Determinación del factor de sobre resistencia en estructuras aporticadas de concreto armado con aisladores de base tipo LRB mediante un análisis estático no lineal (PUSHOVER), Trujillo

RESUMEN La presente tesis tiene por objetivo determinar el factor de sobre resistencia en estructuras aporticadas de concreto armado con aisladores de base tipo LRB mediante un análisis estático no lineal (Pushover), con la finalidad de estipular un factor que se adapte a las solicitaciones sísmicas de nuestro país, debido a que en nuestra actual norma de diseño sismorresistente no se contempla dicho factor, que permite pasar de un espectro elástico a uno inelástico para diseñar adecuadamente. La tesis se divide en 5 capítulos, en el primer capítulo se presenta una descripción de los problemas que conllevan a realizar la tesis, como son la falta de normas propias de nuestro país, la presencia constante de sismos, y las nuevas tecnologías de protección sísmica; la justificación, que se basa en investigaciones desarrolladas por el Dr. Roberto Aguiar Falconí, en cuanto al procedimiento para encontrar el factor de sobre resistencia y Constantinou, M. & Kalpakidis, I, en cuanto al diseño de aisladores sísmicos; se presentan también las limitaciones que se tuvieron para el desarrollo de la tesis, como son las capacitaciones en cuanto al diseño de aisladores y por último el objetivo fundamental que será el factor de sobre resistencia. En el segundo capítulo se describen los antecedentes de trabajos realizados con la finalidad de demostrar que los procedimientos tienes fundamento valido y por ende la obtención de resultados confiables; para fundamentar más la tesis se presentan las bases teóricas con las cuales se realizaran todos los cálculos necesarios para hallar dicho factor, las bases teóricas se subdividen en el aislamiento sísmico, el concreto estructural, el análisis dinámico modal espectral, el análisis no lineal estático (Pushover), el factor de reducción de sobre resistencia y la modelación estructural mediante el programa educativo ETABS. En el tercer capítulo se describe la metodología de trabajo que se realizara en función de datos y procedimientos estadísticos. En el cuarto capítulo se presentan los resultados obtenidos del análisis, se inicia por los resultados completos de un modelo estructural, como son el diseño de sus aisladores, el diseño de sus elementos estructurales, y la obtención de la curva de capacidad; y la obtención de su factor de sobre resistencia, por último, se presentan los resultados de los factores de sobre resistencia de todos los modelos a analizar. En el quinto capítulo se mencionan las discusiones en cuanto a los resultados obtenidos, de los cuales se interpretan para tener una respuesta más clara de dichos resultados. Posteriormente se presentan las conclusiones, las recomendaciones, las referencias y los anexos.ABSTRACT The objective of this thesis is to determine the over strength factor in reinforced concrete structures with LRB type insulators using a non-linear static analysis (Pushover), in order to stipulate a factor that adapts to the seismic stresses of our country, due to the fact that in our current seismic design norm, this factor is not considered, which allows us to go from an elastic spectrum to an inelastic spectrum to design properly. The thesis is divided into 5 chapters, the first chapter presents a description of the problems that lead to the thesis, such as the lack of proper standards of our country, the constant presence of earthquakes, and new seismic protection technologies ; the justification, which is based on research developed by Dr. Roberto Aguiar Falconí, regarding the procedure to find the over-resistance factor and Constantinou, M. & Kalpakidis, I, regarding the design of seismic isolators; the limitations that were had for the development of the thesis are also presented, as are the trainings in terms of the design of insulators and finally the fundamental objective that will be the factor of over resistance. In the second chapter we describe the background of work done in order to demonstrate that the procedures have a valid basis and therefore obtain reliable results; to further substantiate the thesis the theoretical bases are presented with which all the necessary calculations will be made to find this factor, the theoretical bases are subdivided into seismic isolation, structural concrete, spectral modal dynamic analysis, static nonlinear analysis ( Pushover), the factor of over-strength reduction and structural modeling through the ETABS program. The third chapter describes the work methodology that will be carried out based on statistical data and procedures. In the fourth chapter, the results obtained from the analysis are presented, starting with the complete results of a structural model, such as the design of its insulators, the design of its structural elements, and the obtaining of the capacity curve; and the obtaining of its over-resistance factor, finally, the results of the over-resistance factors of all the models to be analyzed are presented. In the fifth chapter the discussions are mentioned regarding the results obtained, of which they are interpreted to have a clearer answer of said results. Subsequently, the conclusions, recommendations, references and annexes are presented

