A Simplified Calculation Method for Spatial Effect in Large-Long-Deep Foundation Pit and its Analysis

2011 ◽  
Vol 243-249 ◽  
pp. 2762-2770 ◽  
Author(s):  
Ming Feng Lei ◽  
Li Min Peng ◽  
Cheng Hua Shi ◽  
Yun Liang Zhang ◽  
Wen Hua Li
Keyword(s):  
Numerical Simulation ◽  
Failure Modes ◽  
Limit Equilibrium ◽  
Equilibrium Analysis ◽  
Theoretical Research ◽  
Flow Rule ◽  
Spatial Effects ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit

According to the research status of construction spatial effects in large-long-deep foundation pit: mainly focus on numerical simulation, but theoretical research is not too many by now, a simplified method for calculating the construction spatial effects of large-long-deep foundation pit in cohesive soil was advanced. The soil layers around deep foundation pit were equal to cohesion-less isotropic soil mass by introducing the concept of equivalent internal friction angle. And then, by means of limit equilibrium analysis method combined with soil plasticity upper bound theory and associated flow rule, the spatial effects of two 3D failure modes: tension crack-shear and pure shear in deep foundation pit was studied concretely, and the corresponding formulas of spatial effects coefficient were put forward, also two examples were analyzed. The research results indicates that the method, which can complete by hand-calculation, avoids the defects of low efficiency, high cost and long period in numerical simulation, and the distribution characteristics and value size of spatial effects coefficient could be obtained directly from its calculation results, which can be used as guidance for the supporting structure, construction scheme design and the test points or sections choice in process of information monitoring.

Numerical simulation of deep foundation pit dewatering and optimization of controlling land subsidence

2010 ◽  
Vol 114 (3-4) ◽  
pp. 251-260 ◽  
Author(s):  
Nianqing Zhou ◽  
Pieter A. Vermeer ◽  
Rongxiang Lou ◽  
Yiqun Tang ◽  
Simin Jiang
Keyword(s):  
Numerical Simulation ◽  
Land Subsidence ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit

On Overloading Design Method for the Slope of Deep Foundation Pit with Layered Soil Braced by Soil Nail

2013 ◽  
Vol 438-439 ◽  
pp. 724-727
Author(s):  
Li Hua Li
Keyword(s):  
Design Method ◽  
Limit Equilibrium ◽  
Work Rate ◽  
Layered Soil ◽  
Plastic Limit ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Soil Nail ◽  
Limit Equilibrium Theory

Based on plastic limit equilibrium theory of soil, the suitable values of energy safety factor are discussed here from energy work rate, the new design method for vertical slope of deep foundation pit with layered soil braced by soil nail with even overloading on slope top is proposed and engineering example is given out.

Numerical Simulation Analysis of Isolation Pile-Steel Shotcrete Combined Support of Deep Foundation Pit Excavation

2014 ◽  
Vol 638-640 ◽  
pp. 507-511
Author(s):  
Chong Ma ◽  
Xin Gang Wang ◽  
Bin Hu ◽  
Hong Bing Zhan
Keyword(s):  
Numerical Simulation ◽  
Geotechnical Engineering ◽  
Rapid Development ◽  
Engineering Problem ◽  
Simulation Software ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Support Design ◽  
Deep Foundation Pit ◽  
Design And Construction

The rapid development of deep foundation pit engineering, has become an important part of the urbanization construction, which brings deep excavation support of geotechnical engineering problem research also became a major issue. This paper uses the international well-known geotechnical engineering numerical simulation software FLAC3D, through 3D finite difference numerical calculation and analysis, to better simulation calculation and analysis of deep foundation pit construction site condition, forecast after excavation of the deep foundation pit deformation displacement and dangerous position, analysis of deep foundation pit excavation process isolation pile - steel shotcrete combined support effect. Three dimensional numerical model analysis and calculation in deep foundation pit engineering design and construction scheme optimization with economy is convenient wait for a obvious advantages, can for deep foundation pit excavation of deep foundation pit support design and construction to provide effective basis.

Comparison and Analysis of Influence of Soil Deformation on the Speeds of Execution for Deep Foundation Pits

2013 ◽  
Vol 353-356 ◽  
pp. 159-162
Author(s):  
Li Liu ◽  
Hong Ru Zhang ◽  
Rui Yu Zhang
Keyword(s):  
Numerical Simulation ◽  
Soil Deformation ◽  
Deep Excavation ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Total Displacement ◽  
Rapid Construction ◽  
Test Points ◽  
Variation Tendency

The excavation of deep foundation pit by numerical simulation is researched in this paper. Different locations of soil are selected to be as test points. Under two velocities, the law of total displacements that reflect the test points in the same locations is discussed. The variation tendency of the pore pressure under the rapid construction and tendency of the volume change under the normal construction are compared. The soil is divided to three parts in numerical simulation: the side, the bottom I and the bottom II of the foundation. The numerical results are as follows: the total displacement of the rapid construction is double for ones of the normal construction, which is on the side and the bottom I of deep foundation pit. Under the different drainage conditions, the soil on the side of deep excavation experiences the dilatancy, and then the shear-contraction, and then the dilatancy; the soil on the bottom II of deep excavation experiences the dilatancy and then the shear-contraction. The soil on the bottom I experiences the dilatancy under the normal construction; but it experiences the dilatancy and then the shear-contraction under the rapid construction.

scholarly journals Numerical Simulation of Deep Foundation Pit Construction under Complex Site Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Huifen Liu ◽  
Kezeng Li ◽  
Jianqiang Wang ◽  
Chunxiang Cheng
Keyword(s):  
Numerical Simulation ◽  
Ground Surface ◽  
Reference Value ◽  
Horizontal Displacement ◽  
Deformation Monitoring ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Ground Surface Settlement ◽  
Stress And Deformation

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.

scholarly journals Numerical Simulation of Soil Displacement and Settlement in Deep Foundation Pit Excavations Near Water

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Zhongjing Hu ◽  
Qingbiao Wang ◽  
Shuo Yang ◽  
Zhenyue Shi ◽  
Bo Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Large Scale ◽  
Yellow River ◽  
Soft Soil ◽  
Ground Surface ◽  
Horizontal Displacement ◽  
Simulation Method ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit

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.

Filed Test Studies on Internal Force of Pile in Pile-Anchor Supporting System for Deep Foundation Pit

2011 ◽  
Vol 383-390 ◽  
pp. 7713-7717
Author(s):  
Chong Fu Wu ◽  
Chang Hong Li
Keyword(s):  
Limit Equilibrium ◽  
Internal Force ◽  
Pile Head ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Building Foundation ◽  
Zero Position ◽  
Prestressed Anchor ◽  
Variation Rule

Through the field test on the laboratory building foundation pit engineering of Northeastern University at Qinhuangdao, the distribution and variation rule of steel stress and pile moment is researched and analyzed in the process of the deep foundation pit excavation. The result shows that foundation pit excavation and applied prestressed anchor are the main factors of pile internal force change, furthermore, the latter is more effective than the former. Meanwhile, the influence of top beam to steel stress and moment of pile head can not be ignored especially. The zero position of steel stress and pile moment are basically same, which lies under foundation pit bottom. The use of limit equilibrium method more economical than elastic subgrade method in design over foundation pit bottom, however, which is opposite under it.

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