Test on interaction of semi-integral abutment and soil based on displacement effect of medium-long-term ambient temperature

To study the influence of ambient temperature effect on the interaction mechanism between a semi-integral abutment and soil behind the abutment, a simplified model of the semi-integral abutment-soil structure was taken as the research object to carry out a displacement-based quasi-static test on the semi-integral abutment-soil interaction under the action of ambient temperature. Research results show that the hysteresis curve of the semi-integral abutment varies as the seasonal temperature changes. The seasonal warming and cooling transformation sections have a highly significant effect on the abutment-soil interaction, while the continuously increasing or decreasing sections have less effect on it. The first warming period of a year has a greater impact on the abutment-soil interaction. With several quarters of temperature loading, the soil behind the abutment is gradually compacted. The earth pressure variation tends to be stable, and the increasing trend slows down. The effect of day-night temperature change on the abutment-soil interaction varies from season to season, with daytime warming in summer having a small effect on the abutment-soil interaction while nighttime cooling having a large effect, and vice versa in winter. With the gradual increase in the seasonal temperature, the hysteresis curve of the abutment-soil interaction develops from concave to convex, showing a fuller shuttle shape. The medium-long-term ambient temperature has a large effect on the abutment-soil interaction. After a full year of temperature action, the earth pressure behind the abutment increases significantly, which produces the ratcheting effect. There is a large correlation between the abutment rotation angle and the loading displacement. With the increase in the number of cycles, the abutment rotation angle first gradually increases and then tends to level off. Under the action of medium-long-term ambient temperature, the semi-integral abutment gradually presents the trend of deflection in its rear direction. The effect of day-night temperature change on the abutment rotation angle cannot be ignored. Under the same loading displacement, the test results of the abutment rotation angle considering the superimposed effect of seasonal temperature and day-night temperature are 94% higher than those when only the seasonal temperature effect is taken into account.