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Expanding urbanization and imperviousness increase the frequency and severity of flooding in cities. Urban planners and decision-makers have implemented green infrastructure solutions in several cities to reduce the impact flooding. This research aims to investigate the effect of surface permeability and green infrastructure implementation on reducing stormwater flooding in Mexico City. First, we modelled the impact of stormwater flooding using the TR-55 methodology in Mexico City in the present condition, without GI. The model was used to identify the city districts with highest flood hazard. Moreover, a combination of scenarios was tested representing five stages of green infrastructure implementation, from 20% to 100% of all adequate areas, under 10, 25, 50, 100, and 500-years precipitation events. Specific criteria for selecting adequate areas for green infrastructure implementation were used. Open geographic data from was used in QGIS. In addition, the maps of estimated flood heights were classified in five hazard classes, from very low to very high. The results showed that implementing 100% of green infrastructure in the adequate areas, reduces the very high flood hazard an average of 12 km2 for five return periods. This study can serve as a reference to other cities to develop plans for green infrastructure implementations.

Our goal was to evaluate the clinical behavior of resin-based composite (RBC) restorations with sealed marginal defects using nano-filled flowable RBCs (FRS) compared with resin-based sealant (RBS); this work used marginal adaptation, marginal staining, and secondary caries according to the World Dental Federation (FDI) criteria.This was a prospective, randomized, double-blind, controlled trial. Fifty-four patients who met the inclusion criteria (older than 18 years old; with high cariogenic risk determined by Cariogram software; and restorations with marginal defects, 3 and 4 according to FDI criteria) were randomly divided into three groups. There were three defective RBC restorations per patient and were repaired (n = 162). The groups were RBS-marginal sealing using a resin-based sealant (Clinpro Sealant, 3 M ESPE, MN, USA) plus adhesive (Single Bond Universal, 3 M ESPE, MN, USA); FRS-sealing using flowable resin (Filtek Flow Z350XT, 3 M ESPE, MN, USA) plus adhesive (Single Bond Universal, 3 M ESPE, MN, USA); and control-no repair treatment. All procedures were performed under complete isolation. Evaluations were evaluated at 1-week post treatment (baseline) as well as at 18 and 36 months after treatment regarding marginal adaptation, marginal staining, and secondary caries according to FDI criteria. The data were analyzed using the Wilcoxon test (α = 0.05) to compare the differences in each treatment group at different evaluation times.Marginal adaptation of micro-repaired RBC restorations were seen in patients with a high risk of caries using flowable resin composite or resin-based sealants. There were differences (P 0.001) when baseline was compared at 18 and 36 months. Marginal staining showed differences when baseline was compared to 18 months (P 0.001) and 36 months (P = 0.001) for both treatments. Secondary caries parameters for RBS treatment showed differences when baseline was compared to 36 months (P = 0.025) and when 18 months was compared to 36 months (P = 0.046).Micro-repair of RBC restorations resulted in clinical deterioration of marginal adaptation and marginal staining. Nano-filled flowable resin composites were sealed on defective restorations; 3 and 4 FDI marginal defects have better clinical performance to prevent secondary caries than resin-based sealants after 36 months.Micro-repair with RBS does not seem to be an effective treatment to prevent secondary caries.

The rocking response of anchored rigid bodies with irregular geometry is evaluated, incorporating the non-linearity of restrainers. A parametric analysis is performed, introducing the concept of Pr...

A destructive intraslab earthquake occurred in Mexico City on September 19, 2017 (Mw 7.1), causing significant damage and hundreds of human losses not only in the epicentral area, but also in the States of Morelos, Puebla, Mexico and in Mexico City. Only in Mexico City itself, around 230 people died, and more than 40 buildings collapsed. The intensities recorded in some lakebed areas of the city, especially in zones with soil periods around 1.5 s, were relatively high, even surpassing spectral values of 1.0 g; the vertical component, due to the proximity of the earthquake, was unusually high for Mexico City. The 2017 earthquake raised questions critical to understanding the city’s seismic vulnerability and resilience, and they are partly answered in this article. Using 77 accelerometric stations, the amplification pattern of the seismic intensities is characterized as well as the correlations of buildings structural characteristics with the site effects. A comprehensive statistical analysis of the damages is shown to analyze and understand the structural behavior of damaged buildings. It is including not only the structural types and the year of construction, but also the main structural problems identified (structural pathologies), such as irregularities, both in elevation and plan, soft story, and corner effect. The building damage database was constructed with 2125 reports of buildings carried out by universities and engineering associations after the earthquake, of which 543 had severe damage. It is also included the information of all buildings with no damage in the city thanks to the cadastral information provided by the Mexico City government, and post-earthquake inspections and visual inspections using Google Street View. A full study of selected neighborhoods, which compares similar buildings with and without damage, is included, yielding relevant statistical information on which pathologies cause more damage and even collapses.

