Geomechanics and Geoengineering-An International Journal最新文献

{"title":"Fault and fracture reactivation analysis by 4D geomechanical integrated modelling in one of a depleted carbonate oil field, southwest of Iran","authors":"M. Tadayoni, Mahmoudreza Khalilbeyg, Radzuan Bin Junin","doi":"10.1080/17486025.2021.1955156","DOIUrl":"https://doi.org/10.1080/17486025.2021.1955156","url":null,"abstract":"ABSTRACT The study field has been an oil-producing area in southern Iran for nearly 50 years. Complex geological structure and varying levels of depletion scenarios require geomechanical analysis of the reservoir to enhance its production and mitigate geomechanical risks. This paper describes creating a time-lapse (4D) integrated geomechanical model by generating 3D maps of mechanical properties and a 3D stress state that can be altered over time as pore pressure changes, then explores pressure depletion and related stress changes effects on faults and fractures reactivation. The first phase of the study was an integrated stress analysis using Image logs and sonic anisotropy interpretation. 1D–3D Mechanical Earth Model was built by gridding the reservoir and populate the model with mechanical properties. The third phase provided a distribution of stresses and associated strains under initial conditions using finite element calculations. Ultimately, stress and strain changes associated with depletion simulated by the reservoir flow model were determined during the fourth phase of study. In the resulting model, different critical coordinates points from the initial year (1992) to 2045 were selected five time-steps. Results show no critical faults reactivation but by increasing production time the instability of fractures gradually rises by stress regime changes.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"17 1","pages":"1536 - 1553"},"PeriodicalIF":1.3,"publicationDate":"2021-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17486025.2021.1955156","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48870350","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}

{"title":"Seal grouting operation of slate and schist rock masses of Zanjan Balvabin Dam site, Northwest of Iran","authors":"S. D. Mohammadi, A. Sadeghi","doi":"10.1080/17486025.2021.1955161","DOIUrl":"https://doi.org/10.1080/17486025.2021.1955161","url":null,"abstract":"ABSTRACT To identify the required parameters of grouting operations in scrutinising the design and execution of seal curtain of the Balvabin dam site, the test grouting operations were conducted in a part of the seal curtain zone located in the riverbed. The test grouting was carried out in the vertical and angled rows according to the properties of discontinuities in the dam foundation zone to intersect the maximum discontinuities. Afterwards, the obtained results were analysed and finally due to the not groutable of the rock mass at the depths of more than 10 metres and according to the presence of peripheral gallery in the foundation, the execution of seal grouting operations was postponed until next dewatering. The measurements after the dewatering of the dam indicate whether grouting is required or it can be eliminated. With the grouting gallery being available, the grouting can be carried out at any other time.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"17 1","pages":"1634 - 1652"},"PeriodicalIF":1.3,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17486025.2021.1955161","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45941908","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}

{"title":"Assessment of swelling and strength characteristics of expansive soil with addition of WRP","authors":"A. Choudhary, Arpit Jain, Jagdanand Jha","doi":"10.1080/17486025.2021.1955160","DOIUrl":"https://doi.org/10.1080/17486025.2021.1955160","url":null,"abstract":"ABSTRACT The moisture migration and high-volume changes due to swelling and shrinkage in the expansive soils have posed severe challenges at many project sites. Additionally, rapid industrialisation in last few decades has posed problems of huge amount of undisposed industrial wastes, which not only cause environment degradation but also occupy huge tracts of valuable land. The paper presents the results of an experimental investigation carried out to assess the effect of waste recycled product (WRP), an industrial waste from steel industries; on the engineering properties of expansive soil and to achieve dual objectives of improving the engineering performance of such soils combined with its gainful utilisation. Test results revealed that addition of WRP to expansive soil in appropriate proportion not only reduces its swelling and shrinkage behaviour but also there is a significant improvement in its strength and deformation characteristics. After adding 30% WRP (by dry weight of soil) in expansive soil, the percentage increase in subgrade modulus and unconfined compressive strength was 89.18% and 68.78%, respectively, and it is concluded that there is significant potential for its use in flexible pavement construction on expansive soil subgrade which in turn provides its safe and economical disposal.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"17 1","pages":"1618 - 1633"},"PeriodicalIF":1.3,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17486025.2021.1955160","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45346639","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}

