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由孔压静力触探测试(CPTU)所提供的锥尖阻力、侧壁摩阻力和孔隙水压力等参数能直观地反映地下土类的变化,目前,国内外基于CPTU的土类划分发展出了许多不同的方法,这些方法对于国内工程场地土类划分的有效性尚未得到验证。本研究在港珠澳大桥主体工程中进行了大量CPTU贯入试验和平行钻孔取样与室内试验,将6种CPTU土分类与室内试验的土分类结果进行了对比分析。发现未经过上覆应力修正的土分类图判别准确率较低,但整体准确率也可达到80%左右;经过应力修正的归一化土分类图能够提供更为准确的土类判别结果,然而所给出的土类分区与实际土分类数据点存在一定的不符,且并未给出各类土所一一对应的土类分区,导致准确率被高估;而经过由国内试验资料修正的中国CPTU实用土分类方法能够提供最为精细且准确的土类判别结果,整体准确率达到90%以上。
The parameters of cone tip resistance, sidewall frictional resistance and pore water pressure provided by the CPTU can directly reflect the change of underground soil. At present, the CPTU-based soil classification at home and abroad has been developed There are many different methods that have not been validated for the validity of the soil classification of domestic engineering sites. In the main project of Hong Kong-Zhuhai-Macau Bridge, a large number of CPTU penetration tests and parallel borehole sampling and laboratory tests were conducted in this study. The soil classification results of six CPTU soil types and laboratory tests were compared and analyzed. It is found that the classification accuracy of soil classification maps without overlying stress correction is low, but the overall accuracy rate can reach about 80%. The stress-corrected normalized soil classification maps can provide more accurate soil classification results, however, The given soil class divisions and the actual soil classification data points there is a certain discrepancy, and did not give all kinds of soil one by one corresponding to the soil division, resulting in the accuracy rate is overvalued; and after the test data to be amended by the domestic China CPTU practical soil classification method can provide the most detailed and accurate soil classification results, the overall accuracy rate of more than 90%.