红层软岩嵌岩桩端阻力研究

Research on the Endbearing Capacity of Asocketed Pile in Red Beds

在我国广泛分布的白垩系至第三系泥质粉砂岩是一种软质岩石,具有较大的地基潜力。按现行规范确定的承载力值往往偏低。文章对当前软岩嵌岩桩桩端阻力的确定方法进行了比较,提出了以三轴抗压强度或旁压试验结果作为设计依据的建议。并以“长沙红层”为例,对不同确定方法带来的差异进行了研究,并对岩石湿度、尺寸效应对岩石抗压强度的影响进行了探讨,对同类地区软岩地基的承载力具有推荐价值和指导意义。

Argillaceous siltstone is a kind of soft rock, which is widespread during Cretaceous to Eogene in China. The potential bearing capacity of this rock is relatively larger. But the bearing capacity evaluated with current Code is quite different to that obtained on site test. According to the chazactecistic of the end - bearing capacity of a socketed pile in rock, the available methods of calculationin specification were compared and a mithod based upon the three axial compression and PMT is proposed in this paper. Focus on the features of end -bearing capacity of Red beds in ChangSha area, the difference of end resistance determined by diffrent mithods is studied . The result of analysis is rather effective for determining the bearing capacity of this kind of soft rocks and is deserved to be applied to practical problems such as those on soft rocks.