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

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.

2011 ◽  
Vol 335-336 ◽  
pp. 1145-1150
Author(s):  
Xiao Rong Yang ◽  
Lei Yu Zhang ◽  
Hai Chao Li ◽  
Li Ying Dong

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.


2015 ◽  
Vol 744-746 ◽  
pp. 574-578
Author(s):  
Jin Fang Hou ◽  
Jian Yu ◽  
Xin Wei Xu

Large size loading plate test for sand compaction pile composite foundations with the replacement ratio being up to 60% was carried out to study the deformation and bearing capacity of the sand compaction pile composite foundation. The test was carried out for 53 days with anchor pile, square loading with the side length of 5.4m, 15m-deep water and twice circulation loading mode. The compression deformation, pile-soil stress ratio and deformation modulus of the sand compaction pile composite foundation was analyzed through load test. Test results indicated that, the ultimate bearing capacity of the sand compaction pile composite foundation in this test was larger than 340kPa; sand compaction pile had a drainage consolidation effect on the soft soil between piles; under the load-keeping condition, sand compaction pile composite foundation would also has settlement; pile-soil stress ratio was 6.3 and deformation modulus was about 8kPa. The success of the test may provide experience and reference for load test of underwater sand compaction pile composite foundation carried out at open sea.


2020 ◽  
Author(s):  
Jian-lin Yu ◽  
Jia-jin Zhou ◽  
Xiao-nan Gong ◽  
Ri-qing Xu ◽  
Jun-yuan Li ◽  
...  

2012 ◽  
Vol 594-597 ◽  
pp. 565-569
Author(s):  
Zi Sen Wei ◽  
Yong Mou Zhang ◽  
Dong Hui Peng

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.


2010 ◽  
Vol 168-170 ◽  
pp. 2352-2358 ◽  
Author(s):  
Xin Sheng Ge ◽  
Jiang Wei Xue ◽  
Xiao Li Zhai

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.


2014 ◽  
Vol 501-504 ◽  
pp. 124-131 ◽  
Author(s):  
Wei Zheng Liu ◽  
Jun Hui Zhang ◽  
Hao Zhang

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.


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