scholarly journals Pile-Soil Stress Ratio and Settlement of Composite Foundation Bidirectionally Reinforced by Piles and Geosynthetics under Embankment Load

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Binhui Ma ◽  
Zhuo Li ◽  
Kai Cai ◽  
Meng Liu ◽  
Minghua Zhao ◽  
...  
Keyword(s):  
Stress Ratio ◽  
Tensile Force ◽  
Difficult Problem ◽  
Composite Foundation ◽  
Stiffness Ratio ◽  
Soil Stiffness ◽  
Composite Modulus ◽  
Soil Stress ◽  
Calculation Results ◽  
Foundation Plate

The settlement calculation of composite foundation bidirectionally reinforced by piles and geosynthetics is always a difficult problem. The key to its accuracy lies in the determination of pile-soil stress ratio. Based on the theory of double parameters of the elastic foundation plate, the horizontal geosynthetics of composite foundation are regarded as the elastic thin plate, and the vertical piles and surrounding soil are regarded as a series of springs with different stiffness. The deflection equation of horizontal geosynthetics considering its bending and pulling action is obtained according to the static equilibrium conditions. The equation is solved by using Bessel function of complex variable, and the corresponding deflection function of horizontal geosynthetics is deduced. Then, the calculation formula of pile-soil stress ratio and settlement of composite foundation is derived by considering the deformation coordination of pile and soil. The results of engineering case analysis show that the theoretical calculation results are in good agreement with the measured values, which indicates that the proposed method is feasible and the calculation accuracy is good. Finally, the influence of composite modulus of horizontal geosynthetics, tensile force of geosynthetics, and pile-soil stiffness ratio on pile-soil stress ratio and settlement is further analyzed. The results show that the pile-soil stress ratio increases with the increase of the composite modulus of the horizontal geosynthetics, the tensile force of geosynthetics, and the pile-soil stiffness ratio, and the settlement decreases with the increase of the composite modulus of the horizontal geosynthetics, the tensile force of geosynthetics, and the pile-soil stiffness ratio. When the flexural stiffness of the horizontal geosynthetics is small, the influence of the tensile action of the geosynthetics on the pile-soil stress ratio and settlement of the composite foundation cannot be ignored.

Study and Analysis on Pile-Soil Stress Ratio of the Composite Foundation of Cement-Soil Mixing Pile under Flexible Foundation

2011 ◽  
Vol 335-336 ◽  
pp. 1145-1150
Author(s):  
Xiao Rong Yang ◽  
Lei Yu Zhang ◽  
Hai Chao Li ◽  
Li Ying Dong
Keyword(s):  
Stress Ratio ◽  
Soft Soil ◽  
Composite Foundation ◽  
Soil Mixing ◽  
Soil Stress ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Flexible Foundation ◽  
Cement Soil ◽  
Friction Pile

In order to analyze the characteristics of pile-soil stress ratio of the composite foundation of cement-soil mixing pile under flexible foundation, this paper points out the displacement mode of friction pile; According to the deformation characteristic of friction pile, ascertain the neutral point of composite foundation. And this paper also derives the exact formula about length-stress ratio which addresses the problem of soft soil foundation according to the deformation co-ordination conditions of the pile composite foundation. The calculation of actual example proves that the formula about pile-soil stress ratio is in accordance with actual measurement number. The pile-soil stress ratio which addresses the problem of soft soil foundation is generally between 2~4. If other conditions keep invariable, pile-soil stress ratio become big when cushion modulus become big. Cushion modulus effect the length-stress ratio greatly.

Finite Element Analysis of Cushion Thickness and Ultimate Bearing Capacity of Lime Soil Pile Composite Foundation

2012 ◽  
Vol 594-597 ◽  
pp. 565-569
Author(s):  
Zi Sen Wei ◽  
Yong Mou Zhang ◽  
Dong Hui Peng
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Stress Ratio ◽  
Shear Failure ◽  
Ultimate Bearing Capacity ◽  
Load Test ◽  
Composite Foundation ◽  
Static Load Test ◽  
Rate Of Increase ◽  
Soil Stress

The static load test of composite foundation was simulated by using the nonlinear finite element programs, and the changes of the pile-soil stress ratio and the pile and soil settlements as well as the plastic deformation of composite foundation were analyzed. The simulation results show that: the cushion of flexible pile composite foundation can effectively regulate the pile-soil stress ratio and make the bearing capacity of the lime soil pile and the soil between piles give full play at the same time. The cushion has a distinct role in reducing the pile settlements, however, has little effect in reducing the soil settlements. The reasonable cushion thickness is about 300mm. The composite foundation will emerge local shear failure when it reaches the ultimate bearing capacity. Reducing the pile spacing can increase the ultimate bearing capacity, and the rate of increase shows a gradually increasing trend.

