ABSTRACT
Soil-nailed walls are commonly used for their cost-effectiveness and ease of implementation. These structures have demonstrated remarkable seismic resilience, as evidenced by post-earthquake surveys following events like the Loma Prieta earthquake. Researchers have attributed their stability to the dynamic mobilization of friction at the soil-nail interface. However, designing soil-nailed walls to withstand seismic forces often results in increased stiffness, which can affect the transfer of motion to the structures they support. Improving the seismic design of these walls requires a closer examination of the local dynamic behavior at the soil-nail interface, a topic that has received limited attention in the existing literature. To address this gap, the RRO laboratory at Gustave Eiffel University has recently developed an innovative impulsive pullout testing device. This paper introduces the device, which is capable of applying static tension forces and a series of dynamic load pulses at the nail’s head, reaching up to 50% of the applied force and operating at specified frequencies ranging from 0.1 to 5 Hz. In addition to traditional tension force and displacement measurements at the nail head, this device incorporates optical fiber technology to monitor micro strains along the entire length of the steel bar with millimeter longitudinal resolution. This new approach enables the comprehensive investigation of the local seismic behavior of the interface, with the goal of proposing an improved design model for soil-nailed walls.
