Numerical Simulation Analysis of Soil Nailing Wall Based on FLAC during the Excavation of the Foundation Pit

2012 ◽  
Vol 594-597 ◽  
pp. 2906-2914
Author(s):  
Chang Wen Chen

On the basis of a typical engineering, a foundation of soil nailing walls supporting simulation model of soil nailing on the structure of the excavation is established with FLAC, the construction process of the supporting structure is analyzed in the dynamic simulation. The deformation characteristics of the supporting structure are analyzed during the construction process, the law of the supporting body deformation with the difference of excavation steps is summarized. The situ test data of the deep foundation horizontal displacement and vertical displacement are obtained by testing in situ. Some useful conclusions are summarized by comparative analyzing the numerical simulation value and situ test data, providing guidance for the design and construction of the pit soil nailing wall.

2013 ◽  
Vol 353-356 ◽  
pp. 403-406
Author(s):  
Yong Kang Yang ◽  
Xiao Yuan Li ◽  
Wu Yang ◽  
Chun Yan Feng

Based on deformation of adjacent building with shallow foundation of foundation pit excavation, Midas GTS is adopted to establish the finite element model. Through the numerical simulation, the maximum horizontal and vertical displacement in different conditions, Influence of different SMW pile stiffness and influence of different anchor position are analyzed. The results show that (1) horizontal deformation of SMW pile is decreased at the anchor construction; (2) compared with maximum horizontal displacement of SMW pile with 25a25b28a, the maximum horizontal displacement of SMW pile with 28b is increased by 50.9, 43.3, 11.5% respectively; (3) compared with the second anchor at 1.5, 3.5m, the horizontal displacement of adjacent building is minimal by the second anchor at 2.5m.


2014 ◽  
Vol 651-653 ◽  
pp. 1201-1204
Author(s):  
Fang Guo

In order to study the vertical displacement distribution of foundation pit in the process of step-by-step excavation, combined with a foundation pit project, numerical simulation analysis with finite element software was carried in the research. The results show that: in the process of excavation, the maximum settlement of soil outside the pit is 41.4 mm, which is 2.95 ‰ of pit excavation depth and conforms to the recommended value in specifications. The maximum vertical displacement of soil at the bottom of foundation pit is in the center of pit. Its value is gradually increasing with the excavation, and the maximum is 60.1 mm, which is 4.32 ‰ of foundation pit depth,also,it conforms to the specifications proposed value. The proposed scheme can satisfy the vertical displacement of foundation pit excavation in the construction process.


2012 ◽  
Vol 446-449 ◽  
pp. 1797-1803
Author(s):  
Ai Jun Yao ◽  
Xin Dong Zhang ◽  
Xian Jun Zou

Taking the deformation of row pile supporting structure of foundation pit in strata with rock-soil combination as the research target and taking an open cut metro deep foundation pit as an example, by in-site monitoring and numerical simulation, analyze the horizontal displacement of retaining piles and the change law of steel support axial force in the strata with rock-soil combination, and summarize the change law of row pile supporting structure in the process of excavation under the conditions of this strata, so that to provide experience and guidance for similar engineering design and construction. The results show that: the structure of foundation pit has obvious effects on deformation and internal force of supporting structure, the result obtained from numerical simulation fits well with the tendency of monitoring data changing. In which, the deformation of row pile supporting structure in the middle and upper part of soil strata is larger, the deformation of middle and lower part of soil strata is comparatively smaller, the lateral deformation of row piles to basement has a tendency of gradual decreasing by taking the interface of rock-soil as a boundary.


2013 ◽  
Vol 838-841 ◽  
pp. 779-785
Author(s):  
Liang Gu

The double-row piles supporting structure is a new type of supporting and protecting for deep foundation excavation. It is widely used to in design of deep foundation pit. Now how to simply and effectively design the structure of double-row piles is in a research and discuss stage. Using the Midas GTS finite element method, the displacement and stress distribution of double-row piles in the different stages of excavation are obtained, and the horizontal displacement and stress distribution of double-row piles in the different stages of excavation are calculated. The results of Midas GTS finite element analysis as follows: (1) after the excavation of foundation pit, the horizontal displacement of pile-top is maximum. The horizontal displacement decreases gradually with depth increases. And the displacement of front row piles is larger than that of back row piles; (2) the maximum shear stress is at the distance 5m to the foundation basement. The higher bending moment at the pile-top and the distance 10m to the foundation basement are consistent with the actual monitoring date. (3) the results of finite element analysis is close to the Richard software and actual monitoring data. It is show that using the finite element analysis to analyze the double-row piles supporting structure with is veritable and credible.


