厦门地区砂砾状强风化花岗岩强度与变形特征试验

Test Study on Characteristics of Strength and Deformation of Sandy Strong-Weathered Granite

目的研究砂砾状强风化花岗岩的特殊工程特征，合理确定砂砾状强风化花岗岩承载力和变形指标的大小．方法通过对厦门地区的砂砾状强风化花岗岩进行现场载荷试验、旁压试验与标准贯入试验的对比研究，探讨了承载力和变形模量与标准贯入试验之间的对应关系，建立了砂砾状强风化花岗岩地基土承载力和变形模量与常规原位测试标准贯入试验击数的定量模型，确定了有关模型的参数．结果砂砾状强风化花岗岩地基承载力特征值宜采用标准贯入试验的实测值与地基承载力特征值的对应关系的相关公式确定，试验结果其承载力特征值fak均大于600kPa，地基承载力提高20％以上；变形模量在30～50MPa，而过去提供的变形模量均大于50MPa，工程设计时需引起重视．结论确定砂砾状强风化花岗岩地基承载力和变形模量的方法是可行的．

In order to study the special engineering geologic behaviors of sandy strong-weathered granite and reasonably determine the values of its bearing capacity and deformation modulus, based on the results of loading test in site, pressuremeter test and standard penetration test（SPT） about sandy strong-weathered granite in Xiamen, the relations among bearing capacity, deformation modulus and standard penetration test were discussed. The quantitative model about the bearing capacity, deformation modulus of sandy strongweathered granite and the blow counts of standard penetration test were proposed to determine relational parameters. Through analyzing the test results, the bearing capacity value of sandy strong-weathered granite should be determined by the relational equations of the measured values of standard penetration test and the characteristic values of subgrade bearing capacity. The characteristic values of bearing capacity fak were over 600 kPa and increased more than 20 per cent, compared to the last generally provided foundation bearing capacity. The deformation modulus were between 30- 50 MPa, but the last provided deformation modulus were larger than 50 MPa, so we should pay attention in the engineering design. The analysis of experiment results showed that it was effective to determine the values of its bearing capacity and deformation modulus by the proposed method.