International Journal for Numerical and Analytical Methods in Geomechanics最新文献_第10页

Analytical modeling and experiments on soft soil consolidation with vacuum preloading-airbag pressurization 利用真空预压-气囊加压进行软土固结的分析建模与实验

IF 3.4 2区工程技术

International Journal for Numerical and Analytical Methods in Geomechanics Pub Date : 2024-07-17 DOI: 10.1002/nag.3810

Hongping Meng, Aifang Qin, Lianghua Jiang, Yajun Wu

{"title":"Analytical modeling and experiments on soft soil consolidation with vacuum preloading-airbag pressurization","authors":"Hongping Meng, Aifang Qin, Lianghua Jiang, Yajun Wu","doi":"10.1002/nag.3810","DOIUrl":"10.1002/nag.3810","url":null,"abstract":"This study aims to provide substantial theoretical support for employing vacuum preloading-airbag pressurization (VP-AP) to enhance soft soil foundations. By integrating the airbags and prefabricated vertical drains (PVDs) within the analytical framework, the consolidation models are developed to accommodate double smear zones and well resistance. Analytical solutions for various airbag pressurization scenarios are derived under the equal-strain assumption. A model test is subsequently conducted to investigate the settlement process of soft soil using the VP-AP method. The validity of the proposed theoretical model is corroborated through comparison with existing analytical solutions and experimental data. The accuracy of the predictive model is further substantiated by the model test results. Lastly, this research offers an in-depth analysis of soil consolidation behavior under diverse influencing factors. The findings indicate that the VP-AP method demonstrates superior efficacy over conventional vacuum-surcharge preloading when the airbag pressure matches the external load pressure. Additionally, an increase in the radius of airbags enhances the soil consolidation efficiency. The analytical model presented in this study elucidates the consolidation mechanisms of the VP-AP method, with experimental research confirming the efficacy of this approach and the predictive model established herein.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"48 15","pages":"3595-3618"},"PeriodicalIF":3.4,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141726252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A multiobjective optimization framework for site investigation program based on Bayesian approach and NSGA-II 基于贝叶斯方法和 NSGA-II 的场地勘测计划多目标优化框架

IF 3.4 2区工程技术

International Journal for Numerical and Analytical Methods in Geomechanics Pub Date : 2024-07-16 DOI: 10.1002/nag.3806

Yang Sun, Ziying Xu, Jinshan Sun, Zhen Chen

{"title":"A multiobjective optimization framework for site investigation program based on Bayesian approach and NSGA-II","authors":"Yang Sun, Ziying Xu, Jinshan Sun, Zhen Chen","doi":"10.1002/nag.3806","DOIUrl":"10.1002/nag.3806","url":null,"abstract":"Site investigation provides essential geotechnical parameter information for analysis and design. However, three conflicting objectives, namely exploration effort, robustness and parameter uncertainty, pose a challenge to the development of an optimal site investigation program. In this study, a three objective optimization framework for the site investigation program is proposed based on the Bayesian approach and the non-dominated sorting genetic algorithm (NSGA-II). The only inputs required by the proposed framework are prior distribution of geotechnical parameters and error information. The prior distribution of geotechnical parameters is derived from integrating engineering experience and measurements from basic exploration boreholes. The error information is obtained based on literature and expert judgment related to the specific project. Firstly, a design pool of candidate investigation programs is generated using Bayesian approach to determine the locations and number of exploration boreholes. The NSGA-II is then applied to identify the optimal program that balances lower cost, higher robustness, and lower uncertainty. The proposed multiobjective optimization framework is illustrated and validated through a real site investigation case in Chongqing, China, aimed at determining the ultimate bearing capacity of the rock foundation. The spatial correlation of parameters within the study area is also considered. The optimal program is represented by the location and number of exploration boreholes. By comparing measurements with predictions from different site investigation programs, the efficiency of the proposed multiobjective framework is demonstrated. Additionally, the influence of engineering experience and random field modeling on the investigation program is discussed.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"48 14","pages":"3537-3560"},"PeriodicalIF":3.4,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141631547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multi-scale mechanics of polydisperse granular materials: From micro-scale and wave propagation experiments to DEM analysis 多分散粒状材料的多尺度力学：从微观尺度和波传播实验到 DEM 分析

