In the whole procedure of concrete casting it is essential that the tremie is for at least 1.5m, up to 5m, beneath the concrete surface to prevent the slurry runs into the tremie.

• 在整个砼浇筑时间内，导管口应埋入先前浇筑的混凝土内至少1.；5m，防止泥浆冲入管内，但不得大于5m。