El Infiernillo Research Articles

Shear strain dependent amplification function of earth dam‐flexible canyon system by the hybrid FEM‐SBFEM technique

AbstractThe finite element method (FEM) is a powerful tool for the nonlinear modeling of dynamic problems. In the present work, the equivalent linear method (EQL) has been implemented into the FEM. For stratifying the radiation damping condition and rigorously modeling canyon as an elastic unbounded domain, the scaled boundary finite element method (SBFEM) was utilized. The FEM‐SBFEM technique, wherein FEM is coupled with SBFEM, has been extended to take into consideration the effect of earth dam material nonlinear behavior. It was observed that the nonlinear behavior greatly affects the natural frequency, the amplification function (AF), and peak crest acceleration of the earth dam located in canyons. The effects of canyon geometry and flexibility on the nonlinear behavior were examined, and it was seen that by increasing the flexibility of the canyon, the effect of nonlinearity was decreased. The El Infiernillo dam was modeled by 3D proposed technique, and a comparison of the crest AF obtained by the proposed method with the recorded data shows the accuracy of the methodology.

Computation of amplification functions of earth dam‐flexible canyon systems by the hybrid FEM‐SBFEM technique

AbstractA dam's responses can be amplified by the geometry and flexibility of its surrounding canyon. To modeling a canyon as an elastic unbounded domain, the radiation damping condition should be satisfied, and in this regard, the Scaled Boundary Finite Element Method (SBFEM) is a powerful tool. In this article, a substructure method was used to combine the standard Finite Element Method (FEM) with the SBFEM, resulting in the hybrid FEM‐SBFEM technique. This hybrid technique treats an earth dam by using FEM and a corresponding elastic unbounded canyon by SBFEM. The proposed approach was verified by data available in the literature. The seismic response of an earth dam‐flexible canyon system was investigated by employing a 3D FEM‐SBFEM method. Several amplification functions corresponding to different canyon conditions were obtained by applying a uniform displacement for the canyon boundary, and a comprehensive study was performed to examine the effects of canyon geometry and flexibility on the steady‐state response of the dam, as these two effects influenced the amplification functions. While the flexibility of the canyon significantly affects the maximum amplification function value for a dam, this value does not change for earth dams in canyons with different shapes but the same length. In addition, the lateral response of earth dams in the time domain was computed in order to analyze the aforementioned effects under an actual earthquake. The proposed amplification functions were used to compare the recorded response spectra of the El Infiernillo dam under the two earthquakes in 1966 with the calculated amplification function, and a reasonable agreement was observed between them.

Hybridization between I-type and S-type granites in the Ordovician Famatinian magmatic arc, Tafí del Valle, Tucumán, NW Argentina.

In the Tafi del Valle region, in northwestern Argentina, several intrusive bodies of lower Paleozoic age were emplaced in the metasedimentary Puncoviscana Formation, belonging to the Sierras Pampeanas. Four intrusive bodies outcrop in the study area: La Ovejeria, El Infiernillo, Loma Pelada and Los Cuartos. La Ovejeria and El Infiernillo intrusive bodies represent the I-type magmatism according to their major element contents and show cotectic evolutions similar to those described by Famatinian I-type batholiths. These moderately peraluminous adakitic trondhjemites have characteristic high Sr/Y ratios and low Fe 2 O 3 +MgO+MnO+TiO 2 contents. They are related to high-pressure conditions at the source, where dehydration melting of basaltic rocks may be involved and garnet is retained in the residue leading to generation of HREE depleted melts. The Loma Pelada granites show characteristics of S-type magmatism (low CaO and MgO, and high SiO 2 and K 2 O contents) typical of granites segregated in the last stages of magmatic differentiation, or anatectic granites. They show an increasing peraluminosity due to garnet entrainment and they are related to the anatectic melts generated in the Puncoviscana Formation. Both the Loma Pelada and Los Cuartos granitoids include samples with intermediate geochemical characteristics that range between those of the El Infiernillo and La Ovejeria and the regional metasedimentary rocks. These characteristics could be explained by assimilation processes involving the I-type intrusive magmas and the metasedimentary host rocks or by hybridization processes between trondhjemitic I-type magmas as La Ovejeria and El Infiernillo and anatectic S-type melts.

