Research on the Large Size Loading Plate Test of Underwater Sand Compaction Pile Composite Foundation

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.

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Jinxing Lai ◽  
Houquan Liu ◽  
Junling Qiu ◽  
Haobo Fan ◽  
Qian Zhang ◽  
...  

Cement fly-ash gravel (CFG) pile is a widely used ground reinforcement technique. This paper aims to address the mechanical characteristics of CFG composite foundation in consolidating saturated mine tailings (MTs) dam. The field static load tests were employed to explore the bearing capacity of the CFG composite foundation, and finite element (FE) models in three dimensions validated through comparison with experimental results were used to discuss the pile-soil stress distribution and pile-soil stress ratio of the CFG composite foundation. The results indicate that the distribution of earth pressure and pile stress is relatively homogeneous and stable over depth and load, while the development of CFG composite foundation bearing capacity is insufficient, in which the developed bearing capacity of CFG piles is less than 50% of its characteristic value. Additionally, compared with the laboratory model test results, the pile-soil stress ratio decreases with the increasing of the load in FEM results proved to better conform to the actual engineering conditions. Furthermore, the deformation modulus and thickness of cushion exert significant influence on pile-soil stress ratio and integral bearing capacity of CFG composite foundation.


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.


2010 ◽  
Vol 163-167 ◽  
pp. 3457-3460
Author(s):  
Zhong Chang Wang

There is high requirement to the foundation of the raceway of container gantry crane. However, the marine soft soil is distributed extensively at Dalian ports. In the paper, the settlement and bearing capacity of natural and composite foundation of raceway of container gantry crane under design load is analyzed by finite element method on the basis of geological data, foundation treatment. The relationship of different deformation modulus and foundation bearing capacity is obtained by considering the strength of foundation and the requirement of settlement. The settlement and the inclination value of two sides of container gantry crane which is less than the permitting value of laws under consolidated ground and corresponding load condition is obtained. The corresponding deformation modulus of consolidated ground is obtained under different load condition. The boundary of basis is easy to failure, the treatment range extension of foundation should be considered.


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.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ming-Quan Liu ◽  
Da Huang ◽  
Yi-Xiang Song ◽  
Duo-Feng Cen

Capped piles are efficient in settlement control and have been widely used in the reinforcement of soft soil foundations for high-speed railways and highways. In this study, scenarios involving both capped piles and ordinary piles without caps are numerically studied using the finite element software (ABAQUS). The settlement characteristics of capped piles composite foundation considering the effects of both the pile spacing and the ratio of pile cap to pile diameter are achieved. Based on the numerical results, assuming that the capped pile and the soil under the cap jointly bear load and settle together, a settlement calculation model for capped piles composite foundation is established. By both replacing the compression modulus with the deformation modulus obtained from the field static load test and calculating the area replacement ratio, the formula for calculating the total settlement of the capped piles composite foundation is derived using the layer-wise summation method. In addition, a real embankment engineering with capped piles composite foundation is adopted to validate the accuracy of this method; by comparing with other methods, the results show that this method is in better agreement with the field monitoring data. Therefore, the proposed method is recommended in the relevant engineering design.


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.


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.


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.


Sign in / Sign up

Export Citation Format

Share Document