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Numerical simulation and land subsidence control for deep foundation pit dewatering of Longyang Road Station on Shanghai Metro Line 18

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Journal of Groundwater Science and Engineering 2019年第2期7卷 133-144页

作者： LI Wen-yong FU Li ZHU Zheng-feng Shanghai Metro Line 18 Development Co. Ltd Shanghai 200135 China Shanghai Guanglian Environmental & Geotechnical Engineering Co. Ltd Shanghai 200444 China

In terms of controlling groundwater in deep foundation pit projects, the usual methods include increasing the curtain depth, reducing the amount of pumped groundwater, and implementing integrated control, in order to reduce the drawdown and land subsidence outside pits. In dewatering design for confined water, factors including drawdown requirements, the thickness of aquifers, the depth of dewatering wells and the depth of cutoff curtains have to be considered comprehensively and numerical simulations are generally conducted for calculation and analysis. Longyang Road Station on Shanghai Metro Line 18 is taken as the case study subject in this paper, a groundwater seepage model is developed according to the on-site engineering geological conditions and hydrogeological conditions, the excavation depth of the foundation pit as well as the design depth of the enclosure, hydrogeological parameters are determined via the pumping test, and the foundation pit dewatering is simulated by means of the three-dimensional finite difference method, which produces numerical results that consistent with real monitoring data as to the groundwater table. Besides, the drawdown and the land subsidence both inside and outside the pit caused by foundation pit dewatering are calculated and analyzed for various curtain depths. This study reveals that the drawdown and the land subsidence change faster near the curtain with the increase in the curtain depth, and the gradient of drawdown and land subsidence changes dwindles beyond certain depths. In this project, the curtain depth of 47/49 m is adopted, and a drawdown-land subsidence verification test is completed given hanging curtains before the excavation. The result turns out that the real measurements basically match the calculation results from the numerical simulation, and by increasing the depth of curtains, the land subsidence resulting from dewatering is effectively controlled.

关键词： Deep foundation pit Engineering dewatering Numerical simulation Groundwater Land subsidence Verification test

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Insufficient lateral stem contact is an influencing factor for significant subsidence in cementless short stem total hip arthroplasty

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World Journal of Orthopedics 2022年第5期13卷 444-453页

作者： Yingyong Suksathien Pattawat Chuvanichanon Thanut Tippimanchai Jithayut Sueajui Department of Orthopedic Surgery Maharat Nakhon Ratchasima HospitalMuang 30000Nakhon Ratchasima ProvinceThailand

BACKGROUND subsidence is one of the concerning early complications in cementless femoral *** publications have studied the influencing factors for subsidence in short cementless stems,due to their metaphyseal anchoring without diaphyseal invasion,they might demonstrate different subsidence patterns than with the conventional *** To analyze the factors associated with significant subsidence in short stems,including any radiographic *** The digitized radiographs of 274 consecutive short stem total hip arthroplasties were retrospectively ***,neck-filling ratio(NFR),seating height and lateral stem contact were evaluated after a minimum of two years follow-up.A threshold of subsidence>3 mm was considered a clinically significant *** For the entire cohort,subsidence occurred in 75 cases(27.4%)with the mean stem subsidence of 0.5 mm.(0-12.7,1.68).Twelve hips(4.4%)had significant subsidence(>3 mm).The univariate regression analysis demonstrated that age,diagnosis,BMI,Dorr’s type B,NFR,and seating height had no significant influence on significant subsidence,whereas insufficient lateral stem contact(≥1 mm)did have a statistically significant influence[Odds ratio(OR)=5.02;95%CI:1.3-18.9;P=0.017].The multivariate regression analysis also demonstrated that insufficient lateral stem contact was a statistically significant influencing factor(OR=5.5;95%CI:1.4-21.4;P=0.014).There was no femoral stem revision for aseptic loosening in our *** This study demonstrated that insufficient lateral stem contact was a statistically significant influencing factor on significant ***,it is a particularly important step to create proper lateral cortical contact when performing the short stem total hip arthroplasty.

