Study on seismic active earth pressure of narrow backfill of balance weight retaining wall rotating around the top

Balance weight retaining walls are commonly used in slope engineering, typically considering only static active earth pressure, while seismic active earth pressure remains under-researched. This paper uses finite element limit analysis to study the failure modes of a balance weight retaining wall with finite backfill width under seismic conditions and the rotational around the wall top (RT) displacement mode. The results show that the slip surface follows a logarithmic spiral, and after contacting the rock slope, a reflected slip surface is formed, maintaining the spiral shape. Using the horizontal differential element method, a calculation formula for seismic active earth pressure is derived. Parameter analysis reveals how seismic acceleration, backfill width-to-depth ratio, internal friction angle, rock layer inclination, and interface friction angle affect the distribution, resultant, and location of seismic active earth pressure. The research provides technical references for seismic design.