检索结果-南通市图书馆

stress path Analysis of Deep-Sea Sediments Under the Compression-Shear Coupling Load of Crawler Collectors

Journal of Ocean University of China 2023年第1期22卷 65-74页

作者： ZHANG Ning MA Ning YIN Shiyang CHEN Xuguang SONG Yuheng School of Water Resources and Hydropower Engineering North China Electric Power UniversityBeijing 102206China Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China Laboratory for Marine Geology Qingdao National Laboratory for Maine Science and TechnologyQingdao 266100China

The mechanical properties of deep-sea sediments during the driving process of crawler collectors are essential factors in the design of mining systems.In this study,a crawler load is divided into a normal compression load and a horizontal shear load.Then,the internal stress state of sedimentary soil is examined through a theoretical calculation and finite element numerical simulation.Finally,the driving of crawlers is simulated by changing the relative spatial position between the load and stress unit,obtaining the stress path of the soil unit.Based on the calculation results,the effect of the horizontal shear load on the soil stress response is analyzed at different depths,and the spatial variation law of the soil stress path is examined.The results demonstrate that the horizontal shear load has a significant effect on the rotation of the principal stress,and the reverse rotation of the principal stress axis becomes obvious with the increase in the burial depth.The stress path curve of the soil is different at various depths.The spatial variation rule of the stress path of the shallow soil is complex,whereas the stress path curve of the deep soil tends to shrink as the depth increases.The stress path of the corresponding depth should be selected according to the actual research purpose and applied to the laboratory test.

关键词： deep-sea sediment crawler collector compression-shear coupling load stress path principal stress axis direction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of stress path on the mechanical properties of calcareous sand

引用

Underground Space 2023年第2期9卷 20-30页

作者： Houzhen Wei Hao Liu Xiaoxiao Li Zhao Tao Yongjie Wu Jianhua Shen Mei Yin State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China College of Civil Engineering and Architecture Guilin University of TechnologyGuilin 541004China Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering Guilin University of TechnologyGuilin 541004China Dept.of Civil and Environmental Engineering Brunel University LondonLondon UB83PHUK

Calcareous sand is widely observed in the foundation of off-shore infrastructure.Although a lot of research has been carried out on the mechanical properties of calcareous sand,study into the influence of the stress–strain path on the mechanical behaviour of calcareous sand is very limited.In this study,a series of triaxial tests were performed on calcareous sand under three different stress paths.The particle morphology of calcareous sand before and after the tests,the stress–strain relationship under different stress paths,and the char-acteristics of shear strength and deformation were investigated.The results show that the consolidation pressure and stress path have significant effects on the volume strain,strength,and particle breakage of calcareous sand.In addition,the underlying mechanisms of the different behaviours of calcareous sand observed in this study were discussed.

关键词： Calcareous sand Triaxial test stress path Particle breakage

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Evolution of mechanical parameters of Shuangjiangkou granite under different loading cycles and stress paths

引用

Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1113-1126页

作者： Liangjie Gu Xia-Ting Feng Rui Kong Chengxiang Yang Yuelin Xia Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines Northeastern UniversityShenyang110819China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China

Surrounding rocks at different locations are generally subjected to different stress paths during the process of deep hard rock excavation.In this study,to reveal the mechanical parameters of deep surrounding rock under different stress paths,a new cyclic loading and unloading test method for controlled true triaxial loading and unloading and principal stress direction interchange was proposed,and the evolution of mechanical parameters of Shuangjiangkou granite under different stress paths was studied,including the deformation modulus,elastic deformation increment ratios,fracture degree,cohesion and internal friction angle.Additionally,stress path coefficient was defined to characterize different stress paths,and the functional relationships among the stress path coefficient,rock fracture degree difference coefficient,cohesion and internal friction angle were obtained.The results show that during the true triaxial cyclic loading and unloading process,the deformation modulus and cohesion gradually decrease,while the internal friction angle gradually increases with increasing equivalent crack strain.The stress path coefficient is exponentially related to the rock fracture degree difference coefficient.As the stress path coefficient increases,the degrees of cohesion weakening and internal friction angle strengthening decrease linearly.During cyclic loading and unloading under true triaxial principal stress direction interchange,the direction of crack development changes,and the deformation modulus increases,while the cohesion and internal friction angle decrease slightly,indicating that the principal stress direction interchange has a strengthening effect on the surrounding rocks.Finally,the influences of the principal stress interchange direction on the stabilities of deep engineering excavation projects are discussed.

