Numerical Analysis of Slot Stability during the Supper-Deep Diaphragm Wall Construction

2013 ◽  
Vol 438-439 ◽  
pp. 1043-1047
Author(s):  
Bao Zhu Yang ◽  
Shu Chao Zhang ◽  
Kai Yun Luan
Keyword(s):  
Specific Gravity ◽  
Numerical Models ◽  
Silty Sand ◽  
Diaphragm Wall ◽  
Silty Clay ◽  
Soil Cement ◽  
Guide Wall ◽  
Wall Construction ◽  
Subway Stations ◽  
The Stability

Two subway stations of line Z1 were built in Tianjin cultural center and Tianjin Yujiapu traffic hub. The diaphragm wall depth of the two stations was more than 60 m. The geological and hydraulic conditions were different in the two site. Keeping stability of slot wall was the key of supper-deep diaphragm wall construction to the both stations. Two 3D numerical models were built by ABQUS software to simulate the grooving process. The conditions of different slurry specific gravity and grooving depth were calculated. The deformation laws of the slot wall and ground settlement around the slot wall were studied. The results showed the upper soft silty clay and deeper silty sand layers were easy collapse. Finally, some technologies such as "] [" type guide wall, properly improving slurry specific gravity, soil cement mixing reinforcement were suggested to improve the stability during the diaphragm wall construction of the two stations.

Construction Techniques of Deep Diaphragm Wall in the Yellow River-Crossing Project in South-to-North Water Transfer

2011 ◽  
Vol 250-253 ◽  
pp. 1212-1216
Author(s):  
Da Hu Rui ◽  
Qing Hong Wu ◽  
Zhen Feng Cao ◽  
Yu Xia Zhao ◽  
Guang Fan Li
Keyword(s):  
Yellow River ◽  
Water Transfer ◽  
Diaphragm Wall ◽  
Shield Tunnel ◽  
Medium Sand ◽  
Construction Techniques ◽  
Geological Conditions ◽  
North Bank ◽  
Guide Wall ◽  
North Water

Yellow River-Crossing Project in South-to-North Water Transfer approach through the use of shield tunnel and its north bank departure shaft adopts diaphragm wall as enclosure structure. The depth of continuous wall of its shielding starting shaft is 76.6m, which is the deepest at present in china. The continuous diaphragm wall travels through the layer of silver sand, medium sand and loam from top to bottom, where the geological conditions are poor with large difficulty of construction. This paper sets forth construction of guide wall, reinforcing measures before construction, Trenching process, groove segment connections, innovative technologies of uplifting huge reinforcing cage and so on, which will provide guidance and lessons for the similar project

Analysis of Global Stability, Anchor Spacing, and Support Cable Loads in Wire Mesh and Cable Net Slope Protection Systems

2005 ◽  
Vol 1913 (1) ◽  
pp. 205-213 ◽  
Author(s):  
Navaratnarajah Sasiharan ◽  
Balasingam Muhunthan ◽  
Shanzhi Shu ◽  
Thomas C. Badger
Keyword(s):  
Numerical Models ◽  
Wire Mesh ◽  
System Failures ◽  
Design Elements ◽  
The Past ◽  
Protection Systems ◽  
Vertical Support ◽  
Stability Of Slope ◽  
The Stability ◽  
Horizontal Support

Wire mesh and cable net slope protection have been in use for more than 50 years along North American highways to control rockfall on actively eroding slopes. The basic design of these systems is comparatively similar throughout North America. It consists of a top horizontal cable suspended by regularly spaced anchors, typically a perimeter or widely spaced grid of horizontal and vertical support cables, and double-twisted, hexagonal wire mesh laced to the support ropes. To date, the design of the slope protection systems has been based primarily on empirical methods, engineering judgment, and experience. Although these systems generally perform well, there is some consensus among geotechnical specialists that some elements in the system may be overdesigned or even unnecessary. In addition, system failures under a variety of loading conditions within the past few decades indicate that certain design elements may in fact be underdesigned for their desired application. Analytical and numerical models to evaluate the stability of slope protection systems are presented. The inclusion of interior horizontal support ropes in addition to the top horizontal rope does not reduce the stress within the mesh and accordingly provides no mechanical benefit. Results also show that the stresses on the vertical support rope are much smaller than the top horizontal support rope. Therefore, the vertical ropes do not need to be as strong as the top horizontal rope. Further, some useful design charts for the design of slope protection system are presented.

scholarly journals Review on Lateral Stability of Piled Riverine Structures in the Estuaries of Sarawak

2018 ◽  
Vol 7 (3.18) ◽  
pp. 21
Author(s):  
Lee Lin Jye ◽  
Shenbaga R. Kaniraj ◽  
Siti Noor Linda bt Taib ◽  
Fauzan Bin Sahdi
Keyword(s):  
Soft Soil ◽  
Natural State ◽  
Soil Conditions ◽  
Silty Clay ◽  
River Bank ◽  
Soil Movement ◽  
Geotechnical Problem ◽  
Construction Activity ◽  
Lateral Soil Movement ◽  
The Stability

Soft soil conditions with very soft and deep silty clay have constantly endangered the stability of the riverine and estuarine structures in Sarawak. There have been many failures of jetties, wharves and bridges in Sarawak. In many cases of failures, the piles were not designed to resist the lateral movement, unless they were included to stabilize unstable slopes or potential landslides. This practice may be due to reasons such as erroneously judging the river bank as stable in slope stability analysis or simply due to the inexperience of designers. Also, when the river bank approaches the limiting stability in its natural state any construction activity on the river bank could result in lateral soil movement. This paper highlights this important geotechnical problem in Sarawak. Then it presents the details of a few failures of estuarine structures. A review of situations causing lateral loading of piles is then presented. The results of the in-soil and in-pile displacement measurements are shown in this paper and it is found that the computation made to compare between field and 3D modeling is agreeable.  

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