Después del sismo ocurrido el 19 de septiembre de 2017 en México, una gran cantidad de negocios establecidos en la Ciudad de México dejó de operar temporalmente e incluso de forma definitiva. De acuerdo con lo observado tras este evento destructivo, en este trabajo se identifican las fuentes de interrupción del negocio: Protocolos de seguridad iniciales, Suspensión de servicios públicos de suministro, Efectos de vecindario y Daños en los componentes del edificio, y se propone un modelo para determinar el tiempo de interrupción de negocio, IN, con base en la inactividad de la edificación. Con la finalidad de tener valores de referencia para los datos de entrada, se documentan los tiempos de evaluación de edificios, restablecimiento de servicios públicos, demolición de edificios, entre otros aspectos relevantes para la CDMX. Finalmente, los conceptos se ejemplifican con un negocio formal hipotético establecido en una edificación de dos niveles de mampostería confinada y en los resultados se obtiene que habría una paralización total de las actividades empresariales por más de un mes debido a daños menores en la infraestructura de energía eléctrica y algunos daños estructurales en la planta alta. Además, se concluye que, aunque la interrupción de negocios depende de múltiples factores, la participación de los Ingenieros Estructuristas es trascendental para minimizar el tiempo de IN, especialmente en la evaluación de la seguridad de los edificios y la rehabilitación de las infraestructuras.

La limitada autonomía de los vehículos eléctricos representa uno de los principales problemas para su comercialización. Por esta razón es importante incrementar su autonomía, generando de esta manera una alternativa de solución a estos inconvenientes. Es necesario entonces, promover la utilización de este tipo de automóviles, dado que su uso disminuye notablemente el grado de dependencia del petróleo, promoviendo así el uso de las energías renovables. La implementación de paneles solares en los automóviles eléctricos es una respuesta al incremento de su autonomía, ya que permite aprovechar una fuente inagotable de energía (solar), permitiendo de esta forma reducir la contaminación ambiental, haciendo que el vehículo eléctrico se vuelva más atractivo para los usuarios. Este artículo detalla la implementación de un panel solar de 350 W en un vehículo eléctrico Dayang CHOK-S bajo diferentes condiciones meteorológicas, obteniendo como resultado el incremento de su autonomía en hasta un 33 % con respecto a su autonomía real. Además, en algún punto dado, este porcentaje podría incrementar bajo condiciones de radiación solar bastante altas. Los resultados demuestran que la carga de las baterías es directamente proporcional a la cantidad de radiación solar; es decir, a mayor radiación solar, mayor va a ser la carga de las baterías del automóvil.

Earthquakes of great intensity often affect businesses because the buildings where they operate are severely damaged, in this sense, the municipal market of Juchitán de Zaragoza represents an interesting case study. This investigation identifies the damage to property during the 8.2 Mw earthquake that occurred on September 7th, 2017, observing that the short column problem occurred in most of the columns, a settlement and shear failures in beams and non-structural walls, and later the structural and non-structural rehabilitation are detailed. Likewise, a statistical report is presented on a survey applied in November 2020 to 165 businesses established in the market to evaluate the business impact of the loss of the building’s operability due to the destructive event. According to the results obtained, only 4.24% of the economic units surveyed did not have direct losses due to the earthquake, on the other hand, 45.46% could not operate for more than a month and 33.94% considered that they stopped earning more than $ 3,000 MXN ( $ 160 USD) during the time of absolute stoppage of its activities.

