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融合差分进化与多策略的阿基米德优化算法

数学的实践与认识 2024年第4期54卷 128-140页

作者：徐小平张钰王峰苏李君西安理工大学理学院陕西西安710054 西安交通大学数学与统计学院陕西西安710049

鉴于阿基米德优化算法存在易早熟,收敛慢等缺点,提出一种融合差分进化与多策略的阿基米德优化算法.首先,通过位置参数,随机选择两种混沌映射初始化种群来增强种群的多样性;其次,通过余弦控制因子的动态边界策略改进密度因子,来平衡算法... 详细信息

鉴于阿基米德优化算法存在易早熟,收敛慢等缺点,提出一种融合差分进化与多策略的阿基米德优化算法.首先,通过位置参数,随机选择两种混沌映射初始化种群来增强种群的多样性;其次,通过余弦控制因子的动态边界策略改进密度因子,来平衡算法的全局探索与局部开发能力;接着,融合差分进化算法,缩小最优位置的范围,以达到快速向最优位置靠拢的目的.最后,选取10个基准测试函数进行仿真实验,并对实验结果进行Wilcoxon秩和检验,结果表明所提算法性能优于对比算法.

关键词：阿基米德优化算法差分进化算法混沌映射余弦控制因子动态边界

Particle breakage and the mobilized drained shear strengths of sand

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Journal of Mountain Science 2016年第8期13卷 1481-1488页

作者： YU Fang-wei su li-jun Institute of Mountain Hazards and Environment Chinese Academy of Sciences Department of Civil Engineering The University of Tokyo

This paper presents particle breakage and the mobilized drained shear strengths of sand with the purpose of clarifying the influence of particle breakage on the mobilized shear strengths of sand. Several drained triaxial tests were carried out on Silica sand No.5 under 3 MPa confining pressure to produce the pre-crushed sands in simulating the high- pressure shear process on soil to result in particle breakage, and then the pre-crushed sands were re- sheared in series of drained triaxial tests to investigate the mobilized strengths of the pre-crushed sands in detecting the influence of particle breakage. It was found that, by deteriorating strain-stress behavior, particle breakage resulted in change of stress-dilataney behavior in translation and rotation of the relation of the dilatancy factor and the effective principal stress ratio. For a given initial void ratio, particle breakage resulted in impairment of dilatancy behavior of soil to be more contractive in deterioration of the mobilized friction angle and the mobilized dilatancy angle and reduction of void ratio. However, particle breakage resulted in increase of the mobilized basic friction angle especially before failure. In addition, the influence of particle breakage on the mobilized strengths was revealed to be influenced by the shear stress-strain state.

关键词： Particle breakage Mobilized strengths Friction Dilatancy Void ratio Sand

Theoretical Investigation on Hyperfine Structures of Perfluoropolyether Radicals

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Chemical Research in Chinese Universities 2011年第1期27卷 117-122页

作者： DONG su-li liU Ya-jun Key Laboratory of Theoretical and Computational Photochemistry Ministry of Education College of Chemistry Beijing Normal University Beijing 100875 P. R. China

The geometries of CF3OCF2, CF3OCFCF3 and CF3OCF2CF2 radicals were investigated by density functional theory（DFT） method. The calculated results indicate that all the three radicals have pyramidal shapes at their centers, and the aC is one top of the pyramids. Based on the DFT optimized geometries, the hyperfine coupling constants（hfec＇s） of the 19F atoms of the three radicals were calculated by B3LYP, MP2（full） and QCISD（full） methods. The calculated values agree with the experimental values, especially for the a values of Fa, the a values are 125.6× 10 -4, 104.2× 10 - 4, and 83.2×10 -4 T of CF3OCF2, CF3OCFCF3 and CF3OCF2CF2, respectively. These results better explain the experimental observation.

