scholarly journals Research on Influence of Deep Foundation Pit Excavation and Dewatering on Pile Foundation of Railway Bridge

2021 ◽  
Vol 283 ◽  
pp. 01019
Author(s):  
Liu Tianyun ◽  
Yu Changyi ◽  
Zhu Nan
Keyword(s):  
Numerical Model ◽  
Pile Foundation ◽  
Three Dimensional ◽  
Railway Bridge ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Maximum Settlement ◽  
Limit Value ◽  
Construction Optimization

The three-dimensional numerical model of the foundation pit engineering is established, and the fluid-structure coupling method is used to calculate the settlement of the pile foundation of the adjacent railway bridge caused by the excavation and dewatering of the foundation pit. The results show that the settlement range of the soil around the foundation pit reaches 140m, and the pile foundation of the railway bridge is within the influence range, but the maximum settlement value does not exceed the limit value specified in the design. The method used in this paper provides effective guidance for the construction optimization of the same type of projects and reduces the project cost.

scholarly journals Evaluation of Deformation of Adjacent Buildings With Different Foundation Types Caused by Foundation Pit Excavation Under Combined Support of Isolation Pile and Diaphragm Wall

2021 ◽  
Author(s):  
Shaokun Ma ◽  
Fapai Tian ◽  
Zhen Huang ◽  
Hu Lu ◽  
Xiaoxi Fu ◽  
...  
Keyword(s):  
Pile Foundation ◽  
Horizontal Displacement ◽  
Diaphragm Wall ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Maximum Settlement ◽  
Deceleration Rate ◽  
Different Types ◽  
Diaphragm Walls

Abstract The process of excavation and unloading of a deep subway foundation pit will cause deformation of the surrounding buildings. There are significant differences in building deformation due to different methods of supporting the foundation pit and building foundation forms. This study takes the deep foundation pit project of the station as an example to investigate this difference. A three-dimensional numerical finite element model of a deep foundation pit has been established that considers different types of building foundations (independent foundation, box foundation, and pile foundation). The sensitivity of the two supporting methods of the diaphragm wall and the combined support of isolation pile and diaphragm wall regarding the maximum settlement value of the building, the horizontal inclination value, the slope angle, and the foundation angular distortions were analyzed. Finally, the sensitivity of the length of the isolated pile to the maximum settlement value and the horizontal displacement value of different types of building foundations are discussed. The results show that the combined support method of isolation piles and diaphragm walls has the highest supporting efficiency (93.5% of independent foundations and 42.3% of box foundations) for angular distortions of shallow foundation buildings. The efficiency of pile foundation support is the lowest (31.4%). For the combined support method of isolation piles and diaphragm walls, the maximum settlement value, and the value of horizontal displacement of the building will decrease with increasing the length of isolation pile. When the depth of isolation pile is greater than 24 m, the settlement deceleration rate of the independent foundation and the pile foundation slows down; when the depth of isolation pile is greater than 27 m, the settlement deceleration rate of the box foundation will slow down, and the deceleration rate of the horizontal displacement of the independent foundation and box foundation will slow down.

Non-Linear Three-Dimensional Finite Element Analysis of Some Extremely Deep Foundation Pit Support

2013 ◽  
Vol 443 ◽  
pp. 79-83
Author(s):  
Zhen Xi Yu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Element Analysis ◽  
Deep Foundation Pit ◽  
Three Dimensional Finite Element ◽  
Support Engineering

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

Analysis of Effect Factors about the Ground Settlement during Foundation Pit Excavation

2014 ◽  
Vol 1065-1069 ◽  
pp. 7-10
Author(s):  
Fei Fei Liang ◽  
Ren Wang Liang ◽  
Xing Hua Xiang
Keyword(s):  
Numerical Model ◽  
Surface Subsidence ◽  
Ground Settlement ◽  
Effect Factors ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Adjacent Buildings ◽  
Negative Effect