IF 3.4 2区工程技术

International Journal for Numerical and Analytical Methods in Geomechanics Pub Date : 2024-07-04 DOI: 10.1002/nag.3798

Nallala S. C. Reddy, Huan He, Kostas Senetakis

{"title":"Multi-scale mechanics of polydisperse granular materials: From micro-scale and wave propagation experiments to DEM analysis","authors":"Nallala S. C. Reddy, Huan He, Kostas Senetakis","doi":"10.1002/nag.3798","DOIUrl":"10.1002/nag.3798","url":null,"abstract":"This paper presents a multiscale experimental study integrated with numerical simulations examining the mechanics of polydisperse granular mixtures composed of coarse-grained particles mixed with varying percentages of fines. The study includes macroscale wave propagation tests using bender elements on isotopically compressed granular samples to investigate the stiffness variation with changes in size ratio (SR) and fines content (FC). Empirical equations were developed to predict stiffness based on the experimental data, using the concept of equivalent void ratio to represent the influence of void ratio on stiffness. A newly introduced parameter called size disparity indicator was used to consider the coupled effects of size disparity and fines content on stiffness. Microscale assessment of the individual contacting grains revealed that stiffness (at grain scale) is affected by changes in grain size, even when the SR is less than 6, however, the experimental observations of the shear modulus behavior from the macroscale test results reveal minimal effect of FC. Furthermore, numerical simulations using the discrete element method were conducted on the polydisperse granular mixtures to demonstrate the coupled effect of SR and FC on the structural matrix formation, thereby influencing the force transfer among contacts resulting in varying stiffness behavior. Our findings provide valuable insights into the behavior of polydisperse granular mixtures in engineering applications.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"48 14","pages":"3515-3536"},"PeriodicalIF":3.4,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141545844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Elastoplastic constitutive model for overconsolidated clays with an advanced dilatancy relation 具有高级膨胀关系的过固结粘土弹塑性结构模型

IF 3.4 2区工程技术

International Journal for Numerical and Analytical Methods in Geomechanics Pub Date : 2024-07-03 DOI: 10.1002/nag.3803

Kehao Chen, Rui Pang, Bin Xu, Xingliang Wang

{"title":"Elastoplastic constitutive model for overconsolidated clays with an advanced dilatancy relation","authors":"Kehao Chen, Rui Pang, Bin Xu, Xingliang Wang","doi":"10.1002/nag.3803","DOIUrl":"10.1002/nag.3803","url":null,"abstract":"The dilatancy behavior of overconsolidated (OC) clays is a key factor in determining their strength and deformation characteristics. Recognizing the limitations of previous dilatancy relations for OC clays, a novel dilatancy relation is proposed that can effectively capture the changes in dilatancy point, volume dilatancy and contraction with the overconsolidation ratio (OCR). As OC clays revert to the normally consolidated (NC) state, the proposed dilatancy relation smoothly transitions to that of the modified Cam-clay (MCC) model, ensuring a unified description of the dilatancy relation between OC and NC clays. The dilatancy relation can be easily incorporated into the constitutive model of different theoretical frameworks. Subsequently, this advanced dilatancy relation is integrated into a new elastoplastic constitutive model for OC clays within the framework of bounding surface and generalized plasticity theory. The validity of the proposed model is confirmed through drained triaxial compression and extension, undrained triaxial compression and extension, as well as complex stress path tests for clays with various OCRs, and the simulation results of the proposed model are compared with those of the SANICLAY model. The comparative analysis demonstrate that the model performs well in simulating the behavior of OC clays.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"48 14","pages":"3475-3493"},"PeriodicalIF":3.4,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A two-stage combined filtration-consolidation model for slurry ground treated by vacuum preloading 用真空预加载法处理泥浆地面的两阶段组合过滤-固结模型