关键词： Perfluoropolyether radical Hyperfine coupling constant Density functional theory

Landslide susceptibility analysis of Karakoram highway using analytical hierarchy process and scoops 3D

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Journal of Mountain Science 2020年第7期17卷 1596-1612页

作者： Barira RASHID Javed IQBAL su li-jun Institute of Geographical Information Systems School of Civil&Environmental EngineeringNational University of Sciences and Technology(NUST)Islamabad44000Pakistan Key Laboratory of Mountain Hazards and Earth surface Processes Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu610041China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing100101China University of Chinese Academy of Sciences Beijing100049China

Landslides are prevalent,regular,and expensive hazards in the Karakoram Highway(KKH)*** KKH connects Pakistan with China in the present China-Pakistan Economic Corridor(CPEC)*** region has not only immense economic importance but also ecological *** purpose of the study was to map the landslide-prone areas along KKH using two different techniquesAnalytical Hierarchy Process(AHP)and Scoops 3 D *** causative parameters for running AHP include the lithology,presence of thrust,land use land cover,precipitation,and Digital Elevation Model(DEM)derived variables(slope,curvature,aspect,and elevation).The AHP derived final landslide susceptibility map was classified into four zones,i.e.,low,moderate,high,and extremely *** 80%of the study area falls under the moderate(43%)and high(40%)landslide susceptible *** assess the slope stability of the study area,the Scoops 3 D model was used by integrating with the earthquake loading *** results of the limit equilibrium analysis categorized the area into four groups(low,moderate,high,and extremely high mass)of slope *** areas around Main Mantle Thrust(MMT)including Dubair,Jijal,and Kohistan regions,had high volumes of potential slope *** results from AHP and Scoops 3 D techniques were validated with the landslides inventory record of the Geological survey of Pakistan and Google *** results from both the techniques showed similar output that coincides with the known landslides ***,Scoops 3 D provides not only susceptible zones but also the range of volume of the potential slope ***,these techniques could be used in other mountainous areas,which could help in the landslide mitigation measures.

关键词： Landslide mapping Landslide hazard zonation Analytical Hierarchy Process(AHP) Scoops 3D China Pakistan Economic Corridor(CPEC) Karakoram Highway

Risk assessment of glacial debris flow on alpine highway under climate change: A case study of Aierkuran Gully along Karakoram Highway

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Journal of Mountain Science 2021年第6期18卷 1458-1475页

作者： li Ya-mei su li-jun ZOU Qiang WEI Xue-li Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing 100101China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China Key Laboratory of Mountain Hazards and Earth surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengduSichuan 610041China China-Pakistan Joint Research Centre on Earth Sciences CAS-HECIslamabad 45320Pakistan University of Chinese Academy of Sciences Beijing 100049China Transportation Planning survey and Design Institute of Xinjiang Uygur Autonomous Region Urumqi 830006China

Glacial debris flows(GDFs) often occur in alpine regions that are subject to rapid climate change, and pose a serious threat to road systems. However, the ways that climate change impacts GDF risks along road systems remain poorly understood. Aierkuran Gully, located in eastern Pamir along Karakoram Highway(KKH), is a hotspot for GDF activity and climate change, and was thus selected to investigate the GDF risk to road systems under climate change conditions. Reg CM4.6 climate data for northwestern China were selected as climate projections during baseline(2011–2020) and future periods(2031–2040) under the Representative Concentration Pathway(RCP) 8.5. To reflect the coupling effect of rainfall and melt water that triggers GDF, a glacial hydrological model DETIM that considers both factors was applied to calculate the peak debris flow discharge. A FLO-2D model was calibrated based on high-quality data collected from a detailed field investigation and historical debris flow event. The FLO-2D model was used to simulate the debris flow depth and velocity during baseline and future periods under RCP8.5. The debris flow hazard was analyzed by integrating the maximum flow depth and momentum. Road structure vulnerability was further determined based on the economic value and susceptibility of hazard-affected objects. The GDF risk along KKH was assessed based on the GDF hazard and vulnerability analysis. Our results show that climate change would lead to amplified peak debris flow discharge, trigger highermagnitude GDF, and induce more severe damage and threats to the road system. Compared with the baseline period, the debris flow damage risk for culverts and bridges would increase and the areas that inundate the road and pavement would expand. Our findings provide valuable insights for the development of mitigation strategies to adapt road systems to climate change, especially in alpine regions with highly active GDFs.