espanolEl terremoto intraplaca del 19 de septiembre de 2017 (Mw7.1), cuyo epicentro se localizo cerca de los limites entre los estados de Puebla y Morelos, aproximadamente a 120 km de Ciudad de Mexico, causo danos severos en estas regiones. Este articulo analiza los cocientes espectrales de estaciones acelerometricas en el lecho lacustre de la Ciudad de Mexico con respecto al espectro promedio de Fourier en sitios de la zona de suelo firme para estudiar y comparar los cambios, en el tiempo, con el comportamiento de los efectos de sitio y su relacion con el dano presentado durante este terremoto; estas cocientes tambien exhiben el problema de asentamiento en algunos lugares de la ciudad debido a la sobreexplotacion del acuifero para el suministro de agua, en donde se ha visto cambios en el periodo del suelo, inclusos cercanos al 40 por ciento. Finalmente, se presentan mapas de pseudoaceleracion y energia histeretica para la Ciudad de Mexico con una discusion de una posible correlacion con los danos reportados.Palabras clave: cocientes espectrales, pseudoaceleracion, energia histeretica, espectro de Fourier, terremoto de Mexico, amplificaciones espectrales EnglishThe September 19, 2017, intraslab earthquake (Mw7.1), whose epicenter was located near the limits betweenthe states of Puebla and Morelos at approximately 120km from Mexico City, caused severe damage in these regions. This article analyzes the spectral ratios of accelerometric stations in the lake-bed of Mexico City with respect to the average Fourier spectra at hill zone sites in order to study and compare over time the changes in the behavior of local effects and their relationship with the damage presented during this earthquake. These ratios also exhibit the settlement problem in some places in the city due to overexploiting the aquifer for water supply purposes, where changes in soil periods, even larger than 40%, are seen. Finally, pseudoacceleration and hysteretic energy maps for Mexico City with a discussion with a possible correlation with reported damages are presented. Key words: Spectra ratios, pseudoacceleration demands, hysteretic energy demands, Fourier spectra, Mexico earthquake, spectral amplifications.

The accumulation of plastic deformations during an intense earthquake may cause structural failures at deformations significantly smaller than those that can be developed under monotonic load. However, there is evidence that, under certain circumstances, the response of a single parameter may not be a good indicator of structural damage. Likewise, most of the seismic regulations, including the Mexican standards, establish their criteria considering the occurrence of strong earthquakes with a very little probability of occurrence, but do not consider if intense earthquake affects the building frequently and, therefore, cumulative damage due to the occurrence of several earthquakes during the life span of the structure is not taken into account explicitly. This cumulative damage is especially important in places like Mexico City, where intense and long-duration earthquakes occur every 10–20 years. To study the issues that Mexico City must face to increase its seismic resilience, in this article, we present an analysis of the dissipated plastic energy demands in Mexico City during the earthquake of 19 September 2017, and the cumulative damage due to recent intense earthquakes that affect the city.

Se presenta un análisis de los daños en estructuras de los estados de México, Morelos, Puebla y la Ciudad de México durante la ocurrencia del sismo del 19 de septiembre de 2017, mediante datos recolectados en diversas fuentes como reportes, visitas técnicas y redes sociales, entre otros. Con los datos recabados fue posible geo-localizar cada estructura a nivel predio e identificar las características de cada inmueble tales como el número de pisos y el sistema estructural, además de posibles agravantes de los daños presentados tales como irregularidades geométricas y daños previos, entre otros. Se presenta un análisis estadístico de estos factores con la finalidad de identificar la vulnerabilidad y poder encontrar tendencias para estimar el riesgo.

This paper presents a framework for the risk assessment of urban power distribution systems under hurricane hazard, focusing on the effects that both line orientation and hurricane time his...

Objetivo: Comprender a la osteogénesis imperfecta través de una revisión detallada de estudios académicos, para establecer directrices en la atención primaria y visibilizar sus aspectos genéticos en el contexto del sistema de salud ecuatoriano. Método: La presente revisión está basada en la selección de estudios y revisiones de Osteogénesis Imperfecta y de la guía de práctica clínica del 2014 del MSP del Ecuador para el manejo de la OI. Resultados y conclusiones: La relación genotipo-fenotipo indica que las dos secuencias de colágeno desempeñan funciones muy diferentes en la integridad del colágeno. Esta nueva correlación genotipo-fenotipo será útil para predecir el pronóstico de la enfermedad OI y el asesoramiento genético. En Ecuador, la situación de los pacientes con enfermedades raras es perecedera, no existe un adecuado seguimiento epidemiológico y datos exactos que nos permitan evaluar el impacto de la enfermedad

The seismic response of structures to strong ground motions is a complex problem that has been studied for decades. However, current seismic regulations do not assess the potential level of damage ...

