scholarly journals Research and Application of Anti-floating Schemes of Deep Foundation Pit of Subway for Underwater Excavation and underwater concrete sealing

2020 ◽  
Vol 165 ◽  
pp. 04001
Author(s):  
Sheng Luo
Keyword(s):  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Main Structure ◽  
The Third ◽  
Third Phase ◽  
Underwater Concrete ◽  
Subway Construction ◽  
Bottom Slab ◽  
Selection Of

To implement deep foundation pit of subway construction with underground continuous wall adopting underwater excavation and waterproofing concrete bottom sealing curtain, the depth of bottom concrete must first meet the anti-floating requirements of the foundation pit. Since the elevation of the bottom slab of the station is certain, the thicker the sealing concrete, the deeper the excavation depth of the foundation pit, the greater the buoyancy of the water to be withstood, and eventually the thicker the sealing concrete, so the selection of foundation pit anti-floating scheme is very critical. This paper combines the practical construction of the deep foundation pit of the main structure of Yongdingmenwai station which is in the third phase of Beijing Metro Line 8 construction project, and analyzes and compares the anti-floating scheme of the foundation pit, so as to select a more reasonable anti-floating scheme, in order to apply experiences for future similar projects and construction.

The Supporting Scheme Selection of Deep Foundation Pit Based on Fuzzy Optimization Theory

2014 ◽  
Vol 541-542 ◽  
pp. 1492-1496
Author(s):  
Zi Sheng Yang ◽  
Ji Xiao Tao ◽  
Hong Ke Pan ◽  
Yong Tao Li
Keyword(s):  
Fuzzy Optimization ◽  
Optimization Theory ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Supporting System ◽  
Simplified Method ◽  
Scheme Selection ◽  
System Selection ◽  
Selection Of

In order to get a quantitative and simple supporting scheme of deep foundation pit, this paper creatively develop a simplified method of supporting system selection based on the fuzzy optimization theory. The simplified method determines a preferred equation of the supporting system at first. Then the best solution is selected based on the preferred equation. Based on the simplified method, the analysis of the foundation excavation for Chuangye Dasha in Taiyuan has been performed. The result of the analysis shows that the method is reasonable and scientific.

Simulation Analysis on Deep Foundation Pit Construction Near the History Style Construction

2013 ◽  
Vol 671-674 ◽  
pp. 113-116
Author(s):  
Chun Yuan Liu ◽  
Wei Wei Cao ◽  
Yu Liu
Keyword(s):  
Simulation Analysis ◽  
Horizontal Displacement ◽  
Construction Safety ◽  
Calculation Model ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Engineering Construction ◽  
Deep Foundation Pit ◽  
The Third ◽  
The Impact

Based on the impact of deep foundation pit excavation to the adjacent history style construction, FLAC3D was adopted to establish the excavation and supporting calculation model of a pit in Tianjin. The excavation deformation was analyzed, and the contact slip effect of the supporting structure and soil was considered. The results of study are as follows. (1) The pit has been dig to the third layer, and the values calculated are consistent with the monitored ones by comparing simulation values and measured results on B1 section. (2) Digging to the bottom of the pit, we can predict the biggest horizontal displacement of soil is 34.6 mm, and the value is 11.2mm in the history style construction. Therefore, the results of the study can play a guiding role in the engineering construction safety.

Research on Improved AHP Evaluation in Supporting the Right to Determine the Weight of Deep Foundation

2014 ◽  
Vol 919-921 ◽  
pp. 731-734
Author(s):  
Hong Yan Jiang ◽  
Gang Gang Yu
Keyword(s):  
Scaling Theory ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Judgment Matrix ◽  
The Right ◽  
Index Weight ◽  
Selection Of

The traditional AHP in the judgment matrix is established by using 1-9 scale, this scale has transfer difference, consistency of judgment matrix and thinking is not equivalent shortcomings. The improved AHP scaling theory is used in deep foundation pit support index weight determination, the selection of foundation pit supporting is more comprehensive scientific reasonable accurate.

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.

scholarly journals An Agent-Based Simulation of Deep Foundation Pit Emergency Evacuation Modeling in the Presence of Collapse Disaster

Symmetry ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 581 ◽  
Author(s):  
Weilong Yang ◽  
Yue Hu ◽  
Cong Hu ◽  
Mei Yang
Keyword(s):  
Emergency Evacuation ◽  
Influential Factors ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Evacuation Modeling ◽  
Agent Based ◽  
Deep Foundation Pit ◽  
Decision Making System ◽  
Escape Process ◽  
Exit Distribution

With the gradual expansion of high buildings and underground spaces, deep foundation pits have been widely used in these engineering projects, but if they are not well-designed, safety problems occur. Proper deep foundation pit design requires proper exit distribution. However, calculating an adequate number of exit distributions for evaluation is difficult due to the numerous influential factors existing in the deep foundation pit environment. To this end, this paper presents a prototype of a decision-making system that uses agent-based modeling to simulate deep foundation pit evacuation in the presence of collapse disaster. By modeling the collapse occurrence process and agent escape process, an agent-based evacuation model is built, and a modified simulation-based particle swarm optimization algorithm is used to solve the optimization problem of exit distribution. Extensive experiments are conducted to verify the system, and the results show that the system provides a feasible framework for deep foundation pit evacuation.

Determination of Spacing between Anchored Piles in Row for Deep Foundation Pit

2012 ◽  
Vol 204-208 ◽  
pp. 2736-2739
Author(s):  
Guang Qian Du ◽  
Shi Jie Wang ◽  
Yan Ting Qin ◽  
Chang Zhi Zhu
Keyword(s):  
Strength Criterion ◽  
Strength Analysis ◽  
Soil Arching ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Pile Spacing ◽  
Soil Arch ◽  
Uniformly Distributed Loads

Based on the pile - anchor structure soil between piles,the unified strength theory is introdued in the strength analysis of soil arching between the piles, and parabolic soil arching computational model is uniformly distributed loads ,which are given to meet the soil between piles arch static equilibrium conditions and intensity of conditions , pile spacing formula. Compared with calculations based on the pile spacing of the Mohr-Coulomb strength criterion , the proposed method can consider the contribution of the intermediate principal stress on the strength of the soil arch , the results are more in line with the actual characters of the supporting structure .

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