scholarly journals Investigation of Groundwater Withdrawal and Recharge Affecting Underground Structures in the Shanghai Urban Area

2019 ◽  
Vol 11 (24) ◽  
pp. 7162 ◽  
Author(s):  
Yong-Xia Wu ◽  
Tian-Liang Yang ◽  
Pei-Chao Li ◽  
Jin-Xin Lin
Keyword(s):  
Land Subsidence ◽  
Urban Areas ◽  
Water Pressure ◽  
Underground Structure ◽  
Pressure Head ◽  
Groundwater Withdrawal ◽  
Underground Structures ◽  
Groundwater Head ◽  
Increased Risk ◽  
Confined Aquifers

In this paper, the hydrogeological features of Quaternary deposits in Shanghai as well as the characteristics of groundwater withdrawal and recharge in urban areas are investigated. One phreatic aquifer and five confined aquifers (AqI to AqV) are present in Shanghai, and these aquifers are separated by five aquitards. Groundwater withdrawal from confined aquifers has resulted in land subsidence in Shanghai. To control land subsidence, the groundwater withdrawal volume has been decreased, and the groundwater recharge volume has been increased since 1965. Correspondingly, the pressure head in confined aquifers has risen. The groundwater head increases in shallow aquifers may impact underground structures and lead to the following issues: i) an increased risk of water in-rushing hazards caused by confined water pressure during structural excavations and ii) an increased instability risk caused by groundwater buoyancy. Both excavation anti-uprush and underground structure anti-floating are discussed in this paper. Based on the risk possibilities, the anti-uprush of the excavation is divided into six regions, and the structural anti-floating is divided into five regions in urban areas. To avoid geohazards caused by the rise in groundwater head, real-time monitoring of the pressure head in AqII is recommended.

scholarly journals The Effect of Soil Reinforcement on the Stress and Strain Field Around Underground Square-Shaped Areas and its Internal Lining Efforts in Urban Areas

2018 ◽  
Vol 4 (11) ◽  
pp. 2756 ◽  
Author(s):  
Alireza Darvishpour ◽  
Asadollah Ranjbar ◽  
Amirmohammad Amiri
Keyword(s):  
Urban Areas ◽  
Underground Structure ◽  
Physical Modelling ◽  
Soil Reinforcement ◽  
Soil Parameters ◽  
Stress And Strain ◽  
Horizontal Distance ◽  
Underground Structures ◽  
Finite Element Software ◽  
Before And After

The passage of underground structures from the bottom of the structures on the ground causes a change in the stresses and strains created in the structure as well as the soil environment surrounding the tunnel due to the existence of an interaction between these two sides. In this way, the existence of the surface structure leads to a change in the strain and stress conditions around the tunnel, and in contrast, the tunnel also leads to a change in the stress and settlement around the structures. Therefore, such a reciprocal behavior is very important. In this research, with the help of Abaqus finite element software, two main possible conditions are considered: the creation of an underground structure in the presence of the superstructure, as well as the reverse state of the concept of constructing a building in the state in which the underground structure already exists. One of the subjects studied in this research is the physical modelling effect of the structure, rather than the effect of its wide load on the ground. Other parameters considered in this research are the number of story, the depth of the tunnel, the width of the tunnel, the thickness of the lining, the effect of changes in the soil parameters in the depth and the horizontal distance of the tunnel center from the building center. The results of this research are validated based on the results obtained by other researchers. According to the results obtained in this research, by the increase of the distance between the tunnel center and structure center and depending on the stiffness of the tunnel lining, significant asymmetric stresses are created in the superstructure. The construction of the structure before and after the tunnel construction can affect the unsymmetrical settlement of the structure The stress and strain created in the lining of the tunnel and the surrounding area are also different due to the amount of mobilized force in the reinforcements.

scholarly journals Chronological reflection on monitoring urban areas subsidence due to groundwater extraction

2019 ◽  
Vol 85 ◽  
pp. 07015 ◽  
Author(s):  
Alina Radutu ◽  
Radu Constantin Gogu
Keyword(s):  
Land Subsidence ◽  
Urban Areas ◽  
Urban Expansion ◽  
Groundwater Withdrawal ◽  
Groundwater Extraction ◽  
Monitoring Methods ◽  
Vertical Displacements ◽  
Order Of Magnitude ◽  
History Of ◽  
Subsidence Monitoring

Land subsidence affects urban areas worldwide. Sometimes it could be driven by intensive groundwater withdrawal to assure different urban needs and functionalities. Some of these urban areas have a long history of subsidence that covers almost a century. The aim of this paper is to present the evolution of several urban areas affected by land subsidence, the methods used to monitor vertical displacements along the decades in relationship to the groundwater extraction associated to the urban expansion, and the mitigation techniques used for countering the effects of intensive groundwater withdrawal. Even the originally applied subsidence monitoring methods (such as geometric levelling) are still very sensitive, in terms of time consuming, covered area, and financial effort, these methods might be complemented by new methods based on Synthetic Aperture Radar Interferometry (InSAR). InSAR methods show also a significant progress during the last decades when considering the subsidence sensed order of magnitude.

