Soils and RocksPub Date : 2023-04-27DOI: 10.28927/sr.2023.013722
Lorena Leite, Paulo Maia, Aldo Farfán
{"title":"Three-dimensional numerical analysis of the generalized group effect in monitored continuous flight auger pile groups","authors":"Lorena Leite, Paulo Maia, Aldo Farfán","doi":"10.28927/sr.2023.013722","DOIUrl":"https://doi.org/10.28927/sr.2023.013722","url":null,"abstract":"The interaction mechanisms related to the group effect between piles and between pile groups significantly influence the soil-structure interaction process. This interaction causes the superposition of stresses and, in general, makes the pile group settlement different from the settlement of an isolated pile. The objective of the present paper is to evaluate the soilstructure interaction mechanisms of buildings with foundations of monitored continuous flight auger piles (CFA) in a stratified soil mass, with the presence of an intermediate soft soil layer. Hence, it is particularly analyzed the group effect between piles of a group and the group effect between all pile groups from a foundation of a study case instrumented by means of numerical modeling, considering the effect of the soft soil layer. The results show the significant group effect on displacements, showing the increase in settlement due to the overlapping of the tension bulbs of the piles and neighboring pile groups.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48394461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soils and RocksPub Date : 2023-04-27DOI: 10.28927/sr.2023.012422
Murilo Conceição, Camilla Pinto, M. Carvalho, S. Machado
{"title":"Fiber reinforcement effectiveness in two different sand specimens","authors":"Murilo Conceição, Camilla Pinto, M. Carvalho, S. Machado","doi":"10.28927/sr.2023.012422","DOIUrl":"https://doi.org/10.28927/sr.2023.012422","url":null,"abstract":"Fiber Reinforced Soils (FRS) are mixtures of discrete fibers with the soil to create a composite with improved mechanical properties compared to unreinforced material that depends on several soil and fiber properties. Therefore, comparative studies are needed to better understand their influence on FRS mechanical response. This paper analyzes the results of a comprehensive triaxial testing program performed on specimens of two different sands at the same relative density focusing on how the grain size distribution affects the composite behavior in terms of shear strength and dilatancy. It is shown that the grain size curve’s uniformity coefficient (Cu) is one of the critical variables controlling FRS’s dilatancy. Dune sand specimens (Cu = 1.79) presented dilatancy even for confining stresses as high as 300 kPa. The shear gains due to reinforcement were controlled by fiber length (L) and percentage (Pf), and size and shape of soil particles. River sand specimens with L = 51 mm and 1% fiber addition (dry mass) presented increments of 47.7 kPa in soil cohesion and a 5.2o increase in the soil friction angle compared to unreinforced material.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48463289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soils and RocksPub Date : 2023-04-21DOI: 10.28927/sr.2023.013422
Filipe Fernandes, Bárbara Moura, M. Almeida, Luciano Souza Junior, S. Tarazona, M. Almeida, J. Barros
{"title":"Determination of the dynamic parameters of Speswhite kaolin with resonant column and centrifuge tests","authors":"Filipe Fernandes, Bárbara Moura, M. Almeida, Luciano Souza Junior, S. Tarazona, M. Almeida, J. Barros","doi":"10.28927/sr.2023.013422","DOIUrl":"https://doi.org/10.28927/sr.2023.013422","url":null,"abstract":"Understanding the dynamic behavior of soils is essential to the study of the influence of seismic loads on the instability of submarine slopes, an important issue in Brazil and other countries. The shear modulus and the damping ratio are two fundamental parameters for the study of this behavior. Determining these parameters for Speswhite kaolin clay is the object of the present study using resonant column tests and dynamic centrifuge tests with accelerometers and pairs of bender elements. The curves obtained in the laboratory are compared with empirical curves and comparable data in the literature. Good agreement was observed between experimental data and the empirical prediction for the degradation curve of the normalized shear modulus. The damping curve for very low strains, obtained with resonant column tests, was consistent with the empirical curve. However, consistent with a trend observed in the literature, the centrifuge test results presented considerable scatter (dispersion), attributable to the difficulty in modelling damping dissipation mechanisms in the centrifuge.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47228535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soils and RocksPub Date : 2023-04-20DOI: 10.28927/sr.2023.010022
C. Silvani, J. Guedes, Jucimara Silva, Eduardo Tenório, Renan Nascimento
{"title":"Brackish water in swelling soil stabilization with lime and sugarcane bagasse ash (SCBA)","authors":"C. Silvani, J. Guedes, Jucimara Silva, Eduardo Tenório, Renan Nascimento","doi":"10.28927/sr.2023.010022","DOIUrl":"https://doi.org/10.28927/sr.2023.010022","url":null,"abstract":"This research shows that brackish water increases the unconfined compressive strength of swelling soil/sugarcane bagasse ash (SCBA)/lime blends. Therefore, brackish water may substitute tap water in soil stabilization. Sodium chloride (NaCl) has been used in lime-ashes-soil treatments. In northeast Brazil, swelling soils are usual and artesian wells sometimes provide brackish water containing NaCl. Northeast Brazil also has a strong sugar and ethanol industry producing sugarcane bagasse ash (SCBA) as a byproduct. Therefore, brackish water can be used in soil-SCBA-lime stabilization. Hence, this