山区高填方地基蠕变沉降特性及简化计算方法探讨  

Characteristics and simplified calculation method of creep settlement of high fill foundation in mountain area

作　　者：宋二祥[1] 曹光栩[1] 

机构地区：[1]清华大学土木工程系土木工程安全与耐久教育部重点实验室,北京100084

出　　处：《岩土力学》2012年第6期1711-1718,1723,共9页Rock and Soil Mechanics

基　　金：国家高技术研究发展计划(863计划)资助项目(No.2007AA11Z113);国家自然科学基金项目(No.50978140)

摘　　要：如何准确计算高填方地基的沉降变形,特别是工后沉降变形已成为目前日益增多的山区高填方工程中亟待解决的问题,但目前有关工后沉降的计算模型及计算分析方法还有待完善。在前人研究的基础上,首先对使用较为广泛的双曲线模型的特点、应用范围以及参数取值等进行了探讨,特别是初步分析了室内试验蠕变变形比现场完成较快的原因,进而在原有模型的基础上针对大面积填方问题提出了一个考虑蠕变过程中荷载变化的计算方法,并通过计算对比展示了其合理可行性。同时,通过分析室内试验成果,发现碎石料在干湿循环作用下发生的变形与循环次数关系明显,在此基础上提出了能考虑当地降雨情况的蠕变变形与干湿循环变形的耦合计算方法。最后应用所提方法对一实际工程进行了工后沉降预测。It is an important topic to predict the settlement,especially post construction settlement,of high fill foundations,which is encountered more and more often in the mountainous areas in western China.However,both the calculation model and calculation method are to be studied further.The characteristics,application scope and parameter values of the hyperbolic model are discussed first;and then the creep mechanism of rockfills is also discussed in depth,especially the reason that creep under laboratory test conditionsalways finishes in a shorter period than that under filled conditionsis explained.After that,a simplified calculation method is proposed to calculate the creep deformation for high fill foundation with uniformthickness in a large area,in which load variations during creep can be properly considered.The rationality and feasibility of the proposed method is demonstrated through numerical comparisons.Besides,by analyzing the results of laboratory tests,the significant relationship between dry-wet cycle deformation and cycle numbers is found,on the basis of which a simplified coupling calculation method that can simultaneously compute the creep deformation and dry-wet cycle deformation is also proposed.Finally,the post construction settlement of a practical engineering project ispredicted bythe proposed method.

关 键 词：高填方 碎石料 蠕变 干湿循环 简化计算方法 

分 类 号：TU411[建筑科学—岩土工程]