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Fluid-solid coupling numerical simulation of micro-disturbance grouting treatment for excessive deformation of shield tunnel

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Underground space 2024年第6期19卷 87-100页

作者： Yanjie zhang Zheng cao Chun Liu Hongwei Huang College of Civil Engineering and Architecture Henan University of TechnologyZhengzhou 450001China School of earth sciences and Engineering Nanjing UniversityNanjing 210023China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China

Micro-disturbance grouting is a recovery technique to reduce the excessive deformation of operational shield tunnels in urban *** grout mass behaves as a fluid in the ground before hardening to form a grout–soil mixture,which highlights the necessity of using fluid–solid coupling method in the simulation of grouting *** a discrete element modeling environment,this paper proposes a novel fluid-solid coupling method based on the pore density flow *** demonstrate the effectiveness of this method,it is applied to numerical simulation of micro-disturbance grouting process for treatment of large transverse deformation of a shield tunnel in Shanghai Metro,*** simulation results reveal the mechanism of recovering tunnel convergence by micro-disturbance grouting in terms of compaction and fracture of soil,energy analysis during grouting,and mechanical response of soil-tunnel interaction ***,the influence of the three main grouting parameters(i.e.,grouting pressure,grouting distance,and grouting height)on tunnel deformation recovery efficiency is evaluated through parametric *** order to efficiently recover large transverse deformation of shield tunnel in Shanghai Metro,it is suggested that the grouting pressure should be about 0.55 MPa,the grouting height should be in the range of 6.2.7.0 m,and the grouting distance should be in the range of 3.0–3.6 *** results provide a valuable reference for grouting treatment projects of over-deformed shield tunnel in soft soil areas.

关键词： Fluid-solid coupling Discrete element method Pore density flow Micro-disturbance grouting Soil-tunnel interaction

The δ^(18)O variation of a stalagmite from Qixing Cave,Guizhou Province and indi-cated climate change during the Holocene

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Chinese science Bulletin 2001年第22期46卷 1904-1908页

作者： CAI Yanjun, zhang Meiliang, PENG Zicheng, LIN Yushi, AN Zhisheng, zhang Zhaofeng & {2. YunningState Key Laboratory of Loess and Quaternary Geology, Institute of earth Environment, Chinese Academy of sciences, Xi’an 710054, china Karst Dynamics Laboratory, Ministry of Land and Resources, Guilin 541003, china department of earth and space science, university of science & Technology of china, hefei 2.002., china State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China Karst Dynamics Laboratory Ministry of Land and Resources Guilin China department of earth and {2. science University of Science & Technology of China Hefei China

A stalagmite from Qixing Cave, Guizhou Province was dated with the TIMS U-series method and its oxygen isotope composition was analyzed. On the basis of the ages and the variations of the δ18O of the stalagmite, the climate change of the last 7.7 ka has been reconstructed in this area: 7.7-5.8 ka, summer monsoon maximum period; 5.8-3.8 ka summer monsoon weakening period; 3.8-0.15 ka, weakened summer monsoon and high amplitude climate fluctuations period. We put forward that the increasing trend of δ18O of the stalagmite reflected not only the weakening of the summer monsoon, which was caused by the decreasing of solar radiation in the Northern Hemisphere, but also the possibly decreasing contribution of the southwest monsoon to the rainfall of this area. These results are consistent with the output of the numerical climate-model modeling. The high amplitude fluctuation of the δ18O may imply the quick shift of the contributions of different moisture sources to the precipitation in this area.

关键词： stalagmite Holocene southwest monsoon.

