scholarly journals A New Method for Evaluating the Bearing Capacity of the Bridge Pile Socketed in the Soft Rock

2021 ◽  
Vol 11 (13) ◽  
pp. 5923
Author(s):  
Yao Lu ◽  
Dejian Li ◽  
Shiwei Jia ◽  
Kai Wang

Aiming at the rock-socketed pile in the soft rock area, this paper studies the inherent constitutive relationship between the vertical restraint stiffness at the pier bottom and the bearing capacity of the pile foundation. A new method to evaluate the bearing capacity of the pile foundation is proposed. Based on the Rayleigh energy method and the Southwell frequency synthesis method, the analytical expression of the vertical vibration fundamental frequency of the pier was calculated, and the constraint stiffness expression of the pier bottom was derived. By investigating the impact of parameters on the bearing capacity coefficient of the pile foundation, the fitting formula of the bearing capacity coefficient was obtained by multiple linear regression. Then, with this method, the vertical fundamental frequency of the pier was obtained through a field dynamic test to calculate the vertical constraint stiffness and evaluate the bearing capacity of the rock-socketed pile in the soft rock area. This method can overcome the shortcomings of the traditional static load test method, such as the high cost, long cycle, and poor representativeness. Finally, this method’s accuracy was verified by comparing field measurements and finite element simulation results. The results show that the difference between the code design constraint stiffness and the constraint stiffness by the frequency synthesis method was about 0.7%, and the bearing capacity difference between the analytical solution and the numerical simulation was small. The new method is accurate and effective.

2020 ◽  
Vol 2 (3) ◽  
pp. 63-68
Author(s):  
Arif Sanjaya ◽  
Resi Aseanto

The foundation is a construction that continues the burden of the upper structure and passes it on to the soil below it. A bored pile foundation is now an option in working on structures in densely populated areas and tall buildings. The purpose of this study is to calculate and compare the carrying capacity of the bored pile foundation based on N-SPT data with the O 'Neil & Reese, and Reese & Wright methods, while the Loading test data with the interpretation of the Davisson method and the Mazurkiewicz method. The results of calculations based on N-SPT data, the average ultimate carrying capacity of the foundation with the O’neil & Reese method of 1211.61 tons, Reese & Wright of 1235.02 tons. While the Interpretation of Loading test method for Marzukiewicz is 1267.00 tons, Davisson is 850.40 tons, and the carrying capacity of PDA test results is 121.72 tons. From the calculation of the bearing capacity of the consecutive foundation of the smallest is the Davisson method, the O'neil & Reese method, the PDA test method, the Reese & Wright method, and finally the Mazurkiewicz method.


ASTONJADRO ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Sapria Adi ◽  
Ferry Fatnanta ◽  
Syawal Satibi

<p>The use of helical foundations to support structures on peat soil is still a new method. Research is needed to develop this foundation. There are 6 types of helical foundation tested on peat soil. To study the effect of helical plate diameter, plate diameters were varied with sizes 25 cm (M), 35 cm (L), and 45 cm (G). Plate positions (1, 2, 3 plates) are designed at 300 mm spacing. The axial compression bearing capacity test is carried out based on the constant rate of penetration procedure. At the beginning of loading, the load increases significantly. At a certain descent, the load begins to decrease slowly. The load-settlement curve shows that the larger the plate diameter, the greater the load it can withstand. The largest bearing capacity is produced by the GGG 30 foundation (3 plates dia.45 cm), which is 10.83 kN. LLL 30 helical foundation (3 plates dia.30 cm) provides a bearing capacity of 7.14 kN. These results clearly explain that the increase in plate diameter is directly proportional to the increase in the axial compression bearing capacity.</p>


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.


1993 ◽  
Vol 30 (1) ◽  
pp. 1-11
Author(s):  
R. Frank ◽  
H. Zervogiannis ◽  
S. Christoulas ◽  
V. Papadopoulos ◽  
N. Kalteziotis

This paper describes the behaviour of two test piles (one bored and postgrouted and one simply bored, both 31.7 m long and 0.75 m in diameter) subjected to horizontal loads. These full-scale pile tests were carried out for the actual design of the pile foundation of a pier of the Evripos cable-stayed bridge. This bridge will link the Euboea Island to mainland Greece. The two piles have already been subjected to bearing capacity tests under axial loadings. The inclinometer measurements, taken during the present tests, yielded, in particular, the deformed shape of the piles as well as the bending moments. Conclusions could be drawn for the final design of the pile foundation with respect to horizontal loadings. Furthermore, various calculation methods using p–y reaction curves for cohesionless soils have been checked: the Ménard pressuremeter method, the method of the American Petroleum Institute recommendations, and the Standard penetration test method of Christoulas. These pile tests show that simple measurements, taken on construction sites, can yield interesting results on the actual behaviour of horizontally loaded piles. Key words : pile, horizontal loading, full-scale test, horizontal loads, bending moment, subgrade reaction modulus, p–y curve, cohesionless soil, Standard penetration test, pressuremeter test.


2002 ◽  
pp. 97-107 ◽  
Author(s):  
Makoto KIMURA ◽  
Hiroshi MAKING ◽  
Katsunori OKAWA ◽  
Hiroyuki KAMEI ◽  
Feng ZHANG

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