Seismic Interaction Characteristics of an Inclined Straight Alternating Pile Group‐Soil in Liquefied Ground

Abstract

In this paper, the pile-soil interaction of a low-rise pile cap foundation of an inclined straight alternating pile on two or three layers of a soil liquefaction site under seismic load is studied. By inputting the 0.5 g El Centro seismic wave in FLAC 3D , the pile-soil interaction rule of the pile foundation of the inclined and straight pile groups of the low-pile cap under seismic action is simulated. By analyzing the soil acceleration, the pore pressure ratio, the horizontal displacement of the pile body, the vertical displacement, and the pile body bending moment, the law of pile-soil interaction between the pile and soil when the lower part of the pile is embedded in the clay layer is studied, and the low-rise pile cap inclined straight alternating group pile foundation on the two-layer soil and the three-layer soil free field is compared and analyzed. e results show that, under seismic load, the maximum acceleration of soil mass in the two-layer soil and three-layer soil model is discrete, and the pore pressure ratio of sand soil increases from bottom to top. By analyzing the displacement and bending moment of pile body, the bending moment at the joint between the pile cap and the top of pile body is the largest and the most vulnerable to damage. e maximum value of pile displacement and bending moment in the three-layer soil is less than the maximum value of the two-layer soil, indicating that the pile group foundation in the three-layer soil free site model is safer.

Numerical Simulation of Seismic Soil-Pile Interaction in Liquefying Ground

“…To study the seismic interaction characteristics of pile-soil interactions with an inclined straight alternating group at a liquefaction site, a numerical calculation model was established for the actual conditions of a project. The foundation of this project is a two-layer land foundation: the upper soil layer is clay with a thickness of 2 m; the lower soil layer is sandy soil with a thickness of 13 m [21]. The bottom is rock with a thickness of 1 m. The pile foundation is 2 × 3 inclined straight alternating group piles, and the arrangement of the group piles is shown in…”

“…Step 3 is to model the opening mechanics and fluid calculation, which sets the dynamic pore pressure model, sets the boundary conditions and mechanical damping, sets monitoring points, inputs the acceleration at the bottom of the model, and then carries out the dynamic calculation [21].…”

“…The parameters of the contact surfaces are listed in Table 3. The constitutive model of the piles' group cap is modeled by an isotropic elastic model, and the seepage model adopts an impermeable model [21].…”

Experimental Study on Mechanical Deformation Characteristics of Inclined and Straight Alternating Pile Groups

“…Its good pullout resistance and compression resistance can better meet the requirements of horizontal bearing capacity, but at present there is little research on the mechanism of loading and deformation of inclined piles and inclined pile groups in China, and the axis of inclined piles is not perpendicular to the ground plane, which makes the bearing and deformation behavior of inclined piles more complicated than that of straight piles, so it is of great engineering practical significance to carry out the research of inclined and straight alternating pile groups [5,6]. In terms of existing theory, Zhao et al tested the load-displacement and pile strain of inclined-inclined, inclined-straight, and straight-straight double piles with caps and straight piles under horizontal load and got the conclusion that the horizontal bearing capacity of load-displacement and pile strain of inclined piles are obviously better than those of straight piles [7,8]; Zhang et al [9,10], Binu et al [11], Kong et al [12], Lu et al [13], and Shao et al [14], respectively, studied the vertical bearing capacity of inclined piles through model tests, which is of great significance for understanding the bearing and deformation characteristics of inclined piles. Ashraf and Ahmed [15], Kong et al.…”

A Study on the Seismic Response Characteristics of an Oblique Pile Group‐Soil‐Structure with Different Pile Caps

“…erefore, whether soil liquefaction in earthquakes leads to the destruction of the pile foundation bridge structure of oblique and straight groups has become a problem that needs to be seriously considered in the earthquake resistance of bridge projects in China [5]. Group piles with low caps and high caps are widely used in bridge engineering [6][7][8].…”