It is easy to form subgrade disease on swelled ground because swelled ground has features of swelling and softening by absorbing water shrinking and cracking by losing water and repeated changing.

膨胀土具有吸水膨胀软化，失水收缩开裂及反复变化的特点，易形成路基病害。

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Silt, clay and adobe often form solid barriers that shed water instead of absorbing, so consider adding sand, mulch or other absorption enhancing materials to low-porosity ground.

淤泥，粘土和土坯往往是固体流，而不是障碍，吸收水，因此考虑在沙子，覆盖或其他材料，以增强吸收低孔隙度地面。

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