scholarly journals Study on the earth pressure of a foundation pit adjacent to a composite foundation with rigid-flexible and long-short piles

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251985
Author(s):  
Yuancheng Guo ◽  
Shaochuang Gu ◽  
Junwei Jin ◽  
Mingyu Li
Keyword(s):  
Three Dimensional ◽  
Earth Pressure ◽  
Friction Angle ◽  
Element Model ◽  
Composite Foundation ◽  
Deep Soil ◽  
Foundation Pit ◽  
Testing Procedures ◽  
Retaining Structure ◽  
Lateral Earth Pressure

Model tests were performed to investigate the lateral earth pressure acting on the retaining structure adjacent to both natural ground (NG) and composite foundation (CFRLP), which were supported with rigid-flexible and long-short piles. Two testing procedures, namely, applying a load to the foundation and rotating the retaining structure along its toe, were considered. The results indicate that the additional lateral earth pressure acting on the retaining structure adjacent to the CFRLP is less than that of the NG in the depth of the reinforcement area strengthened by flexible piles. Compared with NG, the CFRLP yielded a smaller normalized height of application of the lateral earth pressure, suggesting that the CFRLP blocked the horizontal diffusion of the load and had a strong ability to transfer the surcharge load to the deep soil. When rotating the retaining structure, the lateral earth pressure acting on the upper part of the retaining structure experienced limited reduction once the displacement at the top of the retaining structure was greater than 8 mm, whereas the pressure acting on the lower part of the retaining structure continued to decrease with increasing displacement. In addition, a three-dimensional finite element model (FEM) was used to investigate the influence of the pile parameter and the wall-soil friction angle on the additional lateral earth pressure.

Active earth pressure in cohesive soils with an inclined ground surface

2000 ◽  
Vol 37 (1) ◽  
pp. 171-177 ◽  
Author(s):  
Nirmala Gnanapragasam
Keyword(s):  
Analytical Solution ◽  
Ground Surface ◽  
Earth Pressure ◽  
Failure Surface ◽  
Friction Angle ◽  
Active Earth Pressure ◽  
Overburden Pressure ◽  
Retaining Structure ◽  
Lateral Earth Pressure ◽  
Fixed Orientation

An analytical solution is developed to determine the active lateral earth pressure distribution on a retaining structure when it consists of a cohesive backfill (internal friction angle ϕ > 0, cohesion c > 0) with an inclined ground surface. The solution derived encompasses both Bell's equation (for cohesive or cohesionless backfill with a horizontal ground surface) and Rankine's solution (for cohesionless backfill with an inclined ground surface). The orientation of the failure surface is also determined. Results indicate that, unlike the soil-wall scenarios of Bell and Rankine where the failure planes are parallel with a fixed orientation independent of the overburden pressure, for sloping cohesive backfill (ϕ > 0, c > 0) the slope of the failure surface is a function of the overburden pressure and becomes shallower with depth, thus forming a curvilinear failure surface. The solution developed can also be used to check the sustainability of a slope. The analytical solution can be programmed conveniently in a computer.Key words: retaining structure, active earth pressure, cohesive backfill.

scholarly journals Internal Force on and Deformation of Steel Assembled Supporting Structure of Foundation Pit under Thermal Stress

2021 ◽  
Vol 11 (5) ◽  
pp. 2225
Author(s):  
Fu Wang ◽  
Guijun Shi ◽  
Wenbo Zhai ◽  
Bin Li ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
High Strength ◽  
Element Model ◽  
Internal Force ◽  
Foundation Pit ◽  
Dimensional Finite Element ◽  
Influence Of Temperature On ◽  
Scale Experiment ◽  
Three Dimensional Finite Element

The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel’s performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/°C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 °C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection.

Analysis of the Effects on Optimization Design about Double-Row Piles Retaining Structure

2012 ◽  
Vol 204-208 ◽  
pp. 72-78
Author(s):  
Yu Wang ◽  
Yan Ting Yang ◽  
Feng Yu ◽  
Guang Lei Hu
Keyword(s):  
Optimization Design ◽  
Internal Force ◽  
Composite Foundation ◽  
Foundation Pit ◽  
Double Row ◽  
Retaining Structure ◽  
Supporting Structure ◽  
Arch Effect ◽  
Space Effect ◽  
Foundation Pile

Double-row piles retaining structure has been widely used in the project now, but the stress mechanism of double-row pile is more complex; Its internal force and deformation are affected by many factors. Understanding and mastering its effects has an important significance for the design and the optimization of double-row pile supporting structure. According to the comparison of the measured data and theoretical calculation about original support scheme and optimized support plan and combined with the soil test data, this paper takes the Jinan Cultural Arts Center(Theatre) stage bin foundation pit as an example to analyse the main effects of optimization design about double-pile supporting structure. The results show that soil shear strength, soil arch effect, influence of CFG composite foundation, pile-beam synergy effect and space effect of foundation pit play an important role for optimization design about double-pile supporting structure.

