【Daily Question】Utilities – Civil Engineering – 20190416

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Under the same conditions, the bearing capacity of cast-in-place piles is highest at (　　). 　　A. Screw-driven bored pile B. Impact-vibration driven pile C. Single-vibration driven pile D. Double-vibration driven pile 【Answer】D 【Explanation】A vibration-driven pile uses an exciter to vibrate the steel pipe, thereby reducing friction with the soil; under the force of its own weight and that of the exciter, the pipe is pushed into the soil to form a hole. After that, concrete is poured in, and the pipe is removed. The repeated vibration method involves vibrating the steel pipe twice: concrete is poured the first time to compact the soil, and then concrete is poured again. Naturally, the soil surrounding such pile holes becomes dense, the density of the poured concrete is high, and its bearing capacity is also high after it hardens.