Research on Soil Nailing Method for Large Foundation Pit Treatment

2014 ◽  
Vol 638-640 ◽  
pp. 538-541
Author(s):  
Zi Mao Peng
Keyword(s):  
Side Wall ◽  
Design Parameters ◽  
Soil Pressure ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Building Foundation ◽  
Backfill Soil ◽  
Soil Complex ◽  
Large Building

Based on the introduction of the characteristics of the supporting project of a large building foundation pit, the paper analyzed the main reasons for side wall collapse and pile fracture, including leakage water in the backfill soil, complex geological environment and unreasonable soil pressure value, low safety factor and improper design parameters, and then respectively proposed three kinds of treatment schemes for side wall sliding and pile breaking, landslides and other dangers. Finally, tracking observation showed that the satisfactory effect can strongly verify the suitability and validity of the main control parameters for the deformation of deep foundation pit, which may provide reference for the design and construction of similar projects.

scholarly journals Soil Pressure and Deformation Analysis of Small Size Deep Foundation Pit

2022 ◽  
Vol 2148 (1) ◽  
pp. 012061
Author(s):  
Zhao Long ◽  
Yilei Shi ◽  
Weili Li ◽  
Shuaihua Ye
Keyword(s):  
Finite Element ◽  
Limit Equilibrium ◽  
Side Wall ◽  
Soil Pressure ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Finite Element Software ◽  
Pressure Calculation ◽  
Space Effect

Abstract In this paper, the influence of space effect on soil pressure and deformation of deep foundation pit was considered, and the finite soil pressure calculation model was established. The soil pressure of deep foundation pit was calculated by assuming the slip surface and using the finite soil limit equilibrium theory. Then, PLAXIS 3D finite element software was used to establish finite element models of different plane sizes and depths. The distribution regulation of side wall soil pressure and deformation of deep foundation pit was calculated. Finally, the results of finite soil pressure calculation was compared with finite element method. The results shown that: The soil pressure of small deep foundation pit was affected by space effect, and the soil pressure and deformation decrease significantly along the foundation pit depth. Shear fracture Angle was related to the ratio of width to depth of foundation pit, and it was no longer a constant value of 45°+φ/2. Therefore, the spatial effect should be considered in the calculation of soil pressure of small deep foundation pit. The research results can provide some guidance for the design and calculation of similar small size deep foundation pit.

Stability on Supporting Structure of Deep Foundation Pit with Infiltration

2012 ◽  
Vol 170-173 ◽  
pp. 223-226 ◽  
Author(s):  
Xue Song Gao ◽  
Jian Jun Dong ◽  
Xu Zhao ◽  
Peng Yang Yin ◽  
Shao Hua Lv
Keyword(s):  
Bending Moment ◽  
Rainfall Infiltration ◽  
Deep Excavation ◽  
Initial State ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Building Foundation ◽  
Internal Forces ◽  
The Stability

The FLAC3D was used to the fluid-solid coupling numerical simulation of considering the initial state of unsaturated to soil for the deep foundation pit engineering under different rainfall infiltration conditions. By comparing the bending moment, the shearing stress and internal forces of support under the infiltration conditions between non-rainfall and rainfall, the paper focus on the stability of deep foundation pit. Research on the stability of deep excavation under rainfall conditions was a useful attempt. From the detail study of the stability of a foundation pit of Qinhuangdao under rainfall infiltration conditions, the paper have drawn some useful conclusion on the design of building foundation pit, which can be the basis of excavation design and construction under rainfall conditions.

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.

Analysis of the Interaction of Foundation Pit Supporting Structure and Soil

2014 ◽  
Vol 580-583 ◽  
pp. 401-404
Author(s):  
Yu Qin Feng ◽  
Chen Xi Liu
Keyword(s):  
Soft Soil ◽  
Earth Pressure ◽  
Large Area ◽  
Soil Pressure ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Supporting Structure ◽  
Distribution Mode ◽  
Measure Soil Pressure

This paper analyzes an engineering in an area of China which was processed by vacuum preloading technology in the silt soft soil. This engineering was used rigid supporting structure technology of piles in row and bolts for large area of deep foundation pit supporting. It compared the realistic measure soil pressure and theoretical concluded soil pressure, and got the soil pressure distribution mode which is suitable for silt soft soil processed in this way. The conclusion can provide a reference for similar supporting structure system to calculate earth pressure.

