Design of Foundation Pit Retaining Structures

2019 ◽  
pp. 391-436
Author(s):  
Zhen-Dong Cui ◽  
Zhong-Liang Zhang ◽  
Li Yuan ◽  
Zhi-Xiang Zhan ◽  
Wan-Kai Zhang
Keyword(s):  
Foundation Pit ◽  
Retaining Structures

Monitoring and Analysis for the Deformation of SMW Retaining Structures in Subway Station

2014 ◽  
Vol 580-583 ◽  
pp. 1249-1253
Author(s):  
Jiang Tao Xia ◽  
Shao Fei Zhang ◽  
Hua Rong Shen ◽  
Ze Jun Liu ◽  
Shi Qing Huang
Keyword(s):  
Early Stage ◽  
Horizontal Displacement ◽  
Ground Subsidence ◽  
Subway Station ◽  
Deep Soil ◽  
Foundation Pit ◽  
Retaining Structures ◽  
Soil Mixing ◽  
Wall Structures ◽  
Soil Excavation

The monitoring is carried out for deformation of the soil-mixing-wall structures used in Baijihu subway station. The horizontal displacement of deep soil is obtained, as well as the ground subsidence around the edges of the foundation pit. Their variation rules under the influence of some factors, such as soil excavation and support settings etc, is analyzed. The results show that during the process of SMW construction, it is necessary to monitor the horizontal displacement of deep soil and the ground subsidence around the edges of the foundation pit, especially during the early stage of excavation.

scholarly journals A Precise Prediction of Tunnel Deformation Caused by Circular Foundation Pit Excavation

2019 ◽  
Vol 9 (11) ◽  
pp. 2275 ◽  
Author(s):  
Huasheng Sun ◽  
Lingwei Wang ◽  
Shenwei Chen ◽  
Hengwei Deng ◽  
Jihua Zhang
Keyword(s):  
Engineering Practice ◽  
Foundation Pit ◽  
Retaining Structures ◽  
Soil Stiffness ◽  
Circular Excavation ◽  
Nonlinear Constitutive Model ◽  
Bending Strain ◽  
Precise Prediction ◽  
Path Dependent ◽  
Reasonable Choice

In comparison with tetragonal retaining structures, circular retaining structures have an advantage in terms of controlling the deformation caused by foundation excavation, and are a reasonable choice in engineering practice. Many results have been obtained regarding the effect of tetragonal excavation on the deformation of an adjacent tunnel. Nevertheless, a sufficient understanding of the circular excavation’s effect on the deformation of an adjacent tunnel is currently lacking. Therefore, this study focused on the problem of precise predicting tunnel deformation below a circular excavation. A numerical model was established to calculate the tunnel deformation caused by the circular excavation. An advanced nonlinear constitutive model, known as a hypoplasticity model, which can capture path-dependent and strain-dependent soil stiffness even at small strains, was adopted. The models and their associated parameters were calibrated by centrifuge test results reported in the literature. The deformation mechanism was revealed, and the calculated results were compared with those obtained with a square excavation and the same excavation amount. The differences between the deformations caused by these two types of excavation shapes were analyzed. It was found that under equal excavation area conditions, the excavation-induced deformations of the metro tunnel below a circular excavation were approximately 1.18–1.22 times greater than those below a square excavation. The maximum tunnel tensile bending strain caused by the circular excavation was 32% smaller than that caused by the square excavation. By comparing with the measured results, it is proved that the proposed numerical method can provide effective reference for engineers to analyze soil-structure problems.

scholarly journals Study on Deformation and Stability of Rock-Like Materials Retaining Structure during Collaborative Construction of Super-Adjacent Underground Project

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Hongfu Qu ◽  
Lihua Wang ◽  
Chunlei Feng ◽  
Hualao Wang ◽  
Xuan Zhang
Keyword(s):  
Limit Equilibrium ◽  
Adjacent Area ◽  
Underground Engineering ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Retaining Structures ◽  
Retaining Structure ◽  
Collaborative Construction ◽  
Measured Deformation ◽  
The Difference

The collaborative construction of undercrossing tunneling of Gongchang Road and the adjacent Metro Line 6 extension station section in Shenzhen is difficult and of high risk. In view of these characteristics, this paper studied the deformation and stability of rock-like material retaining structures in the process of underground engineering collaboration by combining the measured deformation data and the circular slide theory based on the limit equilibrium method. The results show that due to the difference between the supporting systems of rock-like materials on both sides and other reasons, the upper part of the retaining structure and the limited soil in the adjacent area tilt greatly to one side at the same time, and the surface settlement in the limited soil area also increases with the increase of the excavation depth of the foundation pit. On the basis of measured deformation data analysis, the mechanical model for calculating the stability concerning the relationship between the adjacent distance L of the deep foundation pit and the vertical distance D ′ between the lowest support of the foundation pit and the bottom of retaining structures was established. Then, the calculation formula for the against basal heave stability covering different adjacent degrees was established. Besides, the applicability of the calculation method was verified by combining it with the actual engineering and related prediction theories, which further proves that the research results have certain theoretical value and engineering significance, and can provide a reference for the rock-like material retaining structures design and stability analysis of similar projects.