Finite Element Study of Settlement of Cement Mixing Composite Foundation and Non-Probabilistic Reliability Analysis

2014 ◽  
Vol 638-640 ◽  
pp. 675-679 ◽  
Author(s):  
Huan Sheng Mu ◽  
Ling Gao
Keyword(s):  
Finite Element ◽  
Reliability Analysis ◽  
Load Transfer ◽  
Soft Soil ◽  
Probabilistic Method ◽  
Three Dimensional ◽  
Element Model ◽  
Composite Foundation ◽  
Reliability Method ◽  
Three Dimensional Finite Element

This paper presents a non-probabilistic method for reliability analysis of cement mixing composite foundations. First, the load transfer mechanism of composite foundations is described. Then a three-dimensional finite element model of cement mixing composite foundation under embankment is built. The settlement of subgrade is analyzed. Finally, a non-probabilistic reliability method is used to investigate the settlement reliability. The results show that the cement mixing composite foundation can significantly improve the compressibility of soft soil.

The Research on the Influence of the Forms of Foundation on the Behavior of Adjacent Excavation Based on Building Materials

2013 ◽  
Vol 788 ◽  
pp. 606-610
Author(s):  
Qing Xiang Ji ◽  
Xin Sheng Ge
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Building Materials ◽  
Three Dimensional ◽  
Element Model ◽  
Deep Excavation ◽  
Foundation Pit ◽  
Finite Element Software ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Foundation pit excavation could be affected to some extent by surrounding different kinds of building materials, building structure, foundation form and load distribution, especially in intensive buildings. In this paper, based on the large-scale finite element software ANSYS, a three-dimensional finite element model is established to analyze the consequences of these complex and uncertain factors faced with by deep excavation projects and the conclusions of the excavation affected by different foundations form of adjacent buildings are arrived at.

Effect of Staged Excavation on Retaining Structure in Soft Soil Area

2012 ◽  
Vol 170-173 ◽  
pp. 633-636 ◽  
Author(s):  
Jie Liu ◽  
Xin Guang Xu
Keyword(s):  
Soft Soil ◽  
Horizontal Displacement ◽  
Structure Type ◽  
Operating Conditions ◽  
Deep Soil ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Retaining Structure ◽  
Geological Conditions

Based on a deep foundation pit in Tianjin, the authors introduced the retaining structure type, surrounding conditions, and the geological conditions of proposed field. According to the engineering characteristics, the excavation was divided into three typical operating conditions. Based on the monitoring of staged excavation of deep foundation pit, analysis on horizontal displacement, deep soil displacement, column settlement and bracing axial force was carried out. The general rules of the deformation and internal force of retaining structures induced by staged excavation were given, which will provide the references for similar engineering.

scholarly journals Back analysis of pile and anchor retaining structure based on BOTDA distributed optical fiber sensing technology

2021 ◽  
Vol 248 ◽  
pp. 01036
Author(s):  
Xin Wang ◽  
Xie Hui Luo ◽  
Wan xue Long ◽  
Bo Jiang
Keyword(s):  
Earth Pressure ◽  
Internal Force ◽  
Force Distribution ◽  
Foundation Pit ◽  
Retaining Structure ◽  
Fiber Sensing ◽  
Sensing Technology ◽  
Optical Fiber Sensing ◽  
Anchor Structure ◽  
Distributed Optical Fiber

In order to understand the deformation law and internal force distribution characteristics of the pile-anchor retaining structure in deep foundation pit engineering, the stress of the pile-anchor retaining system in the process of foundation pit excavation was tested by using the distributed optical fiber sensing technology of BOTDA. It uses the supporting pile cloth to set up the strain cable to collect the strain from the excavation process to the stability of the foundation pit, which analyzes the stress and internal force distribution. The results show that the overall deformation of the foundation pit is small and in a stable state. It uses the monitoring strain energy to truly reflect the distribution and transmission law of the pile internal force. It is shown that the bending moment is the maximum at the action position of the anchor cable on the pile anchor structure and 2.5m below the bottom of the pit. The design needs to reinforce the construction of such locations. At the same time, the distribution form of earth pressure calculated in reverse is different from the conventional one. When there are multiple rows of prestressed anchor cables, the earth pressure applied on the support is less than the calculated value of classical earth pressure theory. This pile anchor structure design theory and engineering application has reference value.

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