Objetivo: Analizar los indicadores hematológicos en pacientes con infección por SARS COV-2. Método: Observacional de tipo descriptiva. Resultados: Se ha encontrado la existencia de un patrón común de exámenes anormales del recuento leucocitario con Neutrófilos elevados en 43.69 % (neutrofilia) y los linfocitos, pero por debajo de los valores normales (linfopenia) en un 20.16 %. Además de monocitopenia en un 13.44%. Conclusión: La detección de Proteína C reactiva elevada y neutrofilia se relaciona con casos severos de COVID-19 en pacientes adultos. Ambas pruebas combinadas tienen una alta especificidad y sensibilidad para predicción temprana de casos se veros de COVID -19.

This paper proposes a methodology to assess the wind risk of electrical transmission towers considering the coupling of the tower with the cables and a failure mechanism based on capacity. ...

Landslides caused by a low magnitude earthquake swarm (2.8 ≤ M ≤ 3.6) in 2012 were documented at the Santa Rosa Canyon in northeastern Mexico. Disrupted landslides from falls and slides, in both rocks and soils, were identified based on fieldwork and high-resolution satellite imagery along stream banks from natural cliffs and along the road cut in the epicentral area. Most of the landslides occurred on slopes greater than 40°, where geological features played a key role in triggering slope instabilities. The maximum distance limit for disrupted slides from the epicentral area was 7 km. The area affected by landslides during the early stage of the seismic sequence (July through August 2012) was 90 km2. Landslide identification was limited in some areas by the resolution of the satellite imagery and dense cloud coverage. Both the epicentral distance and the area affected by landslides are above the global bounds reported in literature. The final landslide inventory is the first documented case of earthquake-induced landslides in northeastern Mexico.

A methodology is presented for assessing the expected loss of human lives due to the structural damage, failure of contents and non-structural components inside buildings during earthquakes. This a...

A simplified model to evaluate the dynamic rocking behavior of free-standing irregular rigid bodies under earthquake-induced forces is proposed. The model analyzes the response of a three-dimension...

This paper proposes an earthquake-event-based method for the construction of regional flood hazard maps for tsunami. The method involves five steps. The first is to characterise the seismic hazard as a set of collectively exhaustive and mutually exclusive stochastic events that fully describes the spatial distribution and annual frequency of occurrence in accordance with the location of an earthquake, its depth and magnitude. The second is to compute the vertical sea-floor deformation produced by each one of the earthquakes, after which the propagation of tsunami and the inundation depth produced by each earthquake is calculated. Step four is to present the earthquake-induced tsunami hazard considering only those events that could generate a tsunami as a set of stochastic events that describes the spatial distribution of each tsunami. The final step is to obtain, for any point of interest, the tsunami inundation depth exceedance rate, taking into account the contribution of all tsunamis computed in step four. The method is applied to obtain maps of tsunami hazard for the Mexican Pacific coast for return periods of 150 and 500 years.

The monitoring of basic household services is increasingly accessible to everyone, however, accidents in the home and unnecessary expenditure of limited resources such as electricity, gas and water continue to occur in our society and are not being treated from a preventive and real monitoring perspective. Thanks to the large amount of IoT device available on the market today and the software tools provided by the IBM Cloud ecosystem we are able to deploy real and intelligent monitoring in a home at low cost.

espanolIntroduccion. La docencia clinica es diferente a la docencia de aula, pues esta mas estrechamente vinculada al desarrollo del perfil profesional de los estudiantes de la salud y ocurre en espacios de atencion al paciente. Por lo mismo, requiere competencias especificas de los tutores clinicos que guian este momento formativo.Sujetos y metodos. Se realizo un estudio cuantitativo donde se encuesto a 70 tutores clinicos de cinesiologia. A estos se les aplico el cuestionario de competencias para tutores clinicos, previo consentimiento informado. Resultados. Los tutores clinicos tienen una percepcion positiva de sus competencias pedagogicas, pero son mas criticos de sus capacidades para disenar recursos, evaluar y planificar. Igualmente, estas percepciones mostraron estar asociadas a la capacitacion disciplinar, la capacitacion pedagogica y la especialidad cinesiologica. Conclusion. Los resultados muestran la importancia del perfeccionamiento docente para el desarrollo de competencias pedagogicas, sobre todo de aquellas no vinculadas a la docencia directa. Igualmente, subrayan el caracter contextualiza-do de las competencias. EnglishIntroduction. Clinical teaching is different from classroom teaching, because it is more closely linked to professional development. For this reason, it requires specific competences in clinical preceptors who guide this formative moment.Subjects and methods. A quantitative study was conducted, where 70 clinical preceptors of physiotherapy were surveyed. The Clinical Preceptors Competencies Questionnaire was applied to them, with prior informed consent. Results.Clinical tutors had a positive perception of their pedagogical competencies, but they are more critical of their capacities for resource design, evaluation and planning. Likewise, these perceptions are related to disciplinary training, pedagogical training and physiotherapy specialty. Conclusion.Results show the importance of teaching training for the development of pedagogical competencies, especially those not linked to direct teaching. The context dependent nature of competencies is also underlined.

