【作者】 沈兴正；

【导师】 张俊发； 陈永福；

【作者基本信息】 西安理工大学 ， 建筑与土木工程， 2006， 硕士

【摘要】 拱坝以其结构轻巧、造型美观、工程量省、超载能力强、抗震性能好而被世界各国广泛应用于水利水电工程中。随着国家西部大开发和“西电东送”战略的稳步推进，我国还将在西部及西南部深山峡谷中规划建设一批高拱坝。拱坝是一种外形复杂的空间壳体结构，坝体的应力水平和坝肩岩体稳定状况是评价拱坝安全性的两个重要指标。为了能准确地掌握拱坝坝体应力状况，工程技术界一直在研究探索拱坝的应力分析手段和计算理论、计算方法，促使拱坝应力分析手段和方法日臻完善，为拱坝技术在工程上的应用提供了保证。拱坝的应力分析方法包括纯拱法、拱梁分载法、有限元法、壳体理论计算方法和结构模型试验法。目前国际上计算坝体应力广泛采用拱梁分载法和有限元法。我国现行拱坝规范以“拱梁分载法”作为坝体安全性评价的主要标准。 本文结合黄河李家峡水电站技施设计阶段混凝土双曲拱坝基本体型，针对拱坝坝基开挖完成后的基础体型和地质构造条件变化，并考虑施工、蓄水过程中封拱高程、灌浆温度等与原设计的差异，应用拱梁分载法、三维有限元法等分析方法，得到不同荷载组合工况下的静、动应力和位移计算成果，通过分析复核李家峡拱坝的静、动应力，并与发包设计阶段的应力分析成果进行比较，对高拱坝坝体应力分布规律和变化特征进行了初步探讨，对坝体的安全性作出了综合评价。 计算分析表明，技施阶段李家峡拱坝坝体应力的分布规律与发包设计阶段基本一致。在坝基开挖后基础体型变化、两岸岩体变模降低、考虑分期蓄水和施工过程、局部温度场变化、不同接缝灌浆高程等情况下，各种工况下的拱坝应力基本满足规范要求。经拟静力法和动力法对拱坝抗震性能进行复核分析，拱坝坝体应力满足规范要求。更多还原

【Abstract】 Arch dams are widely used in hydropower projects in the world because of its light structure, beautiful shape, savings of engineering quantity, strong overcapacity and good aseismic performance, etc. With steady advancement of the western development and "electricity transmission from east to west" strategy, a number of high arch dams will be planned and constructed in deep valleys of west and southwest regions. The arch dam is a sort of space shell structure with complicated shapes. The stress level of dam body and the stability condition of abutment rock are the two key indexes to evaluate the safety of arch dam. In order to accurately grasp stress conditions of arch dam, the stress analysis means and calculating theory are explored and researched by technical and engineering sectors at all times so as to make them perfect and ensure the application of arch dam techniques in hydropower projects. The stress analytic method of arch dam covers pure arch method, arch beam sharing method, finite element method, calculating method of shell theory and structural model test method. At present, arch beam sharing method and finite element method are widely applied to calculate stress of dam body in the world. The main criterion of dam safety evaluation is on the basis of arch beam sharing method stipulated in the current Chinese Code of arch dam.Combined with basic shape of concrete double arch dam during construction and design periods, aiming at basic shape upon completion of arch dam foundation excavation and variation of geological conditions, and considering the difference between the gemel arch elevation, grouting temperature during stage impoundment & construction process and the original design, the static & dynamic stresses and displacement calculations under varied load combination conditions were obtained by arch beam snaring method and finite element method, etc. The static and dynamic stresses were analyzed and checked, and were compared with stress analysis results in the contracting design stage. The distribution regularity of stress and varied features for high arch dam were preliminarily discussed and the safety of dam body was comprehensively evaluated.The calculating results reveal that distribution regularity of stress is in conformity with that of the contracting design stage for Lijiaxia arch dam. The stress of arch dam shall meet the Specifications in respect of basic shape variation upon dam foundation excavation, varied module reduction on banks, staged impoundment and construction process, variation of local temperature field as well as jointing grouting elevation. It shall check aseismic performance of arch dam by pseudostatic method and dynamic method, and the dam stress shall meet the stipulations of the Code.更多还原