Browsing by Author "Santacruz Reyes, Karla Johanna"

Now showing 1 - 20 of 25

Análisis de la capacidad portante y la susceptibilidad a consolidación de un suelo fino en la Parroquia Borrero-Charasol, del Cantón Azogues
(Universidad de Cuenca, 2020-06-23) Cárdenas Sanmartín, Franklin Marcelo; Quito Ramón, Paúl Esteban; Santacruz Reyes, Karla Johanna
In the southern sector of Ecuador, several types of soil have problems in the structures implanted on them, an example of this is fine soft soils. This kind of soil goes through volumetric changes due to the increase in the water content in its structure, generating settlements, in addition to a low bearing capacity, which could affect its functionality as a foundation floor. However, these properties may be hidden from the surface, due to the desiccation of the material where: the upper part of the soil can have a much more compact consistency than the deeper soil and therefore higher surface resistance. This phenomenon could confuse the designer, who could overestimate the capabilities of the foundations material that influences in the excavation and foundation depth. The fine soil located in the sector known as Pérez - Perazo in the Borrero-Charasol part of Azogues, is an example of soft fine soil with superficial desiccation, that is why the present work studies this material in detail, and thus warn about the presence and behavior of these types of materials. For this soil, the physical, mechanical, geophysical and consolidation properties are obtained up by choosing samples from the depth of 5 meters in 1-meter intervals, through laboratory and field tests such as humidity, granulometry using sieves, Atterberg limits, specific weight, specific gravity, simple compression, triaxial compression, vane test, multichannel analysis of surface wave, electrical tomography, one-dimensional consolidation and field settlements; through altered and unaltered samples. The results achieved, showed a very significant decrease in soil resistance depending of depth, in addition to variations in the values according to the tests performed, finding undrained shear strengths from the simple compression test of 0.064 to 0.186 kg/cm², from the triaxial test from 0.49 to 1.52 kg/cm², from vane test from 0.2 to 1.25 kg/cm² and for multichannel analysis of surface wave from 0.964 to 1.141 kg/cm²; most tests showed the highest soil resistance at 2 meters deep except for the multichannel analysis of surface wave. The permissible load capacity for the different foundation scenarios (type and depth of displacement) ranges from 12.00 to 1.10 and 9.47 to 0.92 kg/cm² for square and continuous foundation slabs respectively. The consolidation phenomenon is important for the tested soil; a soft soil will generate significant settlements that must be taken into consideration in the design of structures using these materials. The present work analyzes the behavior by consolidation of the soil, obtaining a compression index (Cc) between 0.136 and 0.257, the rebound index (Cs) varies from 0.003 to 0.018, the consolidation index (Cv) from 0.0001 to 0.0005 cm²/s and the secondary compression index (Cα) from 0.0025 to 0.0081 in the laboratory and contrasting them with values estimated by correlations. The field settlement measurement test results in a measured settlement of 75.9 mm at the end of the primary consolidation process and a measure total settlement of 54.0 mm in the 57 days of test duration. Subsequently, an evaluation is performed of David & Poulos's Simple Diffusion theory and Terzaghi's one-dimensional consolidation with the measurements recorded in the field, without getting a good fit of the field data towards the consolidation theories. The settlement analysis is carried out by modifying the combinations of geometry (L / B ratio), depth of shed (Df) and applied foundation load. Finally, conclusions and recommendations are issued for prevention and / or control of the problems identified in the soil.
Análisis de la susceptibilidad a deslizamiento en la parte baja de la conducción Labrado – Tuñi
(Universidad de Cuenca, 2024-09-23) Naspud Herrera, Josué Anthony; Velez Parra, Flabio Jhojan; Santacruz Reyes, Karla Johanna
This study focuses on analyzing the susceptibility to mass movements in the lower part of the Labrado–Tuñi channel, managed by Elecaustro S.A., a sector that has experienced instability phenomena affecting the water conduction channel located in the area. The general objective of this work is to evaluate the susceptibility to mass movements in the study area and analyze possible mitigation processes. To achieve this objective, a methodology was developed that includes data collection, soil characterization, mass movement analysis, susceptibility mapping, and proposals for mitigation measures. The results of the susceptibility map indicate that the study area has predominantly low to moderate susceptibility to mass movements. However, specific areas with high susceptibility to these movements were identified. In these critical areas, various mitigation techniques were evaluated, such as hydroseeding with native vegetation, planting vegetative barriers, and using geocells. These solutions aim to improve the stability of the terrain and minimize the risks associated with mass movements.