Many studies have found that ground-motion duration has a considerable influence on damage to conventional civil structures. Historically, Mexico City has been severely affected by long-duration distant subduction earthquakes because of the heterogeneous local site conditions underlying the subsoil of the city, which significantly amplify the soil response. Using a reliable database of earthquakes that occurred in the subduction zone of the Pacific Coast of Mexico, recorded in the hill zone of the Valley of Mexico from 1985 to 2020, predictive models are proposed in this study from existing definitions of strong-motion duration. These models were developed using a mixed-effects approach, which is a statistical method that can consider the correlation between data recorded from the same event. Such models have valuable applications in seismic and structural engineering because they can accurately define the dimension and randomness of strong-motion duration.

Earthquake databases are not sufficiently complete, particularly for soft soils. Also, there are few and oversimplified formulations that allow an understanding on the relation that exists between the elastic and inelastic energy demands for this type of soils. A study on energy reduction factors aimed at establishing inelastic input and hysteretic energy spectra for narrow-banded motions is presented. Unlike previous works, in this study elastic input energy spectra are used as input for energy functional forms that allow the formulation of inelastic energy spectra. For this purpose, over 250 seismic records recorded in soft soils are used. The energy reduction factors yield inelastic energy spectra that capture in a reasonable manner the energy content of narrow-banded ground motions, and yield a better characterization of inelastic energy demands.

En este trabajo se presenta un estudio de peligro sísmico para el Ecuador. La falta de catálogos sísmicos completos, o en muchos casos la poca información relacionada al tema, hace que sea necesario un análisis probabilista de amenaza sísmica de manera que sea posible considerar las diferentes incertidumbres que se presentan en el proceso de cálculo. Esta metodología ha sido empleada en el presente trabajo para el estudio de peligro sísmico del Ecuador. Se debe partir de un catálogo que sea lo suficientemente depurado, homogéneo y completo, de manera que los parámetros sísmicos de las diferentes fuentes no presenten grandes desviaciones en sus resultados. Posteriormente, se estudiaron diferentes modelos de atenuación, los mismos que son necesarios para conocer las intensidades en cualquier punto de interés. En este estudio se obtienen resultados de peligro sísmico como curvas de peligro, espectros de peligro uniforme (EPU) y mapas de peligro sísmico, para diferentes periodos de retorno. Como aplicación de estos resultados, se obtienen espectros de diseño sísmico para la ciudad de Cuenca, partiendo de un estudio previo de efectos de sitio realizado por la Universidad de Cuenca en el año 2000.Palabras clave: peligro sísmico; catálogo sísmico; espectros de peligro uniforme; curvas de peligro símico; espectros de diseño; efectos de sitio

A new approach is proposed for the probabilistic financial risk assessment of earthquake-induced tsunami. The risk is evaluated in a probabilistic framework for a full set of hazard events including all uncertainties. The hazard is defined as a stochastic and historic set of events, collectively exhaustive and mutually exclusive, that describes the spatial distribution, the annual frequency and the randomness of the hazard intensity. The risk is expressed as losses in different terms: the average annual loss and the loss exceedance curve. These metrics are of particular importance for risk financing schemes and risk transfer instruments. As an illustrative example, this approach is applied to the probabilistic tsunami risk assessment for public schools in southern Mexico.

Current seismic regulations do not assess the seismic performance of structures during a given seismic event, and therefore do not require an estimation of their residual displacement or level of structural damage. Nevertheless, this information is relevant after intense ground motions to assess the possibility of re-occupying a building. This paper develops simple expressions to estimate the maximum displacement demand from the residual displacement of single-degree-of-freedom systems subjected to long-duration narrow-banded ground motions generated in soft soil sites (particularly, those located in Mexico City). To overcome the limited scope of previous studies, more than 35,000 seismic simulations were performed. The influence of the lateral strength of the single-degree-of-freedom systems is considered. A simplified relation between the residual and maximum displacement demands is established.