Determinación del factor de sobre resistencia en estructuras aporticadas de concreto armado con aisladores de base tipo LRB mediante un análisis estático no lineal (PUSHOVER), Trujillo

RESUMEN La presente tesis tiene por objetivo determinar el factor de sobre resistencia en estructuras aporticadas de concreto armado con aisladores de base tipo LRB mediante un análisis estático no lineal (Pushover), con la finalidad de estipular un factor que se adapte a las solicitaciones sísmicas de nuestro país, debido a que en nuestra actual norma de diseño sismorresistente no se contempla dicho factor, que permite pasar de un espectro elástico a uno inelástico para diseñar adecuadamente. La tesis se divide en 5 capítulos, en el primer capítulo se presenta una descripción de los problemas que conllevan a realizar la tesis, como son la falta de normas propias de nuestro país, la presencia constante de sismos, y las nuevas tecnologías de protección sísmica; la justificación, que se basa en investigaciones desarrolladas por el Dr. Roberto Aguiar Falconí, en cuanto al procedimiento para encontrar el factor de sobre resistencia y Constantinou, M. & Kalpakidis, I, en cuanto al diseño de aisladores sísmicos; se presentan también las limitaciones que se tuvieron para el desarrollo de la tesis, como son las capacitaciones en cuanto al diseño de aisladores y por último el objetivo fundamental que será el factor de sobre resistencia. En el segundo capítulo se describen los antecedentes de trabajos realizados con la finalidad de demostrar que los procedimientos tienes fundamento valido y por ende la obtención de resultados confiables; para fundamentar más la tesis se presentan las bases teóricas con las cuales se realizaran todos los cálculos necesarios para hallar dicho factor, las bases teóricas se subdividen en el aislamiento sísmico, el concreto estructural, el análisis dinámico modal espectral, el análisis no lineal estático (Pushover), el factor de reducción de sobre resistencia y la modelación estructural mediante el programa educativo ETABS. En el tercer capítulo se describe la metodología de trabajo que se realizara en función de datos y procedimientos estadísticos. En el cuarto capítulo se presentan los resultados obtenidos del análisis, se inicia por los resultados completos de un modelo estructural, como son el diseño de sus aisladores, el diseño de sus elementos estructurales, y la obtención de la curva de capacidad; y la obtención de su factor de sobre resistencia, por último, se presentan los resultados de los factores de sobre resistencia de todos los modelos a analizar. En el quinto capítulo se mencionan las discusiones en cuanto a los resultados obtenidos, de los cuales se interpretan para tener una respuesta más clara de dichos resultados. Posteriormente se presentan las conclusiones, las recomendaciones, las referencias y los anexos.ABSTRACT The objective of this thesis is to determine the over strength factor in reinforced concrete structures with LRB type insulators using a non-linear static analysis (Pushover), in order to stipulate a factor that adapts to the seismic stresses of our country, due to the fact that in our current seismic design norm, this factor is not considered, which allows us to go from an elastic spectrum to an inelastic spectrum to design properly. The thesis is divided into 5 chapters, the first chapter presents a description of the problems that lead to the thesis, such as the lack of proper standards of our country, the constant presence of earthquakes, and new seismic protection technologies ; the justification, which is based on research developed by Dr. Roberto Aguiar Falconí, regarding the procedure to find the over-resistance factor and Constantinou, M. & Kalpakidis, I, regarding the design of seismic isolators; the limitations that were had for the development of the thesis are also presented, as are the trainings in terms of the design of insulators and finally the fundamental objective that will be the factor of over resistance. In the second chapter we describe the background of work done in order to demonstrate that the procedures have a valid basis and therefore obtain reliable results; to further substantiate the thesis the theoretical bases are presented with which all the necessary calculations will be made to find this factor, the theoretical bases are subdivided into seismic isolation, structural concrete, spectral modal dynamic analysis, static nonlinear analysis ( Pushover), the factor of over-strength reduction and structural modeling through the ETABS program. The third chapter describes the work methodology that will be carried out based on statistical data and procedures. In the fourth chapter, the results obtained from the analysis are presented, starting with the complete results of a structural model, such as the design of its insulators, the design of its structural elements, and the obtaining of the capacity curve; and the obtaining of its over-resistance factor, finally, the results of the over-resistance factors of all the models to be analyzed are presented. In the fifth chapter the discussions are mentioned regarding the results obtained, of which they are interpreted to have a clearer answer of said results. Subsequently, the conclusions, recommendations, references and annexes are presented

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit