【作者】 陈镠芬；

【导师】 洪家宝；

【作者基本信息】 扬州大学 ， 结构工程， 2008， 硕士

【摘要】 本文以泰州长江大桥北锚碇(沉井)周边为研究区,用地下水模拟软件GMS对地下水水流进行数值模拟,预测北锚碇施工期的涌水量和地下水位动态,并根据预测结果评价江堤的渗流稳定、抗滑稳定和地面沉降量。在收集和分析研究区的地形地貌、地质构造、水文地质条件的基础上,系统地阐述了研究区内主要地层的岩性,分析了地下水的赋存条件及分布规律以及地下水的补给、径流、排泄规律和地下水动态特征。在此基础上,确定研究区范围和计算目的层,概化含水层水力特征、垂向、侧向边界后,依据水文地质概念模型建立了地下水数学模型。由建立的数学模型,采用GMS软件,根据现有的钻孔资料、边界条件和各种源汇项,采用网格法与概念模型联合建立模型,通过模型识别拟合各种参数,并将识别的模型进行检验。检验结果表明:建立的三维模型反映了研究区地下水系统的本质特征,再现了地下水的水位动态、运移规律,为沉井施工期地下水涌水量预报、水位预报、地面沉降的控制提供科学依据。渗透变形是造成江堤在施工降水期间险情的主要原因。研究江堤的渗透变形对于合理的评价江堤的安全性、预测渗透破坏的发生形式以及具体位置、对江堤抢险加固进行科学的指导等,都具有重要的理论和实践意义。本文根据模型预报的水位,选择三个江堤的典型断面进行渗流的数值模拟,判定江堤的渗流稳定和边坡稳定。施工降水引起的另一个地质现象就是地面沉降。地面沉降是土层中孔隙水承担的孔隙水压力和土骨架承担的有效应力发生变化的结果。本文采用弹性非线性邓肯理论及比奥固结平面有限元程序(BCF95),建立研究区地面沉降模型,并对沉井施工降水过程中引起的江堤的沉降进行了预测。更多还原

【Abstract】 Taking of north anchorage (caisson) and its surrounding area of Taizhou Yangtse Rive Bridge as the study area, this paper used groundwater simulation software GMS to simulate groundwater flow, and predict the discharge and the trend of groundwater level. After that, evaluate the seepage stability、Stability Against Sliding and land subsidence of River Levee.Based on collection and analysis of topography and geomorphology、geologic structure and hydrogeological condition in study area, this paper systemically expound the lithology of main stratum, existing condition, distribution regularities, circulation condition and the dynamic character of groundwater. Then, this paper ascertains the scope of simulation region and the selective zone of calculation. After generalize the aquifer hydraulic characteristic, vertical boundary and lateral boundary, the groundwater mathematical model has been founded on the basis of the hydrogeology conceptual model.Based on the mathematical model, the model is built according to the borehole data, border condition and various source/sinks items combine grid approach with conceptual model approach. Model calibration is adopted to fit parameters and then verify the model. It is indicates that: This model reflects the characteristics of the system of the groundwater , reproduce the pattern of change and transportation of groundwater, and it can give scientific supports to the prediction of the discharge、groundwater table and the control of the land subsidence.Seepage deformation is the main cause of danger in River Levee during the construction period. In order to evaluate the safety of the River Levee, predict the form and location of the seepage failure and suggest the scientific instruction to reinforce the River Levee, it is of great theoretical and practical importance to research the course of seepage deformation in the River Levee foundation. This paper make use of groundwater level that predict by the model to choose three typical section of River Levee for numerical simulation of seepage, and evaluate the seepage stability and slope stability.Another geological phenomenon that caused by construction precipitation is land subsidence. Land subsidence results from changes in the pressure borne by pore water in the soil and the effective stress borne by soil skeleton. This paper establishes land subsidence model with elastic nonlinear Duncan theory and Biot consolidation plan finite element program (BCF95), and predict the subsidence of River Levee.更多还原