关键词： Total hip arthroplasty Short stem subsidence Metaphyseal anchorage Metha

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Impact,Mechanism,Monitoring of Land subsidence in Coastal Cities(Annual Work of IGCP 663)

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Acta Geologica Sinica(English Edition) 2019年第S01期93卷 158-159页

作者： YAN Xuexin YANG Tianliang XU Yan Luigi TOSI Esther STOUTHAMER Heri ANDREAS LIN Jinxin HUANG Xinlei Key Laboratory of Land subsidence Monitoring and Prevention Ministry of Land and ResourcesShanghai 200072China Shanghai Institute of Geological Survey Shanghai 200072China Shanghai Engineering Technology Research Center of Land subsidence Shanghai 200072China Institute of Marine Sciences National Research CouncilArsenale Tesa104-Castello 2737/F30122-VeniceItaly Institute of Geosciences and Earth Resources National Research Councilvia G.Gradenigo635131-PaduaItaly Department of Physical Geography Faculty of GeosciencesUtrecht University3584 CSUtrechtthe Netherlands Geodesy Research Division Institute of Technology BandungBandung 40132Indonesia

Land subsidence is a worldwide geohazard consisting in the lowering of the ground surface due to natural and human-induced processes occurring in the shallow and deep *** the last two decades,land subsidence has caused damages and widespread impacts to a variety of infrastructures in coastal cities(Ma et al.,2011;Liu et al.,2016;Minderhoud et al.,2018).

关键词： land subsidence coastal cities case studies reclaimed soil

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Monitoring subsidence rates along road network by persistent scatterer SAR interferometry with high-resolution TerraSAR-X imagery

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Journal of Modern Transportation 2013年第4期21卷 236-246页

作者： Bing Yu Guoxiang Liu Rui Zhang Hongguo Jia Tao Li Xiaowen Wang Keren Dai Deying Ma Department of Remote Sensing and Geospatial Information Engineering Southwest Jiaotong University

Ground subsidence is one of the key factors damaging transportation facilities, e.g., road networks consisting of highways and railways. In this paper, we propose to apply the persistent scatterer synthetic aperture radar interferometry （PS-InSAR） approach that uses high- resolution TerraSAR-X （TSX） imagery to extract the regional scale subsidence rates （i.e., average annual sub- sidence in mm/year） along road networks. The primary procedures involve interferometric pair selection, interfer- ogram generation, persistent scatterer （PS） detection, PS networking, phase parameterization, and subsidence rate estimation. The Xiqing District in southwest Tianjin （China） is selected as the study area. This district contains one railway line and several highway lines. A total of 15 TSX images covering this area between April 2009 and June 2010 are utilized to obtain the subsidence rates by using the PS-InSAR （PSI） approach. The subsidence rates derived from PSI range from -68.7 to -1.3 mm/year. These findings show a significantly uneven subsidence pattern along the road network. Comparison between the PSI-derived subsidence rates and the leveling data obtained along the highways shows that the mean and standard deviation （SD） of the discrepancies between the two types of subsidence rates are 0.1 and 4-3.2 mm/year, respectively. The results indicate that the high-resolution TSX PSI is capable of providing comprehensive and detailed subsidence information regarding road networks with millimeter-level accuracy. Further inspections under geo- logical conditions and land-use categories in the study area indicate that the observed subsidence is highly related to aquifer compression due to groundwater pumping. Therefore, measures should be taken to mitigate groundwater extraction for the study area.

关键词： subsidence Road network - Persistent scatterer interferometry TerraSAR-X Highway Railway

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Equivalent materials simulation experimental study on bed separations developing and mining subsidence in constant humidity and constant temperature conditions

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Journal of Coal Science & Engineering(China) 2008年第4期14卷 585-590页

作者：付志亮王素华高延法 School of Resources DeveloPment & Managment Engineering Anhui University of Science &TechnologyHuainan 232001China College of Chemical and Environmental Engineering Shandong University of Science and TechnologyQingdao 266510China College of Hydraulic and Civil Engineering Shandong Agricultural UniversityTai'an 271018China Geotechnical mechanics Research Center China University of Mining &TechnologyBeijing 100083China

A new experiment was made on the developing of bed separations and mining subsidence from Tangshan T2192 working face by equivalent materials *** overburden deformation and the developing of bed separations with working face advanc- ing was simulated by a new *** results show that the maximum value of bed separations moved forward gradually along with the working face advancing;the maxi- mum value of bed separations is 0.31～0.50 times of mining *** key strata have a great influence upon surface subsidence during the overburden movement *** mechanics parameters of new experiment are fitted with results in fields perfectly.

