SUBSTANTIATION OF ASCENDING ANCHOR SUPPORT EFFECTIVENESS AND THE ESTIMATION OF DEEP FOUNDATION PIT WALL BARRIERS STABILITY

Author(s):  
Vikulov Vladimir Mikhailovich ◽  
Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1303
Author(s):  
Chenghua Shi ◽  
Xiaohe Sun ◽  
Shengli Liu ◽  
Chengyong Cao ◽  
Linghui Liu ◽  
...  

At present, jet-grouted horizontal waterproof curtain reinforcement has become an essential method for deep foundation pit groundwater control. However, there is still a lack of an effective theoretical calculation method for horizontal waterproof curtain reinforcement, and there is little research on the seepage laws of foundation pits under different horizontal waterproof curtain conditions. Based on Darcy’s seepage theory, theoretical analysis models of deep foundation pit seepage were established considering the effect of a horizontal curtain in a highly permeable formation. Through the established models, the calculation method of the water inflow and the water pressure under the condition of a horizontal curtain was derived. Then through indoor tests, the reliability of the theoretical calculation method was verified. Furthermore, the established theoretical calculation method is used to analyze the influence of various factors on the water inflow and the water pressure, such as the ratio of hydraulic conductivity of the horizontal curtain to surrounding soil, thickness, and reinforcement position of the horizontal curtain. It is found that the hydraulic conductivity ratio has the most significant influence on the seepage characteristics of the foundation pit. Finally, the design method was applied to an example of the horizontal waterproof curtain of the foundation pit, which is located at Juyuanzhou Station in Fuzhou (China). The water inflow per unit area is 0.36 m3/d in the foundation pit, and this implies that the design method of the horizontal waterproof curtain applied for the excavation case is good and meets the requirements of design and safety.


2011 ◽  
Vol 90-93 ◽  
pp. 485-489
Author(s):  
Li Guo ◽  
Peng Li He ◽  
Guang Jun Zhang

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.


2015 ◽  
Vol 744-746 ◽  
pp. 579-583
Author(s):  
Hui Min Wang ◽  
Zhen Jian Ji ◽  
Liang Cao ◽  
Ji Yao ◽  
Shan Guang Qian

Deep Pit is the main content of modern urban geotechnical engineering. In this paper, based on a deep foundation pit engineering as an example, based on the nonlinear finite element theory, conduct a numerical simulation research for foundation pit excavation process. Obtained the distribution law of pit deformation, stress distribution and the supporting structure of the internal forces, under the various processes. These provide a theoretical basis for safety evaluation of foundation pit engineering.


Symmetry ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 581 ◽  
Author(s):  
Weilong Yang ◽  
Yue Hu ◽  
Cong Hu ◽  
Mei Yang

With the gradual expansion of high buildings and underground spaces, deep foundation pits have been widely used in these engineering projects, but if they are not well-designed, safety problems occur. Proper deep foundation pit design requires proper exit distribution. However, calculating an adequate number of exit distributions for evaluation is difficult due to the numerous influential factors existing in the deep foundation pit environment. To this end, this paper presents a prototype of a decision-making system that uses agent-based modeling to simulate deep foundation pit evacuation in the presence of collapse disaster. By modeling the collapse occurrence process and agent escape process, an agent-based evacuation model is built, and a modified simulation-based particle swarm optimization algorithm is used to solve the optimization problem of exit distribution. Extensive experiments are conducted to verify the system, and the results show that the system provides a feasible framework for deep foundation pit evacuation.


2012 ◽  
Vol 204-208 ◽  
pp. 2736-2739
Author(s):  
Guang Qian Du ◽  
Shi Jie Wang ◽  
Yan Ting Qin ◽  
Chang Zhi Zhu

Based on the pile - anchor structure soil between piles,the unified strength theory is introdued in the strength analysis of soil arching between the piles, and parabolic soil arching computational model is uniformly distributed loads ,which are given to meet the soil between piles arch static equilibrium conditions and intensity of conditions , pile spacing formula. Compared with calculations based on the pile spacing of the Mohr-Coulomb strength criterion , the proposed method can consider the contribution of the intermediate principal stress on the strength of the soil arch , the results are more in line with the actual characters of the supporting structure .


2020 ◽  
Vol 206 ◽  
pp. 01021
Author(s):  
Yueyao Zhao ◽  
Jiawei Zhang ◽  
Haojie Li

The reliable prediction of the surface vertical displacement deformation of deep foundation pits is of great significance to the excavation of large foundation pits. The support vector machine model (LIBSVM) has become a hot spot in the prediction of deep foundation pit deformation and provides a new prediction for the deformation of deep foundation pits. In this paper, taking the deep foundation pit of Daoxianghu Road Station in xx as an example, a prediction model of vertical displacement on the ground is established based on LIBSVM and analysis shows that the prediction results based on the model are in good agreement with the measured data, and the MSE reaches 0.0323. The model is effective and has an effective prospective skill.


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