The slope stability is affected by multiple factors. Thecomprehensive evaluation of the slope stability is a complicateproblem. The principles of extension theory have been used in thispaper to establish the matter-el...The slope stability is affected by multiple factors. Thecomprehensive evaluation of the slope stability is a complicateproblem. The principles of extension theory have been used in thispaper to establish the matter-element model for the evaluation ofslope stability. The quantitative evaluated results have been giventhrough the calculation of the matter-element dependent degree.展开更多
Daihai Lake, a modern lacustrine rift basin, located in Inner Mongolia, North China, serves as an important modern analog for understanding deltaic depositional processes in an active rift setting. Two of the deltas ...Daihai Lake, a modern lacustrine rift basin, located in Inner Mongolia, North China, serves as an important modern analog for understanding deltaic depositional processes in an active rift setting. Two of the deltas （Yuanzigou delta and Bulianghe delta） on the margins of Daihai Lake were surveyed to compare and contrast stacking patterns using aerial photographs, field trenching and sediment sampling. Shallow cores and trench data collected from the margins of Daihai Lake indicate that a variety of depositional processes have been active since Daihai Lake formed. Two 3-D sedimentation models which employ chronostratigraphic correlation technique were generated. The chronostratigraphic sedimentation models predict and represent the architectures and sand-body continuity of sediments. Stratigraphical coincidence of the broad sheeted drifts and channel erosion suggests a coupling between downslope and alongslope processes. Distributary mouth bars are prevalent in the front of deltas on steeper slopes due to the dominance of down-slope flows. On the contrary, the along-slope currents favor the development of distal bar deposits with sheeted sandbodies on gentle depositional slopes. This study provides an insight into the architecture of complex sedimentary facies associated with highlighting key differences between downslope flows and alongslope currents. The distribution of sand within these deltas is of particular interests, with applications in understanding the architecture of hydrocarbon reservoirs formed in lacustrine rift basin.展开更多
Fully automatic finite element(FE) modelling of the fracture process in quasi-brittle materials such as concrete and rocks and ductile materials such as metals and alloys,is of great significance in assessing structur...Fully automatic finite element(FE) modelling of the fracture process in quasi-brittle materials such as concrete and rocks and ductile materials such as metals and alloys,is of great significance in assessing structural integrity and presents tre-mendous challenges to the engineering community. One challenge lies in the adoption of an objective and effective crack propagation criterion. This paper proposes a crack propagation criterion based on the principle of energy conservation and the cohesive zone model(CZM) . The virtual crack extension technique is used to calculate the differential terms in the criterion. A fully-automatic discrete crack modelling methodology,integrating the developed criterion,the CZM to model the crack,a simple remeshing procedure to accommodate crack propagation,the J2 flow theory implemented within the incremental plasticity framework to model the ductile materials,and a local arc-length solver to the nonlinear equation system,is developed and im-plemented in an in-house program. Three examples,i.e.,a plain concrete beam with a single shear crack,a reinforced concrete(RC) beam with multiple cracks and a compact-tension steel specimen,are simulated. Good agreement between numerical predictions and experimental data is found,which demonstrates the applicability of the criterion to both quasi-brittle and ductile materials.展开更多
为预防和控制引水隧洞中围岩失稳事故的发生,将物元可拓法应用于围岩稳定性评价中。以滇中引水工程为背景,选取滇中引水工程某隧洞段,构建引水隧洞围岩稳定性评价指标体系,划分围岩等级,选用灰色关联分析法(Grey Relational Analysis, G...为预防和控制引水隧洞中围岩失稳事故的发生,将物元可拓法应用于围岩稳定性评价中。以滇中引水工程为背景,选取滇中引水工程某隧洞段,构建引水隧洞围岩稳定性评价指标体系,划分围岩等级,选用灰色关联分析法(Grey Relational Analysis, GRA)和因子分析法(Factor Analysis, FA)组合确定权重,基于物元可拓模型进行引水隧洞围岩稳定性评价,以期减少目前评价方法中一些不相容现象及其他问题所带来的影响,从而提升长距离特大输水工程围岩稳定性等级评价的精度。结果表明,GRA-FA-物元可拓模型围岩稳定性评价结果与实际等级基本相符,与逼近理想解排序法(Technique for Order Preference by Similarity to Ideal Solution, TOPSIS)相比,预测评价精度从62.5%提升到87.5%,准确性提升了约25百分点。因此,GRA-FA-物元可拓模型相较以往的评价模型可以更全面和客观地进行引水隧洞围岩稳定性评价,可为其他长距离特大引水工程施工风险评价提供理论支撑。展开更多
基金Hubei Key Scientific and Technological Items(981P1201).
文摘The slope stability is affected by multiple factors. Thecomprehensive evaluation of the slope stability is a complicateproblem. The principles of extension theory have been used in thispaper to establish the matter-element model for the evaluation ofslope stability. The quantitative evaluated results have been giventhrough the calculation of the matter-element dependent degree.