Análisis de la susceptibilidad a movimiento de tierra del tramo medio de la conducción Labrado Tuñi
(Universidad de Cuenca, 2024-11-05) Samaniego Placencia, Ana Rafaela; Santacruz Reyes, Karla Johanna
The bypass channel of the Labrado Embalse to the Tuñi reservoir, belongs to the “Complejo Hidroeléctrico de Machángara”, which is essential to generation of energy, watering and water treatment in the region. Along the bypass channel landslides take place that put the proper functioning of the channel at risk, for this reason the aim of this study is to make a landslide susceptibility mapping, covering the distance from the abscissa 3+000 to 4+500. In the study the information about the factors among the landslides were collected, verified and fixed to build the mapping, according to the Mora & Vahrson methodology and Analytic Hierarchy. After analyzing, it was determined the closer method to obtain mapping is Analytic Hierarchy, due its capacity to assign the differentiated weight to each susceptibility factor. Thus it is possible to establish the greatest influential factors to the landslide susceptibility are slope and precipitation. This study is expected to make a noticeable contribution to improve the control of the area and protect the infrastructure inside the “Complejo Hidroeléctrico de Machángara” bringing important benefits to the “Empresa Electro Generadora del Austro ELECAUSTRO S.A”
Análisis de susceptibilidad a movimiento de tierra tramo Chanlud - Tuñi (Cuenca Alta), Complejo Hidroeléctrico Machángara, Azuay, Ecuador
(Universidad de Cuenca, 2025-03-31) Espinoza Abril, Alex Daniel; Andrade Bustamante, Thalía Estefanía; Santacruz Reyes, Karla Johanna
This document evaluates the landslide susceptibility in a section of the upper basin of the Machángara River, specifically in the upper area of the Chanlud-Tuñi segment, spanning from kilometer marker 0+000 to kilometer marker 3+000. This segment begins at the crest of the Chanlud dam and is part of the water conveyance system of the Machángara Hydroelectric Complex, located on the border between the provinces of Cañar and Azuay, Ecuador.The study is based on the Mora and Vahrson methodology, which integrates six factors: lithology, slope, moisture, vegetation cover, seismic activity, and precipitation. Using lithological, hydrological, seismic, and topographic information collected from various sources and complemented by field and laboratory data, individual maps were developed for each variable defined by Mora and Vahrson. These maps were then combined to produce a final susceptibility map of the study area, highlighting the sectors most vulnerable to potential landslide risks. The resulting susceptibility map revealed that most of the conveyance segment lies in areas of moderate susceptibility, with certain zones of high susceptibility concentrated in the lower part of the conveyance axis. These findings provide a valuable reference and starting point for future evaluations and risk management efforts in the area.
Análisis de susceptibilidad a movimiento de tierras, tramo inicial de la conducción Labrado-Tuñi
(Universidad de Cuenca, 2024-09-17) Maldonado Salcedo, Joaquín Eduardo; Peña Neira, Kevin Sebastián; Santacruz Reyes, Karla Johanna; Daniel Salvador Vélez Parra
The Labrado-Tuñi canal transports water for power generation at the Machángara hydroelectric complex, owned by ELECAUSTRO. Historically, there have been episodes of instability of the nearby slopes, which have reduced the flow transported and decreased the efficiency of energy production. The objective of this study is to elaborate maps of susceptibility to landslides in the first section of the canal, between abscissae 0+000 and 3+000, applying the Mora-Vahrson methodology and Analytical Hierarchy. The information required for the analysis methods was obtained from institutions such as SENAGUA and ELECAUSTRO, complemented with field visits. Characterization tests were carried out on the soils and rock massifs present. Soil types SM and GM were determined according to the SUCS; for the rocky outcrops, a RMR and a SMR class III were determined, i.e., medium quality rock. A Markland analysis identified that there is no risk of flat failure or Toppling in them. Prior to obtaining the maps, adaptations were made in the lithological layer, based on the results of the tests on soils and rock massifs. The maps revealed differences between both methodologies, being the Analytical Hierarchy more accurate in the zoning of the study area and in the distribution of the weights of the variables according to their relevance. It was observed that most of the area has high susceptibility and that slope is the most influential factor. The susceptibility levels were compared for different rainfall periods.