Lithological control of land subsidence induced by groundwater withdrawal in new urban AREAS (Granada Basin, SE Spain). Multiband DInSAR monitoring

2016 ◽  
Vol 30 (13) ◽  
pp. 2317-2331 ◽  
Author(s):  
Davide Notti ◽  
Rosa María Mateos ◽  
Oriol Monserrat ◽  
Nùria Devanthéry ◽  
Tomás Peinado ◽  
...  
Keyword(s):  
Land Subsidence ◽  
Urban Areas ◽  
Groundwater Withdrawal ◽  
Se Spain ◽  
Granada Basin

scholarly journals Land Subsidence Control Zone and Policy for the Environmental Protection of Shanghai

2019 ◽  
Vol 16 (15) ◽  
pp. 2729 ◽  
Author(s):  
Xi-Cun He ◽  
Tian-Liang Yang ◽  
Shui-Long Shen ◽  
Ye-Shuang Xu ◽  
Arul Arulrajah
Keyword(s):  
Land Subsidence ◽  
Urban Areas ◽  
Monitoring Network ◽  
Point Of View ◽  
Groundwater Withdrawal ◽  
Economic Losses ◽  
Control Zone ◽  
Sustainable Environment ◽  
Subsidence Monitoring ◽  
And Control

Land subsidence was once a major geo-hazard in the city of Shanghai, China. From 1921 to 1965, the maximum cumulative land subsidence in the urban areas of China reached 2.6 m. This large subsidence has resulted in high economic losses for Shanghai. The Regulation of Prevention and Control of Land Subsidence of Shanghai Municipality was published in 2013 (simply cited as the 2013-regulation in the following context). The characteristics of the 2013-regulation included the combination of the subsidence monitoring network and the groundwater detection network due to both the effects of groundwater withdrawal and construction. In addition, the setting up of a supervision system was also incorporated in the 2013-regulation. To control the land subsidence, Shanghai demarcated three land subsidence control zones, where special measures have been implemented. From a strategic environmental assessment (SEA) point of view, the 2013-regulation attains a high total score, indicating that the control of groundwater withdrawal and recharge is effective. The observed land subsidence over the past six years also confirms the effectiveness of the 2013-regulation with the most consideration of SEA for sustainable environment protection in Shanghai. However, more effort should be made in the implementation of SEA in land subsidence control in the future.

Influence of Soil Consolidation History on Seismic Response of Underground Structure in Layered Liquefiable Ground

2013 ◽  
Vol 639-640 ◽  
pp. 670-677
Author(s):  
Zhi Fan Xia ◽  
Yan Ling Zheng ◽  
Guan Lin Ye
Keyword(s):  
Constitutive Model ◽  
Pore Water ◽  
Yield Surface ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Underground Structure ◽  
Soil Consolidation ◽  
Underground Structures ◽  
Excess Pore Water Pressure ◽  
Excess Pore

It is shown that liquefaction induced uplift is one of the most typical disasters for underground structures in liquefiable zone. Though a lot of researches were conducted to investigate the uplift phenomenon of underground structures in the past years, further studies need to be carried out to discover its mechanism because the seismic responses were correlated with many factors. In the paper, a fully coupled dynamic analysis was performed to investigate the dynamic responses of underground structure in layered saturated ground. The soils were simulated by a cyclic mobility constitutive model, which adopted some important concepts such as stress induced anisotropy, subloading yield surface, and superloading yield surface. It was verified that the constitutive model can perfectly describe the dynamic character of both liquefiable sand and non-liquefiable clay. Simulated results were obtained for excess pore water pressure and deformation of soil deposit and uplift of underground structure. Special emphasis was given to discuss the influence of soil consolidation history on the seismic responses of underground structure. Simulation indicated that with the occurrence of liquefaction, soils at lateral sides of underground structure flowed toward the bottom of the structure, which led to the uplift of structure. Results also showed that the excess pore water pressure ratio of liquefiable soil decreased with the increasing of soil pre-consolidation pressure. Then the liquefied zones diminished, and the uplift of underground structure reduced.

The experience of monitoring the land subsidence in urban areas by radar satellite interferometry on the example of St. Petersburg

2020 ◽  
Vol 64 (4) ◽  
pp. 399-408
Author(s):  
Shirshova V. ◽  
Keyword(s):  
Land Subsidence ◽  
Urban Areas ◽  
Radar Satellite

Разработана и опробована методика мониторинга на основе метода радиолокационной спутниковой интерферометрии с применением открытых данных радиолокационного спутника Sentinel-1. Обработка радиолокационных снимков была реализована на открытом программном обеспечении SNAP. В результате были получены 40 карт вертикальных смещений города Санкт-Петербург. На основе геоинформационного программного обеспечения QGIS был произведен анализ полученных карт смещений и визуализация результатов интерферометрической обработки.

