Deep Foundation Pit Monitoring Based on CX-3C Inclinometer

2014 ◽  
Vol 484-485 ◽  
pp. 404-407 ◽  
Author(s):  
Qing Guo Ren ◽  
Guang Zhang ◽  
Xiao Guang Yue ◽  
Wen Cheng Liao
Keyword(s):  
Vertical Profile ◽  
Retaining Wall ◽  
Horizontal Displacement ◽  
Displacement Monitoring ◽  
Deep Soil ◽  
Security Risks ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Main Factors

Deep soil horizontal displacement monitoring can measure the retaining wall board, row piles deformed shape, reflect the foundation on the vertical profile of horizontal displacement with depth changes in the law, predict foundation stability and security risks. Combined with Wuhan WANGJiaDun Pit Engineering, this article introduce CX-3C inclinometer work principle, put forward the calculated optimization measures of inclinometer, and analysis the main factors which should be considered to arrange the measuring points.

Effect of Staged Excavation on Retaining Structure in Soft Soil Area

2012 ◽  
Vol 170-173 ◽  
pp. 633-636 ◽  
Author(s):  
Jie Liu ◽  
Xin Guang Xu
Keyword(s):  
Soft Soil ◽  
Horizontal Displacement ◽  
Structure Type ◽  
Operating Conditions ◽  
Deep Soil ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Retaining Structure ◽  
Geological Conditions

Based on a deep foundation pit in Tianjin, the authors introduced the retaining structure type, surrounding conditions, and the geological conditions of proposed field. According to the engineering characteristics, the excavation was divided into three typical operating conditions. Based on the monitoring of staged excavation of deep foundation pit, analysis on horizontal displacement, deep soil displacement, column settlement and bracing axial force was carried out. The general rules of the deformation and internal force of retaining structures induced by staged excavation were given, which will provide the references for similar engineering.

Horizontal displacement monitoring method of deep foundation pit based on laser image recognition technology

2018 ◽  
Vol 89 (12) ◽  
pp. 125006 ◽  
Author(s):  
Peng Liu ◽  
Shulin Xie ◽  
Guangyi Zhou ◽  
Lixiao Zhang ◽  
Guoxian Zhang ◽  
...  
Keyword(s):  
Image Recognition ◽  
Horizontal Displacement ◽  
Displacement Monitoring ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Monitoring Method ◽  
Deep Foundation Pit

Monitoring Analysis and Safety Evaluation of Deep Foundation Pit under Complex Conditions

2014 ◽  
Vol 580-583 ◽  
pp. 636-640 ◽  
Author(s):  
Xu Tao Zhang ◽  
Qiang Yong Zhang ◽  
Chao Wang ◽  
You Fa Wang
Keyword(s):  
Great Influence ◽  
Safety Evaluation ◽  
Horizontal Displacement ◽  
Construction Time ◽  
Deep Soil ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Deformation Control ◽  
Supporting Structure

The horizontal displacement of pit top and horizontal displacement in deep soil of underground garage deep foundation pit in Radio and TV centre of Shandong province was analyzed. Combing the deformation control value of foundation pit, we thought that the supporting structure was safe and reliable. The supporting structure could not only meet the strength requirements but also meet the deformation control requirements. This deep foundation pit was a successful case under complex conditions. Analyzing the variation rules between monitoring data and construction time, the instructive conclusions were obtained. The deformation of foundation pit external corner was largest. The external corner should be avoided in foundation pit. The dynamic loads around foundation pit had a great influence on the safety and stability of pit. The rainfall was disadvantage factors, so the construction of foundation pit should keep away from the rainy season. The foundation pit floor could limit soil deformation and improve the safety of pit. The pit floor should be constructed as early as possible.

Research on Deformation Law of Deep Excavation Supporting Structures in Beijing Metro Station

2011 ◽  
Vol 243-249 ◽  
pp. 2338-2344
Author(s):  
Qing Yuan Li ◽  
Yang Wang
Keyword(s):  
Horizontal Displacement ◽  
Internal Force ◽  
In Situ Monitoring ◽  
Deep Excavation ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Metro Station ◽  
Deep Foundation Pit ◽  
Deformation Law

Taking deep excavation engineering in North Region of Senlin Park Station of Beijing Olympic Subway branch as engineering background, deformation law of enclosure structure of deep excavation are studied by the in-situ monitoring means .It shows that the maximum horizontal displacement of retaining pile is closely related with excavation depth and time. When the deep foundation pit is excavated to a certain depth, and steel brace hasn’t been erected, horizontal displacement of the pile tops is maximum. The location of the maximum horizontal displacement shifts down with foundation pit excavation and steel brace erection. With steel brace application, steel axis force decrease, so steel brace can effectively control horizontal displacements of retaining pile and internal force of steel in the pile. In addition, temperature has a certain effect to axis force of steel brace.