Cambios de la línea costera en el delta del río Balsas, Pacífico mexicano, entre los años 1943-2009

Since the second half of the twentieth century, the undertaking of a number of hydraulic and hydroelectric projects has contributed to the disruption of the balance of water and sediment flows in river basins, leading to accelerated processes of progradation and regression in deltaic and other coastal landforms. The retention of sediments in reservoirs has not only resulted in coastal regression, but has severely impacted natural and socio-productive ecosystems as well. In the case of the deltaic plains of the Balsas river in Mexico, the construction of El Infiernillo and La Villita hydroelectric plants in 1964 and 1973, respectively, led to a marked regression of the delta as well as several morphodynamic changes in riverine and coastal areas. The Balsas river basin is located between 17° and 20° North and 97° 30’ and 103° 15’ West, occupying the border between the states of Guerrero and Michoacan along the Mexican Pacific coast. The delta, itself an expression of fluvial sedimentation at the lower course, as the river leaves the mountainous terrain of the southern Sierra Madre, consists of a vast plain representing one third of the total watercourse from north to south, and is divided into two distributary arms leading all the way into the Pacific Ocean, where clear signs of progradation such as cross stratification and valley fills have been detected on the gentle slopes offshore, far away from the coast. This study analyzes the morphodynamic changes taking place at the Balsas river delta front over 66 years between 1943 and 2009, using documentary evidence from official maps (1964, 1980, 1990, 1998, 2001 and 2003), as well as photographic restitution of the coastline using various aerial photographic materials (1943, 1958-59, 1963, 1974, 1976-1977, 1981-1982, 1985, 1996, 2006 and 2009). In the western sector, between 1943 and 1958, prior to the construction of the engineering projects, a significant trend was observed in the progradation of the delta front of the order of +1,103 m, whereas at the apex of the delta the coastline advanced towards the sea at a rate of +73.53 m/year. The most significant changes in the regression of the delta, with maximum regressive rates of -20.5 m/year, occurred during the stage of controlled water flows between 1963 and 1974, due to the closure of reservoirs, after a long phase of natural progradation from 1943 to 1958. In the western part of the delta, the average progradation rate reached -8.8 m/year (1958-2009), in contrast to the progradation rate of +27.47 m/year prior to the construction of the projects. In the eastern part of the delta, on the other hand, regression prevailed during all the periods analyzed, especially between 1963 and 1974, when even the delta coastline lacked effective protection. The maximum linear regression at the coast reached -391.83 m during that period. Later, in 1979, jetties and breakwaters started to be built to reduce the erosive impact of waves. These coastal protections resulted in a sustained reduction of erosion (average rate of -1.45 m/year) until 2009. When compared to the changes in the western sector, the regressive phase in the eastern part of the delta is notorious. The most significant extreme value occurs in the period 1963 to 1974, with a loss of beach surface of 86.68 ha, indicating an average rate of coastal regression of -10.12 m/year. It is expected that the process of coastal regression at the delta keep a low rate in coming years, given the routine maintenance to coastal protections and other infrastructure at the Lazaro Cardenas industrial port. Though they generally help improve the environmental and socio-economic conditions of upstream areas, dams may cause multiple imbalances and may adversely impact the environment towards the river mouth, leading to problems such as land losses, damages to the flora and fauna, decline of the water table, subsidence of alluvial and deltaic plains by differential sediment compaction, and the intrusion of saline water in areas adjacent to the coast, mainly during high tide, resulting in soil salinization and loss of fertility. These impacts are already identified at the Balsas River delta plain.

Paleomagnetic constraints on the ages of the Holocene Malpaís de Zacapu lava flow eruptions, Michoacán (México): Implications for archeology and volcanic hazards

Four monogenetic Holocene lava flows located within the Michoacan-Guanajuato Volcanic Field, Mexico, were sampled for paleomagnetic dating. These flows (namely, El Infiernillo, Malpais Las Viboras,...

Manejo de recursos vegetales alimenticios en la Quebrada de los Corrales, El Infiernillo, Tucumán (2100-1550 años AP).

