Anchoring force loss is critically concerned for the in-service performance of prestressed ground anchors. This time-dependent loss of pretension exerted at the anchor head is caused primarily by stress relaxation, which integrally manifests the rheological properties of the anchor and the geomaterial in which the anchor is embedded. A load-transfer modeling framework was established to derive the time-dependent anchoring force response. The modeling parameters were directly calibrated via element-scale pullout stress relaxation test using a specially developed setup. The applicability and effectiveness of this analytical modeling framework were verified via large-scale laboratory model tests and in situ tests of prestressed anchors. The predictions derived using the presented modeling framework were in good agreement with measurements in both laboratory model tests and in situ tests, particularly for evolutions of anchoring force over time. Sensitivity evaluation of the model parameters was performed to study their respective impact on the anchoring force loss response. This work can provide insights into the understanding of the anchoring force loss behavior of prestressed ground anchors and facilitate their design practice for in-service performance.

The load-transfer mechanism of tensioned anchors is primarily concerned with in-service performance, which depends on the bond–slip behavior of anchoring interface. Because the interface bond–slip behavior is conventionally modeled using epistemic experience of specific researchers and/or back analysis of specific in situ testing results, it is challenging to develop a straightforward load-transfer analysis with extensive applicability. A generalized load-transfer modeling framework was implemented in this work by incorporating a versatile interface bond–slip model that can be derived from experimental characterization of respective types of element-anchoring interface. The adhesion and friction were modeled with interface slip to constitute the interface bond using rational and exponential functions, respectively. The pullout tests on element-scale and large-scale specimens of a typical anchor type (i.e., tensioned steel tube embedded in cemented soils) were carried out to calibrate the parameters of the interface model and to validate the predicting capability of the modeling framework, respectively. In addition, the versatility of this load-transfer modeling framework was examined for two other anchor types reported in the literature (i.e., tensioned rock anchor and tensioned GFRP anchor embedded in sands). The consistent good agreements between predictions and measurements of these anchor types verified the effectiveness and applicability of the generalized load-transfer modeling framework. Based on the load-transfer analysis for the tensioned steel tube in model testing, a parametric study was performed to investigate the impact of axial stiffness and bond length on load-transfer responses of the tensioned anchor.

An analytical three-dimensional slope reliability evaluation framework was developed in this work independent of use of numerical simulations. The slope stability analysis was necessarily carried out by utilizing an extended three-dimensional Morgenstern–Price method, which was characterized by analytical formulations and competitive computational efficiency. Incorporation of the presented stability analysis method into response surface methodology led to an effective slope reliability evaluation framework. The applicability and superiority of this framework was examined and validated using a real complicated landslide case reported in practice, and a hypothetical slope example widely adopted in the literature. The impact of correlation coefficients and probability distribution patterns on the slope reliability assessment results was further addressed to derive additional benefits of this framework.