深厚软土地区大桥群桩沉降现场监测分析  

Field monitoring analysis of long congregated piles foundation settlement of great bridge in deep soft soil areas

作　　者：陈洪运[1] 马建林[1] 苏春晖[1] 杨彦鑫[1] 

机构地区：[1]西南交通大学土木工程学院,成都610031

出　　处：《安全与环境学报》2014年第5期115-119,共5页Journal of Safety and Environment

基　　金：铁道部重大科技项目(2008G031-B)

摘　　要：为准确预测高速铁路沉降量,严格控制高速铁路沉降,达到高速铁路的平顺性标准,以某一软土地基高速铁路桥梁墩台为监测对象,采用液位-单点联合自动监测法对天津某特大桥沉降进行了长期观测。实测数据分析显示,单点沉降计布置合理的情况下能准确确定压缩层厚度。与现有规范的压缩层及沉降进行对比分析,结果表明,《公路桥涵地基与基础设计规范》误差最大,压缩层厚度比实测值大141.1%,沉降量比实测值大182.9%;按上海市《地基基础设计规范》得到的沉降量计算值比实测值大4.0%;按《建筑桩基技术规范》得到的应力比为10%,沉降量计算值比实测值大8.9%。与液位沉降计测得的总沉降相比,《铁路桥涵地基和基础设计规范》、《公路桥涵地基与基础设计规范》计算的沉降值偏大,其余规范计算的沉降值均偏小。从可靠性和安全角度考虑,建议采用以10%应力比为条件的"应力控制法"计算压缩层厚度,采用铁路规范方法计算高速铁路深厚松软土层的桥梁桩基总沉降。The paper intends to introduce the field monitoring analysis of long congregated piles foundation settlement of large-scale bridge in deep soft soil areas. In order to be able to do strict control and accurate prediction of the high-speed railway settlement and to meet the regular standard of the high-speed railway transportation, we have conducted a long-term monitoring experiment over the bridge settlement under the help of a set of hydrostatic level settlemeat gauges and ＂single-point settlement gauges targeted at monitoring the high-speed railway bridge piers on the soft ground. Single-point settlement gauges were anchored on the top of pile and in the s0il under the pile bottom in different depths, the hydrostatic level settlement gauies were fixed on the top of the pile cap. The analysis of the measured data shows that the thickness of compression layer can be determined accurately with the correctly distributed single-point settlement gauges. The contrast study between the measured settlement data and thoe worked out in compliance with some existing norms proves that the code for roadbed and bridge of highway draws the biggest error. The thickness of the compression layer has been worked out, which is 141.1% larger than the measured data, and the calculated setdement value should be 182.9% larger than the measured value. Based on the code for design of foundation in Shanghai, the calculated settlement value is 4.0 % larger than the measured data. Accordini to the technical code for building pile foundations, the calculated settlement value is 8.9% greater than the calculated data at the stress ratio of being 10% . Based on the settlement data measured with the hydrostatic level meter, the settlement data gained in accord with the design code for roadbed and bridge of highway and code for design on subsoil and foundation of railway bridge and culvert should always be a bit greater than those measured values, while the corresponding data of the bridge should be smaller when considering the other code

关 键 词：安全工程 土木建筑工程测量 岩土工程 高速铁路 深厚软土 超长群桩 沉降 

分 类 号：X947[环境科学与工程—安全科学] TU473.1[建筑科学—结构工程]