HiFAST:An HIdata calibration and imaging pipeline for FAST

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science china(Physics,Mechanics & Astronomy) 2024年第5期67卷 182-199页

作者： Yingjie Jing Jie Wang Chen Xu Ziming Liu Qingze Chen Tiantian Liang Jinlong Xu Yixian cao Jing Wang Huijie Hu Chuan-Peng zhang Qi Guo Liang Gao Mei Ai Hengqian Gan Xu{2. Gao Jinlin Han Ligang Hou Zhipeng Hou Peng Jiang Xu Kong Fujia Li Zerui Liu Li Shao Hengxing Pan Jun Pan Lei Qian Jinghai Sun Ningyu Tang Qingliang {2. Bo zhang Zhiyu zhang Ming Zhu National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 02206China School of Astronomy and space science University of Chinese Academy of SciencesBeijing 100049China Guizhou Radio Astronomical Observatory Guizhou UniversityGuiyang 55000China Max Planck Institute for Extraterrestrial Physics Garching 85748Germany Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Institute of Computational Cosmology Department of PhysicsUniversity of DurhamDurham DHI 3LEUK CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Deep space Exploration Laboratory/department of Astronomy University of Science and Technology of ChinaHefei 230026China School of Astronomy and space science University of Science and Technology of ChinaHefei 230026China Astrophysics Department of PhysicsUniversity of OxfordOxford OX/3RHUK College of earth sciences Guilin University of TechnologyGuilin 541004China department of Physics Anhui Normal UniversityWuhu 241002China School of Astronomy and space science Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics Nanjing UniversityNanjing 20023China

The Five-hundred-meter Aperture Spherical radio Telescope(FAST)has the largest aperture and a 19-beam L-band receiver,making it powerful for investigating the neutral hydrogen atomic gas(HI)in the *** present HiFAST(https://***),a dedicated,modular,and self-contained calibration and imaging pipeline for processing the H?data of *** pipeline consists of frequency-dependent noise diode calibration,baseline fitting,standing wave removal using an FFT-based method,flux density calibration,stray radiation correction,and gridding to produce data *** modules can be combined as needed to process the data from most FAST observation modes:tracking,drift scanning,On-The-Fly mapping,and most of their *** HiFAST,the root-mean-square(RMS)noises of the calibrated spectra from all 19 beams were only slightly(~5%)higher than the theoretical *** results for the extended source M33 and the point sources are consistent with the results from *** moment maps(0,1 and 2.of M33 agree well with the results from the Arecibo Galaxy Environment Survey(AGES)with a fractional difference of less than 10%.For a common sample of 2.1.sources with signal-to-noise ratio S/N>10 from the Arecibo Legacy Fast ALFA(ALFALFA)survey,the mean value of fractional difference in the integrated flux density,Sint,between the two datasets is approximately 0.005%,with a dispersion of 15.4%.Further checks on the integrated flux density of 2. sources with seven observations indicate that the variance in the flux density of the source with luminous objects(Sint>2.5 Jy km s-1)is less than 5%.Our tests suggest that the FAST telescope,with the efficient,precise,and user-friendly pipeline HiFAST,will yield numerous significant scientific findings in the investigation of the H?in the universe.

关键词： fractional luminous correction

Spatial distribution characteristics and influence factor analysis of landslides——case study of the Hanwang area in Qinba Mountains

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earthquake Research Advances 2024年第3期4卷 55-65页

作者： Jikai zhang Yanbo cao Wen Fan Wenbo Zheng Zequan Wang Chengcheng He Hongquan Teng School of Geological Engineering and Geomatics Chang’an UniversityXi'an710054China Mine Geological Disasters Mechanism and Prevention Key Laboratory Xi'an710054China china DK Comprehensive Investigate and Design Research Institute Co. Ltd.Xi'an710054China Shaanxi Engineering Technology Research Center for Urban Geology and Underground space Xi'an710068China Shaanxi Hydrogeology Engineering Geology and Environment Geology Survey CenterXi'an710068China Chang'an university Xi'anShaanxiChina