{"title":"Pseudo-static internal stability analysis of geosynthetic-reinforced earth slopes using horizontal slices method","authors":"Saeed Aroni. Hesari, Sina Javankhoshdel, M. Payan, R. Chenari","doi":"10.1080/17486025.2021.1940316","DOIUrl":"https://doi.org/10.1080/17486025.2021.1940316","url":null,"abstract":"ABSTRACT In this study, the well-established pseudo-static approach along with the horizontal slices method (HSM) is employed to investigate the seismic internal stability of geosynthetic-reinforced earth slopes. Previous simple HSM analyses were based on a primary assumption stating that the normal inter-slice forces are exerted on the mid-length of horizontal sections. However, this simplifying assumption could give rise to substantial errors in the calculation of design parameters, specifically in the case of high seismic excitations or low soil strength parameters. To address this deficiency, a balancing moment is considered as a new variable to account for the corresponding eccentricity. In the current HSM, two sets of unknown variables, including horizontal inter-slice forces and shear forces along failure surface, are determined using the well-known λ coefficient and the Mohr-Coulomb failure criterion. In this new technique, the traditional ‘5N-1ʹ type of HSM analysis is reduced to a robust and rigorous ‘3N’ one with the same predictive capability. The influence of various parameters, including soil characteristics, slope geometry and different earthquake coefficients are rigorously examined. Moreover, a number of useful graphs is provided to help engineers in the preliminary seismic design of geosynthetic-reinforced earth slopes.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"17 1","pages":"1417 - 1442"},"PeriodicalIF":1.3,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17486025.2021.1940316","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47371610","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}

{"title":"Relationships between strength properties and Atterberg limits of fine-grained soils","authors":"S. Shimobe, G. Spagnoli","doi":"10.1080/17486025.2021.1940317","DOIUrl":"https://doi.org/10.1080/17486025.2021.1940317","url":null,"abstract":"ABSTRACT Soil strength is responsible for all aspects of soil engineering regarding geotechnical underground constructions or slope stability. As Atterberg limits, are the easiest but at the same time very important properties to measure soil strength, this paper summarised and interpreted over 1600 data both from literature and novel experimental data. Correlations considering peak effective friction angle, undrained shear strength ratio and coefficient of earth pressure at rest with Atterberg limits are presented. Besides, critical state soil mechanics parameters were interpreted by correlating them with the plasticity index and the undrained strength ratio for normal consolidated soils. The goal of this research is to provide a general overview between Atterberg limits and strength parameters of fine-grained soils. Based on the overview, the existing predicted models in the literature need to be carefully considered if utilised for practical use due to some correlation discrepancies. One of the reasons for dissimilarities is due to the fact that such correlations are developed based on the data pertaining to particular sites and therefore a general validity is still missing.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"17 1","pages":"1443 - 1457"},"PeriodicalIF":1.3,"publicationDate":"2021-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17486025.2021.1940317","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44032878","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}

{"title":"A comparative study of bearing capacity of shallow footing under different loading conditions","authors":"Sujata Gupta, Anupam Mital","doi":"10.1080/17486025.2021.1940310","DOIUrl":"https://doi.org/10.1080/17486025.2021.1940310","url":null,"abstract":"ABSTRACT In the present study, the behaviour of a shallow rectangular foundation placed over the multiple layers of the geogrid reinforced sand under eccentric and oblique loads in both dimensions was studied. Various parameters were investigated in this study including the number of reinforced layers (N), eccentricity (e/B, e/L) and inclination of applied load (α). Bi-axial geogrid (Bx20/20)-reinforced sand and laboratory results were compared with PLAXIS 3D software keeping N, eccentricity ratios and angle of inclination as input parameters. The results present that the value of Ultimate Bearing Capacity (UBC) of model foundation found reduced as the axial eccentricity and inclination of applied loads increased. It also found that multiple geogrid-reinforced layers increased the UBC of about 75%. Finally, the model test results were analysed using PLAXIS 3D. A good agreement was originated between the laboratory results and numerical analysis.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"17 1","pages":"1338 - 1349"},"PeriodicalIF":1.3,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17486025.2021.1940310","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46496837","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}