关键词： Triaxial cyclic loading and unloading test stress path Deformation modulus and elastic deformation increment ratios Fracture degree Cohesion and internal friction angle

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Influence of stress path change on the resistance to plastic deformation of cold rolled sheets

引用

Journal of University of Science and Technology Beijing 2005年第6期12卷 521-526页

作者： Pavel Huml Metal Forming Department of Materials Science and Engineering The Royal Institute of Technology 10044 Stockholm Sweden

Flat workpieces have been tested in order to investigate the influence of stress path change （loading mode） while keeping strain path unchanged. These investigations are pertinent to the testing of cold rolled strips and to subsequent forming. The workpieces which first compressed by plane strain compression in thickness direction were then tested in perpendicular direction in order to measure the influence of strain and stress path. The tension workpieces came from flat die compression test at different deformation histories. Two different materials were investigated： 18/8 Ti stainless steel and AW-1050 aluminium. The results show that the plastic flow by tension in lengthwise direction after pre-strain by compression in thickness direction will begin at an appreciably lower stress than that of the workpieces unloaded after pre-compression. Comparing with two materials, it can be seen that both 18/8 Ti stainless steel and AW-1050 aluminium behave similarly. The drop in yield stress is lower for AW-1050 aluminium than that for 18/8 Ti stainless steel. However, reloading in different directions than in the precious step results in significantly higher strain hardening.

关键词： cold working plastic deformation strain path stress path loading mode flow stress yield stress strain hardening

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of hysteretic stress path behavior on seal integrity during gas storage operation in a depleted reservoir

引用

Journal of Rock Mechanics and Geotechnical Engineering 2020年第4期12卷 886-899页

作者： Pierre Jeanne Yingqi Zhang Jonny Rutqvist Lawrence Berkeley National Laboratory Energy Geosciences DivisionBerkeleyCA94720USA

In this study,we numerically investigate the influence of hysteretic stress path behavior on the seal integrity during underground gas storage operations in a depleted reservoir.Our study area is the Honor Rancho Underground Storage Facility in Los Angeles County(California,USA),which was converted into an underground gas storage facility in 1975 after 20 years of oil and gas production.In our simulations,the geomechanical behavior of the sand reservoir is modeled using two models:(1)a linear elastic model(non-hysteretic stress path)that does not take into consideration irreversible deformation,and(2)a plastic cap mechanical model which considers changes in rock elastic properties due to irreversible deformations caused by plastic reservoir compaction(hysteretic stress path).It shows that the irreversible compaction of the geological layer over geologic time and during the reservoir depletion can have important consequences on stress tensor orientation and magnitude.Ignoring depletion-induced irreversible compaction can lead to an over-estimation of the calculation of the maximum working reservoir pressure.Moreover,this irreversible compaction may bring the nearby faults closer to reactivation.However,regardless of the two models applied,the geomechanical analysis shows that for the estimated stress conditions applied in this study,the Honor Rancho Underground Storage Facility is being safely operated at pressures much below what would be required to compromise the seal integrity.

关键词： Gas storage stress path Geomechanical simulation Caprock integrity Fault stability Modified cam-clay model Honor rancho underground storage facility

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Reservoir stress path and induced seismic anisotropy： results from linking coupled fluid-flow/geomechanical simulation with seismic modelling

引用

Petroleum Science 2016年第4期13卷 669-684页

作者： D.A.Angus Q.J.Fisher J.M.Segura J.P.Verdon J.-M.Kendall M.Dutko A.J.L.Crook School of Earth and Environment University of LeedsLeeds UK Formerly School of Earth and Environment University of Leeds Leeds UK Department of Earth Sciences University of Bristol BristolUK Rockfield Software Ltd. Swansea UK Three Cliffs Geomechanics Swansea UK Repsol Madrid Spain ESG Solutions Kingston Canada

