Numerical Analysis of the Construction Influence of Deep Foundation Pit on Adjacent Open Trench Tunnel

2011 ◽  
Vol 94-96 ◽  
pp. 1902-1907
Author(s):  
Cong Shi Wu ◽  
Wei Da Shen ◽  
Gong Liu

The open trench D ramp of Yingpanlu Xiangjiang tunnel in Changsha and the adjacent building foundation pit construction were excavated almost at the same time. The minimum distance between the two pits was only 8 meters, and keeping both projects safe working became difficult in engineering. Therefore a special project example of numerical analysis model was established, which can simulate the whole construction course. The construction stress was analyze by combining with the soil and retaining structures displacement, and the results were compared with the actual measured data to provide a reference to the design and construction optimization.

2012 ◽  
Vol 446-449 ◽  
pp. 1922-1926
Author(s):  
Chang Zhi Zhu ◽  
Xing Lian Zheng

Based on a project, a numerical analysis model was established by the finite difference program and the process of the deep excavation and support was simulated by computer, the distribution of the horizontal displacement and settlement of the top of slope of the slope soil were obtained. The simulation result was consistent with the test results. It shows that the method of numerical analysis can be used to the simulation of the excavation and support of Deep Foundation Pit, and it will provide the basis for the design and construction of practice project.


2014 ◽  
Vol 638-640 ◽  
pp. 538-541
Author(s):  
Zi Mao Peng

Based on the introduction of the characteristics of the supporting project of a large building foundation pit, the paper analyzed the main reasons for side wall collapse and pile fracture, including leakage water in the backfill soil, complex geological environment and unreasonable soil pressure value, low safety factor and improper design parameters, and then respectively proposed three kinds of treatment schemes for side wall sliding and pile breaking, landslides and other dangers. Finally, tracking observation showed that the satisfactory effect can strongly verify the suitability and validity of the main control parameters for the deformation of deep foundation pit, which may provide reference for the design and construction of similar projects.


2010 ◽  
Vol 44-47 ◽  
pp. 173-176
Author(s):  
Dong Ming Yu ◽  
Zhi Qin Liu ◽  
Feng Guang Chen

The supporting piles of deep foundation pits are usually made in reinforced concrete materials and rarely in prestressed concrete materials. But prestressed concrete materials have higher stiffness and less deformation and are suitable for controlling displacements or settlements. So, in this paper a practical engineering project as an example, the prestressed concrete supporting piles of the deep foundation pit are calculated and designed. Then, the settlement and inclination of the building adjacent the foundation pit with the prestressed concrete piles are calculated in the numerical software, FLAC. The results calculated in FLAC are compared with the actual settlement and inclination of the adjacent building during the foundation pit is excavated. The comparison confirms the feasibility of the supporting structure. This is a useful trial on the design of the prestressed concrete supporting piles.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Bo Li ◽  
Cangqin Jia ◽  
Guihe Wang ◽  
Jun Ren ◽  
Gaofeng Lu ◽  
...  

Based on the Yongdingmen Station of Beijing Metro, the underwater excavation method for deep foundation pit was introduced. This study constructed a numerical analysis model to analyze the performance of surface settlement and lateral wall deflection in the process of underwater excavation. Results showed that this method was better to control the surface settlement and lateral wall deflection compared with other dewatering excavations. In detail, most of the surface settlement was caused during the dry excavation stage and dewatering excavation stage while the deflection caused by underwater excavation only accounted for about 10% of the total settlement. Besides, the maximum settlement occurred 0.25∼0.5 H e behind the retaining wall and the value was 0.04% H e . Similar to the result of the surface settlement, most of the lateral wall deflection had been completed before the underwater excavation, which only caused about 7% of the total deflection. The maximum wall deflection and its location were approximately 0.06% H e and 0.5 H e , respectively. Moreover, a series of 3D numerical analyses were studied on the design parameters of the underwater excavation method. This study can be used as a reference for general performance and structural design of foundation pits with underwater excavation.


2012 ◽  
Vol 170-173 ◽  
pp. 223-226 ◽  
Author(s):  
Xue Song Gao ◽  
Jian Jun Dong ◽  
Xu Zhao ◽  
Peng Yang Yin ◽  
Shao Hua Lv

The FLAC3D was used to the fluid-solid coupling numerical simulation of considering the initial state of unsaturated to soil for the deep foundation pit engineering under different rainfall infiltration conditions. By comparing the bending moment, the shearing stress and internal forces of support under the infiltration conditions between non-rainfall and rainfall, the paper focus on the stability of deep foundation pit. Research on the stability of deep excavation under rainfall conditions was a useful attempt. From the detail study of the stability of a foundation pit of Qinhuangdao under rainfall infiltration conditions, the paper have drawn some useful conclusion on the design of building foundation pit, which can be the basis of excavation design and construction under rainfall conditions.


2011 ◽  
Vol 383-390 ◽  
pp. 7713-7717
Author(s):  
Chong Fu Wu ◽  
Chang Hong Li

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.


2010 ◽  
Vol 168-170 ◽  
pp. 652-657
Author(s):  
Li Ping Wen ◽  
Su Li Wang ◽  
Xu Ping Zhu

Taking the design of composite soil-nailing in deep foundation pit in complex surroundings for example, the paper discusses numerical analysis of soil-nailing using FLAC, a general analysis program of geotechnical engineering, used to predict the displacement and interior force in soil-nailing. Furthermore, a comparison about the interior force in soil nails between the numerical analysis and the traditional methods is made. The measurements show that the numerical analysis is more accurate than traditional methods. The conclusion is drawn that by contrast with the deficiency of traditional methods, more satisfactory results can be got from numerical analysis on composite soil-nailing using the program of FLAC.


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