En este trabajo se presenta una síntesis de la información macrobotánica disponible para el lapso 2100–1550 años AP en la Quebrada de Los Corrales (QDLC, El Infiernillo, Tucumán, Argentina). QDLC está situada por encima de los 3000 msnm en el sector norte del sistema montañoso del Aconquija, en el noroeste de la provincia de Tucumán. El objetivo es evaluar cómo se relacionaron las comunidades que vivieron durante el 1° milenio D.C. en QDLC con los recursos vegetales alimenticios. Las evidencias proceden de un sitio bajo reparo y de contextos domésticos a cielo abierto. El conjunto de plantas alimenticias habría estado constituido por distintos taxones silvestres y domésticos de aprovisionamiento o producción, tanto local como alóctona: algarrobo, chañar, zapallo criollo silvestre, soldaque, poroto común silvestre y doméstico, tubérculos microtérmicos, quinoa y maíz.

Políticas de operación de la presa «El Infiernillo» para generación de hidroelectricidad con programación dinámica estocástica

This work deals with getting operating rules for a dam which take into account the Comisión Federal de Electricidad operator's requests, besides to find a balance between the restrictions imposed by Comisión Nacional del Agua, in order to guarantee on the one hand, the biggest benefits for hydropower generation and on the other hand the lowest spill and deficit scenarios to avoid damages in downstream sites. This problem can be solved by applying a mathematical optimization model using several methodologies for this purpose.In this analysis operating rules were obtained and simulated, for the hydropower system “El Infiernillo” using a stochastic dynamic programming algorithm, this method has been applied since almost two decades in several important hydropower dam systems in Mexico. The objective function used was to maximize the generation benefits, imposing penalties in case of spill or deficit in the system and also adding penalties when an upper or lower guide curve could be overtopped on their limits, these guide curves help to reconcile the operator organizations by setting with an upper level the safe dam storage volume for management purposes in case of extremes hydrometeorogical events and with the lower limits a minimum hydropower generation can be guaranteed in the system. With the application of the algorithm in several occasions proposing different penalty values, optimum operating rules expressed as a data table were obtained. Such rules where simulated with the fortnight inflow historical volume to the Dam from years 1965 to 2013.The extraction volume in the time interval chosen for the simulation can be decided in a simply way by the operator helped with an extraction values table according to the storage in the dam; besides is incorporated, during the simulation, the effect of the inflow volume autocorrelation by adding or subtracting a specified volume taking into account the inflow magnitude from the previous time interval, with respect to the mean historical inflow volume in the same previous time interval.

A 2006 Colima Rift Earthquakes Series and Its Relationship to the Rivera-Cocos Plate Boundary

From 31 July through 13 August 2006 a series of fourteen earthquakes (M 3.9 to 6.1) occurred in the western end of the Central Mexican Volcanic Belt (CMVB) in a twenty-five days period. The most prominent earthquake (Mw 6.1) occurred on 11 August 2006 at 14:30 UTC (9:30 local time) approximately at 18.37° N, 101.25° W and 81 km depth. The epicenter was less than 40 km from Huetamo, Michoacan a 41,250-inhabitant city and 60 km from the El Infiernillo dam embayment the third largest hydroelectric plant in Mexico. This earthquake was widely felt with minor to moderate reported damage. In Mexico City 250 km away from the epicenter the earthquake produced alarm among the population and several buildings were evacuated. The earthquakes series developed into two activity clusters one centered in the coast and separated about 300 km from a second inland cluster. The initial coastal cluster consisted of a nearly linear activity distribution, which includes shallow-depth earthquakes of reverse and normal faulting mechanisms. The inland cluster shows more compact and deeper hypocenters distribution. Earthquakes first-motion polarities indicate that ruptures occurred as a normal faulting, which is a characteristic of the CMVB earthquakes. The overall trend of earthquakes distribution shows two branches, one, along the El Gordo-Colima graben system direction (~N45°E) nearly perpendicular to the coast and another along an east-west direction parallel to the southern border of the CMVB. Our results indicate that these two branches might constitute part of the continental extension of the Rivera-Cocos plate boundary.