关键词： Glacial debris flow Risk assessment Climate change Alpine area Karakoram Highway

Influence of grain segregation on the behavior of sand in triaxial tests

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Journal of Mountain Science 2021年第10期18卷 2776-2790页

作者： YU Fang-wei PENG Xiong-zhi su li-jun Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China China-Pakistan Joint Research Center on Earth Sciences CAS-HECIslamabad 45320Pakistan University of Chinese Academy of Sciences Beijing 100049China Department of Civil Engineering The University of TokyoTokyo 113-8656Japan Department of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China

As a common phenomenon in granular flow, grain segregation plays a great role in affecting the behavior of granular soil by causing a great change of grain-void distribution in granular soil. This paper presents an experimental study on the influence of grain segregation on the behavior of sand, by a number of triaxial tests to interpret the characteristic behavior, friction and dilatancy behavior, excess pore water pressure behavior and critical state behavior of sand incorporating grain segregation. An index-grain segregation index was proposed to quantify grain segregation. Grain segregation affected greatly the characteristic behavior of sand, causing the movement of void ratio-dilatancy relation of sand towards the increase of void ratio and dilatancy of sand. In the drained tests, the mobilized friction angle of sand showed a decrease followed by an increase but the mobilized dilatancy angle of sand increased, with increasing grain segregation index. An increase in grain segregation index impaired the basic friction of sand. In the undrained tests, the mobilized friction angle of sand showed an increase followed by a decrease with increasing grain segregation index. However, grain segregation caused an increase of the mobilized dilatancy of sand followed by a different development. An increase in grain segregation resulted in a higher summit of the dilatancy of sand but with a faster decrease along axial strain. In the q-p′ plane, grain segregation caused a reciprocating rotation of the dilatancy line and failure line of sand. Grain segregation resulted in enhancement of the peak-state dilatancy of sand, affecting greatly peakstate friction angle and peak-state basic friction angle of sand as well as the normalized excess pore water pressure. The excess friction angle of sand showed an increase followed by a decrease in the drained tests but increased linearly in the undrained tests, with increasing grain segregation index. The excess friction angle-over-maxim

关键词： Critical state Dilatancy Friction Grain segregation Landslides Soil behavior Triaxial tests

Experimental and theoretical study of mechanical properties of root-soil interface for slope protection

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Journal of Mountain Science 2020年第11期17卷 2784-2795页

作者： su li-jun HU Bing-li XIE Qi-jun YU Fang-wei ZHANG Chong-lei Key Laboratory of Mountain Hazards and Earth surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China China-Pakistan joint Research Center on Earth Sciences IslamabadPakistan University of Chinese Academy of Sciences Beijing 100049China

Plant roots mechanically enhance the strength of soil and improve slope stability through *** the popularization of ecological slope-protection technology,a quantitative study of how roots help to anchor soil is highly *** object of the present study is thus to investigate how roots and soil combine to affect the mechanical properties of the root-soil *** this end,pullout experiments of cedar roots of different diameters in soils of different density were *** experimental results show that the maximum pullout force increases significantly with increasing root diameter,but only slightly increases with increasing soil density,which indicates that the root diameter has a greater impact on the maximum pullout force than soil ***,based on studies of fiber-reinforced composites,a root-soil pull-out model was proposed to study the evolution of shear stress on root-soil *** approach ensures that the model accurately reflects the dynamic stress distribution evolution at the root-soil interface and can calculate the pullout process of embedded root from *** accuracy of the model is verified by comparing the calculated results with experimental ***,how soil density and root diameter affect the anchoring force was *** results indicate that the maximum anchoring force increases linearly with increasing root diameter,but nonlinearly with increasing soil density until reaching a fixed *** results show that the root soil pull-out model has significant practical value in slope protection.

