Experimental study on soil impermeability based on chemical improvement method

Area of Science:

• Geotechnical Engineering
• Soil Science
• Chemical Stabilization

Background:

• Coastal silty sand foundation pits exhibit high permeability, increasing susceptibility to seepage failure.
• Effective anti-seepage measures are crucial for the stability of these structures.

Purpose of the Study:

• To evaluate the efficacy of three chemical stabilizers (sodium silicate, calcium lignosulfonate, sodium polyacrylate) in mitigating permeability in coastal silty sand.
• To identify the most effective stabilizer for improving anti-seepage properties.

Main Methods:

• Utilized a self-designed seepage test system to assess permeability characteristics.
• Compared the performance of untreated silty sand with soil treated by three different chemical stabilizers.
• Analyzed cumulative erosion mass, erosion rate, and permeability coefficient stabilization.

Main Results:

• Untreated soil showed exponential increase in erosion mass (89.39 g/min rate).
• All stabilizers reduced erosion rates below 30 g/min.
• Sodium polyacrylate (4% dosage, 6h cure) achieved superior results: 3.98 g/min erosion rate, 35g cumulative mass, permeability 10⁻⁶-10⁻⁷ cm/s, and 6.3 min stabilization time.

Conclusions:

• Sodium polyacrylate demonstrates superior performance in reducing permeability and erosion compared to sodium silicate and calcium lignosulfonate.
• The findings provide effective chemical improvement solutions for anti-seepage engineering in coastal foundation pits.
• Sodium polyacrylate meets anti-seepage requirements for high-standard cut-off walls.