对南京规范DGJ32/J12-2005嵌岩桩承载力计算公式问题的讨论

Discussion of Rock-Socketed Pile Bearing Capacity Calculation Formula in “Code for Design of Building Foundation in Nanjing Area”(DGJ32/J12-2005)

在使用《南京地区地基基础设计规范》(DGJ32/J12-2005)嵌岩桩公式计算单桩承载力的过程中,发现在规范规定的其它各种条件都相同的情况下,嵌岩段总阻力特征值在岩石饱和单轴抗压强度frk=5MPa^10MPa区间有异常极值点,其变化规律不符合一般概念性结论;公式中的相关参数需要进一步完善。文章就上述问题进行了原因分析,并提供有关建议供同行和规范编委会参考。

In the process of calculating the bearing capacity of single pile by using the formula of rock-socketed piles of ＂ Code of Foundation Design in Nanjing Area＂（DGJ32/J12-2005）, the author found in a variety of other conditions stipulated by the specification are the same, saturated uniaxial compressive strength of the rock frk = 5 to 10 MPa range, rock-socketed segment total resistance characteristic value have abnormal extreme value point, its change law is not in conformity with the general conceptual conclusions, the relevant parameters in the formula need to be further improved.The author analyzes the causes of the problems mentioned above and provides some suggestions for edition committee and the related industry practitioners.