Numerical Analysis of the Construction Influence of Deep Foundation Pit on Adjacent Open Trench Tunnel

2011 ◽  
Vol 94-96 ◽  
pp. 1902-1907
Author(s):  
Cong Shi Wu ◽  
Wei Da Shen ◽  
Gong Liu
Keyword(s):  
Numerical Analysis ◽  
Analysis Model ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Building Foundation ◽  
Adjacent Building ◽  
Special Project ◽  
Open Trench ◽  
Construction Optimization

The open trench D ramp of Yingpanlu Xiangjiang tunnel in Changsha and the adjacent building foundation pit construction were excavated almost at the same time. The minimum distance between the two pits was only 8 meters, and keeping both projects safe working became difficult in engineering. Therefore a special project example of numerical analysis model was established, which can simulate the whole construction course. The construction stress was analyze by combining with the soil and retaining structures displacement, and the results were compared with the actual measured data to provide a reference to the design and construction optimization.

scholarly journals Analysis of Seepage Characteristics of a Foundation Pit with Horizontal Waterproof Curtain in Highly Permeable Strata

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1303
Author(s):  
Chenghua Shi ◽  
Xiaohe Sun ◽  
Shengli Liu ◽  
Chengyong Cao ◽  
Linghui Liu ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Theoretical Calculation ◽  
Calculation Method ◽  
Design Method ◽  
Water Pressure ◽  
Water Inflow ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Seepage Characteristics

At present, jet-grouted horizontal waterproof curtain reinforcement has become an essential method for deep foundation pit groundwater control. However, there is still a lack of an effective theoretical calculation method for horizontal waterproof curtain reinforcement, and there is little research on the seepage laws of foundation pits under different horizontal waterproof curtain conditions. Based on Darcy’s seepage theory, theoretical analysis models of deep foundation pit seepage were established considering the effect of a horizontal curtain in a highly permeable formation. Through the established models, the calculation method of the water inflow and the water pressure under the condition of a horizontal curtain was derived. Then through indoor tests, the reliability of the theoretical calculation method was verified. Furthermore, the established theoretical calculation method is used to analyze the influence of various factors on the water inflow and the water pressure, such as the ratio of hydraulic conductivity of the horizontal curtain to surrounding soil, thickness, and reinforcement position of the horizontal curtain. It is found that the hydraulic conductivity ratio has the most significant influence on the seepage characteristics of the foundation pit. Finally, the design method was applied to an example of the horizontal waterproof curtain of the foundation pit, which is located at Juyuanzhou Station in Fuzhou (China). The water inflow per unit area is 0.36 m3/d in the foundation pit, and this implies that the design method of the horizontal waterproof curtain applied for the excavation case is good and meets the requirements of design and safety.

Mechanical Analysis of Enclosure Pile under Different Constraints

2011 ◽  
Vol 90-93 ◽  
pp. 485-489
Author(s):  
Li Guo ◽  
Peng Li He ◽  
Guang Jun Zhang
Keyword(s):  
Mechanical Analysis ◽  
Subway Station ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Retaining Structure ◽  
Cantilever Structure ◽  
Reinforcement Measures

The enclosure pile is extensively used as retaining structure in the foundation pit excavation. And it is always combined with other reinforcement measures. So it is unreasonable to a certain degree that the enclosure pile is analyzed as cantilever structure. Taken the deep foundation pit of a subway station in Hefei for instance, the effect of other reinforcement measures on restrained conditions of enclosure piles in the paper was taken into account. And the behavior of enclosure pile under various restrained conditions was analyzed. Based on that, some helpful suggestions for practical retaining structure of foundation pit were put forward.

Simulation of Excavation Process for Deep Foundation Pit Base on Nonlinear Finite Element Theory

2015 ◽  
Vol 744-746 ◽  
pp. 579-583
Author(s):  
Hui Min Wang ◽  
Zhen Jian Ji ◽  
Liang Cao ◽  
Ji Yao ◽  
Shan Guang Qian
Keyword(s):  
Finite Element ◽  
Safety Evaluation ◽  
Nonlinear Finite Element ◽  
Distribution Law ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Simulation Research ◽  
Deep Foundation Pit ◽  
Excavation Process ◽  
Element Theory

Deep Pit is the main content of modern urban geotechnical engineering. In this paper, based on a deep foundation pit engineering as an example, based on the nonlinear finite element theory, conduct a numerical simulation research for foundation pit excavation process. Obtained the distribution law of pit deformation, stress distribution and the supporting structure of the internal forces, under the various processes. These provide a theoretical basis for safety evaluation of foundation pit engineering.

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