大直径嵌岩桩承载机理与设计理论探讨

Discussion on Bearing Behavior and Design Theory of Large Diameter Rock-socketed Pile

目前工程中大直径嵌岩桩的使用日趋增多,由于现场试验难以进行,设计中缺乏类似的经验可循,又没有明确的设计方法和依据,这造成嵌岩桩合理设计成为难题。本文研究表明:在软岩地区,深嵌岩段的桩基承载特性类似于摩擦桩的受力形态,但必须按照嵌岩桩公式进行设计,嵌岩比越大,相应的承载力越大,变形越小。当嵌岩深度超过一定限值时,桩端位移一般很小,导致其桩端阻力发挥程度小。

At present,the use of large diameter rock-socketed piles is increasing day by day. As the field test is difficult to be carried out,and there is no similar experience and clear design method and basis in the design,which makes the reasonable design of rock-socketed pile become a difficult problem. The results show that the bearing capacity of pile foundation in deep rock zone is similar to that of friction pile,but it must be designed according to the formula of rock-socketed pile. The larger the rock-bearing ratio is,the larger the bearing capacity is and the smaller the deformation is. When the rock-embedded depth exceeds a certain limit,the displacement of the pile is generally very small,resulting in a small degree of resistance to the pile end.