Working mechanism and method for theoretical calculation of arch–chord coupled anti‐sliding structure

Abstract

With the increase in the mileage of high‐speed railways around the world, subgrade problems related to the same have been emerging in large numbers. In view of the shortcomings of slow construction speed and large disturbance caused by conventional anti‐slide piles during emergency reinforcement of subgrades, an “arch–chord coupled anti‐slide structure” is proposed in this study, based on the three‐dimensional characteristics of the subgrade creep, and its anti‐slide mechanism is analyzed; furthermore, a theoretical calculation method for the same is proposed. The results show that the arch–chord coupled anti‐sliding structure can form a coupled body containing multiple surrounded piles when subjected to thrust, thus offering a pile–soil composite structure similar to a retaining wall. This results in a large anti‐sliding force. By setting a virtual pile to regularize the layout of the structural pile, the pile internal force can be accurately computed. The findings of this study provide a theoretical basis for the analysis and design of coupled anti‐sliding structures in future.

Parameter analysis of coupling characteristics and load‐sharing law of arch‐chord coupled anti‐sliding structure

“…Arch‐chord coupled anti‐sliding structure is proposed based on uneven distribution characteristics of sliding force 13 . The number of single piles in the anti‐sliding structure is reduced from the middle to both sides according to certain rules, which can provide sufficient anti‐sliding capacity and reduce the number of anti‐sliding piles at the same time, because its plane shape includes both arch and chord (straight line), and focuses on the coupling effect between pile and soil, this new anti‐sliding structure is named arch‐chord coupled anti‐sliding structure.…”

“…The width of arch‐chord coupled anti‐sliding structure is relatively fixed and the pile diameter is small, so it can generally be used for reinforcement in the front of abutment or pier to avoid disturbance to existing structures while achieving the reinforcement effect 13 . The structure has the following remarkable geometric characteristics: In the plane: eight piles are arranged according to the reasonable arch axis, the six piles on the side directly bearing the driving force are arranged in a straight line, the other two piles are arranged in the middle so that all piles form a hexagon, two pentagons and six triangles. The diameter of the single pile is 0.4–0.6 m, and the width and height of the connection beam are 1.0–1.25 times the pile diameter and 1 time the pile diameter, respectively. The pile spacing of the middle hexagon is used as the control pile spacing, and the value of control pile spacing is generally 3–5 times the pile diameter. …”

“…Arch‐chord coupled anti‐sliding structure is a highly targeted anti‐sliding structure, which is mainly used for the reinforcement of the front of the abutment, in order to prevent the deformation of the abutment to its front. The anti‐sliding structure is composed of multiple piles with small diameter, which requires very high coupling effect between pile and soil 13 . However, at present, the research on its internal soil arch is relatively scarce, which cannot effectively evaluate whether the pile and soil are really coupled together, which limits the popularization and application of the structure to a certain extent.…”

Experimental Study on the Mechanical Mechanism of Arch-Chord-Coupled Antisliding Structure

“…In addition to optimizing the pile length and pile spacing, some scholars have also made specific arrangements for the position of the piles of the pile group structure [14], so that the rear and middle parts can provide greater antisliding force without increasing the number of piles, and the arch-chord-coupled antisliding structure is such a new type antisliding structure with these characteristics [15]. As a new type of antisliding structure, the mechanical properties of the arch-chord-coupled antisliding structure still need to be further explored in order to guide the design and construction.…”

“…The diameter of the piles that make up the structure is generally 0.3~0.5 m, and the spacing between the piles is generally 3~5 times the diameter of the piles. The width of the sliding body that can be reinforced by this structure is generally 16~18 m, and the typical application scenario is shown in Figure 1(c) [15]. Arch-chord-coupled antisliding structure is proposed based on uneven distribution characteristics of sliding force.…”