work aims to evaluate the use of brackish water as a substitute for tap water in swelling soil- SCBA-lime blends stabilization. Two series of unconfined compression tests were carried out: one with tap water and the other with brackish water. In each group, the lime content varied from 4% to 8%, and the dry density from 13 kN/m3 to 15 kN/m3. All tests were carried out with a swelling soil-SCBA proportion of 75/25 and a water content of 22%. Results have shown that increasing lime content or dry density or using brackish water allowed to increase unconfined compression strength of swelling soil-SCBA-lime blends. The porosity/volumetric content of lime index (η/Liv) was suitable to predict the unconfined compressive strength of swelling soil-SCBA-lime blends, no matter if tap or brackish water was used in the molding process. Thus, brackish can be a feasible substitute for tap water in swelling soil-SCBA-lime stabilization, increasing blends unconfined compression strength, and preserving tap water, a scarce asset in Northeast Brazil.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47732587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soils and RocksPub Date : 2023-04-19DOI: 10.28927/sr.2023.013522
H. Assis, C. Nogueira
{"title":"Comparative study of deterministic and probabilistic critical slip surfaces applied to slope stability using limit equilibrium methods and the First-Order Reliability Method","authors":"H. Assis, C. Nogueira","doi":"10.28927/sr.2023.013522","DOIUrl":"https://doi.org/10.28927/sr.2023.013522","url":null,"abstract":"This work presents the validation of the Morgenstern-Price method implemented in the Risk Assessment applied to Slope Stability (RASS) computational program to carry out deterministic and probabilistic analyses of slope stability. Deterministic analyses, based on the factor of safety approach, are performed using limit equilibrium methods. The probabilistic ones, on the other hand, are carried out through the direct coupling of these methods to the First Order Reliability Method (FORM). Initially, two benchmark cases are presented for validation of the computational routine related to the Morgenstern-Price method. Next, two illustrative examples are presented, with the investigation of the critical surfaces defined by deterministic and probabilistic criteria, which correspond to the minimum factor of safety, the maximum probability of failure, and the maximum quantitative risk. In the set of stability analyses, it was verified that both the numerical responses and the geometry of the critical surfaces can vary depending on the choice of the limit equilibrium method and the criterion for identifying the critical surface. The different possibilities presented by the methodology used in this study define not only a critical surface, but a set of critical surfaces that can help in the engineering decision-making process and slope risk management, complementing the widely used purely deterministic analyses in geotechnics.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43109729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soils and RocksPub Date : 2023-04-13DOI: 10.28927/sr.2023.013122
Jeferson Fernandes, B. Rocha, H. Giacheti
{"title":"Maximum shear modulus and modulus degradation curves of an unsaturated tropical soil","authors":"Jeferson Fernandes, B. Rocha, H. Giacheti","doi":"10.28927/sr.2023.013122","DOIUrl":"https://doi.org/10.28927/sr.2023.013122","url":null,"abstract":"The maximum shear modulus (G0) and the modulus degradation curve (G/G0 versus γ) are important information in the evaluation of the soil mechanical behavior, both for dynamic and static loads. Dynamic tests (resonant column and cyclic triaxial tests) are not routinely performed in geotechnical practice in Brazil, and the geotechnical literature on the dynamic behavior of unsaturated tropical soils is limited. This paper presents and discusses seismic dilatometer (SDMT), resonant column, and triaxial test with bender elements and internal instrumentation to determine G0 and the modulus degradation curve in an unsaturated tropical sandy soil profile. It was observed that G0 tends to increase non-linearly with soil suction and net stress (σ - ua). It was also observed that the in situ G0 values determined with the SDMT were higher than those from laboratory tests (bender elements and resonant column). The modulus degradation curves determined with resonant column were used to define the reference curve via SDMT for the studied site. Soil suction influence in shear modulus degradation curves determined with unsaturated triaxial compression tests with local instrumentation is also presented and discussed.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43720960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soils and RocksPub Date : 2023-04-05DOI: 10.28927/sr.2023.011922
Sofia Carvalho, M. Sales, André Cavalcante
{"title":"Systematic literature review and mapping of the prediction of pile capacities","authors":"Sofia Carvalho, M. Sales, André Cavalcante","doi":"10.28927/sr.2023.011922","DOIUrl":"https://doi.org/10.28927/sr.2023.011922","url":null,"abstract":"Predicting the pile’s load capacity is one of the first steps of foundation engineering design. In geotechnical engineering, there are different ways of predicting soil resistance, which is one of the main parameters. The pile load test is the most accurate method to predict bearing capacity in foundations, as it is the most accurate due to the nature of the experiment. On the other hand, it is an expensive test, and time-consuming. Over the years, semi-empirical methods have played an important role in this matter. Initially, many proposed methods were based on linear regressions. Those are still mainly used, but recently the use of a new method has gained popularity in Geotechnics: Artificial Neural Network. Over the past few decades, Machine Learning has proven to be a very promising technique in the field, due to the complexity and variability of material and properties of soils. Considering that, this work has reviewed and mapped the literature of the main papers published in journals over the last decades. The aim of this paper was to determine the main methods used and lacks that can be fulfilled in future research. Among the results, the bibliometric and protocol aiming questions such as types of piles, tests, statistic methods, and characteristics inherent to the data, indicated a lack of works in helical piles and instrumented pile load tests results, dividing point and shaft resistance.