孔底沉渣厚度对水下钻孔灌注桩承载力影响的探讨与研究

施工中孔底沉渣对桩基承载力的影响较大。通过试桩试验对孔底沉渣厚度与端承摩擦桩极限承载力关系进行了探讨，在同一桩径下，当孔底沉渣厚度相同（均为10mm）时，最大单位摩阻力变化率、单位端阻力变化率均不大，当孔底沉渣厚度相差较大（分别为10mm／1与250mm）时，最大单位摩阻力下降了45．15％，单位端阻力下降了69．92...

Exploration and Research on Influence of Dregginess Thickness in Hole Bottom on Bearing Capacity of Underwater Bored Pile

The influence of the dregginess in hole bottom on the bearing capacity of pile foundation is comparatively large. The relationship of the dregginess thickness in hole bottom and the ultimate beating capacity of end-bearing friction pile is explored here by test-pile test. In same pile diameter, when the dregginess thickness in hole bottom is identical （10mm）, both the variation of maximum unit side friction and the variation of maximum unit point resistance force are slight. When the dregginess thickness in hole bottom has large difference （lOmm and 250mm respectively）, the variation of maximum unit side friction is decreased by 45.15 %, and the variation of maximum unit point resistance force is decreased by 69.92%. In conclusion, the increasing of the dregginess thickness in hole bottom would make the side friction and point resistance force decreasing simultaneously. The influence of the dregginess in hole bottom on the ultimate beating capacity of pile foundation is significant.