. The construction phase is on track for completion within the stipulated contractual Construction Programme. The completion of the entire works is scheduled for September 2022

LE NUOVE OPERE SOTTERRANEE PRESSO IL CERN (HL-HLC), PUNTO 5: SFIDE PROGETTUALI ED ESECUTIVE

Il Large Hadron Collider (LHC) è il più grande acceleratore di particelle situato presso il CERN di Ginevra. Trattasi di una struttura ad anello di 27 km, realizzata alla profondità di 100 m e dotata di 8 punti sperimentali in sotterraneo. In tale contesto, l’High-Luminosity (HL-LHC) è un recente progetto finalizzato al miglioramento dell’esistente acceleratore di adroni (LHC) che richiede nuove strutture sotterranee presso i punti sperimentali 1 (Svizzera) e 5 (Francia). Il presente articolo illustra le principali sfide incontrate nella progettazione e costruzione delle strutture sotterranee presso il Punto 5. Al fine di analizzare il comportamento tenso-deformativo delle differenti litologie riscontrate, la progettazione si è avvalsa di modelli numerici agli elementi finiti, fondamentali per riprodurre adeguatamente l’avanzamento delle fasi di scavo, valutare le conseguenze sulle adiacenti strutture esistenti e dimensionare i sostegni e rivestimenti. Ad oggi, le principali opere sotterranee sono state realizzate con successo e senza criticità. Il termine dei lavori è previsto per il 2022

GC-IMS screening to cluster the sensory grades of virgin olive oils

In this work, the use of a gas chromatography coupled to an ion mobility spectrometer with a tritium source was investigated for the discrimination of virgin olive oils previously sensory assessed (EU Reg. 1227/2016) and characterized by different quality grades (extra virgin, virgin, lampante). The samples were injected by a headspace system and, after the gas chromatographic separation, the ion mobility data coming from the eluted volatiles were processed with various chemometric tools. The preliminary elaboration evidenced a promising capacity to discriminate the samples according to their quality grade. The proposed approach is also sustainable and fast. This work was developed in the context of the project OLEUM “Advanced solutions for assuring authenticity and quality of olive oil at global scale“ funded by the European Commission within the Horizon 2020 Programme (2014–2020, grant agreement no. 635690). The information expressed in this abstract reflects the authors’ views; the EC is not liable for the information contained therein. The authors are grateful to the six sensory panels of the OLEUM consortium for the sensory evaluation of samples

Development of an algorithm for the management of cervical lymphadenopathy in children : consensus of the Italian Society of Preventive and Social Pediatrics, jointly with the Italian Society of Pediatric Infectious Diseases and the Italian Society of Pediatric Otorhinolaryngology

Cervical lymphadenopathy is a common disorder in children due to a wide spectrum of disorders. On the basis of a complete history and physical examination, paediatricians have to select, among the vast majority of children with a benign self-limiting condition, those at risk for other, more complex, diseases requiring laboratory tests, imaging and, finally, tissue sampling. At the same time, they should avoid expensive and invasive examinations when unnecessary. The Italian Society of Preventive and Social Pediatrics, jointly with the Italian Society of Pediatric Infectious Diseases, the Italian Society of Pediatric Otorhinolaryngology, and other Scientific Societies, issued a National Consensus document, based on the most recent literature findings, including an algorithm for the management of cervical lymphadenopathy in children. Methods: The Consensus Conference method was used, following the Italian National Plan Guidelines. Relevant publications in English were identified through a systematic review of MEDLINE and the Cochrane Database of Systematic Reviews from their inception through March 21, 2014. Results: Basing on literature results, an algorithm was developed, including several possible clinical scenarios. Situations requiring a watchful waiting strategy, those requiring an empiric antibiotic therapy, and those necessitating a prompt diagnostic workup, considering the risk for a severe underling disease, have been identified. Conclusion: The present algorithm is a practice tool for the management of pediatric cervical lymphadenopathy in the hospital and the ambulatory settings. A multidisciplinary approach is paramount. Further studies are required for its validation in the clinical field

Tocilizumab for patients with COVID-19 pneumonia. The single-arm TOCIVID-19 prospective trial

BackgroundTocilizumab blocks pro-inflammatory activity of interleukin-6 (IL-6), involved in pathogenesis of pneumonia the most frequent cause of death in COVID-19 patients.MethodsA multicenter, single-arm, hypothesis-driven trial was planned, according to a phase 2 design, to study the effect of tocilizumab on lethality rates at 14 and 30 days (co-primary endpoints, a priori expected rates being 20 and 35%, respectively). A further prospective cohort of patients, consecutively enrolled after the first cohort was accomplished, was used as a secondary validation dataset. The two cohorts were evaluated jointly in an exploratory multivariable logistic regression model to assess prognostic variables on survival.ResultsIn the primary intention-to-treat (ITT) phase 2 population, 180/301 (59.8%) subjects received tocilizumab, and 67 deaths were observed overall. Lethality rates were equal to 18.4% (97.5% CI: 13.6-24.0, P=0.52) and 22.4% (97.5% CI: 17.2-28.3, P&lt;0.001) at 14 and 30 days, respectively. Lethality rates were lower in the validation dataset, that included 920 patients. No signal of specific drug toxicity was reported. In the exploratory multivariable logistic regression analysis, older age and lower PaO2/FiO2 ratio negatively affected survival, while the concurrent use of steroids was associated with greater survival. A statistically significant interaction was found between tocilizumab and respiratory support, suggesting that tocilizumab might be more effective in patients not requiring mechanical respiratory support at baseline.ConclusionsTocilizumab reduced lethality rate at 30 days compared with null hypothesis, without significant toxicity. Possibly, this effect could be limited to patients not requiring mechanical respiratory support at baseline.Registration EudraCT (2020-001110-38); clinicaltrials.gov (NCT04317092)