Análisis de susceptibilidad de movimientos de masa en la zona central del tramo Chanlud-Tuñi en el complejo hidroeléctrico Machángara
(Universidad de Cuenca, 2025-03-31) Vélez Cobos, Jonnathan Fabricio; Santacruz Reyes, Karla Johanna
This study examines landslide susceptibility in the upper basin of the Machángara River, analyzing how factors such as topography, geology, soil moisture, precipitation, and seismic activity impact terrain stability. The Mora and Vahrson methodology was employed, complemented by an adapted approach incorporating the Topographic Wetness Index (TWI), which allowed for the identification of areas more prone to moisture accumulation and its effects on stability. The results showed that 15% of the surface area has high susceptibility, corresponding to locations where previous landslides have been recorded, while the majority of the area (60%) is classified as having medium susceptibility, indicating favorable conditions under certain circumstances. Human activity, particularly land manipulation, further increases susceptibility in several zones. Additionally, moisture was identified as a critical factor in the area, as its accumulation and spatial distribution play a key role in terrain instability. Based on the findings, susceptibility maps were generated to facilitate the identification of vulnerable áreas.
Análisis en laboratorio de la eficiencia de diferentes tipos de filtros para un suelo limo arcilloso de la ciudad de Cuenca
(2018) Nieto Correa, Katherine Alexandra; Zambrano Jaramillo, Juan Sebastián; Santacruz Reyes, Karla Johanna
In engineering the presence of water in soils is a very common phenomenon that requires a treatment to avoid erosion, scour, fine migration and undesirable pressures. As a solution to this problem, filters are used to help in the evacuation of water without damaging the internal structure of the soil. The problem starts with the selection of filters without adequate technical criteria, either because of the type of soil or the work done, resulting in unnecessary expense, because they do not meet their objective. For this work, for a fine soil containing silt and clays, its physical properties are analyzed as granulometry, plasticity, gravimetric, volumetric and permeability ratios. Based on the Terzaghi criterion, which are the retention and the permeability condition, a granular, geotextile and a combination of the two filters are designed. These are applied to the base soil in tests to determine their permeability and the migration of fines to different hydraulic gradients. The fines migration occurs in 12.50% for the granular filter, 52.61% for the geotextile filter and 34.69% for the combined filter. In the evacuation of the flow, the combined filter has a permeability of 2.65 x10-5 cm/s, compared to 2.62 x10-5 cm/s of the geotextile filter and 1.61x10-5 cm/s of the granular filter. Additionally, related to cost analysis, the granular filter is the most economical. For the selected soil the combined filter is choose because it exhibits the highest efficiency in permeability, guaranteeing a reduction in fines migration.
Aproximación de la capacidad portante de un suelo tipo conglomerado de la ciudad de Cuenca
(2019-10-28) Alvarez León, Diego Andrés; Contreras Duchimaza, Josseline Vanessa; Santacruz Reyes, Karla Johanna
This research deals with the analysis of the mechanical behavior of a conglomerate soil belonging to the Qt5 fluvioglaciar terrace in the city of Cuenca. The conglomerate soil is characterized by presenting a wide granulometric distribution that ranges from large blocks of rock to fine clay material that makes up the matrix in which the blocks are immersed. In this study, the mechanical characterization of the material is represented by the parameters of shear resistance: angle of internal friction (ɸ) and cohesion (c), which have been estimated through the application of empirical relationships and the execution of field tests. For the application of the first methodology it is necessary to perform the physical characterization of the conglomerate, determining properties such as the particle size distribution, relative density and dry specific weight, which, through of the empirical correlations considered, allow the estimation of the friction angle whose value ranges between 35° to 55°. In the field, 4 direct shear tests were carried out on an unaltered sample with a cutting area of 0.64 m², in order to obtain normal and shear stresses and build a failure envelope thus achieving a ɸ=55° and c=0.12 kg/cm² A geophysical prospecting test was also carried out, from which the shear and compression wave velocities are obtained which, through the use of correlations, allow the estimation of various mechanical parameters of the soil and its bearing capacity; through a back analysis process a value of ɸ=31° and c=0.15kg/cm² are obtained. Finally, the results of shear resistance obtained from the different methodologies are compared and used to estimate the bearing capacity of the soil for each case.