The biological and reproductive parameters of the invasive armored catfish Pterygoplichthys disjunctivus from Adolfo López Mateos El Infiernillo Reservoir, Michoacán-Guerrero, Mexico

Invasive Pterygoplichthys disjunctivus (Weber, 1991) (synonymy: Liposarcus multiradiatus) armored catfish were first reported in Mexico in 1995 and have spread successfully in several aquatic ecosystems. In Adolfo López Mateos El Infiernillo Reservoir, Michoacán - Guerrero, the population of this armored catfish is growing substantially because natural predators are not present and exploitation by humans does not occur. Over a complete annual cycle, we studied the following population parameters: weight, total and standard length, the relationship of weight to total length, the hepatosomatic (HSI) and gonadosomatic (GSI) indices, total fecundity (TF) and relative fecundity (RF). The average total (TL) and standard lengths (SL) were 248 ± 37.5 and 188 ± 30.7mm, respectively, and the average weight (W) was 135.3± 66.8g. The largest fish reported was 520mm in TL and weighed 1 280g. The species showed an extended reproductive season from May to November, as indicated by the GSI, TF and RF. The strongest reproductive peak occurred from July through October. During the annual cycle, the highest monthly average fecundity was 2 447 eggs, and the average relative fecundity was 12.6 eggs per g of fish (August and September). This information will be crucial for calculating the current biomass and future growth of the population. The calculation of these results could provide a basis for the exploitation of this resource for human consumption and animal feeds.

La casa y el campo en la Quebrada de Los Corrales (el Infiernillo, Tucumán): reflexiones sobre la espacialidad en el 1° milenio d.C..

La Quebrada de Los Corrales (El Infi ernillo, Tucumán) es un yacimiento arqueológico cuyo lapso de ocupación más intenso se dio entre ca. 2100 y 1560 años AP. Aquí, las áreas agrícolas-pastoriles están separadas de las residenciales, situación que contrasta con otros sitios de la región del mismo período. En este sentido, el objetivo de este trabajo es comprender las condiciones que habrían generado la particular estructuración del espacio y las implicancias que tuvo esto a través del análisis de mapas realizados mediante SIG.

Effect of ground-motion asynchronism on the equivalent acceleration of earth dams

Under seismic loads the deformability of an earth dam may induce several effects, including ground-motion amplification and asynchronism between different points of the dam embankment. The paper analyses the asynchronous effects occurring in two existing earth dams, representing well-documented case histories: the El Infiernillo Dam (Mexico) and the Camastra Dam (Italy). Asynchronous effects are analysed by theoretical predictions of the dam seismic response by adopting an advanced dynamic approach, which takes into account the main features that dam soils exhibit under cyclic loading conditions. For different potentially unstable masses within the dam embankment, equivalent accelerations were computed as the ratio between the resultant of the inertial forces and the weight of the volume V associated to the unstable mass. With the exception of very cortical sliding surfaces – not significant for dam stability – in most of the analysed cases the equivalent seismic coefficients do not exceed the peak acceleration at the dam base.

Seismic behaviour of geotechnical structures

This paper deals with some fundamental considerations regarding the behaviour of geotechnical structures under seismic loading. First a complete definition of the earthquake disaster risk is provided, followed by the importance of performing site-specific hazard analysis. Then some suggestions are provided in regard to adequate assessment of soil parameters, a crucial point to properly analyze the seismic behaviour of geotechnical structures. The core of the paper is centered on a critical review of the analysis methods available for studying geotechnical structures under seismic loadings. All of the available methods can be classified into three main classes, including the pseudo-static, pseudo-dynamic and dynamic approaches, each of which is reviewed for applicability. A more advanced analysis procedure, suitable for a so-called performance-based design approach, is also described in the paper. Finally, the seismic behaviour of the El Infiernillo Dam was investigated. It was shown that coupled elastoplastic dynamic analyses disclose some of the important features of dam behaviour under seismic loading, confirmed by comparing analytical computation and experimental measurements on the dam body during and after a past earthquake.

Influence of past loading history on the seismic response of earth dams

The paper deals with the influence of past loading history on the seismic response of earth dams by interpreting the static and dynamic behaviour of a real case-history: the El Infiernillo Dam. Settlements, pore water pressures and accelerations measured during different stages of the dam lifetime have been interpreted by using a coupled dynamic approach derived from the u– p formulation of the Biot consolidation theory. The approach is solved numerically with the finite element method. The study firstly investigates the effectiveness of the adopted model to predict the observed dam behaviour. Following, a parametric study has been performed to examine what effects, additional loading histories, have on the prediction of seismic-induced freeboard loss. The study brings out soil hardening effects induced by the past seismic history, and investigates to what extent earth dam response to a given earthquake may be affected by previous seismic events.

