The ground penetrating shield tunnel (GPST) method offers a streamlined approach to tunnel construction in soft ground with limited open-cut excavation. To explore the seismic response of GPST linings, a series of large-scale shaking table tests have been conducted, including a variety of seismic excitations. This paper focuses on lateral harmonic excitation. The model tunnel spans a total length of 7.7 m, with the embedment depth ranging from -0.5 to 0.5 times its diameter. The design and fabrication of the model tunnel are presented, including the segmental lining, along with circumferential and longitudinal joints. The soil was modeled with artificial synthetic soil, aiming to simulate the static and dynamic characteristics of the prototype soil. Its composition was adjusted and verified through element tests. The experimental results provide insights into the seismic response of the soil-tunnel system, the ovaling deformation of the segmental lining, as well as the response of the joints between lining segments. The results reveal a strong influence of embedment on tunnel seismic response. The reduction of tunnel embedment leads to a significant increase in lining accelerations and a phase difference, resulting in a whiplash effect. In contrast, the ovaling deformation of the lining and the joint apertures decrease with the reduction of embedment. In the sections of the tunnel that are fully embedded, both the acceleration and deformation response of the lining are governed by soil-structure interaction (SSI). A pronounced whiplash effect is observed in the sections of the tunnel that are not fully embedded, due to the absence of soil confinement. The presented experimental results offer valuable insights into the seismic response of GPSTs, which can be of crucial importance for their seismic design.

The effect of topography on the amplification of seismic forces has been considered in regulations, and they have deemed the use of the seismic force amplification coefficient in the design of adjacent earth-retaining structures necessary. However, the impact of settlement-reducing or anti-sliding piles under the building foundation on the applied acceleration to the foundation is generally not addressed in regulations, and it is necessary to carefully examine this issue for the optimal design. This study sought to empirically assess the impact of using piles as Combined Piled Raft Foundation (CPRF) positioned on the top of slopes, with different slope angles, on the seismic behavior of slopes, scaled at 1/25th, through shaking table experiments. Six sinusoidal waves were created as input motions to simulate a range of earthquake scenarios, applied to the models to collect data for analyzing the seismic response of the system. No.161 Firouzkooh sand was utilized as the soil in this investigation. The amplification factor (AF) of various locations was used to examine the seismic response of the system. The findings underscore the importance of the amplification factor as a critical parameter in evaluating the seismic response of foundations situated on slope crests. Additionally, Implementing CPRF and longer piles had a mitigating effect on accelerations at most points and improved the seismic response of the slopes, reducing amplification factor and led to less damages. Furthermore, the slope angle was shown to significantly influence the seismic response, with steeper angles generally resulting in higher amplifications at the slope crest.

The safety of an isolated structure built on the soft soil ground under the action of earthquakes is of major concern because the current seismic design of isolated structures has not considered the motions of the foundations caused by the effects of the soil-isolated structure dynamic interaction (SISI). On this basis, a shaking-table test method for base-isolated structures on change of soil foundation stiffness was proposed and implemented. The foundation stiffness was controlled by the duration compression ratio and intensity of the input ground motion based on the influence of the increase in the excess pore water pressure ratio on the stiffness of the saturated sandy foundation. Meanwhile, the influence laws of foundation stiffness on the dynamic characteristics of base-isolated structures were summarized and analyzed. The results showed that the first-order natural frequency of base-isolated structures on change of foundation stiffness decreased with an increase in the relative stiffness ratio of the structure-soil foundation (Rs), while its damping ratio increased significantly. The seismic isolation efficiency of the seismic isolation layer and the amplification effect on the rotational angular acceleration of the pile cap were significantly weakened. Meanwhile, under the same conditions, for the soil foundation with relatively small stiffness, the amplitudes of the bending moment and horizontal lateral displacement in the middle and upper parts of the pile remarkably increase because of the effects of the ISI. The research results of this test provide a certain scientific basis and reference for the seismic design of base-isolated structures considering the SISI effects.

Zhuanyao dwellings faced significant seismic risks in rural regions of China. Therefore, a shaking-table test was performed to explore the seismic performance of Zhuanyaos and validate the finite-element simulation results. The results showed that the damage to the pier and roof levels of Zhuanyaos was more severe after earthquakes, resulting in a noteworthy increase in the displacement responses of these two levels compared to that of the vault level. The damage to the front structure (Yaolian) and mid-pier of the Zhuanyao were more severe than the damage to the back wall and side pier, respectively, which caused a significant reduction in acceleration responses of Yaolian and mid-pier. Following the crack development, dynamic response, and field investigation, three typical collapse modes of Zhuanyaos were presented. Subsequently, the parametric analysis was conducted using a verified finite-element simulation method. The results show that using the catenary arch can reduce earthquake damage in Zhuanyaos. Increasing the width of the middle pier can improve the seismic performance of Zhuanyaos to a certain extent; however, it may exacerbate local damage to the structure. Besides, the high seismic vulnerability of Zhuanyaos stemming from an increasing thickness of overlying soil cannot be ignored.

The seismic performance of arch bridges is dependent on the strength of bridges and the built-on soil site types. To investigate the influence of soil-structure interaction (SSI) on the seismic response of an arch-foot arch bridge with a sand-gravel soil site, several shaking-table tests for a 1/90 downscaled arch-foot model placed on sand-gravel soil were conducted based on the engineering prototype of the third Pingnan Bridge with a long-span concrete-filled steel-tube (CFST) arch bridge. The test results showed the following: (1) The seismic acceleration response of both the sand-gravel soil site and arch foot were amplified, which is related to both the non-linear dynamic behavior of sand-gravel soil and frequency-spectrum characteristics of the input seismic waves. (2) The sliding displacement of the arch foot under strong ground motions increased accompanied with a settlement of the soil surface. However, the safety risk of the arch foot may be underestimated in seismic design. (3) The dynamic shear stress-strain loops of sand-gravel soil exhibited a high-energy dissipation capacity, and the energy-transfer mechanism at the interface between the model soil and arch foot was integrated. The results obtained are expected to provide insights into the dynamic interaction behavior of the gravel soil and arch bridge systems and the seismic design of arch bridges built on sand-gravel soil sites in practical engineering.

The understanding of the dynamic behavior characteristics and mechanisms of seismic landslides in seasonal frozen soil areas following severe freeze-thaw damage is currently limited. Taking a compacted loess slope in Lanzhou National New Area of China as the prototype, freeze-thaw cycle tests and large-scale shaking table tests were conducted, and the dynamic responses of freeze-thaw slope and non-freeze-thaw slope under different amplitudes, directions, and intensities of seismic waves were compared and analyzed. The results indicate that the acceleration responses of compacted loess slopes increase with the increase of the slope height and the value of the slope shoulder is the largest. The acceleration responses also increase with higher seismic intensity. On the other hand, earth pressure responses decrease as the slope height increases, but initially increase with higher seismic strength before eventually decreasing prior to slope failure. Comparatively, the acceleration responses of the freeze-thaw slope are stronger than those of the non-freeze-thaw slope, while the earth pressure responses are smaller, particularly in frost-heaving zones The compacted loess slope demonstrates good stability under seismic waves. However, the loosed and wetted surface after freeze-thaw cycles may experience abrupt shear slip during high-intensity seismic waves. These findings hold significance for stability analysis and reinforcement strategies for engineering slopes in the Loess Plateau with seasonal freezing and thawing.