Influence of existing shield tunnels on the stability of adjacent slurry trench

2021 ◽  
Author(s):  
Zhihe Liu ◽  
Chunbai Zhu ◽  
Nianwu Liu ◽  
Zhi Ding
Keyword(s):  
Slurry Trench ◽  
The Stability

The Slurry Trench Cut-off for the Duncan Dam

1971 ◽  
Vol 8 (1) ◽  
pp. 94-108 ◽  
Author(s):  
D. R. Duguid ◽  
D. J. Forbes ◽  
J. L. Gordon ◽  
O. K. Simmons
Keyword(s):  
Stability Analysis ◽  
No Reduction ◽  
Differential Settlement ◽  
Slurry Trench ◽  
Hydrostatic Head ◽  
The Stability

A slurry trench cut-off was constructed for the Duncan Dam. Two failures of the trench wall occurred during construction, one of which required relocation of a portion of the cut-off to avoid delaying construction of the dam. The relocated cut-off was successfully constructed from a higher ground elevation, using a denser slurry, produced by mixing in more silt. To analyze the failures a nomograph was developed which can be used to determine the required slurry density for trench wall stability. The stability analysis, first developed by Morgenstern and Amir-Tahmasseb was confirmed. The hydrostatic head drop across the cut-off varies from 85 to 90 % of the gross head on the dam. Differential settlement of almost 10 ft (3 m) has occurred along the cut-off after completion without detrimental effects. Readings over the last 3 years indicate no reduction in the efficiency of the cut-off.

A full-scale stability experiment on a diaphragm wall trench

2000 ◽  
Vol 37 (2) ◽  
pp. 379-392 ◽  
Author(s):  
Jiin-Song Tsai ◽  
Lee-Der Jou ◽  
Hsii-Sheng Hsieh
Keyword(s):  
Full Scale ◽  
Failure Pattern ◽  
Diaphragm Wall ◽  
Lateral Deformation ◽  
Sandy Ground ◽  
Stability Experiment ◽  
Scale Field ◽  
Slurry Trench ◽  
Scale Experiment ◽  
The Stability

This paper presents the results of a full-scale field experiment on the stability of a slurry-filled diaphragm wall trench. The objective of this experiment was to observe the failure pattern of a slurry-supported trench excavated in sandy ground. Ground responses, including settlement and lateral deformation of the surrounding ground adjacent to the experimental trench, were carefully monitored during the experiment. The stability of the trench was examined by lowering the slurry level in stages. The trench was deliberately failed. Field observations indicated that the experimental trench failed in 2 h in a progressive sliding pattern that resulted in a near-hemispherical cave-in of the adjacent ground. In this paper, a failure mechanism of the trench is proposed and an analytical method is adopted to back-analyze the stability of the trench. The stability of the trench and the failure pattern can be accurately analyzed using the method of Tsai and Chang.Key words: full-scale experiment, field test, slurry trench, stability analysis.

Three-dimensional stability analysis for slurry-filled trench wall in cohesionless soil

1996 ◽  
Vol 33 (5) ◽  
pp. 798-808 ◽  
Author(s):  
Jiin-Song Tsai ◽  
Jia-Chyi Chang
Keyword(s):  
Stability Analysis ◽  
Stability Problem ◽  
Slip Surface ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Soil Mass ◽  
Cohesionless Soil ◽  
Cohesionless Soils ◽  
Slurry Trench ◽  
The Stability

On the basis of the limiting equilibrium and arching theory, a three-dimensional analysis is proposed for slurry-supported trenches in cohesionless soils. This analytical approach is developed by considering the trench stability problem as a vertical soil cut within a fictitious half-silo with a rough wall surronding. Arching effects are considered not only in the vertical direction but also in the horizontal direction. A shell-shaped slip surface of the sliding soil mass is defined by Mohr-Coulomb criterion. The factor of safety is defines as the ratio of the resisting force induced by slurry pressure to the horizontal force required to maintain the stability of the trench wall. Results of the proposed method have been compared with those of two existing analytical methods for a typical trench stability problem. Key words: stability analysis, slurry trench wall, cohesionless soil.