Study on Composite Soil Nailing Wall in Soft Soil Area of Complex Condition with Emphasis on Analysis by Finite Element Analysis

2012 ◽  
Vol 174-177 ◽  
pp. 2020-2023 ◽  
Author(s):  
Bing Wang
Keyword(s):  
Finite Element ◽  
Soft Soil ◽  
Horizontal Displacement ◽  
Deep Foundation ◽  
Circular Area ◽  
Foundation Pit ◽  
Soil Nails ◽  
Deep Foundation Pit ◽  
Soft Soil Area ◽  
Soil Area

Based on a typical projects, the horizontal displacement in depth, horizontal displacement and vertical subsidence of pile top, and settlements of surrounding buildings are monitored with the process on digging of deep foundation pit. The study on digging process of foundation pit is analyzed by using finite element software. Using mapped meshing method, from mixing the pile near the semi-circular area (radius = 50m), the meshing appropriate encryption in order to improve the accuracy of the external semi-circular area (radius = 65m) mesh is less appropriate sparse.Layer by layer to kill the layers of the soil unit and activate the soil nails (spring element), the simulated excavation and synchronization of soil nails construction.Verify the arc form of failure surface in side of deep foundation pit in soft soil area. Which is valuable for reference to similar structure engineering of foundation pit.

Construction Technology of one Unsymmetrical Loaded Deep Foundation Pit Adjacent to Expressway Subgrade

2014 ◽  
Vol 919-921 ◽  
pp. 1411-1415
Author(s):  
Bo Liu ◽  
Pei Sheng Xi
Keyword(s):  
Horizontal Displacement ◽  
Urban Rail Transit ◽  
Construction Technology ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Urban Rail ◽  
Relative Value ◽  
Lower Load ◽  
Loaded State

One deep foundation pit in Hefei urban rail transit project is adjacent to the existed expressway subgrade, it's in the unsymmetrical loaded state. The control of foundation pit deformation and the safety of subgrade must be strictly ensured. Based on it, the design scheme of supporting system, the construction processes of earth excavation, top beam, concrete support and steel support was introduced. The horizontal displacement of fender piles and the settlement of subgrade was monitored. The field monitoring results indicate, there exists a great difference between the retaining structure deformation under the action of unsymmetrical load and the deformation under the action of symmetrical load, the horizontal displacement of fender piles on the side of subgrade is bigger than the other side, the upper pile appears to be a "drift" towards the lower-load side; although the absolute value of horizontal displacement of fender piles and settlement of subgrade seems to be a big number, the relative value is small compared to the whole length of fender pile and expressway, meeting relevant standard requirements. The deep foundation pit and expressway kept safe and stable in the all periods of construction, no one accident was occurred during that time. Thus, it can be seen that this construction technology is effective in controlling the deformation during excavation, which can provide a reference for similar projects in design and construction in the future.

scholarly journals Impact Analysis of Support Structure of Unsymmetrical Loading Deep Foundation Pit Adjoining Highway

2015 ◽  
Vol 9 (1) ◽  
pp. 463-470
Author(s):  
Donglin Wang ◽  
Lei Wang
Keyword(s):  
Impact Analysis ◽  
Simulation Analysis ◽  
Great Influence ◽  
Horizontal Displacement ◽  
Friction Angle ◽  
Deep Foundation ◽  
Support Structure ◽  
Foundation Pit ◽  
Load Effect ◽  
Deep Foundation Pit

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.

scholarly journals Displacement Monitoring during the Excavation and Support of Deep Foundation Pit in Complex Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Zhouqiang Li
Keyword(s):  
Axial Force ◽  
Time History ◽  
Horizontal Displacement ◽  
Underground Water ◽  
Surface Settlement ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Anchor Cable ◽  
The North

Taking a super large deep foundation pit project as an example, the horizontal displacement of crown beam and driveway, surface settlement, axial force of anchor cable, and underground water level in the construction process of the foundation pit are dynamically monitored and analyzed. The excavation deformation rule of the deep foundation pit and the influence of excavation on surrounding buildings are analyzed. The results show that, with the excavation of the foundation pit, the crown beam and driveway of the foundation pit incline towards the direction of the pit and eventually tend to be stable. The variation of axial force of the prestressed anchor cable in the first layer of the foundation pit is basically consistent with the variation of horizontal displacement time history. The variation trend of the groundwater level at each side of the foundation pit is different but tends to be stable in a short time. In the whole monitoring period, the cumulative settlement value of each area of the foundation pit is within the controllable range, but the surface settlement of the north side of the foundation pit and a surrounding building has not reached stability, so it is suggested to extend the monitoring time of settlement in the relevant area.

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.

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