路基沉降预测的三点修正指数曲线法  

Three-point modified exponential curve method for predicting subgrade settlements

作　　者：陈善雄[1] 王星运 许锡昌[1] 余飞[1] 秦尚林[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071 [2]湖北省电力勘测设计院,武汉430024

出　　处：《岩土力学》2011年第11期3355-3360,共6页Rock and Soil Mechanics

基　　金：中国科学院知识创新工程重要方向性项目(No.kzcx2-yw-150);岩土力学与工程国家重点实验室重点项目(No.SKLZ08032)

摘　　要：科学、合理地预测路基工后沉降量是高速铁路建设的关键环节。针对武广高速铁路路基沉降量级小、数据相对波动大的实测数据,探讨了指数曲线法对无砟轨道路基沉降预测的适用性,发现指数曲线法不能直接应用于量级小、数据相对波动较大的沉降预测。把三点法的基本思想引入指数曲线模型,对指数曲线法进行了改进,提出了路基沉降预测的三点修正指数曲线模型。结合武广高速铁路路基沉降观测数据,分析了三点修正指数曲线模型的特性。分析表明,在整个沉降曲线上选取3个关键点作为预测样本,很好地回避了数据波动带来的影响;沉降曲线上"拐点"以后的沉降规律更符合指数曲线模型,因此,应取沉降曲线上"拐点"以后的数据作为样本值,所取三点应能尽量反映沉降发展的趋势。三点修正指数曲线法预测结果稳定、相关系数高,具有一定的工程应用价值。Scientific and rational prediction of post-construction settlement is a key link of high-speed railway construction.Based on the field observation data of subgrade settlement of Wuhan-Guangzhou high-speed railway,aiming at measured settlement data being characteristic of small in magnitude,but large relative fluctuation,the suitability of exponential curve method for predicting settlements of subgrade under ballastless track has been studied synthetically.it was found that exponential curve method can＇t be directly used for predicting subgrade settlements in high-speed railway.The basic idea of three-point method is introduced into exponential curve model,a three-point modified exponential curve method for predicting subgrade settlements has been proposed.Combining the measured settlement data of subgrade in Wuhan-Guangzhou high-speed railway,the characteristics of three-point modified exponential curve model have been analyzed.The analysis shows that selecting three points as forecast sample on settlement-time curve of subgrade can commendably evade the influence brought by data fluctuation;and the settlement regularity after inflection point on settlement-time curve of subgrade more tally with exponential curve,therefore,the samples must be selected after inflection point on settlement-time curve of subgrade;and three samples should reflect the settlement development tendency as far as possible.The prediction results of three point modified exponential curve method are stable with high correlation coefficient.The new prediction method has engineering value.

关 键 词：三点修正指数曲线法 沉降预测 三点法 路基 高速铁路 

分 类 号：TU433[建筑科学—岩土工程]