Performance of a 40 m high reinforced soil slope under high‐altitude cold conditions

Abstract In high‐altitude regions characterized by cold climates and complex terrain, the engineering performance of geosynthetic‐reinforced soil slopes requires careful consideration. This paper discusses the design and construction of a reinforced soil slope based on an ultra‐high voltage converter station project in a high‐altitude region and verifies the reliability of the design scheme through cross‐validation using two numerical software programmes. A 40 m high reinforced soil slope was selected for monitoring and analysis of temperature, slope deformation, settlement, deep horizontal displacement, acceleration, earth pressure and geogrid strain. The results indicate that the safety factors of the slope under normal, earthquake and heavy rainfall conditions all satisfy relevant standard requirements. Both the lateral displacement and settlement of the slope surface increased rapidly during construction and then gradually stabilized. Twenty‐six months after completion, the maximum lateral displacement and settlement were 523.41 and 420.30 mm, respectively, both within the allowable range specified in the standards. Soil temperature exhibited a lag relative to ambient temperature, and temperature variations induced periodic daily fluctuations in deformation. Lateral displacement and settlement showed negative and positive correlations with soil temperature, respectively, whereas repeated freeze–thaw cycles led to the gradual accumulation of deformation over time. The vertical earth pressure within the slope decreased gradually with increasing slope height and showed notable deviations from theoretical values due to the shielding effect of the geogrids. Geogrid strain was higher near the slope surface and decreased with increasing slope height, with a maximum strain of 1.8% observed across all layers. The deep horizontal displacement gradually stabilized 1 year after the slope was completed. No seismic events were recorded at the site during the 2‐year period following slope completion.