IF 3.4 2区工程技术

International Journal for Numerical and Analytical Methods in Geomechanics Pub Date : 2024-07-03 DOI: 10.1002/nag.3804

Xiaoqian Ye, Li Shi, Yuanqiang Cai

{"title":"A two-stage combined filtration-consolidation model for slurry ground treated by vacuum preloading","authors":"Xiaoqian Ye, Li Shi, Yuanqiang Cai","doi":"10.1002/nag.3804","DOIUrl":"10.1002/nag.3804","url":null,"abstract":"The vacuum preloading technique is extensively employed for ground improvement, particularly for slurry ground characterized by high-water content and low strength. Such ground frequently exhibits a delay in pore water pressure dissipation when treated with prefabricated vertical drains. To clarify the drainage and consolidation behaviour of high-water content slurry ground under vacuum preloading, this study proposed a two-stage combined model that integrates both filtration and consolidation processes. Initially, an axisymmetric filtration model was used to describe the formation of the soil column through the radial migration and compaction of the particles. The end-of-filtration radial distributions of void ratio, permeability coefficient, and effective pressure served as initial conditions for the consolidation stage analysis. This stage was depicted using a large strain consolidation model based on the free strain condition. The results showed the necessity of incorporating the filtration stage to capture the overall drainage mechanism and characteristics of slurry ground with vacuum preloading treatment.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"48 14","pages":"3494-3514"},"PeriodicalIF":3.4,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Coupled model for electro-osmosis consolidation and ion transport considering chemical osmosis in saturated clay soils 饱和粘土中考虑化学渗透的电渗固结和离子传输耦合模型

IF 3.4 2区工程技术

International Journal for Numerical and Analytical Methods in Geomechanics Pub Date : 2024-07-03 DOI: 10.1002/nag.3802

Shangqi Ge, Wenhao Jiang, Ji-Peng Wang, Guohui Feng, Lingwei Zheng, Xinyu Xie

{"title":"Coupled model for electro-osmosis consolidation and ion transport considering chemical osmosis in saturated clay soils","authors":"Shangqi Ge, Wenhao Jiang, Ji-Peng Wang, Guohui Feng, Lingwei Zheng, Xinyu Xie","doi":"10.1002/nag.3802","DOIUrl":"10.1002/nag.3802","url":null,"abstract":"The electro-osmosis approach efficiently facilitates the rapid dewatering of soil with high water content and contributes to reducing contaminant levels within the clay soil. However, the changes of chemical field caused by ion transport in the clay soil during electro-osmosis process will also influence the clay soil consolidation effect. Existing theories predominantly tend to disregard this crucial physical process and its resultant effects, thereby restraining a comprehensive analysis of electro-osmosis consolidation (EOC) behavior under intricate chemical conditions. This study introduces a concise model of EOC and ion transport considering chemical osmosis. The model considers the nonlinear variation of clay soil parameters such as compressibility, permeability, and effective diffusion coefficients, along with the interaction between EOC and ion transport. Meanwhile, the correctness of the model is verified from different aspects such as theoretical derivation and model comparison. Based on the proposed model, the impacts of the variation in electrical field intensity and chemical concentration on the coupled behaviors between EOC and ion transport are systematically investigated, with and without incorporating nonlinear consolidation characteristics. The results show that diffusion and electro-migration exhibit a more pronounced effect on ion transport during EOC. Simultaneously, with the increase of ion concentration in clay soil pore solution, the effects of chemical osmosis become increasingly apparent, thereby enhancing clay soil settlement.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"48 14","pages":"3455-3474"},"PeriodicalIF":3.4,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Collapse characteristics of binary granular columns considering inhomogeneous particle size distributions 考虑非均质粒度分布的二元颗粒柱的坍塌特性

IF 3.4 2区工程技术

International Journal for Numerical and Analytical Methods in Geomechanics Pub Date : 2024-06-25 DOI: 10.1002/nag.3799