Model Test Research of Cushion Thickness on the Long-Short Piles Composite Foundation

2010 ◽  
Vol 168-170 ◽  
pp. 2352-2358 ◽  
Author(s):  
Xin Sheng Ge ◽  
Jiang Wei Xue ◽  
Xiao Li Zhai
Keyword(s):  
Skin Friction ◽  
Axial Force ◽  
Stress Ratio ◽  
Load Sharing ◽  
Composite Foundation ◽  
Positive Skin ◽  
Negative Skin Friction ◽  
Soil Stress ◽  
The Impact ◽  
Settlement Distribution

In order to study the impact of cushion thickness on the long-short piles composite foundation,the relation between bearing capacity and settlement,distribution of the axial force and skin friction along pile,pile-soil stress ratio, load sharing ratio and the bearing mechanics of long-short-pile composite foundation with long and short piles were studied based on laboratory tests in three different conditions:zero-centimeter-thick cushion, two-centimeter-thick cushion and five-centimeter-thick cushion in this paper. Conclusions were as follows: The settlement of long-short piles composite foundation increased with the increasing of cushion thickness,Without cushion,the maximum axial force occurred in the pile top.After having paved cushion,it occurred in the neutral dot.The axial force of long and short piles decreased with the increasing of cushion thickness; Without cushion, only positive skin friction occurred. After having paved cushion,negative skin friction came into being existence.The value of long piles skin friction increased with the increasing of the cushion thickness,the value of short piles skin friction decreased with the increasing of the cushion thickness;The pile-soil stress ratio of long pile decreased with the increasing of the cushion thickness while the pile-soil stress ratio of short pile change little,The load sharing ratio of long piles were larger than that of short piles and soil.With the increasing of cushion thickness,the load sharing ratio of long and short piles became smaller while that of soil became larger.

Analysis on Pile-Soil Stress Ratio of Composite Foundation with Sparse Capped-Piles under Lime-Soil Embankment Load

2014 ◽  
Vol 501-504 ◽  
pp. 124-131 ◽  
Author(s):  
Wei Zheng Liu ◽  
Jun Hui Zhang ◽  
Hao Zhang
Keyword(s):  
Stress Ratio ◽  
Load Transfer ◽  
Stress Transfer ◽  
Composite Foundation ◽  
Transfer Model ◽  
Soil Pressure ◽  
Soil Stress ◽  
Rigid Pile Composite Foundation ◽  
Embankment Height ◽  
Piled Embankment

The combined effect of the embankment fill, piles and caps, and foundation soils on the load transfer characteristics of sparse capped-piled embankment is very significant. Using the modified cylindrical shear stress transfer model based on Marston soil pressure theory, a new calculation method for pile-soil stress ratio of sparse rigid pile composite foundation incorporating the arching effect in lime-soil and soil-pile interaction was presented. The presented method is verified by comparison between analytical solutions and the observed results from a practical project. In addition, a parametric study was also conducted to evaluate the influence of the embankment height, the cohesion of fill and pile-soil stiffness ratio on the pile-soil stress ratio.

Research on Pile-Soil Stress Ratio of DJM Pile Composite Foundation

2011 ◽  
Vol 52-54 ◽  
pp. 533-540
Author(s):  
Qing Zhi Yan ◽  
Yan Hua Wang
Keyword(s):  
Stress Ratio ◽  
Static Load ◽  
Yellow River ◽  
Yellow River Delta ◽  
Composite Foundation ◽  
Important Indicator ◽  
The Yellow River Delta ◽  
Soil Stress ◽  
Load Tests ◽  
Field Static

Pile-soil stress ratio is defined as the average stress ratio of the head of pile to the soil around of piles, which is a very important indicator to reflect the level of the together-work of pile and the soil, also a major parameter of calculation of capacity of composite foundation and settlement. How to choose pile-soil stress ratio is still a problem unsolved. Bearing performance of the DJM pile composite foundation is studied by way of field static load tests and pile-soil stress ratio tests. This paper is to analyze the bearing performance of the DJM pile composite foundation in the Yellow River Delta region with the plane strain finite element method and gain the load-sharing ability of soil and regulations of pile-soil stress ratio with the changes of effecting factors.

A New Type of Pile – Long with Cushion-Short without Cushion Rigid Pile

2012 ◽  
Vol 166-169 ◽  
pp. 803-808
Author(s):  
Ming Fei Zhang ◽  
Guang Hua Yang ◽  
En Qi Wang
Keyword(s):  
Stress Level ◽  
Stress Ratio ◽  
Soft Soil ◽  
Vertical Direction ◽  
Composite Foundation ◽  
Finite Element Software ◽  
Rigid Pile ◽  
Soil Stress ◽  
New Type ◽  
The One

At present, in the deep soft soil area, pile types of composite foundation include rigid-flexible and long-short piles, rigid long- short pile , pile partner, and this paper proposes a new type of pile - rigid long-short piles with no cushion short pile. Using the one Finite element software Midas- GTS , this paper compared these pile types ,in vertical direction element stress, pile-soil stress ratio and cushion stress level the cushion of pile-soil stress ratio and stress level, to illustrate the advantages of the new pile.

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