Study on the Design Method of Different Thickness-Diameter Ratios for Composite Foundation with Rigid Long and Short Piles

2014 ◽  
Vol 580-583 ◽  
pp. 723-728
Author(s):  
Jian Xing Tong ◽  
Xun Hai Sun ◽  
Peng Fei Luo ◽  
Ning Jia ◽  
Xin Hui Yang ◽  
...  

Composite foundation can be designed as long and short piles that lie on different bearing strata with high bearing capacities. Researches have shown that for foundation with sufficient stiffness, the ratio of the thickness of cushion to pile diameter (thickness-diameter ratio) plays an important role on the exertion of bearing capacities of pile and soil between piles. Traditional method just applies equal thickness-diameter ratio to design composite foundation with long and short piles, which hinders the exertion of bearing capacity of composite foundation. To overcome this defect, this paper studies the relations between thickness-diameter ratio and the exertions of bearing capacities of pile and soil between piles. The design method of thickness-diameter ratio for composite foundation with long and short piles is also proposed in this study.

2012 ◽  
Vol 256-259 ◽  
pp. 57-60
Author(s):  
Rong Fang Song ◽  
Ling Yun Lang ◽  
Jing Wang

A case of the long-short-pile composite foundation in liquefied soft soil under a 30-storey high-rise building is presented, in which the long and short piles are made of cement-flyash-gravel (CFG) and lime. A new design calculation method of bearing capacity and settlement of composite foundation is introduced, and the calculated value is compared with the actual measurement. The results show that the liquefaction of soft ground is eliminated and the demand of load and settlement for upper building is met. At the same time, it is proved that the design method is feasible.


2019 ◽  
Vol 136 ◽  
pp. 02022
Author(s):  
Xinmin Yu ◽  
Xianri Wang

Micro-pile is a kind of small diameter bored piles, also known as root pile, pile diameter is generally 150-400mm, length-diameter ratio is generally greater than 30,and pile length is usually not more than 30m. Compared with ordinary pile, micro-pile has the advantages of fast construction speed, small working surface, high bearing capacity and small settlement.


2012 ◽  
Vol 479-481 ◽  
pp. 1709-1713
Author(s):  
Kai An Yu ◽  
Tao Yang ◽  
Chang Zhi Gong

In view of the problems of large stress and severe bearing heating in double-drum winch at present, this paper adopted a new method to enhance bearing capacity for double-drum winch by adding anti-pressure wheels between two drums. Finite element methods were used to analyze the strength of 4000kN-traction double-drum winches with anti-pressure wheels and without anti-pressure wheels respectively. The results of the analysis revealed that the stress of the cylinder bearing decreased from 264MPa to 167MPa. The new method by adding anti-pressure wheels had remarkably improved the endurance of the bearing. Therefore, the design method can be widely used in large-traction double-drum winch.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
A. Hemalatha ◽  
N. Mahendran ◽  
G. Ganesh Prabhu

The experimental investigation on the effects of granular fill and geogrid reinforced granular fill on the behaviour of the static liquefaction potential of the subsoil is reported in this study. A series of plate load test were carried out with different thickness of the granular fill, number of geogrid layers, and size/dimension of the footing. The test results were presented in terms of bearing capacity and subgrade modulus for the settlement ofδ10,δ15, andδ20. The experimental results revealed that the introduction of granular fill significantly increases the bearing capacity and effectively control the settlement behaviour of the footing. The introduction of geogrid in granular fill enhanced the Percentage of Control in Settlement and Bearing Capacity Ratio by a maximum of 328.54% and 203.41%, respectively. The introduction of geogrid in granular fill interrupts the failure zone of the granular fill and enhances the subgrade modulus of the footing by a maximum of 255.55%; in addition subgrade modulus of the footing was increased with an increase in the number of geogrid layers. Based on the test results it is suggested that the footing with large size has beneficial improvement on the reinforced granular fill.


2017 ◽  
Vol 2017 ◽  
pp. 1-20
Author(s):  
Ulf Arne Girhammar ◽  
Bo Källsner

The authors present an experimental and analytical study of slotted-in connections for joining walls in the Masonite flexible building (MFB) system. These connections are used for splicing wall elements and for tying down uplifting forces and resisting horizontal shear forces in stabilizing walls. The connection plates are inserted in a perimeter slot in the PlyBoard™ panel (a composite laminated wood panel) and fixed mechanically with screw fasteners. The load-bearing capacity of the slotted-in connection is determined experimentally and derived analytically for different failure modes. The test results show ductile postpeak load-slip characteristics, indicating that a plastic design method can be applied to calculate the horizontal load-bearing capacity of this type of shear walls.