We present a workflow linking coupled fluid-flow and geomechanical simulation with seismic modelling to predict seismic anisotropy induced by non-hydrostatic stress changes. We generate seismic models from coupled simulations to examine the relationship between reservoir geometry, stress path and seismic anisotropy. The results indicate that geometry influences the evolution of stress,which leads to stress-induced seismic anisotropy. Although stress anisotropy is high for the small reservoir, the effect of stress arching and the ability of the side-burden to support the excess load limit the overall change in effective stress and hence seismic anisotropy. For the extensive reservoir, stress anisotropy and induced seismic anisotropy are high. The extensive and elongate reservoirs experience significant compaction, where the inefficiency of the developed stress arching in the side-burden cannot support the excess load.The elongate reservoir displays significant stress asymmetry,with seismic anisotropy developing predominantly along the long-edge of the reservoir. We show that the link betweenstress path parameters and seismic anisotropy is complex,where the anisotropic symmetry is controlled not only by model geometry but also the nonlinear rock physics model used. Nevertheless, a workflow has been developed to model seismic anisotropy induced by non-hydrostatic stress changes, allowing field observations of anisotropy to be linked with geomechanical models.

关键词： Coupled fluid-flow/geomechanics Reservoir characterization Seismic anisotropy stress path

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

stress path constraints on veined rock deformation

引用

Rock Mechanics Bulletin 2022年第1期1卷 69-74页

作者： Junlong Shang James Watt School of Engineering University of GlasgowG128QQUK

Although rock mechanical behaviour has a long record of study,attempts to understand the role of fractures on rock deformation still have unresolved issues.Due to technical and/or economic challenges,natural rock fractures are often dealt with crudely,without detailed consideration of fracture geometry and heterogeneity in many geoscience applications.Veined rocks that are ubiquitous in the upper Earth crust fall in that category where sustained efforts are needed to offer key information for rock mechanics and geomechanics applications.Following on from a recent study on the rupture of veined rocks(DOI:10.1029/2019JB019052),we further examine stress path constraints on the deformation of veined rocks(i.e.,stress-path-dependent behaviour of veined rocks)under polyaxial conditions.The Discrete Element Method is used to establish a calcite veined model where constant mean stress(σm)and constant least principal stress(σ3)paths that are representative in the subsurface activities are considered.The results reveal the stress-path dependency of brittleness for models under different loading paths.Models tested under constant-σm conditions exhibit no brittleness,compared to cases where constant-σ3 is applied.Sliding along the strike of an inclined vein is evident under constant-σm deformation,irrespective of the level of stress.Shear bands along the dominated(inclined)veins exhibit apparent particle trajectory anisotropy for the constant-σm deformations which is demonstrated by the evident colour contrast of the adjacent rock matrix and the displacement dispersion of the particles forming the shear bands.We envisage that the reactivation of veins is of relevance to Enhanced Geothermal Systems(EGS)development in terms of seismicity mitigation and multiphysics control of fracture and reservoir permeability.

关键词： Veined rocks Polyaxial compression DEM stress path Fracture

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mechanical behavior of iron ore tailings under standard compression and extension triaxial stress paths

引用

Journal of Rock Mechanics and Geotechnical Engineering 2023年第7期15卷 1883-1894页

作者： Alexia Cindy Wagner João Paulo de Sousa Silva João Vítor de Azambuja Carvalho Ana Luisa Cezar Rissoli Pedro Pazzoto Cacciari Helder Mansur Chaves Hugo Carlos Scheuermann Filho Nilo Cesar Consoli Universidade Federal do Rio Grande do Sul Porto Alegre90035-190Brazil Mineral Development Centre Vale S.A.Santa Luzia33040-900Brazil Department of Civil Geological and Mining EngineeringPolytechnique MontrealMontrealH3C 3A7Canada

