【作者】 李早；

【导师】 赵树德；

【作者基本信息】 西安建筑科技大学 ， 岩土工程， 2004， 硕士

【摘要】 复合地基是目前应用较为普遍的一种地基处理方法，它是指天然地基在地基处理的过程中部分土体得到增强，或被置换，或在天然地基中设置加筋材料，加固区是由基体(天然地基土体或被改良的天然地基土体)和增强体两部分组成的人工地基。 可靠度的研究早在30年代就开始，在结构设计中的应用大概从40年代开始，在岩土工程中的应用则要更晚一些。由于在岩土工程中存在大量不确定和不确知因素，应用可靠度理论解决岩土工程问题是工程可靠度分析研究中一个比较困难的问题。可靠度设计是一种比传统的定值设计法更为科学的设计方法，然而，目前对复合地基可靠度的研究并不多。 本文通过现有的研究成果和统计资料，根据复合地基极限承载力公式建立了各类型复合地基承载力极限状态方程，并依据可靠指标计算方法(蒙特卡洛法和最优化法)应用FORTRAN90编制了相应的计算程序，通过已有工程实例和模拟算例计算可靠指标，说明了可靠性分析的过程。同时提出了基于可靠度分析的复合地基参数设计反推法，并且考虑了不同随机变量对复合地基可靠性的影响不同，做出可靠指标与随机变量均值关系图，提出了能够反映随机变量对可靠指标影响程度的敏感指标，为可复合地基靠性设计建立了理论框架。更多还原

【Abstract】 Composite foundation is a method of foundation treatment was used widespeead nowadays.It means in the process of foundation treatment a part of natrual foundation was strengthed,or repalced,or palced reinforced materials. The consolidate area is artificial foundation that include original mass(natrual ground soil or improved ground soil)and strengthed mass.The research of reliability started as early as 30’s,which was applied in structure design about 40’s and later in geotechnical engineering.Bacause of so many uncertian and unkonw factors in geotechnical engineering the application of reliability theory in resolving geotechnical engineering problem is more difficult in the research of engineering reliability analysis.However,the research on reliability of composite foundation is not so much.This paper formulate limite state equation of different composite foundation by the formula of limit bearing capacity of composite based on research result and statistical data.Compile the carresponding program with FORTRAN90 based on the computational method. of reliability index(Monte carlo method and optimize method).Compute the reliability index based on practical engineering example and mock example and show the process of reliability analysis.The method to design the parameter of composite foundation based on reliability analysis was given in the paper.Draw the relation map of reliability index and mean-value of random variables,considering the difference influence degree about different random variables to reliability of composite foundation.The sensitivity coefficient that can reflect the influence degree about random variables to reliability was given and set up the theory frame for design of composite foundation based on reliability.更多还原