scholarly journals Prediction of Ground Subsidence During Underground Construction of Metro Line 2, Section 1, Ben Thanh - Tham Luong

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Nhat Luan VO ◽  
Thi Nu NGUYEN ◽  
Minh Toan DO
Keyword(s):  
Geological Structure ◽  
Surface Settlement ◽  
Ground Subsidence ◽  
Ho Chi Minh City ◽  
Deep Excavation ◽  
Ground Settlement ◽  
Underground Construction ◽  
Structure Characteristics ◽  
Shape And Size ◽  
Element Method

Urban metro line No. 2 from An Suong station to Thu Thiem is one of the six metro lines thatis planned to be built in Ho Chi Minh City (HCMC). The metro line goes through the area in which thestratigraphy consists of many units, distributed from 20-80 m. The hydrogeology mainly has 2 aquifers,namely Holocene, and Pleistocene which affecting the deep excavation. During construction, there willbe some problems that will affect the work on the surface such as settlement, cracking, and damage. Byfinite element method on Plaxis software, the article forecasts the surface settlement during this metroline No.2. The results show that the ground settlement is relatively large in areas with soft groundstructures. The settlement results depend on the geological structure characteristics, hydrogeologicalcharacteristics, and the shape and size of the tunnels.

An estimation of ground settlement due to shield tunnelling by the Peck–Fujita method

1994 ◽  
Vol 31 (3) ◽  
pp. 431-443 ◽  
Author(s):  
Y.S. Fang ◽  
J.S. Lin ◽  
C.S. Su
Keyword(s):  
Field Measurement ◽  
Measurement Data ◽  
Field Measurements ◽  
Empirical Method ◽  
Surface Settlement ◽  
Ground Subsidence ◽  
Ground Settlement ◽  
Induced Field ◽  
Ground Conditions ◽  
Shield Tunnelling

In this paper, an empirical method based on Peck and Fujita's study is proposed to estimate the magnitude and extent of surface settlement associated with shield tunnelling. It is found that the ground-settlement curves calculated with the proposed method for various types of shields, ground conditions, tunnel diameters, and depths are in reasonably good agreement with field measurements. For open shields tunnelled through clayey soils, the stability ratio has a significant influence on the surface settlement induced. Field measurement data suggest that the Peck–Fujita method may be used to estimate the ground subsidence associated with the construction of parallel tunnels. Key words : empirical method, field measurement, settlement, soft ground, tunnelling.

scholarly journals Original subsidence in Saigon South and relationship between subsidence with Holocene layer

2017 ◽  
Vol 20 (K4) ◽  
pp. 103-112
Author(s):  
Tu Anh Tran ◽  
Quan Minh Vo ◽  
Nam Giang Nguyen ◽  
Phong Thanh Le ◽  
Long Thanh Vo ◽  
...  
Keyword(s):  
Calculation Method ◽  
Soil Layer ◽  
Urban Infrastructure ◽  
Geological Structure ◽  
Current Situation ◽  
Ground Subsidence ◽  
Ho Chi Minh City

Sai Gon South is the gateway area being focused on developing urban infrastructure of Ho Chi Minh city. However this area have a low-lying terrain and weak geological structure. Therefore the subsidence problems are very serious now due to the urbanization. There is few research obtained to the effects of subsidence in this area the study has been carried out to assess the current situation and forecast the ground subsidence in this area. The study used the geo-statistics method of Kriging and calculation method for subsidence. The interpolated results of 167 boreholes showed the geologycal weakness of the soil layer from 6.5 to 35m which has correlation with the subsidence. (Coefficient r2 = 0.7).

scholarly journals Quantifying Horizontal and Vertical Movements in Ho Chi Minh City by Sentinel-1 Radar Interferometry

2020 ◽  
Author(s):  
Dinh Ho Tong Minh ◽  
Yen-Nhi NGO ◽  
Thu Trang Lê ◽  
Trung Chon Le ◽  
Hong Son Bui ◽  
...  
Keyword(s):  
Time Series ◽  
Large Scale ◽  
European Space Agency ◽  
Ground Subsidence ◽  
Ho Chi Minh City ◽  
Vertical Movements ◽  
Space Agency ◽  
Permanent Scatterers ◽  
The City ◽  
East West

Ho Chi Minh City (HCMC), the most populous city and the economic center of Viet Nam, has faced ground subsidence in recent decades. This work aims at providing an unprecedented spatial extent coverage of the subsidence in HCMC in both horizontal and vertical components using Interferometric Synthetic Aperture Radar (InSAR) time series. For this purpose, an advanced InSAR technique PSDS (Permanent Scatterers and Distributed Scatterers) was applied to two big European Space Agency (ESA) Sentinel-1 datasets composed of 96 ascending and 202 descending images, acquired from 2014 to 2020 over HCMC area. A time series of 33 Cosmos SkyMED images was also used for comparison purpose. The combination of ascending and descending satellite passes allows the decomposition of the light of sight velocities into horizontal East-west and vertical components. By taking into account the presence of the horizontal East-west movement, our finding indicates that the precision of the decomposed vertical velocity can be improved up to 3 mm/year for Sentinel-1 data. The obtained results revealed that subsidence is most severe in areas along the Sai Gon river in the northwest-southeast axis and the southwest of the city with the maximum value up to 80 mm/year, consistent with findings in the literature. The magnitude of horizontal East-West velocities is relatively small and a large-scale westward motion can be observed in the northwest of the city at a rate of 2-5 mm/year. Together, these results reinforced the remarkable suitability of ESA's Sentinel-1 SAR for subsidence applications even for non-Europe countries such as Vietnam and Southeast Asia.

