渤海湾地基土随机场特性及可靠度分析

Random field model and reliability analysis of foundation soil in Bohai gulf

阐述了随机场理论在进行海洋结构物地基可靠度分析中的作用。利用渤海油田在多年开发和建设中积累的大量工程地质资料,开发研制了“海洋土地基可靠度分析系统”。运用该系统的强大数理统计和分析功能,综合理论和实测数据建立起渤海海域海洋土竖直和水平向土性剖面的齐次正态随机场模型,计算得到土性指标的方差折减函数,进而在可靠度分析中运用强度指标的空间平均方差进行可靠度分析,强度指标折减前后的可靠度分析结果表明随机场理论的应用对可靠度分析起到了重要的作用,经过折减的土性指标的变异系数明显较小,从而使可靠度分析的结果接近工程实际。

The theory of random field plays an important role in reliab ility analysis of ocean structure foundations.To establish the random theory model, a large amount of soil data are required.In this paper, a database management system has been built up to manage and analyze the data of the geotechnical properties of founda tion soils.Almost all information of soil properties in the ex isting oil fields in Bohai has been collected and included in the database. Bas ed on the established database, the stationarity and ergodicity of soil profiles in this area have been examined and a random field has been modeled. The correl ation function, correlation distance and variation of reduction function have be e n studied.The developed method may give guidance to introduce the reliab ility theory into soil foundations design of ocean structures.