The geological hazards of landslides in Hanwang Town, Ziyang County, Ankang City, Shaanxi Province, have emerged. Yet, the current understanding of the spatial distribution characteristics and influencing factors of landslides in this area remains unclear. Combining the results of remote sensing interpretation and field investigation, seven influencing factors, namely, elevation, slope direction, slope gradient, distance from rivers, distance from faults, engineering geologic lithology, and distance from roads, are selected for the study. The distribution characteristics of landslides in each influencing factor and the influence of the resolution of the Digital Elevation Model(DEM) on the results are statistically and analytically analyzed. Furthermore, two highrisk landslides within the study area were subjected to comprehensive analysis, integrating the findings from drilling and other field investigations in order to examine their deformation mechanisms. Based on this analysis,the following conclusions were derived:(1) 34 landslides in the study area, mainly small earth landslides, with a distribution density of 0.42.km~2. threatening 414 people and property of about 55.87 million Yuan.(2.The landslides in the study area easily occur in the 2.0 m), the landslide-prone strata are mainly the softer and weaker metamorphic rocks, and the landslides are mainly around roads.(3) The resolution of the DEM should be selected based on the specific conditions of the study area, the requirements of the investigation, and the scale of the landslide. Opting for an appropriate DEM resolution is advantageous for understanding the patterns of landslides and conducting risk assessments in the region.(4) The Zhengjiabian landslide is a trac

关键词： Landslide Spatial distribution Influence factor Landslide density Deformation mechanism DEM

复杂固-液介质的速度应力方程三角形单元间断伽辽金地震波模拟算法

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地球物理学报 2024年第2期67卷 684-695页

作者：曹文忠张伟中国地震局地球物理研究所北京100081 南方科技大学地球与空间科学系广东深圳518055

间断伽辽金法可用于存在复杂边界条件的模型,同时具有高阶精度和易于并行计算的优点,因此近年来在地震波传播模拟研究中得到了快速发展.数值通量是间断伽辽金法的关键组成部分之一.相比于其他通量,基于Rankine-Hugoniot跳跃条件的通量(R... 详细信息

间断伽辽金法可用于存在复杂边界条件的模型,同时具有高阶精度和易于并行计算的优点,因此近年来在地震波传播模拟研究中得到了快速发展.数值通量是间断伽辽金法的关键组成部分之一.相比于其他通量,基于Rankine-Hugoniot跳跃条件的通量(RH-condition通量)在固体和液体介质边界具有更宽的稳定性,可以使用更大的时间步长,尤其是液体和固体之间的波阻抗差异较大时.它已被用于基于四边形网格和速度-应变方程的间断伽辽金地震波固液介质模拟.本文为了模拟陆地自然水体等存在复杂固-液界面形状的地震波传播,并在未来与其他数值方法耦合,发展了基于三角形网格的RH-condition通量间断伽辽金方法,使用一阶速度-压力声波和一阶速度-应力弹性波方程模拟复杂固-液介质中地震波的传播.通过水平层状和sin型起伏固-液模型,验证了该方法模拟结果的准确性.通过数值模拟展示了所提出的间断伽辽金法在不同网格大小和阶数下的准确性和效率.最后通过一个复杂模型的例子表明存在复杂固-液界面时该方法可以准确施加固-液边界条件.

关键词：间断伽辽金地震波模拟固-液介质数值通量

HiFAST:An H?data calibration and imaging pipeline for FAST

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science china(Physics,Mechanics & Astronomy) 2024年第5期Mechanics & Astronomy) .卷 186-203页

作者： Yingjie Jing Jie Wang Chen Xu Ziming Liu Qingze Chen Tiantian Liang Jinlong Xu Yixian cao Jing Wang Huijie Hu Chuan-Peng zhang Qi Guo Liang Gao Mei Ai Hengqian Gan Xu{2. Gao Jinlin Han Ligang Hou Zhipeng Hou Peng Jiang Xu Kong Fujia Li Zerui Liu Li Shao Hengxing Pan Jun Pan Lei Qian Jinghai Sun Ningyu Tang Qingliang {2. Bo zhang Zhiyu zhang Ming Zhu National Astronomical Observatories Chinese Academy of Sciences Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University School of Astronomy and space science University of Chinese Academy of Sciences Guizhou Radio Astronomical Observatory Guizhou University Max Planck Institute for Extraterrestrial Physics Kavli Institute for Astronomy and Astrophysics Peking University Institute of Computational Cosmology Department of PhysicsUniversity of Durham CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of Sciences Deep space Exploration Laboratory/department of Astronomy University of Science and Technology of China School of Astronomy and space science University of Science and Technology of China Astrophysics Department of PhysicsUniversity of Oxford College of earth sciences Guilin University of Technology department of Physics Anhui Normal University School of Astronomy and space science Nanjing University Key Laboratory of Modern Astronomy and Astrophysics Nanjing University