scholarly journals Investigation on Dewatering of a Deep Shaft in Strong Permeable Sandy Pebble Strata on the Bank of the Yellow River

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yuchao Zheng ◽  
Jianyong Lei ◽  
Fei Wang ◽  
Liang Xiang ◽  
Jianfeng Yang ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Yellow River ◽  
Pumping Test ◽  
The Yellow River ◽  
Construction Process ◽  
Deep Excavation ◽  
Ground Settlement ◽  
High Permeability ◽  
Reverse Analysis ◽  
Table Versus

This paper reports the dewatering scheme of a deep excavation in sandy pebble strata. The excavation is in high permeability strata and is close to the Yellow River, making the dewatering difficult during construction. At present, few researchers have specially studied the dewatering scheme of deep excavations in strong permeable strata near the water resource. Field pumping test was conducted before the excavation activity, and the permeability coefficient of the strata was obtained by reverse analysis. According to the characteristics of the project, the dewatering scheme of “ waterproof   curtain + base   grouting + pumping ” was proposed. The influence of vertical waterproof curtain and base grouting on dewatering was analyzed by numerical simulation. In the construction process, the field water table and ground settlement were measured. The results show that (1) the groundwater table versus permeability coefficient curve shows three different stages and (2) the dewatering scheme of “ waterproof   curtain + base   grouting + pumping ” is effective for deep excavation in strong permeable strata.

scholarly journals Choice of technologies of ensuring exploitation suitability of buildings in the underground construction area

Vestnik MGSU ◽  
2020 ◽  
pp. 452-461
Author(s):  
Emil Imran Оglu Alirzaev ◽  
Marina E. Dement'eva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
The Finite Element Method ◽  
Underground Construction ◽  
Underground Structures ◽  
Stress Strain ◽  
Computer Complex ◽  
Stress Strain State ◽  
Element Method

Introduction. One of the serious problems in the construction of underground structures in a dense urban area is the occurrence of excess deformations of the foundations of operating buildings that fall into the zone of influence of underground construction. The subject of the study was the calculated justification of the modern technology of compensatory injection. The relevance of the task is determined by the fact that the choice of the most effective protection technology should be based not only on a comparison of technological precipitation with maximum permissible values, but also on the assessment of the possibility of monitoring and controlling the movements of the foundations of buildings and structures during construction and subsequent operation. The purpose of the study was to compare various methods of protecting the foundations of existing buildings and structures and justify the selection of the most effective of them for further implementation and dissemination in the design and construction of urban underground structures. Materials and methods. On the basis of the survey data of the operated building falling into the impact zone of excavation of the pit for the construction of the installation and shield chamber of the subway, the parameters of the stress-strain state of its foundations are studied by mathematical modeling. The problem was solved by the finite element method based on the software and computer complex Z_Soil v.18.24. Results. Based on the analysis of the results of the examination of the administrative building using the finite element method, a change in the parameters of the stress-strain state of the foundations was modeled with various technologies for strengthening it. In the course of solving the geotechnical problem, it was found that the minimum impact on the foundations of the building during the construction of the pit was obtained in the method of compensatory injection. The system of criteria for making a decision on choosing an effective way to ensure the suitability of buildings in the underground construction zone for operation is substantiated. Conclusions. The results of this work can be used to justify the choice of technology for prevention and control of excess deformations of foundations. The function for calculating the volume of injected material in the Z_Soil software and computer complex can be used to justify the consumption of materials and the economic efficiency of the technological solution.

scholarly journals Analysis of the Additional Stress and Ground Settlement Induced by the Construction of Double-O-Tube Shield Tunnels in Sandy Soils

2019 ◽  
Vol 9 (7) ◽  
pp. 1399 ◽  
Author(s):  
Wen Zhao ◽  
Peng-jiao Jia ◽  
Lin Zhu ◽  
Cheng Cheng ◽  
Jianyong Han ◽  
...  
Keyword(s):  
Ground Surface ◽  
Field Measurements ◽  
Surface Settlement ◽  
Additional Stress ◽  
Underground Construction ◽  
Shield Tunneling ◽  
Engineering Project ◽  
Ground Surface Settlement ◽  
Potential Damage ◽  
Lateral Friction

Double-O-tube shield tunneling has attracted increasing attention because it offers cost-efficiency in underground construction. Prediction of ground surface settlement and the variety of additional stresses induced by shield construction is crucial to underground construction in metropolises since excessive settlement could trigger potential damage to the surrounding environment. The additional stresses induced by the propulsion of double-O-tube shields are calculated by means of the Mindlin’s equations of elasticity. The characteristics of additional stresses are analyzed with compound Gauss-Legendre integral arithmetic, and the frontal additional thrust, the lateral friction, and the ground loss are taken into account. Subsequently, based on field measurements, the maximum settlement coefficient and width of the settlement trough coefficient of the typical Peck formula are modified. The predictive curve of the Peck formula is closer to the engineering measured data than that of the typical formula. The cut-off functions of ground surface settlement caused by double-O-tube tunnel shield construction are proposed and can predict the shape of ground surface settlement, such as single peak or double peak. The correctness of the proposed functions is verified based on an engineering project.

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