Land use, land cover changes and coastal lagoon surface reduction associated with urban growth in northwest Mexico

Coastal land use and land cover changes, emphasizing the alterations of coastal lagoons, were assessed in northwest Mexico using satellite imagery processing. Supervised classifications of a Landsat series (1973–1997) and the coefficients Kappa (K) and Tau (τ), were used to assess the area and verify the accuracy of the classification of six informational classes (urban area, aquatic systems, mangrove, agriculture, natural vegetation, and aquaculture). Pixel-by-pixel change detection among dates was evaluated using the Kappa Index of Agreement (KIA). Besides the overall estimation of the aquatic systems class, variations in the three lagoons present in the study area were analyzed individually. Measures of agreement between the classification and reference data indicate that the accuracy for the classification ranked from moderate to high (K = 0.76 ± 0.07; τ = 0.77 ± 0.06). From 1973 to 1997 urban area has doubled, growing to the north and the northeast, extending mainly over natural vegetation and agricultural land. La Escopama and El Sabalo, two of the lagoons studied, reduced their size to less than half that estimated in 1973, but the main estuarine system in the study area, Estero de Urias - El Infiernillo, has maintained its area without noticeable changes. However, the surrounding landscape in Estero de Urias - Infiernillo is changing from natural vegetation and agriculture to urban land use. Consequently, to limit as much as possible changes in the area to natural causes, some management measures must be considered to design urban development plans and to recover and preserve the natural areas, on a broad scale rather than a local spatial scale.

Site Response of the Dam El Infiernillo, Guerrero-Michoacan, Mexico

We estimated site effects of the earth dam El Infiernillo, located between the states of Guerrero and Michoacan, Mexico. We analyzed 125 strong-motion records from stations located at three different levels of the dam (80, 120, and 180 m) and in the free field. The selected earthquakes are located in the Cocos–North America subduction zone, with magnitudes between 3.8 and 7.9 and epicentral distances that range between 18 and 433 km. We used three methods to estimate the characteristic frequency of vibration ( f n) of the recording sites. First, we calculated spectral ratios between the horizontal and the vertical components of motion (H/V ratios). Second, we estimated f n calculating standard spectral ratios using a free-field station as a reference site. Finally, we made a third estimate using cross-spectral ratios. We found that although the three methods give consistent estimates of f n, on average the H/V ratio gives more stable estimates. The H/V ratios, however, subestimate the site amplification at low frequencies ( f < 8 Hz) at the top and middle sites. We suggest that this result is due to the lateral heterogeneity of the structure that favors wave-field propagation in the vertical direction.

Dynamic behaviour and response of El Infiernillo Dam: Elgamal, A W M; Gunturi, R V Earthq Engng Struct DynamV22, N8, Aug 1993, P665–684

Dynamic behaviour and response of El Infiernillo Dam: Elgamal, A W M; Gunturi, R V Earthq Engng Struct DynamV22, N8, Aug 1993, P665–684

Dynamic behaviour and seismic response of El Infiernillo dam

AbstractEl Infiernillo, a 145 m high rockfill dam in Mexico built in a narrow V‐shaped canyon, was subjected to eight major earthquakes since its construction. In this study, the dynamic dam response is analysed using (i) the recorded November 15, 1975 bedrock‐crest acceleration histories and (ii) the results of a 1970 full‐scale test conducted by UNAM, in which eight upstream–downstream and longitudinal resonant frequencies and configurations were observed and documented. These observed and seismically induced dynamic responses are compared herein to predictions of two different numerical models of El Infiernillo dam; a newly developed simplified three‐dimensional (3D) model, and a 3D finite element model. The dynamic dam response characteristics are assessed, and performance of the employed numerical models is evaluated. It is found that (i) higher modes of vibration had participated significantly in the recorded seismic response and (ii) upstream–downstream response is well represented by the two numerical models employed. Using the simplified model, the September 19, 1985 earthquake non‐linear response is computed and shown to compare satisfactorily with its recorded counterpart in the upstream‐downstream and vertical directions. The largest computed dynamic accelerations, stresses and strains are found to occur within the upper third of the dam body.

