法国开发了一种大尺寸的矩形混凝土灌注桩,已在巴黎地铁车站等工程中应用,桩深２０余ｍ,截面有３．０ｍ×１．０ｍ、２．６５ｍ×１．０ｍ等几种。其施工工艺与大直径钻孔桩基本相同,也用反循环泥浆护壁,但需用一种特殊的液压碾磨机施工,可掘进软硬岩体。这种矩形桩按截面长边 France has developed a large-size rectangular concrete cast-in-place pile, which has been used in the subway station in Paris and other projects. The pile depth is more than 20m, and the section is 3.0m×1.0m, 2.65m×1.0m. The construction process is basically the same as that of large-diameter drilled piles. It also uses anti-recirculation mud to protect the wall. However, it needs a special hydraulic grinding mill to construct and can excavate soft and hard rock masses. This rectangular pile is long in section