scholarly journals Deformation analysis of retaining structure of deep foundation pit in soft soil under over-excavation

2019 ◽  
Vol 304 ◽  
pp. 032046
Author(s):  
Wang-Yan ◽  
Zhang-Fei
Keyword(s):  
Soft Soil ◽  
Deformation Analysis ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Retaining Structure

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.

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.

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