Two-Dimensional Numerical Simulation Analysis of the Diaphragm Wall Earth Pressure and Deformation Used the Cover Reverse Construction Excavation Method

2011 ◽  
Vol 243-249 ◽  
pp. 2732-2737
Author(s):  
Hong Bo Guo ◽  
Ke Sheng Ding ◽  
Yi Jia Zhang ◽  
Xu Li
Keyword(s):  
Simulation Analysis ◽  
Soft Soil ◽  
Constitutive Models ◽  
Earth Pressure ◽  
Diaphragm Wall ◽  
Deep Foundation ◽  
Construction Methods ◽  
The Earth ◽  
Test Parameters ◽  
Practical Engineering

The cover reverse construction excavation is one of the important construction methods which is used in digging extra-deep foundation system of underground continuous wall supporting. The earth pressure distribution and deformation is distinct from different construction methods. Even if the Construction methods and computer program is homogeneous, the earth pressure and deformation of the calculated showed various results because of different test parameters and different constitutive models, Through the application of practical engineering, The appropriate calculation parameters and constitutive model are found out in Abaqus program which is suitable for earth pressure and deformation of the diaphragm wall in the soft soil area.

Analyses of Earth Pressure on Gridding Concrete Retaining Wall in the Excavation of Deep Foundation Pit in Soft Soil Area

2011 ◽  
Vol 52-54 ◽  
pp. 2181-2186
Author(s):  
Guang Zhu Zhou ◽  
Xu Wei ◽  
Chen Yu
Keyword(s):  
Retaining Wall ◽  
Soft Soil ◽  
Earth Pressure ◽  
Front Wall ◽  
Three Dimension ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Finite Element Software ◽  
The Earth ◽  
Practical Engineering

This paper is mainly to study earth pressure on Gcrw used as a new kind of supporting structures in the excavation of deep foundation pits in soft soil region. On the basis of the simulation of step by step excavation by using big finite element software Abaqus/CAE and considering three-dimension elastoplastic stress state, the characteristics of different earth pressure are systematically discussed upon practical engineering. By comparing simulation results with calculated results based on calculation formula of Rankine Theory, it can be seen that the earth pressure in active zone is different from theoretic active earth pressure and earth pressure at rest while walls and soil in the gridding are regarded as a whole, which is greater than the former and somewhere similar to the latter, the earth pressure in passive zone is bigger than theoretic value of passive earth pressure, it is the tensive force from partition wall that prevent the front wall from overturning. These conclusions will be helpful for design and construction of new retaining wall.

Research on the Prefabricated Prestressed Cylinder Foundation of Wind Turbines in the Soft Soil Region

2011 ◽  
Vol 368-373 ◽  
pp. 461-464
Author(s):  
Ren Le Ma ◽  
Ming Yi Zhang
Keyword(s):  
Large Scale ◽  
Wind Farm ◽  
Rapid Development ◽  
Soft Soil ◽  
Earth Pressure ◽  
Element Analysis ◽  
Inland Wetlands ◽  
Lateral Earth Pressure ◽  
Practical Engineering ◽  
Improved Design

With the rapid development of inland wind farm in China, the costal wind farm still has not got large-scale development as the result of the higher cost of fan foundation and the more difficulty of construction. The prefabricated prestressed cylinder foundation (PPC foundation), as a new type of wind turbine foundation designed for the soft soil region such as the inter-tidal coastal zone and inland wetlands, is introduced in this paper. The condition of lateral earth pressure distribution around the foundation which determines the flexural capacity of fan foundation in the soft soil is studied. Through theoretical analysis and mathematical derivation, the result shows that the lateral earth pressure around PPC foundation is changed with depth by 1.5th power curve which has good fitting to the finite element analysis result. The simplified and improved design process is applied into the practical engineering and the good economy of PPC foundation is proved.

scholarly journals An Experimental Study on the Ecological Support Model of Dentate Row Piles

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Yousheng Deng ◽  
Zhihe Cheng ◽  
Mengzhen Cai ◽  
Yani Sun ◽  
Chengpu Peng
Keyword(s):  
Building Materials ◽  
Soft Soil ◽  
Earth Pressure ◽  
Shallow Foundation ◽  
Laboratory Model ◽  
Foundation Pit ◽  
Maximum Displacement ◽  
Single Row ◽  
The Earth ◽  
Soil Foundation