The Five-hundred-meter Aperture Spherical radio Telescope（FAST） has the largest aperture and a 19-beam L-band receiver,making it powerful for investigating the neutral hydrogen atomic gas（H?） in the *** present HiFAST（https://***）,a dedicated,modular,and self-contained calibration and imaging pipeline for processing the H?data of *** pipeline consists of frequency-dependent noise diode calibration,baseline fitting,standing wave removal using an FFT-based method,flux density calibration,stray radiation correction,and gridding to produce data *** modules can be combined as needed to process the data from most FAST observation modes:tracking,drift scanning,On-The-Fly mapping,and most of their *** HiFAST,the root-mean-square（RMS） noises of the calibrated spectra from all 19 beams were only slightly（～5%） higher than the theoretical *** results for the extended source M33 and the point sources are consistent with the results from *** moment maps（0,1 and 2. of M33 agree well with the results from the Arecibo Galaxy Environment Survey（AGES） with a fractional difference of less than 10%.For a common sample of 2.1.sources with signal-to-noise ratio S/N>10 from the Arecibo Legacy Fast ALFA（ALFALFA） survey,the mean value of fractional difference in the integrated flux density,Sint,between the two datasets is approximately 0.005%,with a dispersion of 15.4%.Further checks on the integrated flux density of 2. sources with seven observations indicate that the variance in the flux density of the source with luminous objects(Sint>2.5 Jy km s-1) is less than 5%.Our tests suggest that the FAST telescope,with the efficient,precise,and user-friendly pipeline HiFAST,will yield numerous significant scientific findings in the investigation of the H? in the universe.

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Spatial and temporal distribution of Neolithic sites in coastal china:Sea level changes, geomorphic evolution and human adaption

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science china {2. sciences 2018年第2期61卷 123-133页

作者： ZHENG HongBo ZHOU YouSheng yang Qing HU ZhuJun LING GuangJiu zhang JuZhong GU ChunGuang WANG YingYing {2. YeTing HUANG XianRong CHENG Yue zhang XiaoYu WU WenXiang Research Center for earth System science Yunnan University School of Geography science Nanjing Normal University department for the History of science and Scientific Archaeology University of Science and Technology of China Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences

The East china coastal plain is one of the most important Neolithic culture areas in china, where rich archaeological sites including those producing the earliest domesticated rice are observed. It is also a place where landscape has experienced dramatic evolution during the Holocene when both sea level and climate changed, such that it is an ideal place for studying human-environment interaction. This study investigated over 2.00 sites of pre-history and Shang and Zhou Dynasties, with 655 of which being Neolithic ages, by using DEM and GIS methods. The results suggest that the spatial and temporal distribution of Neolithic sites has largely been controlled by landscape evolution(particularly changes in coastal line), which ultimately governed by sea level changes. During early Holocene, Neolithic sites sparsely distributed in the intermountain basins of east Zhejiang Province, far from the influence of ocean. Over the period of 9–7 ka, the coastal plain(including the shelf) was largely submerged,only the feet of low hills to the south and southwest of the study area, and islands protruding the estuary, cradled limited number of settlements with characteristic "maritime components". At about 7 ka, sea level rise decelerated prominently, while sediments supply in the drainage remained high value, the combination of which led to land formation and propagation. Vast {2. during this period facilitated the growth of settlements in both size and number. In the mean time, however, the coastal plain was vulnerable to extreme environmental events such as storms and flooding owning to its geomorphic nature, which exerted great influence on the rise and fall of Neolithic culture.

