Discussion on the Control and Monitoring of Groundwater in Deep Foundation Pit Engineering

2020 ◽  
Vol 5 (1) ◽  
pp. 14-16
Author(s):  
Jingyi Zhang ◽  
◽  
Hefei Li ◽  
Jie Yang ◽  
Xupeng Zhang ◽  
...  

Ground settlement is very important in the settlement of foundation pit soil, and this index is an important observation index. By comparing the results of the foundation pit deformation simulated by the MIDAS GTS/NX finite element software with the actual monitoring data, the deep foundation pit dewatering construction excavation support simulation under different working conditions is analyzed, and the deep foundation pit deformation is analyzed.

2011 ◽  
Vol 368-373 ◽  
pp. 1327-1331
Author(s):  
Wei Min Qiu ◽  
Hai Lin Zhang ◽  
Gang Wang

With the development of urban construction, deep large pits are often located at intensive underground structure area, and the utility pipe tunnel within various pipelines is the lifeline engineering of urban environment .Thus, there is the very necessary practical significance to research on utility pipe tunnel influenced by adjacent deep Excavation. Using large finite element software ANSYS, we analysis the problem with the deep foundation pit, support system, the soil around and adjacent tubes as an entirety. In considering of the mutual interaction between support structure and soil, as well as the element birth-death technology and restart analysis technology, the deep foundation pit mode is simulated and analyzed according to the actual construction process, including the gravity initial stress analysis and the simulation analysis on the each layer soil excavation. After simulation analysis the level of utility pipe tunnel’s horizontal and vertical displacement environment in different affecting factors and reinforcement measures, it is concluded that the law of utility pipe tunnel’s horizontal and vertical displacement, further the reasonable economic measure is put forward to protect the safety of the utility pipe tunnel. Therefore the conclusion has certain reference value for designing the foundation pit construction and the protection measures on the adjacent utility pipe tunnel.


2011 ◽  
Vol 243-249 ◽  
pp. 2543-2547
Author(s):  
Shi Lun Feng ◽  
Yong Han ◽  
Jun Li ◽  
Pu Lin Li ◽  
Jie Liu

Through the analysis on monitoring data of the deep foundation pit in Tianjin, it was observed that the lateral deformation of the retaining wall at the corner was smaller than the deformation in the middle. Based on the analysis of the results drawn from finite element simulation of the excavation process and the monitoring data, appropriate supporting structure stiffness parameters values used in Plaxis and Qimingxing are recommended for designing deep foundation pits in soft soil area.


2022 ◽  
Vol 2148 (1) ◽  
pp. 012061
Author(s):  
Zhao Long ◽  
Yilei Shi ◽  
Weili Li ◽  
Shuaihua Ye

Abstract In this paper, the influence of space effect on soil pressure and deformation of deep foundation pit was considered, and the finite soil pressure calculation model was established. The soil pressure of deep foundation pit was calculated by assuming the slip surface and using the finite soil limit equilibrium theory. Then, PLAXIS 3D finite element software was used to establish finite element models of different plane sizes and depths. The distribution regulation of side wall soil pressure and deformation of deep foundation pit was calculated. Finally, the results of finite soil pressure calculation was compared with finite element method. The results shown that: The soil pressure of small deep foundation pit was affected by space effect, and the soil pressure and deformation decrease significantly along the foundation pit depth. Shear fracture Angle was related to the ratio of width to depth of foundation pit, and it was no longer a constant value of 45°+φ/2. Therefore, the spatial effect should be considered in the calculation of soil pressure of small deep foundation pit. The research results can provide some guidance for the design and calculation of similar small size deep foundation pit.


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.


