The polymer antiseepage wall is a new technology for the reinforcement of earth dams. It has the advantages of being efficient, ultrathin, minimally invasive, and economical, which makes it even more popular and widespread in many applications. However, research on the seismic response of the polymer antiseepage wall is lacking. Because most earth dams are damaged by seismic loads and the antiseepage system is the weakest part, the related dynamic studies are of great significance for this new type of polymer antiseepage wall. In this study, two physical centrifuge models manufactured with prototype materials were used to investigate the seismic response characteristics of a prototype structure. The results of the seismic response characteristics of the earth dam with a polymer antiseepage wall are presented, along with a comparison of the response characteristics for earth dams with a concrete core. The results show that the earth dam with a polymer antiseepage wall had a good capacity for seismic damage resistance.

The hardening small strain (HSS) model, which considers the non-linear characteristics of the shear modulus of soil in the small strain range, is commonly utilized in the numerical analysis of excavations in sensitive environments. In order to ascertain the parameters of an HSS model for strata typical of Zhengzhou, an extensive series of laboratory tests was executed. Subsequently, a statistical analysis was utilized to establish the relationships between the principal parameters. A three-dimensional finite element model was established based on the excavation of representative strata in Zhengzhou. The accuracy and applicability of the model parameters were verified using the field measurement data. In addition, an analysis of the sensitivity of the main HSS model parameters to the foundation pit deformation was also carried out. The results show that the HSS model can analyze excavation deformation with greater precision than the hardening soil (HS) model or the Mohr–Coulomb (MC) model. The small strain parameters $G_0^{\mathrm{ref}}$ and ${\gamma }_{0.7}$ have a great influence on the horizontal displacement of the support and the vertical displacement of soil behind the wall, respectively. The research results serve as a reliable foundation for both the analysis of excavation deformation and the determination of HSS model parameters for strata typical of Zhengzhou.

The Yellow River alluvial silt has unique engineering properties and is unstable when encountering moisture. The mechanical properties of silt subgrade can be impaired by the increase in moisture content due to rainwater infiltration, which has a negative effect on traffic safety. To further reveal the influence of moisture content on the deformation characteristics of silt, a series of monotonic and cyclic triaxial tests were conducted on the alluvial silt with different moisture contents. The development law of cyclic accumulative permanent strain and the effects of moisture content, cyclic deviator stress and confining pressure on the axial permanent strain of silt were explored. The study shows that the static strength of silt decreases with the increase in moisture content, and the attenuation of static strength is mainly caused by the decrease in cohesion due to the reduction in matric suction. The permanent strain rises linearly with the increase in moisture content and cyclic deviator stress, and decreases with the increase in confining pressure. An empirical model for predicting the permanent strain of silt under long-term cyclic loading considering the effect of moisture content was established. Compared with the test data and other existing models, the established model has easier obtained parameters, higher prediction accuracy and better applicability.

In the paper, through finite element three-dimensional numerical simulation, deformation and internal force variation of double-row piles composite gravity arch supporting system has been analyzed with changing key design parameters such as double-row pile diameter, distance between rows, arch height and arch thickness. Optimization design analysis has also been carried out for this new supporting system. Results show that appropriate increasing pile distance can be used to decrease lateral displacement of supporting system, but it should not be increased blindly for supporting effect. Otherwise the determination method of optimal arch height and thickness values are also put forward in the paper.

In this paper, piezoceramic bender elements technology is first used to test the dynamic shear modulus of polymer grouting materials. The test procedure is designed and the related mould is manufactured. The problems of influencing the...