Numerical Simulation Research on the Mechanical Process of Pile-Anchor Retaining Deep Building Foundation Pit

2013 ◽  
Vol 353-356 ◽  
pp. 421-425 ◽  
Author(s):  
Bao Xue Shan ◽  
Lu Chao Liu ◽  
Cui Wei
Keyword(s):  
Numerical Simulation ◽  
Design Theory ◽  
Internal Force ◽  
Monitoring Data ◽  
Foundation Pit ◽  
Retaining Structures ◽  
Simulation Research ◽  
Mechanical Process ◽  
Economical Design ◽  
Building Foundation

In this paper, based on an actual pit excavation project, the mechanical process of excavating and retaining is simulated. Combined with the monitoring data, the stress, displacement of soil and internal force of retaining structures are analyzed, and the characteristics of deformation and force are summarized. This research offers references for safe and economical design and construction, and helps to improve the design theory of foundation pit support.

Numerical Simulation Using Finite Element and Earth Pressure Analysis on Double-Row Pile Retaining Structures

2011 ◽  
Vol 261-263 ◽  
pp. 923-927
Author(s):  
Jian Zhou ◽  
Zi Han Wang
Keyword(s):  
Finite Element ◽  
Earth Pressure ◽  
Three Dimension ◽  
Spatial Effects ◽  
Foundation Pit ◽  
Double Row ◽  
Retaining Structures ◽  
Finite Element Software ◽  
The Earth ◽  
Pressure Analysis

The characters on double-row pile retaining structures are affected significantly by spatial effects. In this paper, double-row pile retaining structures are simulated numerically in three-dimension by finite element software PLAXIS. The behavior differences among piles in different positions around the foundation pit are analyzed. The results show that the deformation and moment are biggest in the middle of long side of the foundation pit. It is suggested that the earth pressure between the rows above the pit bottom is close to active earth pressure.

scholarly journals Transverse Force Analysis of Adjacent Shield Tunnel Caused by Foundation Pit Excavation Considering Deformation of Retaining Structures

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1478
Author(s):  
Xinhai Zhang ◽  
Gang Wei ◽  
Xinbei Lin ◽  
Chang Xia ◽  
Xinjiang Wei
Keyword(s):  
Bending Moment ◽  
Confining Pressure ◽  
Shield Tunnel ◽  
Additional Stress ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Retaining Structures ◽  
Absolute Value ◽  
Retaining Structure ◽  
The Absolute

In order to research the theory for the variety of transverse forces of the adjacent shield tunnels caused by foundation pits excavation, the effect mechanism of foundation pit excavation on the adjacent shield tunnel was analyzed. The sidewall unloading model of the foundation pit, considering the deformation of the retaining structures, was introduced to calculate the additional stress of soil caused by foundation pit excavation. On this basis, the additional confining pressure variation model of the adjacent shield tunnel was established, considering the influence of the longitudinal deformation. Take the deep foundation pit project by the side of the shield tunnel of Hangzhou Metro Line 2 as a case study, the variation in confining pressure distribution of the adjacent shield tunnel caused by foundation pit excavation was analyzed, and a simplified finite element model was established to calculate the internal force of the segment ring structure. Moreover, the influence factors were analyzed, such as the deformation of the foundation pit retaining structure, the clearance between the foundation pit and the adjacent tunnel, and the buried depth of the tunnel. The present study suggests that the foundation pit excavation reduces the confining pressure of the adjacent shield tunnel, increases the absolute value of bending moment and shear force, and decreases the axial force at the top and bottom of the tunnel’s segment ring. With the increase in the deformation of the foundation pit’s retaining structure, the absolute value of the additional confining pressure on the adjacent tunnel increases, and the response of the bending moment to the foundation pit excavation unloading is more obvious than the variation in the confining pressure. When the buried depth of the adjacent shield tunnel is deeper than the excavation depth of the foundation pit, the influence of the excavation on the tunnel will be obviously weakened. With the decrease in the distance between the pit and tunnel, the influence of the excavation on the tunnel will be enhanced.

Condition evaluation of water retaining structures by a functional approach. Comparative practices in Canada and France

2011 ◽  
Vol 15 (3) ◽  
pp. 335-356
Author(s):  
Laurent Peyras ◽  
Richard Gervais ◽  
Damien Serre ◽  
Luc Chouinard ◽  
Youssef Diab ◽  
...  
Keyword(s):  
Functional Approach ◽  
Retaining Structures ◽  
Condition Evaluation
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