- Performance of CAPS Method Considering its Interaction with Adjacent Structures - The Q7 Station of Tehran Metro Line 7
- Behnam Eslami ; Aliakbar Golshani
- Book Title / Journal: International Journal of Geoengineering Case Histories
- Year: 2018 , Volume: 4
- Underground Structures
- Keywords: Surface settlement ; CAPS method ; Q7 station ; λ factor ; FLAC3D ; numerical simulation
- Abstract
In recent years, innovative underground construction techniques have been extensively utilized for many purposes in Iran. Using construction methods such as CAPS (concrete arc pre-supporting system) in the case of nearby special structures is regarded as a valuable technique. CAPS technique applied in this work is a supporting system implemented in urban areas, where the excavation-induced distribution of the soil settlement is considerably lower compared to other sequential excavation (SEM) methods. Our case study is Q7 station, which is an intersection station in Tehran metro line 7 located near Tohid Twin Tunnel and Gardoon Tower. Based on investigations carried out and presented in this paper, CAPS demonstrates an excellent performance and serviceability for structures located within congested urban areas. Q7 station was modeled using FLAC3D code. To ensure the accuracy of our model, monitoring data were compared with the numerical results. By performing sensitivity analysis on the shear parameters of the rehabilitated soil (c, φ) and the distance between beam elements (λ factor), we observed that increasing the shear parameters of the soil mass decreases the vertical displacement of the ground. The optimum value for the λ factor was estimated in this work based on the Rankin criteria for Gardoon Tower (a 20-story building) and Tohid Twin Tunnel. PDF |
- Uplift of an Underground Tank in Northern Malabar Region, India
- Nilesh P. Shirode ; Kedar C. Birid ; S. R. Gandhi ; Rajesh Nair
- Book Title / Journal: International Journal of Geoengineering Case Histories
- Year: 2017 , Volume: 4
- Underground Structures ; Laboratory Testing ; GPR ; Geophysics
- Keywords: uplifting ; hydrogeological survey ; hydrostatic pressure ; Ground Penetrating Radar ; seismic refraction
- Abstract
An underground reinforced concrete tank was constructed for a project in the southwest region of India. The tank was 90 m x 35 m in plan and 7.3 m deep resting on partly filled-up and partly native soil. During the peak monsoon, a sudden uplifting of the base slab by about 300 mm and subsequent failure of the foundation raft and a partition wall was observed. Laboratory testing was executed and hydrogeological survey was carried out using ground penetrating radar, seismic refraction and infiltrometer testing, and an analytical study was carried out to identify the root cause of the tank uplifting. Based on this study, it was observed that the uplifting and structural failure was essentially due to the peculiar land terrain and soil properties and the development of excess hydraulic head below the bottom of the tank. After considering different options, the rectification measures were carried out by provision of dewatering wells along the tank periphery to release the excess hydrostatic pressure and stabilize the foundation raft. The structural repair of the top of the foundation raft and partition wall was carried out to strengthen the reinforced concrete members. The rectification measures worked well to increase the structural stability of the tank and to prevent build-up of excess hydrostatic pressure preventing uplift and subsequent damage in the future. PDF |
- Soil Constitutive Models to Simulate Pipeline-soil Interaction Behaviour
- D Robert ; K. Soga ; A Britto
- ICGE Colombo 2015
- Year: 2015
- Numerical & Constitutive Modeling ; Underground Structures
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- Numerical Modeling of Long-Term Performance of Buried Pipes
- H.J. Siriwardane ; S.B.K. Varre ; R.K. Gondle
- ICGE Colombo 2015
- Year: 2015
- Numerical & Constitutive Modeling ; Underground Structures
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- 3D numerical back-prediction of tunnelling-induced settlements on an existing reinforced concrete building
- A. Amorosi ; D. Boldini ; V. Fargnoli
- Year: 2015
- Tunneling ; Underground Structures
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- Tunnel face stability investigation by means of 3D numerical analysis and hand calculations
- D. Borbely ; R. Lorincz
- Year: 2015
- Tunneling ; Underground Structures
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- Predictive tools for the ground deformation induced by EPB tunnelling: a comparative study
- M. Ochmanski ;
- Year: 2015
- Tunneling ; Underground Structures
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- Monitoring dataset of deformations related to deep excavations for North-South Line in Amsterdam
- M. Korff ; F. J. Kaalberg
- IS SEOUL '14
- Year: 2014
- Deep Excavations ; Underground Structures ; Instrumentation
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- Settlements of buildings and buried pipelines induced by adjacent deep excavation in Shanghai soft ground
- Y. P. Dong ; H. J. Burd ; G. T. Houlsby
- IS SEOUL '14
- Year: 2014
- Settlements ; Underground Structures ; Deep Excavations
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- Relevant relations in order to better assess preconsolidation pressure values for the design of underground constructions in soft ground
- J. C. Gress
- IS SEOUL '14
- Year: 2014
- Underground Structures ; Site Characterization & In-situ Testing (General)
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- A field case study on construction of underground passageway with non-open excavation method
- Y. -S. Jang ; S. Shin ; J. H. Heo
- IS SEOUL '14
- Year: 2014
- Transportation Geotechnics ; Underground Structures
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- Case study of deep excavation in existing underground structure of three-story basement and diaphragm wall
- C. J. Kuo ; Y. K. Lin ; C. L. Hung ; S. S. Lin
- IS SEOUL '14
- Year: 2014
- Deep Excavations ; Underground Structures ; Earth Retaining Structures
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- Impact of in situ stresses on underground cavern design
- K. F. Chan ; P. C. Stone
- IS SEOUL '14
- Year: 2014
- Underground Structures ; Numerical & Constitutive Modeling
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- A preliminary study on the structural stability of room-and-pillar underground structures
- C. Lee ; H. -S. Shin ; S. -H. Chang
- IS SEOUL '14
- Year: 2014
- Underground Structures
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- Underground space planning in Helsinki
- A. Vähäaho
- Year: 2014 , Volume: 6
- Tunneling ; Underground Structures
- Keywords: land use planning ; underground resources
- Description
- This paper gives insight into the use of underground space in Helsinki, Finland. The city has an underground master plan (UMP) for its whole municipal area, not only for certain parts of the city. Further, the decision-making history of the UMP is described step-by-step. Some examples of underground space use in other cities are also given. The focus of this paper is on the sustainability issues related to urban underground space use, including its contribution to an environmentally sustainable and aesthetically acceptable landscape, anticipated structural longevity and maintaining the opportunity for urban development by future generations. Underground planning enhances overall safety and economy efficiency. The need for underground space use in city areas has grown rapidly since the 21st century; at the same time, the necessity to control construction work has also increased. The UMP of Helsinki reserves designated space for public and private utilities in various underground areas of bedrock over the long term. The plan also provides the framework for managing and controlling the city's underground construction work and allows suitable locations to be allocated for underground facilities. Tampere, the third most populated city in Finland and the biggest inland city in the Nordic countries, is also a good example of a city that is taking steps to utilise underground resources. Oulu, the capital city of northern Finland, has also started to ‘go underground’. An example of the possibility to combine two cities by an 80-km subsea tunnel is also discussed. A new fixed link would generate huge potential for the capital areas of Finland and Estonia to become a real Helsinki-Tallinn twin city.
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