【作者】 杨威；

【导师】 束一鸣；

【作者基本信息】 河海大学 ， 水工结构工程， 2004， 硕士

【摘要】 堤防是我国防洪工程体系的重要组成部分，在筑堤材料，堤体分区，堤体稳定，渗流，沉降及应力应变分析，基础处理，填筑标准，施工机具等一系列关键技术上，已经积累了丰富的经验。但由于许多堤防经过几十年的运行或经济发展的需要，自然或人为地对大堤造成了很大的坡坏，影响了大堤的正常使用，给人民的生命财产安全造成了极大的威胁。本文结合江苏省徐州市湖西大堤地下采煤的具体情况，利用数值分析理论及堤防加固技术，在深入分析研究的基础上，提出相应有效，可行的加固措施。 主要内容如下： （1）回顾总结我国堤防发展的基本状况及运行现状，对堤防病害的种类及评判方法进行归纳。 （2）对三维快速拉格郎日有限差分法进行了深入研究，并运用此理论对地下采动的结构和过程进行了数值模拟，对湖西大堤姚桥矿段由于地下采煤而引起的不均匀沉降进行了计算，得出堤体及其周围地基的三维位移场，分析了由于不均匀沉降而产生的拉应力区和剪切破坏区域。计算分析结果表明，在堤体两段拉应力区范围较大，存在横向贯穿性裂缝，并有相当深度的纵向裂缝存在，这些裂缝的存在对堤体的渗流和抗滑稳定均产生了不利的影响。剪切破坏主要发生在堤体两侧的地基，堤身表面局部区域也存在剪切破坏。上述分析与观测值较为吻合，由此本文又对后继开采可能造成的影响进行了预测性计算分析，对地下采动进行了一些规律性的研究，结果表明，影响采动沉降的主要因素是弹性模量，内摩擦角和内粘聚力的影响较小。 （3）上述计算得出的位移场、应力场、裂缝深度等数据为堤防加固提供了理论上的依据。本文又对堤防加固的各种措施方法进行了归纳整理，通过方案比选，选择用迎水面斜铺土工膜的方法进行防渗加固，并对土工膜的材料选择进行了计算。 （4）通过计算得出的数据和实际的观测资料，结合湖西大堤现状，对存在纵向裂缝的堤防进行了抗滑稳定和渗流的有限元计算，结果表明，由于防洪堤防的老化和采动破坏的影响，大堤现状已不能满足设计洪水位下的抗滑稳定要求，且堤身渗漏严重，直接威胁了当地人民的生命财产安全。进行堤体防渗加固后，不但可以减少渗漏，降低堤身浸润线，还可以有限度地提高抗滑稳定安全系数，改善堤身及地基的应力场，使在高水位作用下产生的不利于堤体安全的水平位移和竖向位移减小。对在后继采动中可能造成的防渗材料的破坏进行了校核，结果表明材料是安全的。 （5）针对边坡稳定的安全问题，本文进行了参数敏感度分析。结果表明，弹性模量E、泊松比ν、剪胀角ψ和侧压力系数κ₀对边坡的安全系数影响不大，影响边坡安全系数的土体参数主要为内摩擦角φ和内粘聚力c，为边坡稳定的治理提供了理论依据。更多还原

【Abstract】 Bank is an important part in Chinese system of controlling flood. It has accumulated much experience in the choice of bank’s material, division of bank’s body, stabilization of dam, seepage, settlement, analysis of stress and strain, treatment of foundation, criterion of reclamation and machine of construction and so on. But after many years running or for satisfying the need of economic development, many bank and its foundation has much disease, its normally use and benefit are naturally or man-madly influenced. According to status of HUXI Bank in XuZhouJIANGSU province, using numerical value analysis theory and technique of dam construction, this paper put forward efficiency strengthen method in the base of study and analysis .The main work this paper do are these like below:(1) this paper reviewed and summarized the development and actuality of bank in china, induced the variety of bank’s disease and the measure of judge etc.(2) Introduced and studied Fast Lagrangian Analysis of Continua .FLAC3D is a three-dimensional explicit finite-difference program..Uing this program, obtained the three-dimensional settlements of HUXI Bank and analyzed the tention area and the cut-off area.The result shows that there are a lot of andscape orientation cracks and portrait cracks in the bank.These cracks bring some disadvantage influence to slope stabilization and seepage of bank.(3) The upper result of settlement field,stress field and crack deepness offers a theoretics gist for Reinforcing bank.The paper concludes several methods of Reinforcement.Through choosing project, made certain adopting geomebrance to Reinforce the bank.(4) On the basis of Analysed result and the status quo of HUXI bank,computing the slope safety and seepage of bank by FEM.The result shows that the tarus quo of HUXI bank could not satisfy theslope safety on designed flood lever.After the Reinforcement of seepage,the method can not only reduced leakage ,debace the soggy but also ameliorate stress fields.lt also can reduce horizontal displacement and certical displacemeng which have disadvantages to bank.(5) For slope safety problem,the paper analyzed the sensitivity of parameter.Theresult shows that E, v, , k0 have little affecting on slope safety, friction angle and cohness c are main factors. Providing a theoretics gist for Reinforcing bank.更多还原