关键词： subsidence bed separations constant humidity constant temperature equivalent simulation experiment

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Houston16:A stable geodetic reference frame for subsidence and faulting study in the Houston metropolitan area,Texas,U.S.

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Geodesy and Geodynamics 2019年第5期10卷 382-393页

作者： Timothy J.Kearns Guoquan Wang Michael Turco Jennifer Welch Vasilios Tsibanos Hanlin Liu Dept.of Earth and Atmospheric Sciences National Center for Airborne Laser MappingUniversity of HoustonHoustonTX77204USA Harris-Galveston subsidence District FriendswoodTX77546USA

Houston,Texas,is one of the earliest regions to employ continuous GPS technology for land subsidence ***,there are over 200 permanent GPS stations located in the greater Houston *** need for a consistent and stable reference frame to precisely interpret local ground deformation has become critically important since the 1990s,because of the significant spreading of *** have established a stable Houston reference frame,designated Houston16,using publicly available GPS observations(>5 years)from 15 Continuously Operating Reference Stations(CORS)located outside of the greater Houston *** of the reference frame in subsidence and faulting studies are demonstrated in this ***16 is aligned in origin and scale with the International GNSS Reference Frame of 2008(IGS08).A 7-parameter method was employed to transform the GPS-derived positional time series from IGS08 to *** primary product of this study is the seven parameters for transforming Earth-Centered-Earth-Fixed XYZ coordinates from IGS08 to *** frame stability of Houston16 is approximately 1 mm/***16 will be updated every few years to mitigate degradation of the frame’s stability with time and to synchronize with future updates of the IGS reference frame.

关键词： Faulting GPS Houston IGS08 Reference frame subsidence

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Geostatistical evaluation of spatial variability of land subsidence rates in Lagos, Nigeria

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Geodesy and Geodynamics 2020年第5期11卷 316-327页

作者： Femi Emmanuel Ikuemonisan Vitalis Chidi Ozebo Olawale Babatunde Olatinsu Department of Physics Faculty of ScienceUniversity of LagosAkokaLagosNigeria

Accurate land subsidence prediction is fundamental for effective management of land subsidence and other associated geohazards. Lagos, the most densely populated city in Nigeria, has been adversely affected by widespread land subsidence. Previous studies have largely been restricted to analyzing space geodetic technique data. Unfortunately, this technique imposes spatial limitations resulting in incomplete coverage of the study areas due to atmospheric effects, orbital satellite characteristics, or surface characteristics. The application of geostatistics to georeferenced data obtained from space-based measurements can reliably provide complete information on spatial variability. The objective of this study is to provide an overview of current subsidence rates and to assess the spatial variability of land subsidence in the study area by using geostatistics that integrate semivariogram and ordinary kriging. The study area was partitioned into eight subregions;for each subregion, the experimental variogram was determined from the observed data and fitted to the optimal models. Seven subregions were fitted to exponential models and one was fitted to the spherical model. The model semivariograms were used in the kriging analysis to estimate the spatial variability of subsidence rates. The results showed that the nugget-to-sill ratio lies between 44 and 70%, indicating that the spatial variation of subsidence rates at the scale under study is moderately distributed and the mechanism of deformation is similar. The nugget effect of the subsidence rate is between 0.25 and 0.75, indicating that subsidence rates are influenced by various contributions. The predicted spatial variability of subsidence rates by Ordinary Kriging presents reliable values of R-squared(0.32 e0.42) and RMSE(0.21 e0.30). Critical subsidence rates characterised the areas around the Atlantic Ocean coastal alluvium deposit, the Lagos lagoon, and the Ogun River flood *** study successfully demon

关键词： subsidence variability coastal

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Characterisation and mapping of land subsidence based on geodetic observations in Lagos,Nigeria

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Geodesy and Geodynamics 2020年第2期11卷 151-162页

作者： Ikuemonisan Femi Emmanuel Ozebo Vitalis Chidi Department of Physics Faculty of ScienceUniversity of LagosAkokaLagosNigeria

