福建平潭风化花岗岩原位测试及岩土参数取值研究

因风化花岗岩具有结构性强，遇水软化、常规钻探取原状土样难等特点，所以通过常规土工试验获得的风化花岗岩的抗剪强度和变形参数往往偏小很多。为了合理确定风化花岗岩的抗剪强度和变形参数，以福建平潭某工程为项目背景，对福建平潭地区具有代表性且结构性强的风化花岗岩地层开展了旁压试验、标准贯入试验、剪切波速测试和平板载荷试验等系列原位力学特性试验研究，通过相关理论对原位试验结果进行了分析研究并推算了风化花岗岩的抗剪强度和变形参数。将旁压试验计算结果与平板载荷试验及室内试验进行了对比分析和验证，发现旁压试验计算结果与平板载荷试验推算的结果较为一致且明显大于室内试验结果。研究结果表明旁压试验结果在很大程度上反映了深部风化花岗岩的原状特性，利用旁压试验结果推算风化花岗岩的抗剪强度和变形参数是合理的。针对风化花岗岩，旁压试验是值得广泛推广应用的一种原位试验手段。

In-situ test and parameter value study of weathered granite in Pingtan of Fujian

The weathered granite has some characteristics，like strong structural，softened by water and difficult to obtain the original soil sample. Therefore，the shear strength and deformation parameters of the weathered granite obtained by conventional geotechnical tests are often much smaller. In order to reasonably determine the shear strength and deformation parameters of weathered granite，a project is used to carry out a series of tests for the representative and structurally weathered granite strata in Pingtan，Fujian. These in-situ mechanical properties tests contain pressuremeter test，penetration test，shear wave velocity test and plate loading test. The calculation results of the pressuremeter test are compared with the plate load test and the indoor test. It is found that the calculation results of the pressuremeter test are consistent with the calculated results of the plate load test and significantly larger than the indoor test results. These results show that the pressuremeter test largely reflect the undisturbed nature of the deep weathered granite. It is reasonable to use the results of the pressuremeter test to estimate the shear strength and deformation parameters of the weathered granite. For weathered granite，the pressure test is worthy of widespread application.