Caracterización de las fuentes de materiales más utilizadas en el Azuay, enfocado hacia su empleo para subbase, base y capas de rodadura
(Universidad de Cuenca, 2023-06-08) Machado Cordero, Mateo Gabriel; Palacios Quezada, César Mateo; Santacruz Reyes, Karla Johanna
An adequate road infrastructure helps a prosperous economic growth and an appropriate development of the region. This in turn depends mainly on the material used and its correct characterization; however, in the province of Azuay, the lack of a source of data on the available material and its scarcity make this difficult. In this study, the different sources of materials are analyzed. Twenty-seven mines were collected (14 Base/Sub-base and 13 Ballast). Ten of these were found near El Descanso sector, being the most relevant for Base/Sub-base and without previous characterization found: Atenas (Graiman), Rookaazul, Virginia and Cerro Tamuga. The materials are analyzed according to current regulations by means of the respective tests. The mines analyzed provide adequate characteristics for Bases/Sub-bases, except for the Cerro Tamuga mine, which presents a slightly higher plasticity index, which could be corrected through the addition of pozzolans, and the Atenas mine, which for its Sub-base type material presents small mismatches with the standard granulometries. Although the existing mines have adequate materials, these may not be available at times, due to political-administrative issues and generate shortages in the sector. To avoid dependence on these, a complete study on new sources of materials is needed, for which a compilation map of the most used in Azuay is developed, detailing their characteristics and providing guidelines for the study.
Caracterización de suelos expansivos de la ciudad de Cuenca
(2019-10-16) Idrovo Angumba, Byron Steven; Santacruz Reyes, Karla Johanna
The urban development of the city increasingly invades new lands, where there is no record of old buildings or any experience with the type and behavior of the soil of the place. It becomes necessary then to collaborate in the identification of certain areas that may have problems regarding expansive soils. This property of the soil, can cause significant damage to the structures and even a general collapse. However, the expansion of a coil is not a property that is commonly evaluated within the design of a structure, unless there is some indication in this regard. The objective of the proposed research is to identify soils with expansive problems, within the city of Cuenca and its surroundings. It is intended to evaluate the expansive characteristics of these soils and contrast the results obtained with different laboratory methods and empirical correlations for the characterization of expansive soils that will serve as a reference, at the time of construction to make a good design of the building and in the case of no construction in these areas. Five soils located in the Gapal, Valle, Challuabamba, Sidcay and Miraflores sectors in the city of Cuenca are analyzed, as well as one in the city of Azogues. These soils are classified according to the SUCS and degree of expansiveness such as: Low clay plasticity expansive grade Medium, Sand clay expansive grade Low, Clay high plasticity expansive grade Very high, Sand clay expansive grade Low, Clay high expansion grade Very High and Sand clay expansive grade Low respectively. Tests of free expansion, controlled expansion, Lambe test and test of free expansion in test tube are contrasted, in addition to the analysis of properties such as Atterberg limits, specific gravity, particle size. Correlations and recommendations are obtained regarding the use of these tests to determine the degree of expansion of a soil.
Caracterización de suelos inestables frente a deslizamiento en dos laderas situadas en los alrededores de la ciudad de Cuenca
(2019-04-22) Sánchez Guamán, Geovanna Paola; Sumba Naula, Adriana Priscila; Santacruz Reyes, Karla Johanna
Cuenca and its surroundings have a typical Highland topography, steep slopes and plains; geological structure of the soils is variable, since new fluvial deposits until Mesozoic metamorphic rock. These conditions, together with trigger agents such as seismic and pluviometric activity, cause soil instability. It is so some significant episodes of instability have been reported in the city, generating human losses and material damages. In the present work, a reliable database of different geotechnical parameters is generated for the sectors: Carmen de Guzho and Borja High school (Baños), which have instability. In the first sector, the information is wide and allows obtaining high confidence levels, for the second the lack of registry generates low confidence levels. Regarding the soils classification, both study areas evince clayey, silty soils and in some cases organic soils with a range of organic matter content 5,7-7,9% for Guzho and 2,6-9,3% for Baños. For both places SUCS soils classification is clays and silts of high plasticity. In Guzho the granulometric distribution is: sand 17,2 – 25,3% and fines 74,6 – 82,8%; in Baños is: sand 8,0–34,2% and fines 65,7 – 91,1%. The dry density for Guzho is 1,344-1,597 g⁄〖cm〗^3 and for Baños is 1,289-1,491 g⁄〖cm〗^3 . Within the mechanical properties the cohesion value is between 45,7-93,4 kN⁄m^2 and 52,6-84,9 kN⁄m^2 for Guzho and Baños respectively.
