A Local Pushover Testing Mechanism for Geotechnical Engineering: Implementation and Preliminary Verification

The experimental method is significant for exploring the mechanical response and damage evolution of geotechnical engineering. However, quasi-static tests on geotechnical engineering structures subjected to non-uniform loading excitation remain scarce. Based on quasi-static testing and soil response analysis methods, a local pushover testing method was proposed. First, a novel pushover testing platform was developed. It consisted of a composite model container, a reaction frame, and a multi-channel electric servo loading system. The non-uniform loading program was implemented by establishing a lateral driving system that included a local pushover plate and horizontal electric servo actuators. Subsequently, the applicability of the proposed pushover testing method was preliminarily verified through an experimental pushover test conducted on sandy soil. The results show that this method effectively captures the non-uniform deformation behavior of soil subjected to non-uniform loading excitation. The local pushover loading pattern can lead to a noticeable difference in soil displacement between the driving plate zone and the slave zone. A stress attenuation mechanism in the soil was revealed, with stress decreasing in the following order: highest at a pushover distance of 30 cm in the driving zone, followed by 100 cm in the same zone, and lowest in the slave zone. This study can provide a foundation for further investigation into the responses of soil–underground structure systems under non-uniform loading.