{"title":"Soil-structure interaction analysis using neural networks optimised by genetic algorithm","authors":"Maede Beyki Milajerdi, F. Behnamfar","doi":"10.1080/17486025.2021.1940313","DOIUrl":"https://doi.org/10.1080/17486025.2021.1940313","url":null,"abstract":"ABSTRACT The soil-structure systems are infinite in nature regarding the solid medium. This geometrical infinity has been tackled by devising different remedies in the shape of limiting the system dimensions to consistent or transmitting boundaries. Yet, an exact soil-structure system is too difficult and time consuming to analyse especially when nonlinearities are involved in the problem. Moreover, the mentioned boundaries have mostly been introduced only for simple geometries. In recent years, use of smart data-based methods for simulation and analysis of complex engineering problems has attracted many relevant research works. In this paper, application of optimised neural networks, as an important branch of data-based procedures, for solving the soil-structure problem is examined. Classification based on the cross validation and K-fold validation approaches and optimising inclination and weight values using the genetic algorithm are utilised to optimise performance of the devised neural network. For this purpose, available centrifuge experimental results are manipulated to predict the natural period, damping ratio, and structural responses. The results revealed the fact that between the examined procedures, the neural network optimised by the genetic algorithm has performed better than the other two approaches in terms of accuracy and computation time, for solving a soil-structure interaction problem.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"17 1","pages":"1369 - 1387"},"PeriodicalIF":1.3,"publicationDate":"2021-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17486025.2021.1940313","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42528593","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}

{"title":"Constitutive Model for Fibre Reinforced Cemented Silty Sand","authors":"Muhammad Safdar, T. Newson, Faheem Shah","doi":"10.1080/17486025.2021.1940314","DOIUrl":"https://doi.org/10.1080/17486025.2021.1940314","url":null,"abstract":"ABSTRACT In this study, a modified version of Severn–Trent constitutive model was used to simulate the mechanical behaviour of composite materials under drained and undrained triaxial compression loading conditions. Two additional parameters obtained from the laboratory tests were added to the standard Severn–Trent model to simulate the stress-strain behaviour of cement and fibre-reinforced Toyoura silty sand. The model parameters were derived based on the experimental results performed, parametric study, trial and error and by comparison with previous research studies. The comparisons covered ranges of material from 0% to 3% fibre, 0% to 3% cement, 20% to 60% relative densities, and silt contents of up to 75%. The experimental results and model simulations were compared in terms of deviatoric stress versus axial strain, volumetric strain versus axial strain, and stress path behaviour. A close agreement of model simulations with the experimental results is observed for many of the tests performed on pure Toyoura sand, cemented, fibre, and fibre-reinforced cemented Toyoura silty sand. The extracted parameters are used to predict the response of those experiments until a reasonable (e.g. ± 5–10% peak strength) comparison is obtained.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"17 1","pages":"1388 - 1405"},"PeriodicalIF":1.3,"publicationDate":"2021-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17486025.2021.1940314","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42004203","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}

