Influence of Tip Movements on Inclinometer Readings and Performance of Diaphragm Walls in Deep Excavations

2010 ◽  
Author(s):  
Hsiao-Chou Chao ◽  
Richard N. Hwang ◽  
Chung-Tien Chin
Keyword(s):  
Deep Excavations ◽  
Diaphragm Walls ◽  
And Performance

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 Prediction and Performance of Deep Excavations for Courthouse Station, Boston

2015 ◽  
Vol 141 (4) ◽  
pp. 04014123 ◽  
Author(s):  
Andrew J. Whittle ◽  
Gonzalo Corral ◽  
Lucy C. Jen ◽  
Robert P. Rawnsley
Keyword(s):  
Deep Excavations ◽  
And Performance

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.

Transmission Scanning Electron Microscopy and Energy Analysis with the Siemens ELMISKOP 101

1972 ◽  
Vol 30 ◽  
pp. 450-451
Author(s):  
H. M. Thieringer
Keyword(s):  
Objective Lens ◽  
Transmission Microscopy ◽  
Image Recording ◽  
Mode Of Operation ◽  
Scanning Transmission ◽  
Electron Microscopes ◽  
And Performance ◽  
Convergent Beam ◽  
Ray Path ◽  
Beam Diffraction

It has repeatedly been show that with conventional electron microscopes very fine electron probes can be produced, therefore allowing various micro-techniques such as micro recording, X-ray microanalysis and convergent beam diffraction. In this paper the function and performance of an SIEMENS ELMISKOP 101 used as a scanning transmission microscope (STEM) is described. This mode of operation has some advantages over the conventional transmission microscopy (CTEM) especially for the observation of thick specimen, in spite of somewhat longer image recording times.Fig.1 shows schematically the ray path and the additional electronics of an ELMISKOP 101 working as a STEM. With a point-cathode, and using condensor I and the objective lens as a demagnifying system, an electron probe with a half-width ob about 25 Å and a typical current of 5.10-11 amp at 100 kV can be obtained in the back focal plane of the objective lens.

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