scholarly journals Analysis of Situ Test Results of Earth Pressure and Pile Internal Force under Pile-Anchor Support in a Deep Foundation Pit in Xi’an

2022 ◽  
Vol 2148 (1) ◽  
pp. 012051
Author(s):  
Ruibin Yang ◽  
Xinsheng Li ◽  
Dongzhou Xie ◽  
Hongte Meng
Keyword(s):  
Earth Pressure ◽  
Internal Force ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Support Design ◽  
Limiting State ◽  
Obvious Effect ◽  
Deep Foundation Pit ◽  
The Earth ◽  
Monitoring Test

Abstract At present, in deep foundation pit engineering, on the one hand, practice is ahead of theory, and on the other hand, theory can not correctly reflect the actual construction process and environmental effects. In order to further study the distribution and change law of earth pressure and internal force of pile body in deep foundation pit pile-anchor supporting system, field monitoring test of earth pressure and pile body reinforcement stress was carried out. The monitoring results show that before excavation, the distribution of earth pressure has a great relationship with the layering of the soil, and it is distributed in sections along the depth. Compared with the theoretical static earth pressure, the measured data of the upper depth is relatively small; after excavation, the overall earth pressure is distributed along the depth in a “z” shape under the non-limiting state. As the excavation progresses, the magnitude of the reduction of the earth pressure varies from place to place, and the magnitude of the decrease of the soil with better properties is not large; after the excavation, the stress and earth pressure of the pile reinforcement correspond to each other, and the distribution is also nonlinear. The existence of anchor tension has an obvious effect on improving the internal force of the pile. The selected earth pressure calculation methods have some discrepancies in the calculation of the earth pressure value of the project, and they need to be further improved. The research in this paper can provide reference and reference for the calculation of earth pressure and support design of pile-anchor supported foundation pit.

scholarly journals Determination of Embedded Depth of Soldier Piles in Pile-Anchor Supporting System in Granite Residual Soil Area

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yiao Liu ◽  
Changming Wang ◽  
Xiaoyang Liu ◽  
Ruiyuan Gao ◽  
Bailong Li ◽  
...  
Keyword(s):  
Earth Pressure ◽  
Residual Soil ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Maximum Displacement ◽  
Deep Foundation Pit ◽  
The Earth ◽  
Granite Residual Soil ◽  
Surrounding Soil ◽  
Soil Area

Reasonable depth of pile embedment is one of the key factors for the success of deep foundation pit projects. This paper has taken a deep foundation pit project in a granite residual soil area in Shenzhen as an example and used physical model tests to study the deformation law of the piles and the surrounding soil during the excavation of the deep foundation pit, revealing the variation law of earth pressure in time and space in the pit and then verified it by numerical simulation. The influence of the embedded depth of the pile on the deformation and earth pressure of the deep foundation pit is then explicitly discussed. The study shows that the embedded depth has a significant effect on the deformation and earth pressure distribution of the foundation pit. The earth pressure in front of the pile tends to approach the passive earth pressure as the embedment depth decreases, while the earth pressure behind the pile is in between the Rankine active earth pressure and the static soil pressure; the settlement value and settlement range of the surrounding soil are doubled. The pile displacement increases as the maximum displacement point rises. The maximum displacement of the pile body was used as the basis for determining the instability of the foundation pit. The optimum embedded depth is obtained when the depth of embedment of the pile is 0.22 H (H is the excavation depth of the foundation pit).

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.

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.

scholarly journals Correction of Earth Pressure and Analysis of Deformation for Double-Row Piles in Foundation Excavation in Changchun of China

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Yijun Zhou ◽  
Aijun Yao ◽  
Haobo Li ◽  
Xuan Zheng
Keyword(s):  
Physical Model ◽  
Model Test ◽  
Large Scale ◽  
Similarity Theory ◽  
Earth Pressure ◽  
Physical Model Test ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Double Row ◽  
The Earth

In order to study the earth pressure and the deformation behavior of the double-row piles in foundation excavation, a large-scale physical model test was introduced to simulate deformation of double-row piles in foundation excavation based on the principle of similarity theory in this paper. Represented by the deep foundation pit engineering of Changchun, the strain and the displacement of the double-row piles and the earth pressure are calculated by the above-mentioned physical model test. Then a numerical simulation has been carried out to validate practicability of the physical model test. The results show that the strain and the displacement of the front-row piles are larger than the back-row piles. The earth pressure of the front-row piles appears to be “right convex,” correcting the specification of the earth pressure and putting forward the coefficient of β. The results in this paper may provide constructive reference for practical engineering.