Factors that contribute to urban–rural gradients in risk of schizophrenia: Comparing Danish and Western Australian registers

2021 ◽  
pp. 000486742110096
Author(s):  
Oleguer Plana-Ripoll ◽  
Patsy Di Prinzio ◽  
John J McGrath ◽  
Preben B Mortensen ◽  
Vera A Morgan
Keyword(s):  
Confidence Interval ◽  
Western Australia ◽  
Urban Areas ◽  
Proportional Hazards ◽  
Cox Proportional Hazards ◽  
Hazard Ratio ◽  
Indigenous Status ◽  
Increased Risk ◽  
The Relationship ◽  
Western Australian

Introduction: An association between schizophrenia and urbanicity has long been observed, with studies in many countries, including several from Denmark, reporting that individuals born/raised in densely populated urban settings have an increased risk of developing schizophrenia compared to those born/raised in rural settings. However, these findings have not been replicated in all studies. In particular, a Western Australian study showed a gradient in the opposite direction which disappeared after adjustment for covariates. Given the different findings for Denmark and Western Australia, our aim was to investigate the relationship between schizophrenia and urbanicity in these two regions to determine which factors may be influencing the relationship. Methods: We used population-based cohorts of children born alive between 1980 and 2001 in Western Australia ( N = 428,784) and Denmark ( N = 1,357,874). Children were categorised according to the level of urbanicity of their mother’s residence at time of birth and followed-up through to 30 June 2015. Linkage to State-based registers provided information on schizophrenia diagnosis and a range of covariates. Rates of being diagnosed with schizophrenia for each category of urbanicity were estimated using Cox proportional hazards models adjusted for covariates. Results: During follow-up, 1618 (0.4%) children in Western Australia and 11,875 (0.9%) children in Denmark were diagnosed with schizophrenia. In Western Australia, those born in the most remote areas did not experience lower rates of schizophrenia than those born in the most urban areas (hazard ratio = 1.02 [95% confidence interval: 0.81, 1.29]), unlike their Danish counterparts (hazard ratio = 0.62 [95% confidence interval: 0.58, 0.66]). However, when the Western Australian cohort was restricted to children of non-Aboriginal Indigenous status, results were consistent with Danish findings (hazard ratio = 0.46 [95% confidence interval: 0.29, 0.72]). Discussion: Our study highlights the potential for disadvantaged subgroups to mask the contribution of urban-related risk factors to risk of schizophrenia and the importance of stratified analysis in such cases.

scholarly journals Utilization of Building Information Modeling for Arranging the Structural Kingposts

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 323
Author(s):  
Vachara Peansupap ◽  
Pisal Nov ◽  
Tanit Tongthong
Keyword(s):  
Underground Structure ◽  
Visual Programming ◽  
Information Modeling ◽  
Construction Technology ◽  
Underground Structures ◽  
Building Information Modelling ◽  
Engineering Knowledge ◽  
Building Information ◽  
Rule Based Approach

The kingpost was a vertical element that was used to support the structural strut in the deep excavation. The structural kingpost was commonly arranged by experienced engineers who used two-dimensional construction drawings. Thus, it was still time-consuming and error-prone. Currently, an available construction program has been developed to arrange the structural kingpost by identifying the clash problems in the 3D environment. However, they have a limitation for detecting the clash that was unable to visualize the concurrent clashes between kingpost and many underground structures. Then, the engineer cannot see all the clash incidents with each kingpost and move the kingpost to avoid the clashes successfully. Since the kingpost arrangement was still an inefficient practice that was limited in the visualization aspect, this research used engineering knowledge and advanced construction technology to detect and solve the clashes between kingposts and underground structures. The methodology used engineering knowledge of kingpost arrangement to develop the system modules by using a rule-based approach. Then, these modules were developed into the system by using visual programming of Building Information Modelling (BIM). To test the system, an underground structure from building construction was selected as a case study to apply the developed system. Finally, the finding of this study could overcome human judgment by providing less interaction in the kingpost arrangement and visualization improvement of clash occurrences in the 3D model.

Simple approach to obtain ground amplification motion of surface soil deposits with a radical change of depth

2005 ◽  
Vol 42 (2) ◽  
pp. 491-498
Author(s):  
Dae-Sang Kim ◽  
Kazuo Konagai
Keyword(s):  
Seismic Design ◽  
Surface Soil ◽  
Underground Structure ◽  
Free Field ◽  
Alluvial Soil ◽  
Radical Change ◽  
Simple Approach ◽  
Clear Understanding ◽  
Underground Structures ◽  
Soil Deposits

Earthquake observations at different sites within alluvial soil deposits have demonstrated that the motion of buried underground structures closely follows that of the surrounding soil. Therefore, it is usual in a seismic design process to apply free-field ground displacements through Winkler-type soil springs to an underground structure to evaluate stress patterns induced within its structural members. Using a simplified approach, this paper provides a clear understanding of resonant horizontal ground displacement of and strain in a surface soil deposit with a radical change of depth and of where they occur.Key words: simple approach, seismic design, earthquake, resonance, underground structures.

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