Research on Material Optimization of CSM Method Structures in Highly Weathered Strata

To address the challenges of low strength and poor impermeability of soil–cement walls formed with ordinary cement materials when applying the CSM (Cutter Soil Mixing) method in highly weathered strata, this study carried out structural optimization by combining the CSM method with H–section steel. This optimization effectively resolves issues such as low efficiency and high cost associated with the CSM method integrated with cement–filled piles. Meanwhile, using ordinary Portland cement as the base material, basalt fiber, sodium bentonite, and fly ash were added to investigate the influence of each component on the performance of the new composite. A novel CSM material suitable for highly weathered strata was developed, which exhibits excellent mechanical strength and impermeability. The optimal mix proportion of the soil–cement material was determined as follows: basalt fiber 0.5%, fly ash 15%, and sodium bentonite 3%. This research provides a quantitative basis for the efficient and economical application of the CSM method in highly weathered strata.