关键词： Ecological slope-protection Anchoring force Pullout experiment Pullout model Model prediction

Influence of particle breakage on the isotropic compressibility of sands

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Journal of Mountain Science 2022年第7期19卷 2086-2099页

作者： YU Fang-wei su li-jun PENG Xiong-zhi Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu610299China Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing100101China China-Pakistan Joint Research Center on Earth Sciences Islamabad45320Pakistan University of Chinese Academy of Sciences Beijing100049China Department of Civil Engineering The University of TokyoTokyo113-8656Japan Department of Civil Engineering Southwest Jiaotong UniversityChengdu610031China

Particle breakage is a theme of great focus on affecting the behavior of granular *** paper presents an experimental investigation on the influence of particle breakage on the isotropic compressibility of the precrushed sands using a number of drained isotropic consolidation *** breakage resulted in movement of the compression lines followed by the rebound lines towards a decrease in the void ratio,implying that particle breakage caused a more contractive *** breakage impaired the bulk deformation modulus by increasing the compression coefficient for the compression behavior of the precrushed sands,but showed a complex effect on the bulk deformation modulus and rebound coefficient for the rebound behavior of the precrushed ***,particle breakage caused an increase in the compression indexes of the precrushed sands but showed a complex effect on the rebound indexes of the precrushed *** the e-p’plane and the e-logp’plane,the compression lines and rebound lines of the precrushed sands were curved.A generalized model was proposed to straighten the compression and rebound lines of the precrushed sands in the e-(p’p_(a))^(α) *** breakage resulted in a general rotation and translation of the linear compression and rebound lines of the precrushed sands in the e-(p’p_(a))^(α)*** critical state line and isotropic consolidation line on the loosest state of silica sand no.5 were curved in the e-logp’plane but straightened in the e-p’^(α=0.7) *** the e-p’^(α=0.7 )plane,a reasonable linear critical state line of silica sand no.5 was proposed by adjusting it to match the isotropic consolidation line on the loosest state.

关键词： Compression Isotropic consolidation Particle breakage Rebound Sands Triaxial tests

A back-propagation neural-network-based displacement back analysis for the identification of the geomechanical parameters of the Yonglang landslide in China

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Journal of Mountain Science 2017年第9期14卷 1739-1750页

作者： YU Fang-wei PENG Xiong-zhi su li-jun Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China Department of Civil Engineering Southwest Jiaotong University Chengdu 610031 China CAS Center for Excellence in Tibetan Plateau Earth Sciences Bering 100101 China University of Chinese Academy of Sciences Beijing 100049 China

Xigeda formation is a type of hundredmeter-thick lacustrine sediments of being prone to triggering landslides along the trunk channel and tributaries of the upper Yangtze River in China. The Yonglang landslide located near Yonglang Town of Dechang County in Sichuan Province of China, which was a typical Xigeda formation landslide, was stabilized by anti-slide piles. Loading tests on a loading-test pile were conducted to measure the displacements and moments. The uncertainty of the tested geomechanical parameters of the Yonglang landslide over certain ranges would be problematic during the evaluation of the landslide. Thus, uniform design was introduced in the experimental design,and by which, numerical analyses of the loading-test pile were performed using Fast Lagrangian Analysis of Continua(FLAC3D) to acquire a database of the geomechanical parameters of the Yonglang landslide and the corresponding displacements of the loadingtest pile. A three-layer back-propagation neural network was established and trained with the database, and then tested and verified for its accuracy and reliability in numerical simulations. Displacement back analysis was conducted by substituting the displacements of the loading-test pile to the well-trained three-layer back-propagation neural network so as to identify the geomechanical parameters of the Yonglang landslide. The neuralnetwork-based displacement back analysis method with the proposed methodology is verified to be accurate and reliable for the identification of the uncertain geomechanical parameters of landslides.

关键词： Back-propagation neural network Displacement back analysis Geomechanical parameters Landslide Numerical analysis Uniform design Xigeda formation