Interaction Analysis of Foundation Pit Excavation and Adjacent Existing Building's Pile Foundation

2014 ◽  
Vol 501-504 ◽  
pp. 286-290
Author(s):  
Shan Shan Xu ◽  
Qiu Sheng Gao

Construction site-monitoring on adjacent existing building’s pile foundation,using ANSYS finite element software to simulate the deformation of adjacent pile foundation when foundation pit excavation. Combined with measured data to analyze the interaction of foundation pit excavation and adjacent existing building’s pile foundation and draw the conclusion that the measured settleme-nt of pit’s adjacent pile is greater than the model’s theoretical value and the pit excavation has certain influence on the pile foun-dation’s vertical displacement of existing buildings.

2011 ◽  
Vol 55-57 ◽  
pp. 193-196
Author(s):  
Xin Gui Zhang ◽  
Xiang Gang Kong ◽  
Zhen Song

In this paper, based on measured data of practical engineering, the characters of single short pile under the static vertical load action in the normal stratum combination model of dualistic structure has been simulated by using ABAQUS finite element software. Then simulated result and measured one has been compared and analyzed carefully. The analysis result indicated the applicability and reliability of ABAQUS finite element software in the simulation analysis of short pile. All these can provide some theoretical reference for design of short pile foundation.


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.


2014 ◽  
Vol 651-653 ◽  
pp. 1201-1204
Author(s):  
Fang Guo

In order to study the vertical displacement distribution of foundation pit in the process of step-by-step excavation, combined with a foundation pit project, numerical simulation analysis with finite element software was carried in the research. The results show that: in the process of excavation, the maximum settlement of soil outside the pit is 41.4 mm, which is 2.95 ‰ of pit excavation depth and conforms to the recommended value in specifications. The maximum vertical displacement of soil at the bottom of foundation pit is in the center of pit. Its value is gradually increasing with the excavation, and the maximum is 60.1 mm, which is 4.32 ‰ of foundation pit depth,also,it conforms to the specifications proposed value. The proposed scheme can satisfy the vertical displacement of foundation pit excavation in the construction process.


2013 ◽  
Vol 353-356 ◽  
pp. 640-643
Author(s):  
Jie Liu ◽  
Heng Heng Cao ◽  
Xiao Feng Jiang

This paper based on a foundation pit in Tianjin shown the monitoring data and simulated the excavation process by finite element software ABAQUS. The lateral and vertical displacement of the top of slope obtained by calculating at different excavation stages were compared with the measured values. At last this paper made a conclusion about the deformation rules in the process of excavation, which can provide reference for design and construction of similar engineering.


2012 ◽  
Vol 487 ◽  
pp. 855-859
Author(s):  
Shi Lun Feng ◽  
Yu Ming Zhou ◽  
Pu Lin Li ◽  
Jun Li ◽  
Zhi Yong Li ◽  
...  

Abaqus finite element software can implement three-dimensional excavation design calculation, so authors used Python of Abaqus core language made the 3D design of foundation pit supporting program come ture and also did intensive study of mesh optimization during the process. Authors also did intensive comparison and analysis about grid division of the complex geometry foundation pit, through a regularization partion about a variety of special-shaped pit, we made the automatic division about the structural grid of all kinds of shapes foundation pit successful. On this basis, we achieved better calculation effects of the model. The article will introduce problems about optimization of grid in procedure.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Hua-feng Shan ◽  
Shao-heng He ◽  
Yu-hua Lu ◽  
Wei-jian Jiang

Excavation beneath existing buildings may cause the superstructure to tilt and crack, which seriously affects the normal use of the superstructure. Due to the new working conditions of excavation beneath existing buildings, related case reports are rare and limited. In the case of No. 3 section basement construction project of Ganshuixiang, we monitored the excavation construction by burying test instruments at the designated location. Afterwards, Plaxis 3D finite element software was used to establish an underpinning pile-cap-excavation model, which can analyze the influence of different pile cutting sequences on the bearing behavior of new basement structural pillars. By comparing the in situ measurement data with the finite element model, it can be concluded that when the excavation depth rises, the axial force of the underpinning pile gradually increases, and the pile skin friction is slowly exerted from top to bottom. Different cutting sequences will influence the bearing behavior of the structural pillar. Moreover, the pile cutting process also significantly impacts its bearing behavior and the settlement behavior of the superstructure. Compared with the clockwise pile cutting sequence, the symmetrical pile cutting is more advantageous. In the whole process of the storey adding and reconstruction, the superstructure settlement is related to the working condition of digging and adding layers. In the stage from soil excavation to the concrete curing period of the structural pillar, it increases slowly with time and tends to be stable in the concrete curing period. However, in the pile cutting stage, the superstructure settlement increases sharply, and after pile cutting, it becomes stable.