The Stability of a Slurry Trench in Cohesionless Soils

Géotechnique ◽  
1965 ◽  
Vol 15 (4) ◽  
pp. 387-395 ◽  
Author(s):  
N. Morgenstern ◽  
I. Amir-Tahmasseb
Keyword(s):  
Cohesionless Soils ◽  
Slurry Trench ◽  
The Stability

scholarly journals Stability Analysis of a Slurry Trench in Cohesive-Frictional Soils

2019 ◽  
Vol 11 (1) ◽  
pp. 888-900
Author(s):  
Wei Li ◽  
Chengping Zhang
Keyword(s):  
Local Stability ◽  
Failure Process ◽  
Failure Mechanisms ◽  
Three Dimensional ◽  
Local Failure ◽  
Underground Engineering ◽  
Strength Reduction Technique ◽  
Slurry Trench ◽  
The Stability ◽  
Rotational Failure

Abstract The slurry trench has become increasingly common in underground engineering and the stability of a slurry trench has been an important design issue. Although many studies have focused on the overall stability of a slurry trench, few of that are related to its local stability. Based on the limit analysis, both two dimensional and three dimensional rotational failure mechanisms for the local failure of a slurry trench in a sandwiched weak layer are proposed, and the upper solutions of 2D and 3D safety factors for local failure mechanisms are derived to evaluate the stability of a slurry trench. Moreover, a numerical analysis combined with the strength reduction technique is performed to investigate the local stability and the local failure process of a slurry trench. The proposed analytical method is verified through the comparison with the results of FLAC3D. Finally, a parametric study on the influences of geometric and geologic parameters on the local stability of the slurry trench are investigated. The results show that the investigation on the local stability of a slurry trench is effective and reasonable, which can provide a reference for the engineers in the practical engineering.

scholarly journals Application of a 3-D Limit Equilibrium Method for Evaluation of the Stability of Slurry Trench Walls.

2000 ◽  
pp. 29-35
Author(s):  
Keizo UGAI ◽  
Takeshi ISHII ◽  
Kunio SAITO ◽  
Shuji TOMITA ◽  
Takashi SAITO ◽  
...  
Keyword(s):  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Equilibrium Method ◽  
Slurry Trench ◽  
The Stability

Design, construction, and performance of a slurry trench wall next to foundations

1977 ◽  
Vol 14 (3) ◽  
pp. 324-339
Author(s):  
Peter Rosenberg ◽  
G. St.-Arnaud ◽  
N. L. Journeaux ◽  
H. Vallée
Keyword(s):  
Ground Level ◽  
Engineering Problem ◽  
Existing Structures ◽  
Slurry Trench ◽  
Below Ground ◽  
Crack Movement ◽  
And Performance ◽  
The Stability ◽  
Two Stages ◽  
Design Construction

The stability of excavations adjacent to existing structures is an engineering problem and challenge. With the amount of construction increasing many such excavations are being planned and constructed. This paper documents the design, construction, and performance of a tied-back retaining system constructed by the slurry trench method. The system was necessary to retain the sides of a 30-ft (9.1-m) deep cut in glacial till immediately adjacent to the heavily loaded foundations of historically important and settlement sensitive structures. The main structures next to the excavation included the façade of the south transept and the 266-ft (81.1-m) high steeple of St. Jacques Church. Foundation loads imposed by these structures vary from 5.5 to 6.5 tons/ft2 (527–622 kPa)at a depth of 5 ft (1.5 m) below ground level. The slurry trench, up to 50 ft (15.3 m) in depth, approached to within 8 ft (2.44 m) of these foundations. Excavation was in two stages with tiebacks holding the wall at each level. The slurry trench and surrounding structures were instrumented using settlement points, crack movement devices, horizontal measurement points, inclinometers, and load cells. The soil investigation and design methods adopted are described.

Open discussion

1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti
Keyword(s):  
Buenos Aires ◽  
Large Mass ◽  
List Type ◽  
Common Phenomenon ◽  
Open Discussion ◽  
The Stability ◽  
Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

Symmetric Multistep Methods Revisited: II. Numerical Experiments

1999 ◽  
Vol 173 ◽  
pp. 309-314 ◽  
Author(s):  
T. Fukushima
Keyword(s):  
Multistep Methods ◽  
Computational Time ◽  
Integration Time ◽  
Implicit Methods ◽  
Symmetric Methods ◽  
Celestial Bodies ◽  
The Stability ◽  
Predictor Corrector ◽  
Symmetric Multistep Methods ◽  
Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

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