On the Use of Numerical Methods for the Design of Deep Excavations with Diaphragm Walls in Urban Areas: Possibilities and Limitations

2010 ◽  
pp. 329-350
Author(s):  
P.A. Calderón
Keyword(s):  
Numerical Methods ◽  
Urban Areas ◽  
Deep Excavations ◽  
Diaphragm Walls

scholarly journals Hazard Reduction in Deep Excavations Execution

2022 ◽  
Vol 14 (2) ◽  
pp. 868
Author(s):  
Mateusz Frydrych ◽  
Grzegorz Kacprzak ◽  
Paweł Nowak
Keyword(s):  
Cost Optimization ◽  
Bridge Engineering ◽  
Diaphragm Wall ◽  
Modern Approach ◽  
New Approach ◽  
Deep Excavations ◽  
Ground Anchors ◽  
Calculation Methodology ◽  
Diaphragm Walls ◽  
Bridge Technology

In this article, the authors consider a completely new approach in design, which is related to the use of previously un-adapted technologies known to bridge engineering in geotechnical issues for prestressing of diaphragm wall during deep excavations execution. The bridge technology described here is the prestressing of concrete structures. Hazards related to deep excavations and methods of digging them, such as the ceiling method and top&down method, are presented. Current problems in supporting deep excavation slopes are related to the use of extensive quantities of materials (such as steel struts, ground anchors, or concrete and reinforcement steel). The authors’ method helps to achieve a higher level of sustainability, which is important in a modern approach to geotechnical engineering. The non-linear arrangements of the cables according to the occurrence of the prestressing moments for a given phase are presented. Results related to numerical analysis—showing the correctness of the method and cost optimization results, showing possible savings are presented. The article is a part of the set. In the second (already published) article titled “Modern Methods of Diaphragm Walls Design”, the authors present the concept of the calculation methodology for diaphragm wall design.

scholarly journals Deep excavation in urban areas – defects of surrounding buildings at various stages of construction

2018 ◽  
Vol 146 ◽  
pp. 02012 ◽  
Author(s):  
Jarosław Rybak ◽  
Alexander Ivannikov ◽  
Elena Kulikova ◽  
Tomasz Żyrek
Keyword(s):  
Urban Areas ◽  
Soil Mass ◽  
Technical Condition ◽  
Deep Excavation ◽  
Sheet Pile ◽  
Ground Anchors ◽  
New Construction ◽  
Diaphragm Walls ◽  
Wall Construction ◽  
City Centres

Deep excavation and tunnelling works in city centres always bring some risks to surrounding structures, especially in the case of old town centres, where the technical condition and structural stiffness of historical buildings is rather doubtful. When the new desired excavation depth goes deeper than the foundation of the surrounding buildings or when tunnelling works are conducted directly under them, the existing objects are subject to stress, vibrations and displacements imposed at almost every stage of building the new construction. The presented paper outlines, on the basis of the authors’ experience, the typical damages appearing during the supporting wall construction (sheet pile driving, piling and formation of diaphragm walls) and tunnelling works. Other damages appear due to soil mass unloading (caused by excavation stages) and horizontal loading during pre-stressing of struts or ground anchors. The selected case studies of steel sheet pile wall installation is given with regard to typical failures caused by an unplanned excavation and its impact on neighbouring structures.

scholarly journals Novel Excavation and Construction Method for a Deep Shaft Excavation in Ultrathick Aquifers

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Chengyong Cao ◽  
Chenghua Shi ◽  
Linghui Liu ◽  
Jianwen Liu ◽  
Mingfeng Lei ◽  
...  
Keyword(s):  
Ground Surface ◽  
Lateral Wall ◽  
The Novel ◽  
Deep Excavations ◽  
Deep Aquifers ◽  
Pumping Wells ◽  
Ground Surface Settlement ◽  
Innovative Solution ◽  
Diaphragm Walls ◽  
Drainage Technique

Dewatering using the dewatering systems composed of diaphragm walls and pumping wells is commonly adopted for deep excavations that are undertaken in deep aquifers. However, dewatering can sometimes induce environmental problems, especially when diaphragm walls cannot effectively cut off the aquifers. This paper mainly presents an innovative excavation technique combining dewatering excavation and underwater excavation without drainage, which is employed for a deep shaft excavation in ultrathick aquifers (up to 60–70 m thick aquifer) in Fuzhou, China. The shaft excavation with the depth of 41.6 m below the ground surface (BGS) is divided into two major phases, that is, (1) the first part of the excavation (the depth of 23.6 m BGS) is conducted by the way of conventional dewatering and braced excavation (Phase I) and (2) the second excavation with the depth of 23.6 m to 41.6 m BGS is carried out by the novel underwater excavation without drainage technique (Phase II). Field monitoring results show that the ratios of maximum ground surface settlement δvm to the excavation depth He in this case ranged from 0.03% to 0.1%. Most of the ratios of maximum lateral wall deflection δhm to excavation depth He are less than 0.1%. All these results are lesser than that predicted by empirical methods, which also confirmed the applicability of this innovative excavation. Thus, this innovative solution can be applicable to other deep excavations that are undertaken in ultrathick aquifers, especially for the excavation of coarse sediments with high permeability.

scholarly journals Intelligent Risk Assessment for Dewatering of Metro-Tunnel Deep Excavations

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
X. W. Ye ◽  
L. Ran ◽  
T. H. Yi ◽  
X. B. Dong
Keyword(s):  
Risk Assessment ◽  
Urban Areas ◽  
Design Method ◽  
Urban Traffic ◽  
Assessment System ◽  
Deep Excavation ◽  
Rapid Urbanization ◽  
Transit System ◽  
Deep Excavations ◽  
Metro Tunnel

In recent years, China has been undergoing a metro railway construction boom in order to alleviate the urban traffic congestion problem resulting from the rapid urbanization and population growth in many metropolises. In the construction of metro systems, deep excavations and continuous dewatering for construction of the metro tunnels and stations remain a challenging and high risk task in densely populated urban areas. Intelligent computational methods and techniques have exhibited the exceptional talent in dealing with the complicated problems inherent in the deep excavation and dewatering practice. In this paper, an intelligent risk assessment system for deep excavation dewatering is developed and has been applied in the project of Hangzhou Metro Line 1 which is the first metro line of the urban rapid rail transit system in Hangzhou, China. The specific characteristics and great challenges in deep excavation dewatering of the metro-tunnel airshaft of Hangzhou Metro Line 1 are addressed. A novel design method based on the coupled three-dimensional flow theory for dewatering of the deep excavation is introduced. The modularly designed system for excavation dewatering risk assessment is described, and the field observations in dewatering risk assessment of the airshaft excavation of Hangzhou Metro Line 1 are also presented.

Deep excavations in urban areas—finite element modelling for three geotechnical scenarios and retaining solutions

2012 ◽  
pp. 51-76 ◽  
Author(s):  
M de Matos Fernandes ◽  
A Cardoso ◽  
A Gomes ◽  
J Borges ◽  
N Guerra ◽  
...  
Keyword(s):  
Finite Element ◽  
Urban Areas ◽  
Finite Element Modelling ◽  
Deep Excavations ◽  
Element Modelling
Sign in / Sign up

Export Citation Format

Share Document