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.

scholarly journals Finite-Difference Numerical Simulation of Dewatering System in a Large Deep Foundation Pit at Taunsa Barrage, Pakistan

2019 ◽  
Vol 11 (3) ◽  
pp. 694 ◽  
Author(s):  
Ijaz Ahmad ◽  
Muhammad Tayyab ◽  
Muhammad Zaman ◽  
Muhammad Anjum ◽  
Xiaohua Dong
Keyword(s):  
Hydraulic Conductivity ◽  
Finite Difference ◽  
Three Dimensional ◽  
Rehabilitation Program ◽  
Diaphragm Wall ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Constant Head ◽  
Design Depth

This study investigates a large deep foundation pit of a hydraulic structure rehabilitation program across the Indus river, in the Punjab province of Pakistan. The total area of the construction site was 195,040 m2. Two methods, constant head permeability test and Kozeny–Carman equation, were used to determine the hydraulic conductivity of riverbed strata, and numerical simulations using the three-dimensional finite-difference method were carried out. The simulations first used hydraulic conductivity parameters obtained by laboratory tests, which were revised during model calibration. Subsequently, the calibrated model was simulated by different aquifer hydraulic conductivity values to analyze its impact on the dewatering system. The hydraulic barrier function of an underground diaphragm wall was evaluated at five different depths: 0, 3, 6, 9, and 18 m below the riverbed level. The model results indicated that the aquifer drawdown decreases with the increase in depth of the underground diaphragm wall. An optimal design depth for the design of the dewatering system may be attained when it increases to 9 m below the riverbed level.

Research on Deformation Monitoring on Supporting Structure of Deep Foundation Pit Engineering Based on GPS

2012 ◽  
Vol 239-240 ◽  
pp. 595-598
Author(s):  
Zhong Xin Liu ◽  
Xue Jian Zhang
Keyword(s):  
Effective Means ◽  
Three Dimensional ◽  
Automatic Monitoring ◽  
Deformation Monitoring ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Supporting Structure ◽  
Observation Methods ◽  
Safety Warning

High-rise building deep foundation pits affect the peripheral physiognomy deformations directly, and brings serious hidden danger．deformation monitoring on supporting structure of deep foundation pits engineering is an effective means of construction safety warning. Three-dimensional coordinates of observation points can be available by GPS high precision positioning, and it is easier to realize of continuous, real-time and automatic monitoring than conventional observation methods.

The Technique of Deep Foundation Pit and Pile Foundation Construction

2012 ◽  
Vol 204-208 ◽  
pp. 308-311 ◽  
Author(s):  
Rui Li ◽  
Yi Qiao ◽  
Yong Jie Liu
Keyword(s):  
Pile Foundation ◽  
Construction Technology ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Construction Technique ◽  
Deep Foundation Pit ◽  
Foundation Construction ◽  
High Rise ◽  
High Rise Building ◽  
Building Project

As the population growth and land resources declining, high-rise building project is increasingly common in the construction work. Through in-depth thinking and active exploration, specific attention to matters of deep foundation pit and pile foundation construction technique, which is the key construction techniques in the high-rise building project, was summarized in this article. It suggests to make a careful and detailed geological survey, and then choose the right design program and develop a reliable construction plans. This scheme was proved to be a useful reference and guidance for the development of high-rise building construction technology.

Analysis of Three-Dimensional Effects for Deep Foundation Pit with FLAC3D

2012 ◽  
Vol 256-259 ◽  
pp. 328-331
Author(s):  
Lin Zhang ◽  
Ming Xuan He
Keyword(s):  
Three Dimensional ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Dimensional Effects

Using FLAC3D Software for Analysis of Foundation Pit, the Stress that Caused by Sidewall Displacement of Foundation Pit Has Been Analyzed. the Influence Scope and its Rules of Foundation Pit Three-dimensional Effects Were Obtained.

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