The Statistical Analysis And Engineering Application Study On The Soil Index In Of Ningbo Rail Transit

With the rapid development of China’s infrastructural construction, such engineering problems as railtransport, deep foundation pit of high-rise building, soft ground construction of municipal engineeringoccurres, especially in the soft soil area along the coast. Due to the construction of Ningbo rail transitengineering, analysis results on the measure data of all soil layers in the completed engineering can play arole of accumulation and can provide an important reference for the construction and design work of thefollowing line. Therefore, the survey data of the Ningbo Rail Transit Line1and Line2are collected andare used to analyze the probability statistics and spatial variability,which can present a guiding for theengineering practice. The main content of this paper includes:1. A total of58984records from2343effective drills of the Ningbo Rail Transit Line1andLine2are collected, the physical and mechanical and in situ test indexes of each layer of soil are analyzed,and the suitable probability distribution model are proposed. According the method of regression analysis,the relationship between physical indicators, physical indicators and mechanics indicators, the physicalindicators and situ indicators, situ indicators are developed, which may give some advices for the reliabilitydesign of geotechnical engineering in Ningbo area.2. Considering structural and random spatial variability of the geotechnical parameters, the verticalspatial variability of in situ test parameters CPT’send-resistance qcand DMT’s flat dilatometer index ID,and calculate the vertical correlative distance of different soil layers are analyzed by using variogramfunction in geostatisticss.3. With the help of FLAC3D program, numerical simulation on the static pile of Fuqing Road stationin Ningbo rail transit is executed. The numerical results are comared with the measure values. It isindicated that the numerical results and the measure values are mainly identical. In addition, based on theindex statistics of this paper, the sedimentation value interval of the static load test is calculated using upperand lower limits of the parameters. The relative error of the upper and lower limits of the final settlementand the measured value is in the range of40%. Therefore, in the case of the lack of specific soil parameterswhen a project cannot be accurately simulated, we can preliminary estimate the final settlement with thesedimentation value interval. Generally, the measured Q~S curve locates on between the interval of theupper and lower limit parameter simulation.