But for triple stratum foundation, if the top sand layer is relatively thin, piping is vertical. The damage zones are large in width and depth that expand to the sand layer and gravel layer.

当三层堤基浅砂层较薄时，将发生深层管涌破坏，管涌破坏区涉及浅砂层及下部砂砾石层，其宽度和深度较双层堤基大，出口涌砂量也较多。

youdao

The sand falls from the top of the sand glasses to the bottom.

沙子从沙漏的顶部落到底部。

youdao

Relentless winds have scored fine lines into the top of a dune and swept sand into a mangrove forest, smothering trees that are now reduced to denuded trunks.

无情的大风在沙丘顶部刻下一道道细线，把沙子刮进红树林，闷死了树木，如今只留下一根根光秃秃的树干。

youdao

It could be removed later by scraping up the top layer of sand.

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Though five-star resorts such as the Intercontinental, the Hyatt and the Kempinski have long made their mark on this most diminutive of Indian states (all characterised by top-notch service, opulent surroundings and calm, sand-raked beaches) there is nevertheless much charm to be had in forsaking the mammoth swimming pools and generic - if generous - resort bedrooms, and plumping instead for a stay in one of Goa's most evocative, charismatic, heritage boutique hotels.

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