Comparación entre diferentes métodos de diseño, para muros con suelo reforzado con geosintético
(Universidad de Cuenca, 2020-10-16) Remache Orellana, Jorge Mauricio; Santacruz Reyes, Karla Johanna
For several decades, reinforced soil has been used as an alternative in construction processes in the field of Civil Engineering and according to these processes, various design methods have been developed, which include input data, calculation processes and particular results. for each of them. In the current bibliography there are several design methods for walls with geosynthetic reinforced soil, however, the results that these methods generally have significant differences, and it is not explained why each method differs from the other. In this titling work, a comparison of three main design methods is made: the first method proposed by the Federal Highway Administration (FHWA) in its publication number FHWA-HRT-11-026, the second one proposed by National Cooperative Highway Research Program (NCHRP) in its report 556, and a third method called FHWA Simplified Procedure developed from the AASHTO LRFD Bridge Design Specifications. The three methods are applied to four specific cases of local soil types. The characteristics have been obtained from field investigations by the PRECUPA project; all this based on the comparison of the input data, in selected ranges of values, processes that execute each of the methods and the results they produce. Geogrids and geotextiles have been used in the design as they are the recommended types for soil reinforcement. The most versatile method in the face of variations in the values of the proposed parameters, complying with the limits and specifications is the third method, FHWA Simplified procedure, considered the most used for the design of mechanically stabilized earth walls, MSEW, it has factors of load and resistance, safety factors for the design of the reinforcement, for which it is considered as a balance-limit design; with stability compliance percentages greater than 75% and percentages of influence of parameter value variations less than 51%. The most influential parameters on the three methods in general are: the friction angle of the reinforced soil, vertical spacing of the geosynthetic reinforcement, dead load due to the bridge, height of the upper wall, and the type of soil retained-foundation, the latter being the one with the highest percentage of variation with respect to the values of the base design. Both the spacing of the reinforcement and the height of the reinforced wall have a great influence only on Method 2, FHWA GRS - IBS Method, due to the amount of data that the equations handle for the calculation of failure modes.
Correlaciones entre el ensayo de penetración dinámica super pesada, presiómetro de Ménard y verificación con ensayos geotécnicos en suelos arcillosos y limosos del sector Challuabamba-Cuenca
(Universidad de Cuenca, 2024-01-02) Cabrera Barrera, David Andrés; Muñoz Sacoto, Paúl Sebastián; Santacruz Reyes, Karla Johanna
The high sensitivity of geotechnical test results to field-collected parameters underscores the need to focus efforts on exploring methods that allow for the correlation of geotechnical parameters based on more accessible sources of information, both from an economic and technical standpoint. This study examines two methods of collecting geotechnical information to establish an initial correlation between parameters obtained through the Dynamic Super Heavy Penetration Test (DPSH) and the Menard Pressuremeter Test (PMT). These methods were applied to five terrains consisting of fine soils in the Challuabamba sector, along with information from the OCP project conducted in the province of Sucumbíos. The collected information was processed using the SUCS method. The intervened terrains were classified as fine, predominantly inorganic silts, with 8 records falling under this classification, in addition to 3 records of clayey soils. The T-Paired test statistical method was employed to verify the equality between the two treatments. Finally, a linear fit was proposed between the results of the bearing capacity of the two mentioned tests. The study found that a combined correlation model of silts and clays does not have a satisfactory fit. However, by limiting the analysis information to silty soils, the fit aligns satisfactorily with the expected results, presenting a Pearson coefficient of 0.95. This leads to the conclusion that an important criterion to consider in the search for correlations in this context is the correct SUCS classification of soils
Determinación de las propiedades elásticas del conglomerado de las formaciones Turi y Terrazas fluvioglacíaricas de la Ciudad de Cuenca a partir de las propiedades de su matriz
(2009) Santacruz Reyes, Karla Johanna; Samaniego Alvarado, Esteban Patricio
Determinación de una correlación entre el valor de CBR y el ensayo DCP para suelos del cantón Cuenca
(Universidad de Cuenca, 2022-05-27) Ordóñez Salazar, Diego Fernando; Santacruz Reyes, Karla Johanna
