The experimental studies were performed to examine the failure mechanism and the capacity of BFRP bolt-anchorage system under laboratory and field conditions in supporting clay slopes in Sichuan Basin, China. The results indicate that BFRP anchor bolts, designed based on the principle of equal strength replacement between bolt tensile strength and the bonding strength of the first interface, can meet the safety standards required for slope engineering. During the stable phase of the slope, the mechanical behavior and deformation characteristics of BFRP anchor bolts are comparable to those of steel anchor bolts, with the axial force of BFRP bolts being 1/3 to 1/4 lower than the designed value. When the slope enters the accelerated creep stage, the axial force of steel anchor bolts exceeds the designed value by 40 %, while the axial force of BFRP bolts remains at only 2/3 of that of steel bolts. The failure mechanisms of the BFRP bolt-anchorage system primarily involve shear failure at the bolt-mortar interface and pullout failure of the bolt body, which are attributed to the cumulative damage of the polymer material. Based on the experimental findings, it is recommended that the minimum tensile safety factor for BFRP bars used in temporary slope support should be set at 1.26. This study enhances the understanding of BFRP anchorage systems in clay soil environments and provides valuable insights for the design and construction of infrastructure projects in similar geological conditions.

Basalt fiber-reinforced polymer (BFRP) anchors are increasingly utilized in geotechnical anchoring engineering; however, there remains significant potential for studying the erosion characteristics of the BFRP anchor-slope system under rainfall conditions. This paper investigated the hydrological and spatial-temporal characteristics of three-level bridge foundation slope (TLBFS) reinforced by BFRP anchors through laboratory rainfall experiments. An index (rill density beta\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\beta$$\end{document}) was defined to quantify the degree of slope erosion. The experimental setup included a flume measuring 2 m in length, 1.2 m in width, and 1.5 m in height, a uniform rainfall intensity of 20.0 mm/h, and four sensors used for monitoring moisture content V, earth pressure E, anchor dynamometer T, and strain gauge S. The results indicated that the rill densities of third-level and first-level slopes after soil saturation were 2.37% and 0.98%, respectively. However, relying solely on the rill density index may lead to an overestimation of slope stability. Conversely, the high moisture content (25.72%) of the first-level slope correlated with its deformation and failure. It is proposed that the moisture content index can serve as a reliable indicator for evaluating slope stability. A strong correlation existed between moisture content omega\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\omega$$\end{document} and erosion amount delta\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\delta$$\end{document}, which suggested that real-time monitoring of slope erosion can be conducted using the moisture content index. The damage to TLBFS resulted from the coupling of the internal and external factors, and the specific failure mode was identified as shallow slip. While the flexible reinforcement capabilities of BFRP anchors effectively mitigated slope deformation, but additional engineering measures need to be added to TLBFS. These findings provide valuable insights for soil and water conservation and disaster prevention in multi-level slopes.

In areas with high seismic activity, enhancing the seismic performance of subway station structures is of paramount importance. This paper presents a novel approach involving the application of an ECC-BFRP (Engineered Cementitious Composite with Basalt Fiber Reinforced Polymer) composite layer to reinforce central columns of subway stations situated in loess site. To evaluate the effectiveness of this reinforcement method, a three-dimensional finite element model of subway station structure, accounting for soil-structure interaction (SSI) effects, was meticulously developed using the finite element software Abaqus. The seismic responses of the subway stations with various reinforcement scenarios such as reinforced by the cement mortar, ECC, Mortar-BFRP and ECC-BFRP layer were respectively analyzed in comparison to the unreinforced station. Both the structural displacement response and the changing pattern of damage development for the overall and local structural members were obtained. The results indicated that the ECC-BFRP composite layer could effectively improve the stiffness of the central column and reduce the seismic response of the station. Meanwhile, the seismic damage of the central column was significantly reduced, and the seismic damage distribution of other structural members was uniformly distributed. Consequently, the seismic performance of the station was effectively improved. The research results provided valuable guidance for the seismic design of underground structures.