沪昆客运专线为高速无碴铁路，路基铺轨后允许沉降仅为 1.5 cm 。线路沿线分布大量粉土地层，设计中路基沉降主要根据室内试验估算，计算参数的取值对路基沉降计算起着至关重要的影响。选取现场典型地段，通过大型平板载荷试验 (PLT) 获取试验数据，并和室内试验及静力触探测试数据进行对比，分析不同测试方法、试验结果的优劣，并为该地区粉土地层上的路基沉降计算提供力学参数。

The Shanghai-Kunming special railway line for passenger traffic is a high-speed and ballastless railway. The subgrade allows only 1.5 cm of settlement after rail-laying. There is a large quantity of silt distributed along the line, and the designed subgrade settlement is calculated mainly based on laboratory test. The calculation parameter has significant impact on the calculation of subgrade settlement. Typical section of the railway is selected to conduct large-scale plate loading test (PLT) in order to obtain test data, which were further compared with the data of laboratory tests and cone penetration tests(CPT) to analyse the advantages and disadvantages of different test methods and different test results, and also to provide mechanical parameters for the subgrade settlement computation of the silt layer.