We present ground-motion prediction equations, based on Bayesian regressions, to predict response spectra at sites located within the hill and lake-bed zones of Mexico City for intermediate-depth, normal-faulting intraslab earthquakes with magnitude ranges 5.2 ≤ Mw ≤ 7.4; distances from sites to the fault surface 103 ≤ R ≤ 464 km; and focal depths of the events 40 ≤ H ≤ 128 km, all at sites located in hill and lake-bed zones in Mexico City. The equations are built as functions of magnitude and distance to the fault surface, using more than 20 intraslab earthquakes. We compare our results with previous attenuation models for intraslab (hill zone) and interplate earthquakes (hill and lake-bed zones) in Mexico City. The results also show that the uncertainty for intraslab earthquakes at sites located within the hill zone is larger than that for sites located in lake-bed zone.

This study proposes a risk index (RI) to identify the potential areas at national, sub-national and local levels that may suffer losses to natural hazards, taking into account the expected physical damage to the structures. The quantitative measure of the risk is the expected annual loss obtained as a result of the formal probabilistic estimation of structural damage. To estimate RI, a computational system that takes into account the occurrence of all possible events and its exceedance rates for a given hazard and the characteristics of the local construction is employed. Although losses can be obtained for individual structures in percent, the proposed RI establishes a scale of qualitative levels: Very Low, Low, Medium, High and Very High. RI is transparent, robust and representative of the risk, and can be used as a first sound approach in order to better use resources to carry out site- and building-specific studies for the regions at the highest risk. As a case study of RI, three natural hazards (seismic, hurricane and flood) for dwellings located in areas of Mexico are shown. The benefits of this approach are two: (1) to set risk results as a standard for decision-making in fields other than financial ones, and (2) a straight use of these risk results to prioritize resources at areas (or buildings or any other asset) according to the highest or lowest risk result, in a way that may be easier to communicate to decision-makers even if they are not familiar with formal risk studies.

We present regional maps of earthquake-induced liquefaction hazard in Mexico considering the lateral or horizontal spreading displacement, as index, D LL . The methodology to prepare the liquefaction hazard maps consists of five steps: (1) identifying zones with soil deposits that are more susceptible to displaying liquefaction based on geologic available information at a 1:1,000,000 scale; (2) characterizing the seismic hazard as a set of stochastic events that collectively describe the hazard, compatible with the distribution of location, depth, frequencies, magnitudes and attenuation of the seismic strong ground motion; (3) employing a parametric method, based on empirical data, to estimate the demand of permanent ground deformation expected due to liquefaction (in this study, the lateral spreading displacement of the ground, D LL ) by event and for the site required; (4) characterizing the earthquake-induced liquefaction hazard as a set of stochastic events that describe the spatial distribution demand of liquefaction for each event; and (5) performing a probabilistic analysis of liquefaction hazard. The results of liquefaction hazard associated with return periods of 150 and 500 years are shown on maps of Mexico. Those maps are compared qualitatively with historical information collected from sites where, based on descriptions, the phenomenon of earthquake-induced liquefaction is seen to have occurred from the year 1593 to 2010. The results obtained in this study provide a first approximation to the liquefaction hazard zones in the country, in accordance with sites where historical evidence of liquefaction has been reported. In addition, the application could be important in land-use planning and urban development, particularly in regions with a historical certainty of earthquake-induced liquefaction, but with little or no geotechnical and/or geophysical studies. These maps can be used to locate zones where more in-depth studies are required to estimate, with less uncertainty, the potential for earthquake-induced liquefaction.

The Mexico City Building Code (MCBC-2004) – Reglamento de Construcciones del Distrito Federal, Gaceta Oficial del Distrito Federal, 29 de enero de 2004 in Spanish – is a state-of-the-art code; the most comprehensive and advanced set of requirements in the country; and it serves as a model for codes in Mexico's regions. However, many recently built mid-rise dwellings seem too weak to withstand earthquakes, with evident structural deficiencies. Insufficient official mechanisms exist for supervising the design and construction of such new structures. This study evaluates current practice and compares it with the guidelines of the MCBC-2004 using a sample of structures of 150 buildings constructed after 2004. Structural analysis and design revisions were made for a subset of 20 buildings. This study confirms that a large number of new buildings in Mexico City do not have a reliable record of technical information. Therefore, it is difficult to reanalyse buildings to assess their earthquake performance. Many b...