2013 ◽  
Vol 443 ◽  
pp. 79-83
Author(s):  
Zhen Xi Yu

In recent years, with the enhancement of overall national strength in China, the computer simulation technology has been developed rapidly and widely applied to engineering construction. Particularly, investment proportion of the technology in deep foundation pit engineering is immense. Yet affected by national conditions in China, the construction and application of deep foundation pit engineering have many extensive factors. It also results in insufficient vigor of finite element analysis of deep foundation pit support construction. In this way, construction problems arise frequently under the condition that there exist buildings around. With some deep foundation pit support engineering, the thesis conducts simulation analysis of the engineering through the technology of nonlinear three-dimensional finite element.Project profile


2014 ◽  
Vol 580-583 ◽  
pp. 787-790
Author(s):  
Hai Xia Sun ◽  
Ke Zhang ◽  
Si Li Chen

This article mainly expounds the importance of in-situ monitoring on the construction process of deep foundation pit. Taking the deep foundation pit of some Shenyang metro station for example, the deformation features of the supporting structure and the internal and external of foundation pit is analyzed, according to the monitoring data of the fender pile displacement during the excavation of deep foundation pit. The conclusion is obtained that the timely and accurate in-situ monitoring information is necessary to guaranteeing construction safety. We should pay more attention to the excavation speed and exert the interior support timely during the excavation of foundation pit to avoid large deformation and danger. The analytical results of monitoring data shows that the whole stage of foundation pit excavation is stable and the fender pile with internal supports can guarantee the stability of foundation pit.


2012 ◽  
Vol 174-177 ◽  
pp. 2020-2023 ◽  
Author(s):  
Bing Wang

Based on a typical projects, the horizontal displacement in depth, horizontal displacement and vertical subsidence of pile top, and settlements of surrounding buildings are monitored with the process on digging of deep foundation pit. The study on digging process of foundation pit is analyzed by using finite element software. Using mapped meshing method, from mixing the pile near the semi-circular area (radius = 50m), the meshing appropriate encryption in order to improve the accuracy of the external semi-circular area (radius = 65m) mesh is less appropriate sparse.Layer by layer to kill the layers of the soil unit and activate the soil nails (spring element), the simulated excavation and synchronization of soil nails construction.Verify the arc form of failure surface in side of deep foundation pit in soft soil area. Which is valuable for reference to similar structure engineering of foundation pit.


2014 ◽  
Vol 1065-1069 ◽  
pp. 7-10
Author(s):  
Fei Fei Liang ◽  
Ren Wang Liang ◽  
Xing Hua Xiang

The excavation usually cause the settlement of surrounding soils, which will have a negative effect on the adjacent buildings. To find the effective measures to reduce the surface subsidence,a numerical model which is based on a project example is developed in this paper to analyze the settlement of surrounding soils during the excavation of a deep foundation pit by using FLAC3D.The influence of excavation on settlement outside the foundation pit is investigated when changing one of the factors which include reinjection pressures、waterproof curtain. The results show that: (1) The settlement of surrounding soils decreases gradually with the increase of reinjection pressures. Moreover ,the settlement with reinjection are around two times the value without reinjection.(2) The settlement of surrounding soils decreases gradually with the curtain depth increases. In the actual projects,we can decrease the settlement of surrounding soils by increasing the reinjection pressures and curtain depth.


2013 ◽  
Vol 438-439 ◽  
pp. 588-592
Author(s):  
Kai Yun Yang ◽  
Xiang Yu Li ◽  
Lin Hao Li ◽  
Quan Long Li

In view of the problems of complex geological conditions with high underground water level, large permeability coefficient of soil and the presence of large seepage hazard of deep cut canal and deep foundation pit project of South-to-North Water Transfer Project, China, research on seepage characteristics of digging canals under dewatering well is carried out by finite element analysis, and the FORTRAN procedure is programmed. The three-dimensional finite element model of a digging canal is built, and the seepage field of the different conditions of the canal is simulated, the water head distribution, saturation line and leakages are obtained, and the rules and characteristics of steady seepage field under design impervious system are analyzed. The results indicate that the method can exactly determine the key overflow point and saturation line of canal, and well predict seepage field in canal. The results should be of guiding significance to design and construct retaining engineering in deep cut canal and deep foundation pit.


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