Influence of Deep Foundation Pit Construction to the Surrounding Buildings - Take a Foundation Pit in Haikou as Example

2012 ◽  
Vol 268-270 ◽  
pp. 673-676
Author(s):  
Ji Nan Zou ◽  
Bei Te Cai ◽  
Hong Wei
Keyword(s):  
Large Deformation ◽  
Daily Rainfall ◽  
Shallow Foundation ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Obvious Effect ◽  
Deep Foundation Pit ◽  
Design And Construction

This paper takes example of a foundation pit in Haikou, analyzing the influence on the surrounding buildings in the course of the excavation depth, daily rainfall, foundation form of the building and other factors. The results show that the excavation depth and strong rainfall may lead large deformation of the surrounding buildings, and the deep foundation pit has obvious effect on surrounding building with shallow foundation. Therefore, those factors should be considered adequately in the design and construction of deep foundation pit

The Study of Deformation Law of a Super Deep Foundation Pit in the Process of Dismantling the Inner Support

2014 ◽  
Vol 638-640 ◽  
pp. 614-619
Author(s):  
Bo Liu ◽  
Qing Nan Liu ◽  
Yi Yan Zhao ◽  
Bing Hui Chen
Keyword(s):  
Horizontal Displacement ◽  
Deformation Monitoring ◽  
Maximum Point ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Supporting Structure ◽  
The Earth ◽  
Earth Pressures ◽  
Deformation Law

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.

Numerical Analysis of a Pile-Anchor Retaining Structure of Deep Foundation Pit Engineering

2014 ◽  
Vol 638-640 ◽  
pp. 496-502
Author(s):  
Ying Wang ◽  
Jiang Bo Shi
Keyword(s):  
Earth Pressure ◽  
Horizontal Displacement ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Deformation Control ◽  
Maximum Value ◽  
Negative Moment ◽  
Dip Angle ◽  
Pile Length

Based on a deep foundation pit engineering of Tangshan, considering the interaction of pile-anchor-soil, the finite difference software FLAC3D is adopted in this paper to simulate and analyze the effect of dip angle of anchor and the embedded depth of pile on the horizontal displacement and the variation laws of earth pressure, horizontal displacement of pile with the process of excavation. The results show that the maximum value of horizontal displacement and positive moment of pile appear in 0.85H (H stands for the depth of excavation) and the negative moment appears in 1.3H after the excavation; the maximum value of active and passive earth pressure appear in 1.3H rather than the bottom in the range of pile length; the requirements of deformation control and overall stability of foundation pit can be satisfied with 0.5H which as the embedded depth of the pile, and the dip angle of anchor is appropriate when it ranges from 5°to 25°but less than 30°.

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.

scholarly journals Deformation Behavior of Deep Foundation Pit under Both Overloading and Unloading Conditions

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Wei Gang ◽  
Zhou Xin-Xin ◽  
Xu Yin-Feng ◽  
Zhang Li ◽  
Zhang Xin-Hai
Keyword(s):  
Maximum Rate ◽  
Earth Pressure ◽  
The South ◽  
Deep Foundation ◽  
Foundation Pit ◽  
South Side ◽  
Deep Foundation Pit ◽  
High Rise ◽  
The North ◽  
North Side

A deep foundation pit in a station of the Hangzhou subway is adjacent to new high-rise residential buildings on the north side and to the Evergrande foundation pit being excavated on the south side. This work considers the excavation of the foundation pit in the subway station as the research subject, focuses on the difference of the deformation and Earth pressure between the north side and the south side of the foundation pit under these special working conditions through the analysis of the measured data, and compares it with an ordinary foundation pit. Analyzing the measured data reveals that the horizontal displacement of the retaining wall and the ground settlement are far larger on the north side than on the south side, and both often exceed the deformation alarm value; the deformation of the ordinary foundation pit is between the deformation of the overloaded (north) side and that of the unloaded (south) side of the foundation pit. Moreover, the maximum rate of the horizontal creep of the soil and the maximum rate of the creep caused by the ground settlement on the north side of the foundation pit are larger than those on the south side of the foundation pit; the maximum rate of the horizontal creep of the ordinary foundation pit is between the two. The active Earth pressure on the pit wall on the north side is higher than that on the south side of the foundation pit, and because of the surrounding unloading, passive Earth pressure is generated at the bottom of the pit wall on the south side of the foundation pit, which causes it to shift to the outside of the foundation pit. The settlement of the surrounding high-rise buildings and the settlement of the columns are all within the range of the alarm values; also, the buildings settle evenly. Due to the excavation and unloading on the south side of the foundation pit, the uplift of the columns is not considerable.

Numerical Simulation of Construction of Super-Large Deep Soft Soil Foundation Pits and Analysis of its Spatial and Temporal Effects

2015 ◽  
Vol 724 ◽  
pp. 79-83
Author(s):  
Xiao Qin Wang ◽  
Ting Ting Sun
Keyword(s):  
Constitutive Relations ◽  
Soft Soil ◽  
Earth Pressure ◽  
Deep Foundation ◽  
Support Structure ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Deep Soft Soil

The constitutive relations of soil in the super-large deep foundation pit project and the law of interaction between soil and the support structure were studied. The excavation of the foundation pit was simulated. The coupling of soil and the support structure and the change in earth pressure with the progress of excavation were analyzed, and the scope of influence of foundationsubsidence was obtained.

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