In this study, a nonlinear prediction model of antislide pile top displacement is proposed. Based on the quantitative analysis of the rock mass structure characteristics of the soft and hard interbedded sliding bed in the Jurassic strata, the post-thrust force and geometric characteristics of the top of antislide pile displacement, and bending moment, the main controlling factors affecting the displacement of the top of antislide pile were determined by maximal information coefficient (MIC). Through orthogonal experiment design and 3DEC numerical experiment, a database of main controlling factors (sliding bedrock inclination, thrust size, embedded depth, and pile section size) of pile top displacement was established and a nonlinear prediction model of the displacement of the top of antislide pile based on the main controlling factors was proposed. Finally, two engineering examples were used to validate the performance of this model, with the comparisons of four prediction methods (SVR, MIC-SVR, LSTM, and ELMAN). The results show that the MIC-SVR model has a practical reference value for the prediction of the displacement of the top of an antislide pile in the Jurassic landslide in the Three Gorges Reservoir Area.

The objective of this research is to characterize the high strain rate impact performance of fiber-reinforced polymer (FRP) impregnated with shear thickening fluid (STF) by using a split Hopkinson pressure bar (SHPB) test. Three types of FRP with aramid, basalt, and carbon fibers are prepared, followed by impregnated with 15 wt.% STF and 20 wt.% STF to develop FRP composited materials (FRP-STF), respectively. The results demonstrate that STF impregnated significantly enhances the high strain rate impact performance for the AFRP, BFRP, and CFRP. Nevertheless, the enhancing effect is different for different types of FRP. Under 3800 s-1, when the mass fraction of STF is 20%, the increase rate of BFRP stress peak is the highest, reaching 58.9%. However, the best increase of energy absorption peak is AFRP, reaching 226.8%. Under 6100 s-1, the stress response of AFRP-20%STF is the best, and the energy absorption peak of CFRP-20%STF reaches 710.5 J, about 2.3 times that of pure CFRP. This is also reflected in the energy absorption per unit density curve. The results also show three FRPs have significant strain rate effects, especially on the energy absorption peak. The maximum increase rates are 101.9%, 710.7%, and 1070.5%, respectively.

This study investigates the effect of multi-walled carbon nanotubes (MWCNT) on the high strain rate properties of carbon fiber reinforced polymer (CFRP) fabric impregnated with shear thickening fluids (STF). Three GFRP-STF and twelve GFRP-MWCNT/STF composite specimens were conducted using a split Hopkinson pressure bar (SHPB). Spherical silica nanoparticles (20.0 wt%) and polyethylene glycol were used to prepare silicon-based-STF (SiO2/STF). On this basis, MWCNT with 0.4, 0.8, and 1.2 wt% were further used to synthesize the MWCNT/STF, respectively. The SHPB test showed that MWCNT/STF has a more significant strain rate effect, with stress increases of 71.1%, 57.5%, and 26.0% under 3800 s−1, 5100 s−1, and 6100 s−1, respectively. The results also showed that MWCNT significantly improved the yield stress and strain energy absorption of SiO2/STF under a high strain rate. The maximum yield stress increase was 71.1%, and the maximum increase in strain energy absorption was 229.1%. The results of CFRP-MWCNT/STF revealed that MWCNT/STF treatment enhanced the high strain rate impact properties of CFRP-SiO2/STF. The improved effect is up to 27.9%, 133.6%, and 165.7% in yield stress, impact toughness, and energy absorption efficiency, respectively. The mass fraction of MWCNT significantly affects the impact properties of CFRP-MWCNT/STF under high strain rate loading, but this effect decreases with the increase of strain rate. Thus, CFRP-MWCNT/STF is more suitable for application in a high strain rate impact environment than CFRP-SiO2/STF.