EXPERIMENTAL STUDY ON REINFORCED-AT-HIGH-STRESS-REGION SOIL-CEMENT RETAINING STRUCTURE FOR DEEP FOUNDATION PIT

2005 ◽  
Author(s):  
DAYU ZHU
Keyword(s):  
Experimental Study ◽  
High Stress ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Retaining Structure ◽  
High Stress Region ◽  
Soil Cement ◽  
Stress Region

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.

scholarly journals Investigation of the Axial Force Compensation and Deformation Control Effect of Servo Steel Struts in a Deep Foundation Pit Excavation in Soft Clay

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Honggui Di ◽  
Huiji Guo ◽  
Shunhua Zhou ◽  
Jinming Chen ◽  
Lu Wen
Keyword(s):  
Axial Force ◽  
Soft Soil ◽  
Control Effect ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Deformation Control ◽  
Retaining Structure ◽  
Hydraulic Servo ◽  
Ordinary Steel

This study presents a comparative analysis of the deformation control effect of the hydraulic servo steel struts and ordinary steel struts of a foundation pit based on the measured axial force of the steel struts, lateral wall deflection, and ground surface settlement due to pit excavation. The results indicate that ordinary steel struts installed via axial preloading exhibit a disadvantageous axial force loss with a maximum value equal to 86.7% of the axial preloading force. When compared with ordinary steel struts, the hydraulic servo steel strut exhibits a superior supporting effect. The hydraulic servo steel strut adjusts the axial force in real time based on the deformation of the retaining structure and the axial force of the struts. Thus, the ratio of maximum lateral deflection to the excavation depth of a deep foundation pit in soft soil is less than 0.3%. Concrete struts undergo unsupported exposure during the excavation process, leading to sharply increasing deformation of the retaining structure. Therefore, regarding a foundation pit with strict requirements for deformation control, the use of hydraulic servo steel struts rather than concrete struts is recommended.

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.

scholarly journals Retaining Structure Force-Deformation Analysis Model for an Ultradeep Foundation Pit

2013 ◽  
Vol 2013 ◽  
pp. 1-18
Author(s):  
Qi Hu
Keyword(s):  
Load Level ◽  
Mode Analysis ◽  
Deformation Analysis ◽  
Analysis Model ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Element Analysis ◽  
Foundation Soil ◽  
Deep Foundation Pit ◽  
Retaining Structure

An ultradeep foundation pit is a complex system composed of a retaining structure, foundation soil, and groundwater. Design and construction of foundation pits for use at greater depths than in the past require continual improvement in the design methods and analysis methods applied. In this paper, a load-deformation analysis model of a retaining structure based on a bearing-mode analysis of an ultra-deep foundation pit is proposed. A calculation method was theoretically derived for the horizontal foundation stiffness coefficient for this model, and the influences of factors such as space size, stress path, load level, and seepage were analyzed. A numerical example and a case study of an ultra-deep foundation pit in the Hangzhou Metro Line number 1 test section are presented. The calculated results for deformation of the structure and for earth pressure were found to be similar to the results obtained from elastic-plastic finite element analysis and similar to the measured results. The results of this study indicate that the proposed analysis model adequately reflects the force-deformation characteristics of an ultra-deep foundation pit and show that the proposed analysis model appropriately considers the influences of various factors.

Analysis of Foundation Pit Deformation Monitoring Results about Xia Shengou Station in Shenyang

2013 ◽  
Vol 838-841 ◽  
pp. 858-862 ◽  
Author(s):  
Bin Zhang ◽  
Rong Jin ◽  
Xiang Lian Yu
Keyword(s):  
Ground Surface ◽  
Deformation Monitoring ◽  
Time Effect ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Retaining Structure ◽  
Pile Deformation ◽  
Northeast Of China ◽  
Ground Surface Subsidence

In the northeast of China,the research of subway foundation pit is still infancy,which needs enriching. This paper relies on the deep foundation pit engineering of Xiashengou Subway Station in Shenyang. Through the analysis of deformation foundation pits to study deformation characteristics.Through the monitoring data,we can know that combined the bored and steel support the deformation of the retaining structure and the ground surface subsidence can be well controlled.The deformation of the envelope and the surface has a strong time effect and increases with time,in the excavation stage,pile deformation presented randomness. In the excavation stage, pile deformation presented randomness.When the excavation completed 45 days,from the top of the pile to the pile at 13m depth,the lateral volume is almost equal, and thus down to the pile end the lateral volume gradually becomes zero.

Study of Seepage and Stability of Foundation Pit under Continuous Rainy Conditions

2014 ◽  
Vol 501-504 ◽  
pp. 83-87
Author(s):  
Zeng Rong Liu ◽  
Hai Bing Qiu ◽  
Ming Qing Peng
Keyword(s):  
Water Content ◽  
Pore Pressure ◽  
Functional Relationship ◽  
Pressure Field ◽  
Soil Layer ◽  
Strength Theory ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Retaining Structure

Based on unsaturated soil seepage and shear strength theory , to explore the pore pressure dissipation law , it has been analyzed seepage about slope of deep foundation pit in Xian , supporting by pile-anchor retaining structure under the condition of continuous rainy by MIDAS software . The simulation result shows a temporary saturated region would appear on the surface of slope in continuous rainy days , then soil water content increasing as the rainwater infiltrate into a deeper soil layer gradually .For the sake of different cohesion of different time , Combine moisture filed , coming from pore pressure field , with the functional relationship between water content and cohesion , of simulated with filed test dates .The influence law of continuous rainy is derived from stability analysis by strength reduction fem about slope safety factor and stress of retaining structure .

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