Numerical Simulation Study Of Squeezed Branch Piles Based On Post-grouting Technology

The squeezed branch pile has strong resistance to pressure, pullout and horizontal force, and it also has excellent stability, which makes it widely used in the field of electrical engineering. Based on the ABAQUS, the paper simulates the vertical bearing situation of post-grouting squeezed branch piles, by setting up Set two comparisons of single pile and squeezed branch pile, the bearing capacity, load transfer mechanism and failure mode of post-grouting squeezed branch piles were comprehensively analyzed and compared. Studies have shown that the bearing capacity of the squeezed branch piles with post-grouting technology has increased by 68.1% compared with the traditional squeezed branch piles, and the bearing characteristics of the branches have changed greatly. In this process, the end-bearing function of the branch plate is fully exerted, and the high load-bearing capacity of the grouted strata soil is used to reduce the settlement.

Study on the Effects of Grouting and Roughness on the Shear Behavior of Cohesive Soil–Concrete Interfaces

Grouted soil–concrete interfaces exist in bored piles with post-grouting in pile tip or sides and they have a substantial influence on pile skin friction. To study the effect of grouting volume on the shearing characteristics of the interface between cohesive soil and concrete piles with different roughness, grouting equipment and a direct shear apparatus were combined to carry out a total of 48 groups of direct shear tests on cohesive soil–concrete interfaces incorporating the grouting process. The test results showed that the shear behavior of the grouted cohesive soil–concrete interface was improved mainly because increasing the grouting volume and roughness increased the interfacial apparent cohesion. In contrast, increasing the grouting volume and roughness had no obvious increasing effects on the interfacial friction angle. Interfacial grouting contributed to the transition in the grouted cohesive soil from shrinkage to dilation: as the grouting volume increased, the shrinkage became weaker and the dilation became more obvious. The shear band exhibited a parabolic distribution rather than a uniform distribution along the shearing direction and that the shear band thickness was greater in the shearing direction, and it will become thicker with increasing grouting volume or roughness. The analysis can help to understand the shear characteristics of soil–pile interface in studying the vertical bearing properties of pile with post-grouting in tip or sides.