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。

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.

youdao

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。

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.

youdao