Analysis of Settlement of Composite Foundation with Sparse Pile to Control Settlement

2012 ◽  
Vol 204-208 ◽  
pp. 664-669
Author(s):  
Jun Hui Zhang ◽  
Zhi Yong Yin ◽  
Jian Long Zheng

The embankment soil arching effect of the composite foundation with sparse piles to control settlement is caused by the differential settlement between the embankment fill and the piles. So, the settlement is an important behaviour of the composite foundation. The effects of the height of embankment, the elastic modulus of geosynthetic and pile material, the stiffness of cushion and substratum, the pile cap and the distance of piles on the settlement are investigated using the computer code ABAQUS in this paper. The results indicate that the maximum settlement and differential settlement decrease with the elastic modulus of geosynthetic, the stiffness of cushion and substratum. The maximum settlement decreases and the differential settlement increases with the elastic modulus of pile material. At the same time, the differential settlement of the embankment surface decreases with the height of fill and there will be an equal settlement plane when the fill reaches certain height. In addition, the distance of piles has a more significant influence on settlement than the dimension of pile cap.

2012 ◽  
Vol 204-208 ◽  
pp. 674-679
Author(s):  
Jun Hui Zhang ◽  
Zhi Yong Yin ◽  
Jian Long Zheng

The composite foundation with sparse piles to control settlement has been used to rapid construction and strict deformation of the structure widely currently, which can enhance the efficient of load transfer and decrease the differential settlement used with the geosynthetic. Considering the confine of analytical solution and the traditional method with a changeless modulus of geosynthetic and pile, the effects of the height of fill, the elastic modulus of geosynthetic and pile material on the differential settlement, embankment soil arching effect and tensioned membrane effect etc. are investigated using the computer code ABAQUS in this paper. The results indicate that the modulus of geosynthetic and pile has a notable influence on the differential settlement and the arching effect, which should be considered in the design. At the same time, the maximum tension in geosynthetic occurs near the edge of the pile cap.


2014 ◽  
Vol 638-640 ◽  
pp. 656-670
Author(s):  
Huan Feng Qiu ◽  
Shao Jun Fu

The behaviour of pile-groups subjected to lateral soil pressure is a key consideration in establishing the design parameters of pile-groups. In this paper, one representative section of the Chongqing Jiangdong slope is taken as an example. The existence of an arching zone around pile groups for granular and fine-grained soils is first examined using the finite element computer code CORE-3D. Pile load-displacement curves and the arching effect are considered together to explain how the stresses are transferred from the soil to the piles. The key parameters controlling the soil arching effect are centre-to-centre pile spacing (S), thickness of stable soil mass (H), depth (L) of pile embedment, pile diameter (D) and these were studied extensively. An empirical equation summarising the results is presented and the results have been adopted by the designer in practice.


Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1627
Author(s):  
Kangyu Wang ◽  
Jun Cao ◽  
Xinquan Wang ◽  
Yingjie Ning

Soil arching, which occurs in the piled embankments, plays an important role in stress redistribution between the relatively soft subsoil and the stiffer piles. The formation of the soil arching depends on the differential settlement of the embankment fill above the pile and the subsoil. The soil arching effect is barely investigated in the literature from the perspective of differential settlement of piles and soils. Based on the discrete element method (DEM), this paper develops a classic trapdoor test model to investigate the differential settlement in piled embankment during the downward movement of the trapdoor, and to explore the formation mechanism of soil arching in equal settlement pattern by changing the width of the pile cap and the height of the embankment. Due to symmetry, only one section of the laboratory test model is simulated herein. It was found that the soil arching formed under the equal settlement pattern remained unchanged after a certain degree of development, and the height of the equal settlement did not change at 0.7(s-a), where s is the pile spacing, and a is the width of the pile cap. The height of the embankment (H) and the width of the pile cap (a) have a significant influence on the formation of the equal settlement pattern when the width of the trapdoor is kept constant. Both the decrease in “H” and the increase in “a” facilitate the differential settlement of the soil between the piles and the pile-soil, enabling the slip surface to develop upward gradually, thereby hindering the formation of the equal settlement pattern.


2019 ◽  
Vol 56 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Han-Lin Wang ◽  
Ren-Peng Chen ◽  
Wei Cheng ◽  
Shuai Qi ◽  
Yu-Jun Cui

This study presents a full-scale model investigation on variations of soil stress in a geosynthetic-reinforced pile-supported track bed at various water levels and loading cycles, with four testing procedures: water level rising, cyclic loading at high water level, water level lowering, and cyclic loading at low water level. The soil arching effect was revealed, characterized by higher stress above the pile cap. With the water level rising and loading cycles increasing at high water level, this effect becomes more pronounced, until a peak value of dynamic stress concentration ratio is reached. The stable state of soil arching is obtained earlier near the crown of soil arching, but this arching effect develops more significantly at the foot of soil arching. With the water level lowering and loading at low water level, the soil arching effect remains steady, with slightly changed dynamic stresses in the track bed. The geogrid shows a significant impact on the load transfer mechanism for the quasi-static stress: the quasi-static pile-cap stress presents higher values below the geogrid, whereas the opposite trend is observed for the water-bag (subsoil) area. Nevertheless, this mechanism is not obvious with respect to the dynamic stress, with the values showing no distinct difference above and below the geogrid.


2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Guangfu Chen ◽  
Liangchao Zou ◽  
Qing Wang ◽  
Guodong Zhang

Anti-slide pile is one of the most frequently used measures in landslide control globally. Pile-spacing has always been determined by the load capacity of single piles or according to engineering empirical experience. Many engineering practices and laboratory experiments show that the soil arching effect exists in landslide control with anti-slide piles. In this study, we aim to calculate pile-spacing in terms of the soil arching effect. We investigated the pile-soil interaction mechanism and propose that, at the limit, the pile-back soil arch resists landslide thrust only. According to Mohr–Coulomb strength theory and limit equilibrium theories, we derived a new pile-spacing calculation equation. We verified the derived pile-spacing calculation equation with real projects. The calculated results are similar to those of practical engineering designs, in which the difference is within 10%. The equation can be used in anti-slide pile preliminary design. This study can be a reference for pile-spacing calculation based on the soil arching effect.


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