Bamboo is highly renewable and biodegradable with good short-term strength, which meets the requirement for temporal support structures in shallow foundation pits. Based on this, we conducted a laboratory model test on the dentate bamboo micropile support structure combined with environmentally friendly building materials and new type of piles, to explore the stress characteristics, stress change regularity, and the support effect of the system in soft soil foundation pits. The results show that the earth pressure on the pile sides above the excavation surface gradually decreases with an increase in the excavation depth. The bending deformation of the bamboo pile was also significant. The results also show that the earth pressure and the pile strain below the excavation surface change slightly during the excavation process. When the short sides of the foundation pit were loaded, the highest strain was recorded in the piles 4 and 11. A maximum strain of 358.93 με was recorded, and the maximum displacement of the pile in the top part was obtained to be only 2.14 mm. The most subsidence of dentate pile obtained is only 1.88 mm, whereas that of the single-row pile is 2.35 mm. Compared to the traditional single-row pile, the dentate piles can effectively reduce the horizontal deformation as well as the surface subsidence effectively. They can also support more external lateral load, and hence maintain the foundation stability and give better support. The results provide a theoretical basis for ecological bamboo support technology and have great value to be promoted.

Prediction and analysis of subsidence induced by shield tunnelling in the Madrid Metro extension

2002 ◽  
Vol 39 (6) ◽  
pp. 1273-1287 ◽  
Author(s):  
Manuel Melis ◽  
Luis Medina ◽  
José M Rodríguez
Keyword(s):  
Earth Pressure ◽  
Tunnel Construction ◽  
Pressure Balance ◽  
Ground Movements ◽  
Construction Methods ◽  
The Earth ◽  
Predictive Methods ◽  
Shield Tunnelling ◽  
Earth Pressure Balance ◽  
Numerical Modelling And Analysis

The development of tunnelling projects under heavily populated cities has been rapidly increasing around the world during the last decades. Since tunnel construction can have disastrous effects on buildings, structures, and utilities near the excavation, construction methods have necessarily to provide maximum safety inside and outside the tunnel. To predict and correct dangerous ground movements due to the tunnelling works, the authors developed a numerical model to simulate the earth pressure balance (EPB) excavation procedure and injection to complement some deficiencies found in previous analytical or empirical subsidence estimating procedures. This model takes into account the full excavation sequence and has been validated by a large amount of monitoring data from the previous Madrid Metro extension. In the present paper, several predictive methods are used to predict the ground movements generated during a new Madrid Metro extension project consisting of 48 km of tunnel (1999–2003). At the end of the works the results will be compared with data from monitored sections placed in all five cities linked by the extension. Conclusions about the applicability and accuracy of the methods will be established with the aim of helping researchers and engineers in their future projects.Key words: ground movements, monitoring, numerical modelling and analysis, settlement, tunnels.

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.

scholarly journals Deformation Law of the Diaphragm Wall during Deep Foundation Pit Construction on Lake and Sea Soft Soil in the Yangtze River Delta

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yuan Mei ◽  
Dongbo Zhou ◽  
Xueyan Wang ◽  
Liangjie Zhao ◽  
Jinxin Shen ◽  
...  
Keyword(s):  
Soft Soil ◽  
Yangtze River Delta ◽  
Diaphragm Wall ◽  
Lateral Deformation ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Deformation Law ◽  
Wall Deformation ◽  
Subway Stations

So far, there have been a large number of diaphragm walls in the Yangtze River Delta as engineering examples of deep foundation pit maintenance structures in subway stations, but there is a lack of systematic research and summary on the deformation characteristics of ground connecting walls. This study aimed to clarify the deformation law of the diaphragm wall during the excavation of a deep foundation pit in a soft soil region. Based on the monitoring data of the diaphragm wall of the deep foundation pit of the Hangzhou metro station, the monitoring data of the deep foundation pits of 15 subway stations in Shanghai and Ningbo cities around Hangzhou were considered. Grouping and classification methods were used to analyze the similarities and differences in the deformation characteristics of the diaphragm wall in the three regions. The results indicate the following: the maximum lateral deformation of the diaphragm wall in Hangzhou increases linearly with the relative depth of the maximum lateral deformation. The maximum lateral deformation of the foundation pit in Hangzhou is 0.072% H∼0.459% H, with a mean of 0.173% H. The wall deformation in Hangzhou varies significantly with the depth of the foundation pit, but the influence of the depth of the foundation pit on the wall deformation is considerably less than that in Shanghai and Ningbo. The corresponding position of the maximum lateral deformation in the excavation depth increases linearly with the excavation depth of the foundation pit, and the corresponding position of the lateral deformation of the diaphragm wall in Shanghai is more affected by the excavation depth of the foundation pit. The lateral deformation of the diaphragm wall increases rapidly in the range of 0 H–0.5 H, and the maximum lateral deformation occurs at 0.5 H–1.1 H.