{"title":"Artificial Neural Network (ANN) based Soil Temperature model of Highly Plastic Clay","authors":"M. S. Khan, J. Ivoke, M. Nobahar, F. Amini","doi":"10.1080/17486025.2021.1928765","DOIUrl":"https://doi.org/10.1080/17486025.2021.1928765","url":null,"abstract":"ABSTRACT Artificial neural networks (ANNs) are one of the popular methods of artificial intelligence that seek to follow the human mind function and nervous system with its successful application increased in many areas of engineering. The current study is focused to develop an ANN-based predictive model of the soil temperature of Yazoo clay using based on field instrumentation data. To provide an acceptable dataset for developing the predictive model, the investigation was carried out in six instrumented slopes within the 25 miles (40.2 km) radius from metropolitan Jackson in Mississippi. The six selected slopes were instrumented with soil moisture sensors, automated rain gauge, air, and soil temperature sensors starting from mid-August 2018. Volumetric moisture content, precipitation, air, and soil temperature values at 1.5 m (5 ft) depth at the crest of the six slopes were collected using automated data loggers and observed for more than seventeen months. The established database consisting of 13650 datasets was implemented for ANN intelligent system and multiple-degree Fourier series non-linear regression technique for predicting the hourly soil temperature. The total hourly natural rainfall and time, average previous soil temperature, and average hourly air temperature were set to be the inputs of the model and the hourly soil temperature was set to be the output of the model. These datasets were used as the training data and validated with each target slope. Sensitivity analysis was also conducted, and the most influential input parameters on the data output were determined. In this study, the change of soil temperature with atmospheric temperature was investigated, and a predictor model was developed by adopting the Levenberg-Marquardt (LM) algorithm method and the Tan-sigmoid transfer function. The developed ANNs model showed an excellent fit with the observed field values.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"17 1","pages":"1230 - 1246"},"PeriodicalIF":1.3,"publicationDate":"2021-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17486025.2021.1928765","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44380953","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}

{"title":"Discussion on ‘ArcGIS mapping, characterisations and modelling the physical and mechanical properties of the Sulaimani City soils, Kurdistan Region’ by Ahmed et al. (2020b)","authors":"Y. Alshkane, K. Rashed","doi":"10.1080/17486025.2021.1940311","DOIUrl":"https://doi.org/10.1080/17486025.2021.1940311","url":null,"abstract":"The results and conclusions of the paper by Ahmed et al. (2020b) are really confusing because the information of this paper is very similar to a paper published recently by Ahmed et al. (2020a) which is about the prediction of geotechnical properties of soils in Sulaimani city, Iraq. The authors mentioned that they have collected about 630 data of Unconfined Compression Strength (UCS) tests with density tests from the geotechnical reports in a period between 2017 and 2019 which were extruded, tested and reported by the Ministry of Construction and Housing/ Sulaimni Construction Laboratories (SCL) in Sulaimani City between 2017 and 2019. We would like to inform that during that period only three of these reports were written by Dr. Maysoon Kh. Askar from Masatha Company in Iraq for SCL during 2017 without conducting any Unconfined Compression Strength (UCS) test and the other reports (about 75) were written by Dr. Alshkane as a consultant geotechnical engineer for SCL since 2018. During that period (2018 and 2019) only five Unconfined Compression Strength (UCS) tests (see Table 1) were conducted on undisturbed samples which were obtained by Shelby Tube sampler because the consistency of fine-grained soils in Sulaimani city is very hard and is mostly difficult to obtain undisturbed samples using Shelby Tube for UCS and density tests. Dr. Alshkane has only relied on Standard Penetration Tests (SPT) and plasticity index to determine the allowable bearing capacity of building foundations. In addition, the Sulaimani Constructional Laboratories (SCL) have not conducted any hydrometer tests and swelling tests for building projects and the plasticity chart was only used to find the type of fine-grained soils. The data of the paper by Ahmed et al. (2020b) are fabricated and do not represent the geotechnical properties of Sulaimani city. The authors stated that Equation (1) (presented in two forms: see Table 1 and Equation (6) by Ahmed et al. 2020b) was developed based on data collected from literature (374 data) and the geotechnical reports of Sulaimani city (630 data), but they did not give the details and the sources of the collected data from literature although their study should focus on soils of Sulaimani city as mentioned in the paper title which is the focus of their study. The range of the measured Su for Sulaimani soil was between 10 and 115 kPa whereas according to Figure 13 (Ahmed et al. 2020b) the range was from about 30 to 100 kPa. This range is not true for Sulaimani city soils (see Tables 1 and 2) because finegrained soils are generally hard and their SPT (N) is more than 10 according to our knowledge and based on Table 1 which presents that the range is from 34.5 to 324 kPa, the latter number indicates a very hard clay soil.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"17 1","pages":"1350 - 1352"},"PeriodicalIF":1.3,"publicationDate":"2021-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17486025.2021.1940311","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47419753","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}