The disposal of mining tailings has increasingly focused on the use of dry stacks.These structures offer more security since they use filtered and compacted material.Because of the construction method and the heights achieved,the material that compounds the structure can be subjected to different stress paths along the failure plane.The theoretical framework considered in the design of these structures generally is the critical state soil mechanics(CSSM).However,the data in the literature concerning the uniqueness of critical state line(CSL)is still controversial as the soil is subjected to different stress paths.With respect to tailings,this question is even more restricted.This paper studies two tailings with different gradings due to the beneficial processes over extension and compression paths.A series of drained and undrained triaxial tests was conducted over a range of initial densities and stress levels.In the q-p'plane,different critical stress ratio(M)values were obtained for compression and extension stress paths.However,the critical state friction angle is very similar with a slightly higher critical state friction angle for extension tests.Curved stress path dependent CSLs were obtained in the n-lnp0 plane with the extension tests below the CSL defined in compression.Regarding the fines content,the studied tailings presented very similar M and critical state friction angle values.However,the fines content af-fects the volumetric behavior of the studied tailings and the CSLs on the n-lnp0 plane shift downwards with the increasing fines content for compression and extension tests.In relation to dilatancy analysis,the fines content did not present an evident influence on the dilatancy of the materials.However,different values of mean stress ratio N were obtained between compression and extension tests and can corroborate the existence of non-unique CSLs for these materials.

关键词： Iron ore tailings(IOTs) Dry stacking Critical state soil mechanics Extension tests stress path

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Analysis of dynamic stresses in ballasted railway track due to train passages at high speeds

引用

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第6期23卷 443-457页

作者： Jing HU Xue-cheng BIAN Department of Civil Engineering Fuzhou UniversityFuzhou 350108China Department of Civil Engineering Zhejiang UniversityHangzhou 310058China MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang UniversityHangzhou 310058China

Repeated train passages bring detrimental effects on train operations,especially at high speeds.In this study,a computational model consisting of moving train vehicles,track structure,and track foundation is used to investigate the stress distribution in the track substructure and underlying soil,particularly when the train speed approaches the critical speed via 2.5D finite element method.The numerical model has been validated by in-situ test results from a ballasted high-speed railway.The computational results reveal that the substructure is shown to be effective in reducing the stresses transmitted to the ground;however,a simple Boussinesq approximation is proved to be inaccurate because it cannot properly take account of the effect of multi-layered substructures and train speeds.It is acceptable to assume a simplified smooth track in the analysis model for determining the maximum stresses and displacements for a low-speed railway(≤100 km/h)but,for a high-speed one,the dynamic amplification effect of track irregularities must also be considered in subgrade design.Analysis of the stress paths revealed that the load speed and track irregularity increase the likelihood of failure for the subgrade;track irregularity can induce many times of principal stress rotations even under a simple single moving load.

关键词： Ballasted railway stress analysis Track irregularity stress path High speed

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Characteristics of structural loess strength and preliminary framework for joint strength formula

引用

Water Science and Engineering 2014年第3期7卷 319-330页

作者： Rong-jian LI Jun-ding LIU Rui YAN Wen ZHENG Sheng-jun SHAO Institute of Geotechnical Engineering Xi'an University of Technology Open Research Laboratory of Geotechnical Engineering Ministry of Land and ResourcesChang'an University

The strength of structural loess consists of the shear strength and tensile strength. In this study, the stress path, the failure envelope of principal stress （ Kf line）, and the strength failure envelope of structurally intact loess and remolded loess were analyzed through three kinds of tests： the tensile strength test, the uniaxial compressive strength test, and the conventional triaxial shear strength test. Then, in order to describe the tensile strength and shear strength of structural loess comprehensively and reasonably, a joint strength formula for structural loess was established. This formula comprehensively considers tensile and shear properties. Studies have shown that the tensile strength exhibits a decreasing trend with increasing water content. When the water content is constant, the tensile strength of the structurally intact soil is greater than that ofremolded soil. In the studies, no loss of the originally cured cohesion in the structurally intact soil samples was observed, given that the soil samples did not experience loading disturbance during the uniaxial compressive strength test, meaning there is a high initial structural strength. The results of the conventional triaxial shear strength test show that the water content is correlated with the strength of the structural loess. When the water content is low, the structural properties are strong, and when the water content is high, the structural properties are weak, which means that the water content and the ambient pressure have significant effects on the stress-strain relationship of structural loess. The established joint strength formula of structural loess effectively avoids overestimating the role of soil tensile strength in the traditional theory of Mohr-Coulomb strength.

关键词： structurally intact loess, remolded loess, tensile strength shear strength stress path failure envelope of principal stress （ Kf line） strength failure envelope joint strength formula

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：