El Infiernillo and La Villita Dams: Seismic Behavior

El Infiernillo and La Villita rockfill dams in Southern Mexico underwent an earthquake of magnitude 7.6 (Ricter) on March 14, 1979, with epicenter about 68 mi(110 km) from each dam. As a consequence measurable deformations occurred in both dams, including settlement, slope distortion and cracking. These deformations and the earthquake accelerations on the rock foundations and on the embankments were recorded. The patterns of permanent deformation are analyzed and the relative contributions of compaction and shear distortion are estimated. In both dams the fraction of the observed crest settlement attributable to compaction was larger than that due to shear distortion, and a clear correlation was observed between cracking and settlement patterns. The observed settlements attributable to shear distortion were found to lie between those computed from sliding-block methods (lower estimate) and those from a method of accounting for overall embankment deformations (upper estimate).

Taxonomy and evolution of the "Prolepsis-complex" in the Americas (Diptera, Asilidae)

A reclassification of the species formerly included in the genera Prolepsis Walker, Dizonias Loew, Sphageus Loew, Tolmerolestes Lynch Arribálzaga and Cylicomera Lynch Aribálzaga is proposed in the present paper. Examination of types and dissection of male genitalia, among other characters studied, showed the close interrelationships among the species of the "Prolepsis-complex", now considered to belong to two genera, namely Prolepsis Walker and Cylicomera Lynch Arribálzaga. The proposed new arrangement of the "Prolepsis-complex" is as follows: Genus Cylicomera Lynch Aribálzaga, 1881 with the following species: rubrofasciata Lynch Arribálzaga, 1881 [= fraterna Lynch Arribálzaga, 1881], and genus Prolepsis Walker, 1851 [= Cacodaemon Schiner, 1866; = Dizonias Loew, 1866; ( = Sphageus Loew, 1866; = Tolmerolestes Lynch Arribálzaga, 1881; = Cacodaemonides Strand, 1928], including the following species: fax (Lynch Arribálzaga, 1881) [= brethesi Gemignani, 1936], pluto (Lynch Arribálzaga, 1881) [= rubripes Lynch Arribálzaga, 1881], fenestrata (Macquart, 1838), rosariana (Carrera, 1959), tristis (Walker, 1851) [= quadrimaculatus Bellardi, 1861; = lucasi Bellardi, 1861; = phoenicurus Loew, 1866; = bicinctus Loew, 1866; = pilatei Johnson, 1903; = albifasciatus Back, 1904; = bromleyi Carrera & d'Andretta, 1950], chalcoprocta (Loew, 1866), sandaraca (Martin, 1966), elotensis (Martin, 1966), crabroniformis (Schiner, 1866), and lucifer (Wiedemann, 1828) [= satanas Wiedemann, 1828; = rufipennis Macquart, 1838; = fumiflanima Walker, 1851; = quadrinotatum Bigot, 1878]. The following new species are described herein: Cylicomera dissona, from Argentina, Tucumán, San Pedro de Colalao, Prolepsis huatajata, from Bolivia, L&#945; Paz, Huatajata, P. pseudopluto, from Argentina, Tucumán, El Infiernillo, P. colalao, from Argentina, Tucumán, San Pedro de Colalao, P. martini, from Argentina, Córdoba, Villa de María, P. indecisa, from Argentina, Tucumán, P. costaricensis, from Costa Rica, Liberia, and P. funebris, from Brazil, Goiás, Jatai. Two tentative keys to species are given, one based on external morphological characters, the other on the male genitalia, with an interpretation and discussion, of the probable phylogeny of the "Prolepsis-complex" and the history of its geographical distribution.

Finite Element Analysis of El Infiernillo Dam

A simple trapezoidal element is presented for use in the analysis of thin core rockfill dams with nonlinear soil parameters. Handling of nonlinear soil parameters and allowance for the intermediate principal stress in plane strain problems are discussed. The analysis of El Infiernillo rockfill dam using trapezoids in the core and transitions, and variable Young's modulus and Poisson's ratio, reveals the transfer of stress that takes place around the core. Comparisons of strain observations at El Infiernillo Dam with results from the analysis are good, except in zones of compacted rockfill. It appears that the actual stiffness of compacted granular fills may be seriously underestimated, if soil parameters are based on data obtained from triaxial tests on normally consolidated samples. A fundamental understanding of soil deformation behavior would lead to an improvement in the finite element analysis of soil structure.