Hao Sun, Jun-Ze Jia, François Nicot, Xiao-Xiao Wang, Li-Shan Zhao

{"title":"Collapse characteristics of binary granular columns considering inhomogeneous particle size distributions","authors":"Hao Sun, Jun-Ze Jia, François Nicot, Xiao-Xiao Wang, Li-Shan Zhao","doi":"10.1002/nag.3799","DOIUrl":"10.1002/nag.3799","url":null,"abstract":"Debris avalanches and dry granular flows exhibit similar characteristics. In order to comprehend the fundamental mechanisms and improve the accuracy in predicting disasters such as landslides, debris flows, and rock avalanches, the collapse characteristics of a binary granular column are investigated through a three-dimensional discrete element model. A novel approach is proposed by incorporating the concept of local granular velocity fluctuation and applying a cluster analysis method. Then, the flow mechanism of the binary granular column is analyzed, by considering the inhomogeneous particle size distribution. The research results show that: (1) The normalized final packing height of the granular column gradually increases when the content of coarse particles exceeds 20% and when the coarse-fine particle size ratio increases. Conversely, the normalized run-out distance of the granular column decreases gradually with the increase in coarse particle content and the coarse-fine particle size ratio. (2) The particles with higher granular velocity fluctuations tend to move together and form clusters, demonstrating dynamical heterogeneity. As the coarse particle content and coarse-fine particle size ratio increase, there is a greater tendency for particles to assemble into larger-scale active clusters. This means that a larger number of particles exhibit collective behavior during the collapse process, resulting in increased resistance to shear deformation. Ultimately, this leads to a greater packing height and a reduced run-out distance when observed from a macroscopic perspective.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"48 13","pages":"3413-3431"},"PeriodicalIF":3.4,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141453070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Application of factorization machine with quantum annealing to hyperparameter optimization and metamodel-based optimization in granular flow simulations 将因子机与量子退火应用于粒流模拟中的超参数优化和基于元模型的优化

IF 3.4 2区工程技术

International Journal for Numerical and Analytical Methods in Geomechanics Pub Date : 2024-06-25 DOI: 10.1002/nag.3800

Junsen Xiao, Katsuhiro Endo, Mayu Muramatsu, Reika Nomura, Shuji Moriguchi, Kenjiro Terada

{"title":"Application of factorization machine with quantum annealing to hyperparameter optimization and metamodel-based optimization in granular flow simulations","authors":"Junsen Xiao, Katsuhiro Endo, Mayu Muramatsu, Reika Nomura, Shuji Moriguchi, Kenjiro Terada","doi":"10.1002/nag.3800","DOIUrl":"10.1002/nag.3800","url":null,"abstract":"This study examined the applicability of factorization machines with quantum annealing (FMQA) to the field of landslide risk assessment for two specific black-box optimization problems, hyperparameter optimization (HPO) for metamodeling and metamodel-based simulation optimization (MBSO) targeting granular flow simulation using discrete element method (DEM). These two optimization problems are solved successively: HPO is first performed to determine the hyperparameters of the Gaussian process regression (GPR) metamodel, which is then used as a low-cost, fast approximate solver of granular flow simulations for MBSO. After conducting a series of granular flow simulations using DEM, a metamodel is created that outputs a risk index of interest, the run-out distance, from its input parameters by employing GPR with two hyperparameters, length-scale and signal variance. Subsequently, HPO is performed to obtain the optimal set of hyperparameters by applying FMQA and other optimization methods using another set of hyperparameters determined using the gradient-ascent method as the reference solution. Finally, using the metamodel created by each optimization method as an approximate solver for DEM simulations, MBSO is performed to find the optimal target output, the maximum run-out distance, in the space of physical input parameters for risk assessment. A comparison of the performance of FMQA with that of other methods shows that FMQA is competitive in terms of efficiency and stability with state-of-the-art algorithms such as Bayesian optimization.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"48 13","pages":"3432-3451"},"PeriodicalIF":3.4,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/nag.3800","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141452867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Emergence of critical state in granular materials using a variationally-based damage-elasto-plastic micromechanical continuum model 利用基于变异的损伤-等塑性微机械连续模型研究颗粒材料临界状态的出现

