Step by Step Calculation and Application of Multi-Type-Pile Composite Foundation

2012 ◽  
Vol 170-173 ◽  
pp. 252-255
Author(s):  
Xiao Hui Mao ◽  
Qiang Yue

The flexible pile and the rigid pile, the gravel pile and CFG pile are arranged in a group as compound piles, which utilize their merits and avoid their shortcomings. Based on the study of the existing calculation methods for the bearing capacity of multi-pile composite foundation, the working behavior of loaded multi-pile composite foundation and the general influence of different construction methods to the bearing capacity of the soil are considered. The coefficient of the bearing capacity exertion of master piles, the coefficient of the bearing capacity exertion of minor piles, the coefficient of the bearing capacity exertion of the soil between piles and the coefficient of the bearing capacity improvement of the soil are introduced. The new step-by-step calculation method for the bearing capacity of multi-pile composite foundation is put forward. Through designed a high-rise frame structure with multi-type-pile composite foundation, the results show that the multi-type-pile composite foundation is more whole and possess stronger capacity of load transfer compared with single-type-pile composite foundation. It can satisfy the requirements of load bearing capacity and deformation under special foundation conditions.

2011 ◽  
Vol 243-249 ◽  
pp. 3141-3146
Author(s):  
Jing Hui Tao ◽  
Shu Ting Liang ◽  
Wei Ming Gong ◽  
Chun Liang Wu

To study the working behavior of a rigid pile composite foundation of high-rise buildings, an in-situ loading test and stress test on piles and soil were carried out. According to the test results, the stress distributions and variations, load transferring characteristics, and stress distributions of piles were analyzed. The results showed that the piles with the formation of non-soil compaction technology can consolidate soil among piles. When the load level was greater than 240 kPa, a better consolidation effect can be obtained. The development negative friction at the top of piles was relevant to the load level. The adjustment effect of cushion on the composite foundation was mainly embodied before the load level reached the characteristic bearing capacity of the composite foundation. Under vertical load, the stress distributions along the internal and external sides of pile shaft were different and the loading plate would bring influence to stress distributions of the pile shaft. The influence range was from the middle to the top of the pile. Based on the test results, it is recommended to reduce the evaluation standard of the bearing capacity determined in the pressing plate test. The results can provide a reference for similar engineering.


2013 ◽  
Vol 639-640 ◽  
pp. 688-693
Author(s):  
Jin Yi ◽  
Guo Jing He ◽  
Si Si Liu ◽  
Zhi Yong Li ◽  
Zu En Zheng

This paper introduced construction method for deep pile of Zishui bridge through karst region and the checking results of the pile bearing capacity. Firstly, main structure of Zishui bridge was simply introduced. Secondly, according to the special geological conditions, construction methods for bored piles in water and drilling platform were described. The discussion focused on the problem of boring and grouting in karst foundation and their solutions. Finally, to ensure that the pile capacity can meet the design requirements, load transfer method was used on the part of pile foundation to calculate the bearing capacity. Results showed that pile bearing capacity meet the requirements, and the feasibility and correctness of construction method of Zishui bridge was also verified,which provides references for the design and construction of the same civil engineering.


2013 ◽  
Vol 438-439 ◽  
pp. 1399-1403
Author(s):  
Wei Ding ◽  
Qing Liu ◽  
Kang Kang Sun ◽  
Feng Tao Sui

There are a lot of factors that influence the bearing capacity of composite foundation, and the relationship between them is complex and nonlinear. Based on study of main factors that have great influence on bearing capacity of cement-flyash-gravel (CFG) pile composite foundation, the least squares support vector machine (LS-SVM) model of bearing capacity of composite foundation was established. The results show that the model has excellent learning ability and generalization and can provide accurate data prediction only with fewer observed sample. It is proved that the new method is a promising method for the determination of bearing capacity of CFG pile and other rigid piles composite foundation.


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.


2012 ◽  
Vol 170-173 ◽  
pp. 110-114
Author(s):  
Yan Gao ◽  
Hui Min Li ◽  
Ji Ling Yao

Through project example, analysis of the multi-type-pile composite foundation (lime pile plus CFG pile) in the practical application of liquefied foundation of high-rise building, especially using the ZFZ construction technology which forwards formed a hole and reverses packed into a compaction pile by a long spiral drilling machine to eliminate liquefaction of foundation soil and improve the bearing capacity of foundation is very notable, in addition, it also produces good economic and social benefits, so it has great value of promotion and use.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Xiao-jun Zhu

Disconnected piled raft (DPR) foundations are characterized by having no structural connection to a raft. The raft-pile gap is filled with a granular cushion, which creates a more uniform pressure distribution on the raft and reduces the differential settlement. A series of tests has been performed to investigate the load transfer mechanisms of a DPR. The effects of the thickness and stiffness of the cushion and the pile diameter are presented and discussed. A simple failure mode of the cushion is also put forward according to the cushion slip plane obtained by using the digital image correlation technique that tracks the pixels in the images and generates a displacement field. Then a new theoretical analysis has been presented for rigid pile composite foundation. Through comparative studies, it is found that the present method is validated as reasonable by laboratory tests and is in agreement with several current design methods.


2014 ◽  
Vol 490-491 ◽  
pp. 1706-1711
Author(s):  
Man Yuan ◽  
Ji Hui Ding ◽  
Pan Xing Zhang ◽  
Xiao Juan Quan

The three kinds of the typical pile type are selected, which containing flexibility pile (e.g. rammed cement-soil pile is for short RCSP), rigid pile (e.g. cement-flyash-gravel pile is for short CFGP) and loose material pile (e.g. sand-gravel pile is for short SGP). The seven kinds of the composite foundation are designed, which are CFGP, CSP and GP composite foundation, CFG long pile and sand-gravel short pile (for short CFGLP-GSP), CFG long pile and CFG short pile (for short CFGLP-CFGSP), CFG long-short pile and rammed cement-soil short pile (for short CFGLP-RCSP) , and CFG core pile rammed cement-soil loop pile (for short CFGCP-RCSP) combined composite foundation. According to the load-settlement curves to determining the increment deformation modulus of the every load step, the layer-wise summation method to calculate the settlement of composite foundation is given, and the calculation results and the load-settlement curves are consistent.


2013 ◽  
Vol 438-439 ◽  
pp. 1409-1413
Author(s):  
Qing Liu ◽  
Wei Ding ◽  
Ben Wang ◽  
Hong Hai Liu ◽  
Bing Yu Wang

Based on the compaction effect of the gravel pile, the thick-walled tube model is established. Considering the gravel pile and pile materials with different properties of tension and compression of soil pile in the process of expansion, the influence of intermediate principal stress to improving the bearing capacity of foundation in the process of expansion, we use the planar axisymmetric double shear unified strength theory and present a gravel pile ultimate bearing capacity of single pile composite foundation unified expression. The theory study of gravel pile composite foundation and engineering practice has a certain guiding significance.


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