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.

Performance Simulation Analysis and Design of the Scale Model for the Earth Pressure Balance Shield

2011 ◽  
Vol 346 ◽  
pp. 364-371 ◽  
Author(s):  
Xu Chen ◽  
Zhu Feng Shao ◽  
Xiao Qiang Tang ◽  
Ping Fa Feng
Keyword(s):  
Optimization Design ◽  
Driving Forces ◽  
Simulation Analysis ◽  
Earth Pressure ◽  
Scale Model ◽  
Pressure Balance ◽  
Analysis And Design ◽  
The Earth ◽  
Earth Pressure Balance ◽  
Epb Shield

Referring to the Earth Pressure Balance (EPB) shield with the diameter of 6.25m, a new experiment station of EPB shield is proposed, which is loaded with mechanical structure instead of traditional soil box. The structure of the experiment model is designed for the performance analysis of the EPB shield. The mechanical loading device, which is called the soil simulator, can simulate different geological environments. The soil simulator is capable of realizing three work states, such as earth balance pressure, earth under pressure, and earth over pressure. By adopting virtual prototype technology, parametric model of the shield station is established and the co-simulation scheme is determined. Besides, the kinematic analysis as well as variation principles between the displacement and driving forces of the propulsion system are obtained, which build the foundation for optimization design and control of the shield prototype.

Study on Engineering Materials with the Comparison and Discussion of Support Scheme in a Foundation Pit

2013 ◽  
Vol 788 ◽  
pp. 623-626
Author(s):  
Zheng Zhen ◽  
Ren Wang Liang
Keyword(s):  
Numerical Simulation ◽  
Shear Force ◽  
Simulation Analysis ◽  
Bending Moment ◽  
Engineering Material ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Cost Performance ◽  
Deep Foundation Pit ◽  
Practical Engineering

Taking a deep foundation pit engineering in Taiyuan as research background, this paper used two different supporting structure of foundation pit to make numerical simulation analysis by using Li zheng software. The engineering material had high cost performance. In addition, the paper studied the displacement, bending moment, shear force with the change of the excavation depth, and it came to the conclusion that some outcome can be used for reference in the practical engineering.

scholarly journals Optimizing Basement Construction Methods

2021 ◽  
Vol 1 (3) ◽  
pp. 51-61
Author(s):  
Nguyen Huu Bao
Keyword(s):  
Retaining Walls ◽  
Diaphragm Wall ◽  
Construction Work ◽  
Underground Part ◽  
Construction Costs ◽  
Deep Foundation ◽  
Construction Methods ◽  
Technical Requirements ◽  
Floor Structure ◽  
Ground Stability

The underground part of SSG TOWER includes 4 basements, 4 basements at a height of -13.2m. Combined with the construction of 3m deep foundation, therefore, the minimum excavation depth is required to -16.2m. Due to the construction work in residential area, relatively ground, with large excavation depth and geology of the interaction area (clay layer up to 30m), the options for using diaphragm wall with drilled piles Small area, Laser piles or solier piles to make retaining walls during construction do not have that feature, so the author chooses the option of using reinforced concrete barrette walls for retaining walls during construction and as tunnel walls for this project. The semi-topdown construction method was chosen to ensure safety during construction because the excavation depth of the work is quite large and the geology of this area is quite weak. This measure completely solves the strut system because using the floor structure of the building to support this system has high stability. Limiting the influence of settlement, cracking, and slippage to neighboring works a lot. Fast construction but in return for high technical requirements, high construction costs. Choose diaphragm wall thickness of 1.0m, base depth of 46.6m including standard barrete panels.  The author uses 2D Plaxis simulation to calculate ground stability, stress and displacement, moment, and shear force generated in diaphragm wall during basement construction. The author analyzes using the optimization algorithm to compare and find the suitable solution.

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