The CBR for its acronym in English (California Bearing Ratio), is an important factor in the design of pavements, and in the evaluation of pavements. However, the execution of the test represents a high cost and time. For the determination of the CBR in situ, the ASTM standard and other authors have established correlations with the field test called DCP by its acronym for Dynamic Cone Penetration Test; allowing to relate the CBR in situ with the DCP value obtained in the field. However, since there is no relationship between these parameters applied to the city of Cuenca, and even to other parts of Ecuador, the use of existing correlations between the two parameters has been stopped. Therefore, the determination of the CBR is considered important, based on a correlation with the DCP test applied to soils in the city of Cuenca, and it is proposed to establish it through a statistical analysis of linear regression and validate it based on existing correlations in the literature. The present work gets two correlations, between the DCP and the CBR in situ with a determination coefficient R2 of 0.911; and between the DCP, the dry field density, and the CBR, obtaining an adjusted coefficient of determination R2 of 0.930. The correlation established between the CBR and DCP was compared with the expressions proposed in the specialized literature, and it was determined that it maintains a similar behavior, establishing that the correlation obtained is valid, and a fast and economical way to obtain the parameter CBR for different soils in our city.
Elaboración de un mapa de susceptibilidad al movimiento de masas en el tramo final de la conducción Chanlud – Tuñi
(Universidad de Cuenca, 2024-11-05) Moscoso Astudillo, David Esteban; Romero Aucancela, Wilson Eugenio; Santacruz Reyes, Karla Johanna; Vélez Parra, Daniel Salvador
This study focuses on the development of a landslide susceptibility map for the initial segment of the Chanlud-Tuñi conduit, located in the upper basin of the Machángara River, Azuay Province, Ecuador. The study employs a modified Mora-Vahrson methodology, integrating factors such as terrain slope, geology, vegetation cover, soil moisture, precipitation, and seismicity, which allows for the identification and classification of areas susceptible to mass movements. The main objective is to identify areas with a higher likelihood of landslides and to map them, in order to provide relevant information for risk planning and mitigation. The analysis revealed that areas with high and very high susceptibility to landslides are primarily located near the road leading to the Chanlud dam, characterized by steep slopes and the presence of colluvial materials, which have limited drainage capacity, increasing their vulnerability to saturation and, consequently, to landslides. In addition to the susceptibility map, the work presents a landslide inventory for the critical areas identified in the zone, which was used to validate the methodology employed and to describe the historical evolution of the landslides present in the study area through the review of satellite images and field surveys. The methodology has proven effective in identifying areas of greatest risk. However, to increase the accuracy of the results, it is recommended to intensify data collection, with special attention to aspects such as soil moisture.
Estimación de los parámetros de resistencia cortante para suelo tipo conglomerado
(Universidad de Cuenca, 2023-06-12) Aguirre Abad, Paúl Andrés; Muñoz Espinoza, Juan Diego; Santacruz Reyes, Karla Johanna
The present work focuses on the study of conglomerate, a heterogeneous soil formed by blocks, rocks that cover a wide range of sizes (larger than 3") and the matrix formed by gravel, sand and fines. This soil is commonly found on the banks of rivers in the city of Cuenca. The main objective is to approximate the parameters of shear strength, friction and cohesion, by means of two methodologies: empirical relationships and back-analysis; for this, first, characterization and strength tests were performed on the matrix. For the first methodology, the theory for Bimsoils presented by Kalender et. al (2014), and the one presented by Duncan (2012) were applied, the first one requires parameters such as: percentage and characteristics of the blocks, and resistance of the matrix, after applying this methodology an approximate friction angle of 39° and a cohesion between 12 and 24 KPa were obtained; on the other hand, the second empirical methodology takes into account parameters such as granulometry, relative density and confining pressure, with this one a friction angle of 51.37° was determined. With the back-analysis methodology, a friction angle close to 53° and cohesion of 2.6 KPa were determined. Finally, comparing results it is identified that the difference in the values obtained is due to the different conditions under which the study is performed, being the empirical methods a more practical and applicable option than the back analysis due to the limitations of the method and the information it requires.