2013 ◽  
Vol 353-356 ◽  
pp. 11-15
Author(s):  
Deng Qun Wang ◽  
Yan Peng Zhu

Finite element software was employed to establish a model to simulate the compound soil nailing. The model simulates the process of constructing prestressed compound soil nailing. Compared the condition prestressed with no prestress, analyzed the Impact of prestress anchor on the deformation in the process of construction and the effect on axial force of soil nail. Applying prestress is able to control the horizontal displacement obviously, but has not obvious effect on vertical displacement, especially place the anchor bolt at the lower part of the slope. In the process of construction, prestress has an advance effect on the deformation of foundation pit and the axial force of soil nails near the anchor bolt.


2015 ◽  
Vol 9 (1) ◽  
pp. 463-470
Author(s):  
Donglin Wang ◽  
Lei Wang

The air shaft deep foundation pit 6 is influenced by subgrade unbalance loading of highway 312, specifically its deep horizontal displacement of supporting piles and subgrade settlement of expressway 312 under unsymmetrical load effect. This paper carries out construction monitoring and numerical simulation analysis and gives a detailed study on the influenced factors of support structure deformation. Calculation results show that subgrade unsymmetrical load has a great influence on deep horizontal deformation of supporting piles. The maximum horizontal displacement at the bias side is about three times more than non-bias side’s; when the distance of subgrade to foundation pit is the same as the depth of excavation, the influence of subgrade on pit can be ignored; as the cohesion and internal friction angle increases, the horizontal displacement of fender piles decreases. However, enlarging the embedded depth of supporting piles has no significant influence on the stability of foundation pit.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Huifen Liu ◽  
Kezeng Li ◽  
Jianqiang Wang ◽  
Chunxiang Cheng

Based on the deep foundation pit project of Laoguancun station of Wuhan rail transit line 16 and according to the engineering characteristics of the construction conditions and the site surrounding the environment, the method of combining field monitoring and finite element numerical simulation is adopted to analyze the law of stress and deformation of the deep foundation pit during excavation and support construction; it includes the horizontal displacement of the underground diaphragm wall, supporting axial force, and the ground surface settlement, which can be compared with measured data. Finally, some suggestions for monitoring and construction of the deep foundation pit in the subway station have been put forward and have certain reference value and practical guiding significance for the design and construction of similar engineering projects. The deformation monitoring of the retaining structure at the middle of the long side of the foundation pit should be strengthened during the construction process.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Zhongjing Hu ◽  
Qingbiao Wang ◽  
Shuo Yang ◽  
Zhenyue Shi ◽  
Bo Liu ◽  
...  

Advancing urbanization in China requires large-scale high-rise construction and underground transportation projects. Consequently, there is an increasing number of deep foundation pits adjacent to water bodies, and accidents occur frequently. This study uses a numerical simulation method to study the stability of the deep foundation pit near water based on the Biot three-dimensional seepage-stress coupling model, with the open-cut section on the south bank of the Jinan Yellow River Tunnel Project as the engineering field test. This indicates the following: (1) the maximum horizontal displacement of the diaphragm wall occurred in the fifth excavation stage, and a horizontal brace effectively controlled the inward horizontal displacement of the foundation pit; (2) considering the effect of seepage in the soft soil foundation, the maximum vertical displacement of the ground surface at each excavation stage occurred adjacent to the underground continuous wall. As the depth of the foundation pit increased, the vertical surface settlement decreases gradually in the direction away from the excavation face; (3) considering the seepage conditions, within each interval of excavation of the foundation pit, the horizontal displacement of the continuous underground wall and ground settlement declined; and (4) the numerical simulation and field monitoring data were in good agreement. Under the conditions of accurate model simplification and parameter selection, numerical simulations can adequately forecast conditions of the actual project.


2014 ◽  
Vol 638-640 ◽  
pp. 614-619
Author(s):  
Bo Liu ◽  
Qing Nan Liu ◽  
Yi Yan Zhao ◽  
Bing Hui Chen

Dismantling the inner support of deep foundation pit is a risk point.It is of great importance to guarantee the safety of foundation pit when removing the inner support, and the deformation monitoring and analysis in the process of dismantling inner support is crucial. In this paper, a super deep foundation pit engineering as the research background.Through monitoring and analyzing the law of a deep horizontal displacement of the supporting structure,ground settlement, vertical settlement and axial force of support in the process of support demolition,which can be obtained that: the settlement of surface ground around the foundation shows spatial and temporal clearly and the distribution of deep horizontal displacement of supporting structure is similar to the parabolic which the maximum point constant upward shift with supporting continuous removed.Soil pressure of supporting shared with support removing process is changing, and the earth pressures support sharing is increasing. From the monitoring results, the demolition scheme is reasonable and effective and meets the requirements of design and environment.


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