IF 3.4 2区工程技术

International Journal for Numerical and Analytical Methods in Geomechanics Pub Date : 2024-06-22 DOI: 10.1002/nag.3795

Nurettin Yilmaz, M. Erden Yildizdag, Francesco Fabbrocino, Luca Placidi, Anil Misra

{"title":"Emergence of critical state in granular materials using a variationally-based damage-elasto-plastic micromechanical continuum model","authors":"Nurettin Yilmaz, M. Erden Yildizdag, Francesco Fabbrocino, Luca Placidi, Anil Misra","doi":"10.1002/nag.3795","DOIUrl":"10.1002/nag.3795","url":null,"abstract":"The mechanical response of granular materials, exemplified by frictional grain interactions, is characterized by a critical state in which deformation occurs without change of material volume or stresses when subjected to large shear deformation. In this work, a granular micromechanics approach (GMA) based continuum model is used to investigate the emergence of such a critical state. The continuum description is constructed through mechanical concepts based upon elastic and dissipation energies defined for a generic grain-pair interaction. A hemivariational principle provides the basis for considering the evolution of damage and plasticity phenomena comprising grain-pair contact loss and irreversible deformation. As a consequence, the Karush–Kuhn–Tucker (KKT)-type conditions are derived, which give the evolution equations for the irreversible phenomena. Notably, in this derivation there is no invocation of flow rules and other similar assumptions of classical phenomenological continuum damage and plasticity. Further, Piola's ansatz is elaborated to kinematically connect granular micromechanics of grain-pair to the continuum description. While the concept of critical state analysis has been handled with either phenomenological approaches or discrete numerical frameworks, in the present paper this concept is examined within a micromechanics-based continuum description. The constitutive model is established and the coupled damage and plastic irreversible quantities are assessed. The critical state is shown to emerge as grain-pair related damage and plastic evolution in a competitive/collaborative manner during the imposed loading path.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"48 13","pages":"3369-3391"},"PeriodicalIF":3.4,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141448323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Competition among simultaneously stimulated multiple hydraulic fractures: Insights from DEM simulation with the consideration of fluid partitioning 同时激发的多条液压裂缝之间的竞争：考虑流体分区的 DEM 模拟的启示

IF 3.4 2区工程技术

International Journal for Numerical and Analytical Methods in Geomechanics Pub Date : 2024-06-22 DOI: 10.1002/nag.3801

Xuejian Li, Kang Duan, Moli Zhao, Qiangyong Zhang, Luchao Wang, Rihua Jiang

{"title":"Competition among simultaneously stimulated multiple hydraulic fractures: Insights from DEM simulation with the consideration of fluid partitioning","authors":"Xuejian Li, Kang Duan, Moli Zhao, Qiangyong Zhang, Luchao Wang, Rihua Jiang","doi":"10.1002/nag.3801","DOIUrl":"10.1002/nag.3801","url":null,"abstract":"Stimulating long and persistent fractures from multiple perforations in horizontal wells plays a vital role in enhancing the recovery of hydrocarbons from unconventional reservoirs. However, interaction among fractures may lead to dramatic nonuniformity, but the mechanism that drives the competition still eludes explanation. We proposed an improved two-dimensional discrete element model to simulate fluid competition and stress interaction among perforations in the same fracturing stage. The fluid partitioning is implemented by dynamically dividing the injected fluid into different perforations to maintain pressure consistency and fluid conservation. The model is validated by comparing the induced stress, fracture aperture, and the evolution of the fracture height and the injection pressure with theoretical models. The influences of the perforation friction, fluid viscosity and injection rate are examined systematically. Simulation results reveal that fluid competition tends to stimulate one dominant fracture with other perforations suppressed. The effect of increasing the perforation friction for promoting the fluid partitioning is not remarkable while using more viscous fracturing fluid helps to initiate more fractures at the perforations. With a higher injection rate all fractures can propagate to the borders but the asymmetrical fracture pattern cannot be avoided. Four typical fracture patterns are distinguished by changing operational parameters.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"48 13","pages":"3392-3412"},"PeriodicalIF":3.4,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141448166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0