Estudio de mejoramiento de suelos expansivos con la adición de fibras de polipropileno
(Universidad de Cuenca, 2025-09-24) López Reinoso, Josué Sebastián; Pacurucu Álvarez, Andrea Carolina; Santacruz Reyes, Karla Johanna
The purpose of this study is to evaluate the behavior of a clayey soil through the addition of polypropylene fibers at different dosages. For this purpose, laboratory tests were conducted, including Atterberg limits, standard Proctor compaction, free swell, and controlled swell tests. Polypropylene fibers were incorporated in dosages of 0.5%, 0.6%, 0.7%, 0.8%, 0.9% and 1% by weight, based on the standard Proctor test. The results show that, as the fiber content is increased up to a dosage of 0.7%, a reduction in the percentage of free swell and controlled swell of the soil is observed, demonstrating the effectiveness of polypropylene fibers in the improvement of expansive soils. This behavior is due to the fibers' ability to act as a three-dimensional reinforcement, which restricts the soil’s expansion and contraction movements.
Influencia de la humedad natural del suelo en su potencial expansivo, estudiada en suelos del austro ecuatoriano
(Universidad de Cuenca, 2022-03-15) Espinoza Calle, Jonnathan Fabricio; Vargas Rosvik, Bjarne Nicolás; Santacruz Reyes, Karla Johanna
In the field of geotechnical engineering, the expansive soils behavior has been a topic that has generated uncertainty throughout history, becoming over time, a key problem to be addressed in civil constructions, either for safety or economic factors. In this way, multiple investigations with different results have demonstrated the importance of addressing expansivity; despite this, a limitation of information prevails, especially when it is necessary to know the relationship between the expansive potential and the natural moisture soils may have. This knowledge could contribute to a better understanding of the soils behavior when they are exposed to sudden changes in moisture. With this background, the present study aims to determine how moisture affects expansive potential of soils from the southern zone of Ecuador, which we have worked with a quantitative methodology, and a correlational scope, starting with a bibliographic compilation of swelling pressure and expansion percentage together with the soil qualities under study and its location in the southern zone of Ecuador. Then, tests based on regulations have been elaborated, obtaining the soil characterization and own values of swelling pressure for sites located in Cuenca and its surroundings: Miraflores, Challuabamba and Cojitambo. The results obtained correspond to initial moisture vs. swelling pressure curves obtained by means of second-degree multiple regression, which can be used to determine the expansion as a function of water content and dry density (𝛾ௗ) for these particular sites. The conclusions indicate low expansive potential values for the Cojitambo sample, which is characterized as a low expansive soil, inferring that it is not a bentonite material, as stated in the literature. A different case is analyzed for the soils of Miraflores and Challuabamba, with relatively high values of swelling pressure and expansive deformation, which are in agreement with the correlations according to their degree of expansivity and a modified equation proposed by Nayak & Christensen (1979).
Métodos para controlar el potencial expansivo en suelos arcillosos de la ciudad de Cuenca
(2019-04-17) Bravo Heredia, Pablo Esteban; Daza Orellana, Pablo Andrés; Santacruz Reyes, Karla Johanna
There are different types of soil’s properties that can complicate structures above them, a clear example are the expansive soils. These materials suffer changes in their volume due to the variation of water content in their pores. By increasing their water content, they swell and generate expansion pressures, in certain cases is so high that they even lift up structures; to the contrary, when these soils lose moisture, they suffer contractions, which are equally harmful to structures. There are several methods to control this unwanted behavior in expansive soils. In the following work, three types of expansive soils of the city of Cuenca will be analyzed, and the one with the most unfavorable properties will be selected, later different treatments will be applied to control their expansive potential, the effect of each treatment will be verified. The soil to be used will be selected from soils coming from the sections of Baños, Challuabamba and Miraflores; of all the soils will be characterized, through laboratory tests such as: method of sieve analysis and hydrometer, Atterberg limits, free expansion, pressure expansion, test tube method, Lambe method, and tests in unaltered and remodeled soils. Subsequently, different types of chemical treatments will be applied to stabilize the most expansive soil; additives such as lime, cement, fly ash, silica fume (SikaFume) and gypsum will be used. The procedure will consist in adding different stabilizers to the remodeled soil with a specific dosage for each one; later review the swelling presented by the improved soil samples, and together with a brief analysis of costs and environmental impact, choose the most appropriate method to reduce the expansive nature of the soil.