The pervasive seasonal flooding,aquifer contamination,and saline water intrusion in parts of Lagos are some of the long-term effects of land subsidence caused by the excessive groundwater exploitation and land reclamation that has been taking place in the *** to monitor the extent and pattern of land deformation will help in many ways to mitigate the effects of flooding and other geohazards associated with land *** this study,we characterised and mapped the land subsidence in the Lagos city based on the analyses of geodetic data,which included Global Positioning Satellite(GPS),Envisat,Sentinel-1,and GRACE *** applied the SBAS technique to the Envisat and Sentinel-1 datasets acquired from 2004-2011 and 2015-2019,respectively,and to perform multi-temporal analyses and produce corresponding subsidence maps over the Lagos *** GRACE data were used to infer the extent and trend of groundwater changes at the GPS *** results indicate that the subsidence is a widespread phenomenon in Lagos city,with subsidence rates varying between-2 mm/year and-87 mm/*** highest subsidence rate was observed around the coastal zones and areas where heavy structures are built on *** the highest rate at present,subsidence has gradually increased in the last 15 *** the development of indiscriminate groundwater exploitation,urbanization,and rapid population growth,the subsidence rate in Lagos city is likely to rise significantly in the coming years,which,in turn,may further escalate the flood rate and other associated geohazards.

关键词： InSAR P-SBAS Deformation time series Land subsidence Lagos

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Land subsidence in Xiong’an New Area,China Revealed by InSAR Observations

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Journal of Geodesy and Geoinformation Science 2021年第1期4卷 70-76页

作者： Keren DAI Peilian RAN Zhenhong LI Julian AUSTIN Jan-Peter MULLER Qiming ZENG Jingfa ZHANG Leyin HU College of Earth Sciences Chengdu University of TechnologyChengdu 610059China State Key Laboratory of Geohazard Prevention and Geoenviroment Protection Chengdu University of TechnologyChengdu 610059China College of Geological Engineering and Geomatics Chang’an UniversityXi’an 710054China Key Laboratory of Western China’s Mineral Resource and Geological Engineering Ministry of EducationXi’an 710054China School of Mathematics Statistics&PhysicsNewcastle UniversityNewcastle upon Tyne NE17RUUK Mullard Space Science Laboratory Department of Space and Climate PhysicsUniversity College LondonHolmbury St Mary RH56NTUK School of Earth and Space Sciences Peking UniversityBeijing 100871China Key Laboratory of Crustal Dynamics Institute of Crustal DynamicsChina Earthquake AdministrationBeijing 100085China Beijing Earthquake Agency Beijing 100080China

In 2017,China’s central government approved the national strategy to build Xiong’an New Area(XNA,100 km southwest to Beijing),which was announced as a"millennium strategy"and a"demo area"for a sustainable,modern,and innovative urban ***’an will draw in as much as$380 billion investment and is expected to help accelerate the development of the wider Beijing-Tianjin-Hebei(Jingjinji)*** this paper,present subsidence in the XNA area is investigated using InSAR observations for the first *** 24 SAR images acquired by European Space Agency’s Sentinel-1 satellites during the period from June 2017 to July 2018 suggest that in the north of Xiong County,the subsidence rate reaches up to 90 mm/y,which is highly correlated with the exploitation of geothermal *** the construction in the XNA area will significantly accelerate and its high-quality development,the InSAR findings could provide valuable information for future sustainable urban planning and underground infrastructure construction.

关键词： Xiong’an New Area subsidence InSAR geothermal heating Sentinel-1

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DAMAGE MECHANICS MODEL PREDICTING METALLIC MINE subsidence

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中国有色金属学会会刊：英文版 1993年第1期3卷 16-21页

作者： Yin, Deqian Zeng, Zhuoqiao Ko, Xinjian Central South University of Technology, Changsha 410083, China

The mine subsidence and ground movement is a complicated mechanical phenomenon. Based on the rock mass being a part of the geologic body suffering deformation and failure, whereas mine subsidence is a phenomenon of rock mass redeformation and refailure, the damage mechanics model for predicting metallic mine subsidence and a planar finite element program considering the damage are proposed; The organizations and rules of metallic mine subsidence are studied. The numerical results agree nicely with the observed data.

关键词： mine subsidence damage mechanics Elastic Finite Element (FEM)

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