Shaking Table Tests on a New Antislide Pile under Earthquakes

Jie Lai,Wei Wang,Yun Liu,Nhon Nguyen Thanh

doi:10.1155/2021/9304705

Abstract

A retaining form of a shock-absorbing antislide pile is proposed for slope engineering. A flexible material (shock-absorption layer) is filled in front of an ordinary antislide pile, which is used to absorb a large amount of seismic energy, thereby decreasing the transmission of seismic energy to the antislide pile. The flexible material thus reduces the seismic response, hence improving the aseismic capacity of the antislide pile. To verify the seismic performance of the shock-absorbing antislide pile, a shaking table contrast test was conducted and the results were compared with those from an ordinary antislide pile. The test results show that the flexible material absorbs a portion of the seismic deformation of the slip mass, decreasing the final displacement of the shock-absorbing antislide pile compared to that of the ordinary antislide pile, thereby reducing the sensitivity of the pile body to the displacement. Under the same conditions, the acceleration response of the slope body at the same height is lower for the shock-absorbing antislide pile than that for the ordinary pile, with the seismic performance of the former being superior to that of the latter. Furthermore, the shock-absorbing antislide pile is similar to the ordinary pile in terms of the dynamic earth pressure distribution form of the pile shaft; however, its value is relatively smaller, and the former exhibits better dynamic stress performance than the latter. The test results should prove useful for aseismic design of slopes.

Highlights

Ensuring the seismic safety of underground structures has become an imminent need for social and economic development
In addition to the above-mentioned research on the seismic performance of common underground structures, some scholars have proposed approaches to improve the seismic performance of underground structures by absorption of seismic energy using vibration-absorptive materials [8,9,10]; their research has focused on tunnel energy dissipation from the aspects of theory and testing
We propose a new antislide pile form, in which a flexible material is filled in front of antislide piles to act as a shockabsorption layer

Summary

Mechanism of Action for Shock-Absorbing Antislide Piles

E normal operating frequency of the shaking table is 0.5–50 Hz. where M′′ and Q′′ are the bending moment and shear force of the ordinary antislide pile, respectively, and R′′ [1 + (ElIl/Kl)(2π/λ)4]− 1. In the shaking table test, the model box effect has a significant influence on the test results To mitigate this adverse effect and ensure that the model box can reproduce the seismic response law of the free field for structures, we added polystyrene foam flexible material around the inner wall of the model box to absorb the boundary wave, thereby eliminating the corresponding boundary effect in the test [11].

Model Test

Comparison of Monitoring Data in the Test

Findings

Conclusion