2013 ◽  
Vol 353-356 ◽  
pp. 11-15
Author(s):  
Deng Qun Wang ◽  
Yan Peng Zhu

Finite element software was employed to establish a model to simulate the compound soil nailing. The model simulates the process of constructing prestressed compound soil nailing. Compared the condition prestressed with no prestress, analyzed the Impact of prestress anchor on the deformation in the process of construction and the effect on axial force of soil nail. Applying prestress is able to control the horizontal displacement obviously, but has not obvious effect on vertical displacement, especially place the anchor bolt at the lower part of the slope. In the process of construction, prestress has an advance effect on the deformation of foundation pit and the axial force of soil nails near the anchor bolt.


2010 ◽  
Vol 456 ◽  
pp. 103-114
Author(s):  
Shi Ling Xing ◽  
Jian Shu Ye ◽  
Hang Sun

In order to use finite element software to complete the design or calculation of bridge multi-pile foundation, this paper discusses the finite element model (FEM) of a bridge multi-pile based on the theory and provisions in Code for Design of Ground Base and Foundation of Highway Bridges and Culverts (CDGBFHBC 2007) of china. For the FEM of a bridge-multi pile foundation, cap is regarded as a rigid body, piles are taken as beams, and boundary constraints are a series of horizontal springs and vertical springs. First, the formula of stiffness for horizontal springs and bottom vertical spring is derived according to elastic ground base theory and winkler hypotheses. Secondly, for the friction pile, the stiffness of vertical springs on piles side is derived basis of the principle of friction generated and simplified distribution of pile shaft resistance. Then, the FEM of multi-pile needs pay attention to three issues: the simulation of connections between piles and cap, elastic modulus needs discount, and the weight for pile underneath the ground line (or local scour line) needs calculate by half. Taking pile section bending moment often control the design and calculation of pile into account, this paper gives a simplified FEM of pile. Finally, an example is used to introduce the application of the FEM of bridge multi-pile foundation.


2012 ◽  
Vol 170-173 ◽  
pp. 1419-1426
Author(s):  
Yong Tao Gao ◽  
Qing Liang Wu ◽  
Shun Chuan Wu ◽  
Mao Wei Ji ◽  
Ai Ping Chen ◽  
...  

Because of the Limited urban space and the development of transport, underground space development, especially the metro construction, is vigorously developed in many cities. Subway passing through the existing building inevitably may cause the settlement and deformation of the buildings and their foundations. Therefore, research on the influence of tunneling on existing buildings has important significance. In order to study the influence of tunneling on settlement of existing pile foundations, soil elastic modulus, cohesion, friction angle, tunneling sizes, distance between tunnel opening boundaries and existing pile foundation etc. are discussed as analysis factors in this paper. The calculation schemes are designed based on orthogonal design, and then the influence of tunneling on existing buildings is researched according to the numerical calculation model which is established by the finite element software. Finally, the sensitivity of pile foundation settlement to various factors is analyzed according to the results of simulation analysis. we can draw the conclusions: the influence of tunneling on settlement of existing pile foundation is positively correlated with tunneling sizes, and is negatively correlated with soil parameters and distance between tunnel opening boundaries and existing pile foundations; The settlement of pile foundations can be effectively controlled by application of composite anchor isolation piles around the existing buildings piles, but with the increase of soil parameters and distance between tunnel opening boundaries and existing pile foundations, the strengthening effects are decreased; soil elastic modulus and excavation sizes are the key impact-factors of pile settlement within the distance of 5m between tunneling boundaries and existing pile foundations, which have extremely remarkable effect on the subsidence of pile foundations.


Author(s):  
José Manuel Avila Aguilar ◽  
Raul Lesso Arroyo ◽  
Jorge Martínez Cruz

The finite element analysis is a useful tool to investigate the behavior of a body subjected to different loads. The objective of this work was the analysis of an aluminum diesel piston provided with a cooling gallery, Cu-Zn bushings, and a Ni-resist insert. This piston is used in 1.9 L turbodiesel engines. The investigation was undertaken in order to observe the mechanical behavior of the piston at the operating temperatures and pressures and thus to study the performance of the different parts of the piston. The analysis was performed using a finite element software, taking into account a coupled field analysis and involving a fluid passing through the cooling gallery, temperature and pressure at the piston head which resulted in heat flow and thermo-mechanical stresses in the piston. According to the obtained results, it is worth noting the important role of Cu-Zn bushings in the piston as they support the highest stress of about 359 MPa and protect the piston against failure, and these bushings are able to support more stress that the body of the piston (aluminum yield stress limit 290 MPa). Also it is observed that the cooling gallery acts as a thermal barrier by preventing the heat flow from the head piston (approximately 213 ° C) toward the piston body (approximately 80 ° C). Another important aspect is the structural thermal interaction analysis and it can be observed the influence of high temperatures in the piston, increasing stress up to 100%. Finally it was concluded that the piston is able to withstand the operating pressures and temperatures.


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