基金supported by the Chinese National Natural Science Fund Project(41072084)National Program on Key Basic Research Project(973 Program)(No. 2009CB219502-3)Prof.Qiu Yinan at RIPED(Research Institute for Petroleum Exploration and Development) of CNPC(China National Petroleum Corporation) for his belief in this work and financial support of the research
文摘Daihai Lake, a modern lacustrine rift basin, located in Inner Mongolia, North China, serves as an important modern analog for understanding deltaic depositional processes in an active rift setting. Two of the deltas （Yuanzigou delta and Bulianghe delta） on the margins of Daihai Lake were surveyed to compare and contrast stacking patterns using aerial photographs, field trenching and sediment sampling. Shallow cores and trench data collected from the margins of Daihai Lake indicate that a variety of depositional processes have been active since Daihai Lake formed. Two 3-D sedimentation models which employ chronostratigraphic correlation technique were generated. The chronostratigraphic sedimentation models predict and represent the architectures and sand-body continuity of sediments. Stratigraphical coincidence of the broad sheeted drifts and channel erosion suggests a coupling between downslope and alongslope processes. Distributary mouth bars are prevalent in the front of deltas on steeper slopes due to the dominance of down-slope flows. On the contrary, the along-slope currents favor the development of distal bar deposits with sheeted sandbodies on gentle depositional slopes. This study provides an insight into the architecture of complex sedimentary facies associated with highlighting key differences between downslope flows and alongslope currents. The distribution of sand within these deltas is of particular interests, with applications in understanding the architecture of hydrocarbon reservoirs formed in lacustrine rift basin.
基金the Scientific Research Foundation for Re-turned Overseas Chinese Scholars, MOE (No. J20050924)the United Research Foundation of the National Natural Science Com-mittee and the Ertan Hydropower Development Co. Ltd., China (No. 50579081)
文摘Fully automatic finite element(FE) modelling of the fracture process in quasi-brittle materials such as concrete and rocks and ductile materials such as metals and alloys,is of great significance in assessing structural integrity and presents tre-mendous challenges to the engineering community. One challenge lies in the adoption of an objective and effective crack propagation criterion. This paper proposes a crack propagation criterion based on the principle of energy conservation and the cohesive zone model(CZM) . The virtual crack extension technique is used to calculate the differential terms in the criterion. A fully-automatic discrete crack modelling methodology,integrating the developed criterion,the CZM to model the crack,a simple remeshing procedure to accommodate crack propagation,the J2 flow theory implemented within the incremental plasticity framework to model the ductile materials,and a local arc-length solver to the nonlinear equation system,is developed and im-plemented in an in-house program. Three examples,i.e.,a plain concrete beam with a single shear crack,a reinforced concrete(RC) beam with multiple cracks and a compact-tension steel specimen,are simulated. Good agreement between numerical predictions and experimental data is found,which demonstrates the applicability of the criterion to both quasi-brittle and ductile materials.
文摘为针对性地解决转炉炼钢作业时的消防安全问题,提出将熵权-最优最劣法(Best Worst Method,BWM)和物元可拓模型相结合的转炉车间火灾风险评估模型。通过将指标分为人、物料设备、环境、管理及消防设施5大类,构建转炉车间火灾风险评估指标体系;利用复合语言对35个指标进行评价,引入有序加权平均算子(Ordered Weighted Averaging,OWA)计算各语言的犹豫语言术语集(Hesitant Fuzzy Linguistic Term Set,HFLTS)模糊包络,再根据各专家权重进行加权计算并将语言量化构成评价矩阵;基于熵权、BWM分别算得各指标权重,再运用最小二乘法得到综合权重;最后利用物元可拓模型确定各指标及转炉车间的火灾风险等级。以河北省某炼钢转炉车间为例进行评估得出:该转炉车间的综合风险等级为I级(安全),其中动火监护的人员监管情况、氧枪法兰松紧度、炉前温度环境、作业现场物品摆放情况、作业巡查及设备检查情况和消防疏散通道堵塞情况仍需改善。
文摘为预防和控制引水隧洞中围岩失稳事故的发生,将物元可拓法应用于围岩稳定性评价中。以滇中引水工程为背景,选取滇中引水工程某隧洞段,构建引水隧洞围岩稳定性评价指标体系,划分围岩等级,选用灰色关联分析法(Grey Relational Analysis, GRA)和因子分析法(Factor Analysis, FA)组合确定权重,基于物元可拓模型进行引水隧洞围岩稳定性评价,以期减少目前评价方法中一些不相容现象及其他问题所带来的影响,从而提升长距离特大输水工程围岩稳定性等级评价的精度。结果表明,GRA-FA-物元可拓模型围岩稳定性评价结果与实际等级基本相符,与逼近理想解排序法(Technique for Order Preference by Similarity to Ideal Solution, TOPSIS)相比,预测评价精度从62.5%提升到87.5%,准确性提升了约25百分点。因此,GRA-FA-物元可拓模型相较以往的评价模型可以更全面和客观地进行引水隧洞围岩稳定性评价,可为其他长距离特大引水工程施工风险评价提供理论支撑。
