The Unified Solution of Gravel Pile Limit Bearing Capacity of Single Pile Composite Foundation

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.

2013 ◽  
Vol 353-356 ◽  
pp. 1005-1010
Author(s):  
Xiang Qiu Wang ◽  
Wen Tao Yang

The bearing capacity of slime friction pile based on the Mohr-Coulombs strength criterion couldnt make full use of the potential strengths ability of rock-soil. But the double shear unified strength theory can depict really the bearing characteristics of rock-soil because it can consider the effect of intermediate principal stress comprehensively. On this condition, based on the Mindlins displacement solution and the double shear unified strength theory, a calculated formula of bearing capacity was proposed for the slime friction pile, and then the distribution regularities of lateral friction-resistance force for the slime friction pile were discussed.


2013 ◽  
Vol 690-693 ◽  
pp. 797-804
Author(s):  
Jian Feng Xu ◽  
Peng Wu ◽  
Jun Hai Zhao ◽  
Yan Li ◽  
Wen Biao Liang

Directed against the stiffened and thin-walled square concrete-filled steel tubular (CFST) short columns, the paper simplifies the square CFST columns into the circle ones by introducing the strength reduction coefficient of concrete and the equivalent constraint reduction coefficient. On the basis of the unified strength theory, the united solution of the ultimate bearing capacity for square CFST columns is deduced after considering the influence of strength-differential in tension and compression and intermediate principal stress. Some influencing factors are also analyzed in the paper. Through comparing the results of proposed formula with that of experiments of relevant literatures,the rationality of proposed formula is proved. The solution may provide theoretical references for the study of the ultimate bearing capacity for stiffened and thin-walled square CFST short columns.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yongtao Zhang ◽  
Yuqing Liu ◽  
Huiwu Luo ◽  
Peishuai Chen ◽  
Dejie Li ◽  
...  

AbstractIn engineering practice, the measured bearing capacity of a sand pile composite foundation in a mucky soil layer is much larger than the design value. Based on the sand pile construction and the load application process, a method of calculating the bearing capacity of the foundation based on the effective stress was proposed. Cavity diameter expansion in sand pile construction was simplified into a planar problem, and the cavity expansion theory was used to establish the expression of the rate of displacement and the horizontal stress increase. Based on the e–p curve and the calculation of the degree of consolidation, the relationships between the horizontal and vertical effective stress and the void ratio were obtained. According to the close relationship between the bearing capacity of the foundation in a mucky soil layer and the water content, an expression describing the relationships between the bearing capacity of the foundation, effective stress, void ratio, and water content was established. For the temporary engineering foundation treatment project, which needs a high bearing capacity but allows large foundation deformation, the design of sand pile composite foundations uses these relationships to take the consolidation effect of mucky soil into consideration, thereby reducing the replacement rate and lowering the construction cost.


2012 ◽  
Vol 159 ◽  
pp. 151-155 ◽  
Author(s):  
Xiao Wei Li ◽  
Jun Hai Zhao ◽  
Qi Yao Wang

Based on unified strength theory, the equation for estimating the maximum reduction in thickness in a single sheet forming pass is obtained. Included the contribution of both intermediate principal shear stress and varying tension-compression-ratio to material mechanical property, the equation developed by this paper can reasonably apply to a wide range of material. It can be proved that the equation for estimating the maximum reduction based on unified strength theory becomes that based on unified yield criterion, when material has equal strength in tension and compression, i.e., the tension-compression-ratio of material is equal to units; and, that the values of the maximum reduction obtained previously based on Mises, or Tresca criterion, are all just special cases of those based on unified yield criterion. In addition, the maximum reduction in thickness for sheet drawing and extrusion is equal to one another.


2011 ◽  
Vol 94-96 ◽  
pp. 1205-1210
Author(s):  
Zhao Liu ◽  
Jun Hai Zhao

The mechanical behavior and ultimate bearing capacity of the circular bar-reinforced concrete filled steel tube (BRCFST) short columns under axial compression are analyzed in this paper based on the unified strength theory. Considering the restriction effect of steel tube and hoop bar on concrete, the calculation formula of bearing capacity of the column is deduced. Parametric studies are carried out to evaluate the effects of intermediate principal stresses, diameter-thickness ratio of steel tube and the stirrup ratio on the bearing capacity of the column. A good agreement is reached by comparing the results calculated by the formula with the test results. It is concluded that the unified strength theory is applicable in the theoretical analyses of the BRCFST columns.


2013 ◽  
Vol 690-693 ◽  
pp. 742-746
Author(s):  
Peng Wu ◽  
Jian Feng Xu ◽  
Jun Hai Zhao ◽  
Qian Zhu ◽  
Su Wang

Based on unified strength theory, the mechanical behavior of core-concrete of concrete-filled square steel tubular stub columns was analyzed. Through controlling the constraint effect between square steel tube and core-concrete by width-thickness ratio, the ultimate bearing capacity formula for concrete-filled square steel tubular stub columns under axial compression was proposed, and the influencing factors of which was also discussed. The rationality of proposed formula was proved from the comparison of the analytical results obtained in this paper and experimental data.


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 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.


2012 ◽  
Vol 256-259 ◽  
pp. 612-615
Author(s):  
Gui Lin Sheng ◽  
Ya Ge Zhang

The axial stress and axial displacement distribution curves of reinforced mixing single pile are researched by ANSYS software; and the differences of the single pile ultimate capacity of reinforced mixing pile between different core pile length and area replacing ratio are analyzed; It compared and analyzed envelope diagrams of bending moment and shear of reinforced mixing pile in different core pile length and area replacing ratio under seismic response. Some conclusions which may be of some value for design and construction of reinforced mixing pile composite foundation are drawn


Sign in / Sign up

Export Citation Format

Share Document