摘 要
高速铁路路基工程中经常会遇到软土问题，处理的质量与选择的方法将直接影响到轨道结构的稳定性与安全使用，因此，软土地基处理技术对高速铁路建设十分重要。本设计概述了软土的定义，分类和主要的分布区域，软土路基工程的特点，并对高速铁路特点、发展现状，高速铁路路基的特点与现状做出了介绍。文章根据几种软土地基处理方法的具体理论和施工工艺，主要针对高铁软土地基，分别对以下三段里程进行了横断面设计，即：DK613+625、DK613+725及DK613+820。然后根据该路段的工程地质情况，对地基承载能力进行了验算。并采用分层总和法计算了天然沉降量，得出了三个断面处的沉降量分别为82.9cm、31.6cm和55.4cm，均远远超过了规范要求的1.0cm。因此就三个断面处地基进行了CFG桩加固处理，进而计算出工后沉降量分别为0.69cm、0.33cm和0.44cm，均小于1.0cm，满足设计要求。
关键词：高速铁路；软土路基；沉降计算；软土地基处理方法；CFG桩
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Abstract
Soft soil engineering problems often encountered in high-speed railway subgrade, The quality and choice of treatment method will directly affect the stability and safety of the track structure to use, so soft processing technology is very important for high-speed railway construction. This design outlines the definition of soft soil, classification and main distribution area, the characteristics of soft soil roadbed construction, and features high-speed railway, development status, Article according to the specific treatment of several soft theory and construction technology, mainly for high-speed rail soft, respectively, of the following three paragraphs mileage conducted a cross-sectional design: DK613 +625, DK613 +725 and DK613 +820. Then according to the section of the engineering geological conditions, the
bearing capacity of the foundation checking. And the use of natural stratification method to
calculate the sum settlement, obtained three sections at the settlement were 82.9cm, 31.6cm and 55.4cm, are far greater than the regulatory requirements of 1.0cm. Therefore carried out three sections at the foundation of CFG pile reinforcement, then calculate the amount of the settlement after labor were 0.69cm, 0.33cm and 0.44cm, were less than 1.0cm, meet the design requirements.
Keywords: High-speed rail; soft soil roadbed; settlement calculation; soft ground; CFG pile
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目 录
摘 要 ............................................................... I
关键词： ..................................................................................................................... I Abstract ............................................................ II 目 录 ............................................................. III 1绪 论 ............................................................. 1
1.1高速公路路基的特点 .......................................................................................... 1 1.2软土的成因类型及分布 ...................................................................................... 2
1.2.1软土的概念 ............................................................................................... 2 1.2.2软土的成因类型 ....................................................................................... 2 1.2.3软土的分布 ............................................................................................... 3 1.3软土的工程性质 .................................................................................................. 5
1.3.1软土的工程性质和力学性质 ................................................................... 5 1.3.2松软土的力学性质 ................................................................................... 7 1.3.3软土地基常见工程问题 ........................................................................... 8
2路基的横断面设计 .................................................. 10
2.1工程地质条件 .................................................................................................... 10
2.1.1设计范围及类型 ..................................................................................... 10 2.1.2工程地质及水文地质概况 ..................................................................... 10 2.2设计依据 ............................................................................................................ 10 2.3路基横断面设计 ................................................................................................ 11
2.3.1高速铁路路基面形状 ............................................................................. 11 2.3.2高速铁路路基面宽度 ............................................................................. 12 2.3.3高速铁路路堤横断面设计 ..................................................................... 14
3沉降量计算 ........................................................ 16
3.1基本概念 ............................................................................................................ 16 3.2软土路堤的沉降计算 ........................................................................................ 17
3.2.1地基中的应力分布 ................................................................................. 18 3.2.2沉降量的计算 ......................................................................................... 18
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4软土地基处理方案选择及设计 ......................................... 25
4.1软土地基处理概述 ............................................................................................ 25 4.2软土地基的破坏形式 ........................................................................................ 26 4.3软土地基加固处理方法分类 ............................................................................ 27
4.3.1置换及灌入固化物法 ............................................................................. 28 4.3.2振密、挤密法 ......................................................................................... 28 4.3.3堆载预压及排水固结法 ......................................................................... 29 4.3.4加筋法 ..................................................................................................... 29 4.4断面CFG桩处理 .............................................................................................. 30
4.4.1基本理论 ................................................................................................. 30 4.4.2断面DK613+625处理 ............................................................................ 34 4.4.3断面DK613+725处理 ............................................................................ 37 4.4.4断面DK613+820处理 ............................................................................ 39
结 论 .............................................................. 43 致 谢 .............................................................. 44 参考文献 ............................................................ 45 附录一 DK613+625 双线路基断面图 附录二 DK613+725 双线路基断面图 附录三 DK613+820 双线路基断面图 附录四 DK613+625处CFG桩处理设计图 附图五 DK613+725处CFG桩处理设计图 附录六 DK613+820 处CFG桩处理设计图
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