2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Yuanqi Li ◽  
Xiaoliang Qin ◽  
Jinhui Luo ◽  
Meng Xiao ◽  
Cong Hua

This paper is focused on the experimental study and numerical simulation of isolated spread concrete foundation slab with a large width-to-height ratio (in short ISCFS-LWR) to investigate the failure modes and uplift bearing capacity, as well as the design method of uplift capacity. First, a total of 16 isolated spread concrete foundation slabs with the width-to-height ratio varied from 1.5 to 4 and the hypotenuse slope varied from 10° to 30° were tested under uplift load. Based on the test results, effects of the width-to-height ratio and the hypotenuse slope on uplift bearing capacity of ISCFS-LWR were analyzed and discussed. Then, several numerical models were built using the finite element software ABAQUS and the results of numerical analysis agreed well with the test results. Furthermore, the cross-sectional performance of ISCFS-LWR was studied, and the coefficients of internal force arm were also evaluated further using previous validated numerical models. To obtain the suggested design method of uplift capacity for the foundation slab, effective width correction coefficient k and slope correction coefficient j were introduced to propose a design formula. Finally, the proposed design method was applied to a practical engineering, and the economic indicators obtained from the suggested design method were compared with that from the original design method. The results of this paper showed that the correction coefficient jsks based on numerical analysis agreed well with the recommended correction coefficient jk, and the error was between 1% and 3.4%, by which the reasonability of the proposed design method of uplift capacity for ISCFS-LWR has been proved. It can also be found that the economic benefits of the practical engineering in this paper were obvious due to the suggested design method, and this paper can provide a reference for other engineering practices and the further research work on ISCFS-LWR.


2014 ◽  
Vol 937 ◽  
pp. 438-443
Author(s):  
Xiao Tong Ma ◽  
Guang Long Liu

Composite foundation settlement of piled raft structure in Da Xi passenger dedicated line is analyzed by the large finite element software MIDAS/GTS and established calculation model of foundation treatment. The problem of pile-soil contact is highlighted in the trail and analyzes the settlement nephogram and pile-soil stress nephogram. On this basis the foundation settlement factors was analyzed systematically that focus on the elastic modulus of pile, pile spacing, pile diameter and pile length in foundation treatment, especially for the characteristics parameters of contact element. Result shows that increasing the pile modulus, pile diameter, pile length and decreasing the pile spacing is all conducive to reducing settlement. The best advice is got that the pile diameter should be not more than 0.5m, pile length not more than 27m and the pile spacing be around 2m.


1996 ◽  
Vol 118 (4) ◽  
pp. 502-506 ◽  
Author(s):  
M. D. Xue ◽  
K. C. Hwang ◽  
W. Lu¨ ◽  
W. Chen

The analytical solution is given for two orthogonally intersecting cylindrical shells with large diameter ratio d/D subjected to internal pressure. The modified Morley equation is used for the shell with cutout and the Love equation for the tube with nonplanar end. The continuity conditions of forces and displacements at the intersection are expressed in 3-D cylindrical coordinates (ρ, θ, z), and are expanded in Fourier series of θ. The Fourier coefficients are obtained by numerical quadrature. The present results are in good agreement with those obtained by tests and by FEM for ρ0 = d/D ≤ 0.8. The typical curves of SCF versus t/T and d/DT and reinforcement coefficients g, h versus D/T0 for each ρ0 are given on the present method.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zhe Wang ◽  
Shuwei Wu ◽  
Kaiwen Weng ◽  
Wangjing Yao ◽  
Sifa Xu ◽  
...  

Fiber-reinforced polymer (FRP) composite sheet piles are usually favored for slope and river-retaining structures due to their construction and environmental efficiency. Their applications, however, have been hindered by the lack of understanding of the bearing capacity. This paper studies the vertical and lateral bearing capacity of FRP composite sheet piles through three full-scale tests conducted in Haiyan, a soft soil site in the Yangtze River Delta of China. In the three tests, we measured the vertical bearing capacity of the FRP composite sheet piles, the bearing capacity of the composite foundation, and the lateral capacity of the FRP composite sheet piles, respectively. The test results show that the Q-S (load on the top of the pile versus settlement) curve of the FRP composite sheet piles exhibits a steep fall while that of the composite foundation is relatively flat. Moreover, the ultimate bearing capacity of the FRP composite sheet piles is measured to reach 23.8 kN while that of the composite foundation increases by 47.1 %, reaching 35.0 kN. It shows that the FRP composite sheet piles under the composite foundation have a favorable bearing performance. Finally, the final horizontal displacement of the FRP composite sheet pile in the reinforced area with anchoring the sheet pile is smaller than the final horizontal displacement in the nonreinforced area, indicating that the horizontal bearing capacity can be significantly improved by anchoring the sheet pile.


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