Experimental Study of the Dynamic Characteristics of a New Antidrainage Subgrade Structure for High-Speed Railways in Diatomaceous Earth Areas

Area of Science:

• Geotechnical Engineering
• Civil Engineering
• Railway Engineering

Background:

• Engineering in diatomaceous earth areas lacks sufficient experience.
• Diatomaceous earth exhibits poor hydrophysical properties and low disintegration resistance (3.1%–9.0%).
• The Hang Shaotai high-speed railway traverses a challenging diatomaceous earth region in Shengzhou, Zhejiang Province.

Purpose of the Study:

• Analyze the hydrological and mechanical properties of diatomaceous earth.
• Propose and validate a new antidrainage subgrade structure for high-speed railways.
• Examine the dynamic characteristics and deformation of the roadbed in diatomaceous earth.

Main Methods:

• Field surveys and laboratory analysis of diatomaceous earth properties.
• Proposal and field testing of a novel antidrainage subgrade structure.
• Dynamic excitation tests to assess subgrade performance under load and water immersion.

Main Results:

• The proposed antidrainage subgrade structure shows excellent water resistance and stability.
• Stabilized dynamic stress and vibration acceleration were recorded at 6.37 kPa and 0.94 m/s² after 700,000 cycles.
• Negligible settlement (0.08 mm) was observed in the diatomaceous earth foundation after 2 million excitations.

Conclusions:

• The novel antidrainage subgrade structure is effective for railway construction in diatomaceous earth areas.
• The structure ensures long-term stability and minimal deformation under dynamic loading and water exposure.
• Findings offer valuable insights for future engineering projects in challenging diatomaceous earth environments.