关键词： East china coastal plain Neolithic Spatial and temporal distribution of Neolithic sites Sea level change Geomorphic evolution

Scalings for the Alfvén-cyclotron instability in a bi-kappa plasma

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地球与行星物理:英文版 2023年第6期7卷 631-639页

作者： YueQun Lou Xing cao MingYu Wu BinBin Ni TieLong zhang Shenzhen Key Laboratory of Numerical Prediction for space Storm Institute of Space Science and Applied TechnologyHarbin Institute of TechnologyShenzhen 518055China Key Laboratory of Solar Activity and space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China department of space Physics School of Electronic InformationWuhan UniversityWuhan 430072China Chinese Academy of sciences Center for Excellence in Comparative Planetology Hefei 230026China space Research Institute Austrian Academy of SciencesGraz 8042Austria

The particle velocity distribution in space plasma usually exhibits a non-Maxwellian high-energy tail that can be well modeled by kappa *** this study,we focus on the growth rates of the Alfvén-cyclotron instability driven by ion temperature anisotropy in a kappa *** solving the kinetic linear dispersion equation,we explore the sensitivity of growth rates to the spectral indexκof a bi-kappa distribution under different plasma conditions,including a variety of plasma beta β_(hp) and temperature anisotropy A_(hp) values of hot ***,a concise,analytic scaling formula is derived that relates the dimensionless maximum growth rate to three independent variables:the spectral index and the plasma beta and temperature anisotropy of hot *** results show that as theκ-value increases,the instability bandwidth narrows and the maximum growth rate increases *** higherβ_(hp)and A_(hp)′the maximum instability undergoes a sharp increase as *** our fits of dimensionless maximum growth rates are compared with solutions to kinetic linear dispersion theory,the results generally exhibit good agreement between *** under the circumstances of largeκ-values and highβ_(hp)and A_(hp)′the scalings of maximum growth rates primarily accurately model the numerical *** analytic expressions can readily be used in large-scale models of the earth’s magnetosphere to understand wave generation due to the Alfvén-cyclotron instability.

关键词： Alfvén-cyclotron instability kappa distribution kinetic linear dispersion theory scaling formula

Spatial pattern analysis of forest trees based on the vectorial mark

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Journal of Forestry Research 2022年第4期33卷 1301-1315页

作者： Honglu Xin Toby Jackson Yujie cao Huanyuan zhang Yi Lin Alexander Shenkin Institute of Remote Sensing and Geographic Information Systems School of Earth and Space SciencePeking UniversityBeijing 100871People’s Republic of China Environmental Change Institute School of Geography and the EnvironmentUniversity of OxfordSouth Parks RoadOxford OX13QYUK department of Plant sciences University of CambridgeDowning StreetCambridge CB23EAUK College of Surveying and Geo-Informatics Tongji UniversityShanghai 200092People’s Republic of China SICCS Northern Arizona UniversityFlagstaffAZ 86001USA

Analysis of spatial patterns to describe the spatial correlation between a tree location and marks(i.e.,structural variables),can reveal stand history,population dynamics,competition and ***,most studies of spatial patterns have concentrated on tree location and tree sizes rather than on crown asymmetry especially with direct analysis among marks characterizing facilitation and competition among of trees,and thus cannot reveal the cause of the distributions of tree locations and quantitative *** explore the spatial correlation among quantitative and vectorial marks and their implication on population dynamics,we extracted vertical and horizontal marks(tree height and crown projection area)characterizing tree size,and a vectorial mark(crown displacement vector characterizing the crown asymmetry)using an airborne laser scanning point cloud obtained from two forest stands in Oxfordshire,*** and vectorially marked spatial patterns were developed,with corresponding null models established for a significance *** analyzed eight types of univariate and bivariate spatial patterns,after first proposing four *** accuracy of the pattern analysis based on an algorithm-segmented point cloud was compared with that of a truly segmented point *** algorithm-segmented point cloud managed to detect 70–86%of patterns *** eight types of spatial patterns analyzed the spatial distribution of trees,the spatial correlation between tree size and facilitated or competitive interactions of sycamore and other *** four types of univariate patterns jointly showed that,at smaller scales,the trees tend to be clustered,and taller,with larger crowns due to the detected facilitations among trees in the study *** four types of bivariate patterns found that at smaller scales there are taller trees and more facilitation among sycamore and other species,while crown size is mostly homogeneous across *** results indicate that

关键词： Spatial pattern Spatial correlation Quantitative mark Vectorial mark Summary statistics