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44625217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soils and RocksPub Date : 2023-04-03DOI: 10.28927/sr.2023.078521
{"title":"Estimation of short-term settlements of MSW landfill materials using shear wave velocity","authors":"","doi":"10.28927/sr.2023.078521","DOIUrl":"https://doi.org/10.28927/sr.2023.078521","url":null,"abstract":"Limited availability of simple yet adequately validated tools for estimating the deformation potential of municipal solid waste (MSW) material poses difficulty in planning and managing landfill operations. Estimation of settlement of MSW landfills has remained a challenge because of heterogeneity and time-varying mechanical behavior of MSW materials and difficulty of extracting representative samples and reconstituting them for laboratory testing. An empirical correlation is proposed here for estimating the short-term settlement of landfill materials. The relationship was developed by calibrating laboratory data from axial (1D) compression and consolidated drained triaxial tests against field-measured shear wave velocities from five landfill sites with varied waste compositions. The correlation was validated against three full scale load tests; one obtained in this research and two reported by others, and a field compaction study from a fourth landfill. Although the proposed correlation was more accurate than an alternative developed earlier, overall it underestimated settlements by about 12%. The proposed relationship could therefore provide a conservative guidance in MSW landfill design and operation.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43409947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soils and RocksPub Date : 2023-02-26DOI: 10.28927/sr.2023.077721
Raphael Carneiro, K. Guerra, C. Romanel, D. Gerscovich, B. Danziger
{"title":"Closed-form consolidation solutions for known loading functions","authors":"Raphael Carneiro, K. Guerra, C. Romanel, D. Gerscovich, B. Danziger","doi":"10.28927/sr.2023.077721","DOIUrl":"https://doi.org/10.28927/sr.2023.077721","url":null,"abstract":"In engineering practice, loading varies with time. However, the classical one-dimensional theory of consolidation assumes the stress increase is instantaneously applied. Many approaches to the problem of time-dependent loading have been proposed over the years, from approximate methods to full developments of differential equations. The paper presents a simple method for finding a closed-form consolidation solution for time-dependent loading without the need for differential equations. Two sets of general equations were derived for both excess pore pressure and average degree of consolidation. Equations were solved for linear, parabolic, sinusoidal, and exponential load functions. Stepped and cyclic loads were also addressed and a numerical solution was developed to verify the obtained result. The method proved to be easy to apply and provides solutions with great simplicity. A case study of non-instantaneous loading on soft clay was also analyzed, and settlement prediction showed good results when compared to readings of the settlement plates.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45504264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soils and RocksPub Date : 2023-02-26DOI: 10.28927/sr.2023.000123
Bárbara Pereira, J. Garcia
{"title":"Numerical analysis of the contribution of side resistance to caisson bearing capacity","authors":"Bárbara Pereira, J. Garcia","doi":"10.28927/sr.2023.000123","DOIUrl":"https://doi.org/10.28927/sr.2023.000123","url":null,"abstract":"The use of deep foundations is a common practice in geotechnical civil engineering designs, in which the bearing capacity of these foundations occurs by side resistance, tip, or through the combination of both. In the case of caisson, the bearing capacity is often obtained by considering only the resistance of the lower end due to its bell-shaped geometry, neglecting the skin friction resistance of the shaft, which may represent an oversizing in some cases. In this context, this paper analyzed the behavior of nine caisson prototypes laid at 10 m, 15 m and 20 m deep. At each depth, three types of caissons were analyzed, with and without an expanded base, and a third type with deformable material at the top of the base. The axisymmetric numerical analyses were conducted by using the finite element method considering an isotropic medium. Thus, it was found that with increasing depth, the skin frictional resistance of the surrounding soil of shaft contributes significantly to the bearing capacity of the caisson suggesting that little load would reach the base of the caisson in situations that would negligible the side resistance of the shaft in the design phase. This may be an important consideration in foundation design using caisson, as it would reduce risks to human life, as well as reduce material consumption and the generation of carbon released into the atmosphere.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42781315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}