Search Results (3)

In this paper, low circumferential reciprocating load foot-scale tests were performed on two nontruncated PHC B 600 130 tubular piles with bearing nodes to characterize the damage process and morphology of the specimens and to investigate the load-carrying performance of the members. The test results reveal that under the action of tensile-bending-shear loading, the bearing concrete in the node area buckles and is damaged, the anchored reinforcement in the node area yields, the constraint is weakened, an articulation point is formed, and the node rotational capacity increases. When the embedment depth increases from 200 mm to 300 mm, the ultimate bearing capacities of the positive and negative nodes increase by 31.04% and 36.16%, respectively. A numerical simulation is used to verify the test results. Considering the four types of piles without truncated nodes, the numerical simulation is used to analyze the node-bearing capacity at different embedment depths. Finally, a preferred node type is proposed as follows: a terminal plate welded anchor bar and pipe pile core-filled longitudinal reinforcement anchored into the bearing node, with a preferred embedment depth of 250 mm. Full article

To investigate the load-carrying performance of the nodes between tubular piles and bearing platforms, low circumferential reciprocating load foot-scale tests were performed on two truncated PHC B 600 130 tubular piles. The development law of node destruction was explored. The test results revealed that under the action of tensile–bending–shear loading, the bearing concrete in the node area buckled and was damaged, and an articulation point was formed. When the embedment depth increased from 200 mm to 300 mm, the ultimate bearing capacities of the positive and negative nodes increased by 57.60% and 54.60%, respectively. Numerical simulation was used to analyze the bearing capacities of nodes with different types and embedment depths. Formulas for the bearing capacity of the nodes were proposed. Furthermore, two preferred node types were proposed as follows: pipe pile core-filled longitudinal reinforcement anchored to the bearing node and pipe pile body longitudinal reinforcement anchored to the bearing node + pipe pile core-filled longitudinal reinforcement anchored to the bearing node, with preferred embedment depths of 350 mm and 200 mm, respectively. Full article

Socket connection need a groove reserved in the cap to accommodate a bridge pier, which greatly weaken the vertical bearing capacity of the cap. The conventional treatment measure is to increase the thickness of the cap, and the corresponding cost will increase. The measures to enhance the vertical bearing capacity of socket caps without increasing the thickness of the cap were discussed in this paper, including a rough interface at the bottom of the pier, additional hanging bars, high-strength grouting material in the seam, and large-diameter metal corrugated pipes, etc. Based on a previous test, the finite element analysis of the vertical bearing capacity of pile caps with new socket connections was carried out. The analysis parameters included the construction method, steel bar diameter in the bottom of the cap, socket depth, thickness of the bottom plate, pile length, and friction coefficient, etc. The bearing capacity M–N relation of the full-scale model was also analyzed. Research indicated the vertical bearing capacity of the cap is mainly provided by rough interfaces, the bottom plate, and the additional hanging bars, and the contribution of the three parts was about 40%, 34%, and 26%; the vertical bearing capacity was proportional to the areas of steel bars on the cap and the thickness of the bottom plate, and was inversely proportional to the length of the pile. To obtain the vertical bearing capacity of the overall cast-in-place plan for the socket cap, the thickness of the cap needs to be increased by 27%. At last, a design formula for the calculation of the vertical bearing capacity was proposed. Full article