复杂地质条件下桥梁基础选型研究

发布时间：2018-01-18 13:21

本文关键词：复杂地质条件下桥梁基础选型研究　出处：《南京大学》2017年硕士论文　论文类型：学位论文

【摘要】：国家的快速发展和城市化进程的推进,使我国公路建设和高铁建设迅速进入快车道,在建设规模和发展速度上震惊世界,成为世界桥梁行业的风向标和最前沿。桥梁,作为跨越大江大河、不良地质区域甚至海峡的有效形式也得到了迅猛发展。我国桥梁技术已从最初期的形式单一和技术、器械落后发展到现在进入世界先进行列。我国长江下游地区,江面宽、水深、水流湍急,其地基工程地质条件复杂多变,在这一复杂的自然地理条件和场地工程地质条件下进行桥梁建设,基础施工的难度越来越大。而基础工程是隐蔽工程的代表,假设存在损坏,不仅发现困难,更难以恢复成最初状态。桥梁基础作为将桥梁上部结构的荷载传递到岩土部分的特殊结构,是控制桥梁结构安全的中流砥柱。而桥梁基础安全稳定性主要受地基工程地质条件控制。所以本文从工程地质学的角度,对大跨桥梁基础选型及在施工中的技术问题及解决的工程措施进行了相关研究。主要研究成果如下:1、对我国目前桥梁技术的发展进行系统归纳总结,将其归纳为以下四方面:①不断突破超大跨径;②新式桥梁形式和结构不断涌现;③设计理念和意图、施工技术能力和高性能材料、新式技术得到创新突破;④使桥梁结构实用性得以体现的同事兼具美学特征。2、系统分析了桥梁基础选型所需考虑的主要控制因素要确保桥梁基础稳定性,则不得不考虑工程场区的水文地质条件与工程地质条件、结构所受荷载及其耦合性质、构筑物用途及布置形式、原材的使用成本以及实施的可行性及投入产出比等因素的控制,结合使用安全可靠,技术简便可行和经济合理高效原则,对不同类型的方案进行详细对比分析,优化确定桥梁基础选型方案。3、论文对沪通大桥的地基进行工程地质方面分析研究,并作出评价与定性、定量持力层的选择针对长江下游地区新建南通至上海铁路沪通长江大桥(公铁合建)在工程场区内复杂的地质条件:工程场区内的场地特征(包括气象条件、地理位置、地形地貌等)、场区内地质条件(包括地层的岩性、新构造运动影响、地质条件构造、主要断裂情况及其活动性、地震和岩土体特征及其参数)、场区内地层的基本物理力学性能及其检测结果、水文地质的特性及特殊性质土层或岩层和地质灾害发生几率等方面在工程地质方面作出评定。通过勘察结果并结合工程地质评价以及考虑现有基础型式的特点、作用机理以及适用范围进行各类拟采用基础的持力层选择。4、深水基础选型优化分析通过收集整合国内外几百座已建和在建桥梁的深水基础形式和设计意图,进行综合对比分析,遴选跨江、跨海等深水桥梁基础有效、可行、经济的基础类型,建立给出天生港专用航道桥深水基础可采用的基础选型库。再从工程地质学、力学角度及经济学,利用层次分析法和模糊综合评判法,进行桥梁基础选型优化,给出某桥梁深水基础类型。本文结合长三角地区某新建的跨江通道工程实例,进行分析。从地质勘探、地层分析、该地区类似大跨桥梁相关资料并结合当地水文地质条件和气候条件、通航要求,确定持力层,根据设计意图和使用要求进行选择可采用基础形式,并通过层次分析和模糊综合评判法选择了最适宜的基础形式并作出了岩土工程评价。我国现阶段处在桥梁尤其铁路(公铁合建)桥梁的飞速发展时期,桥梁发展逐步从内陆小河、城市立交、沟谷深壑、黄河长江、近海的中小跨度到现在不得不征服外海、海峡等的深水大跨。地形地貌和地质条件的纷杂多样以及使用功能要求等因素的存在,促进了我国桥梁基础及结构和施工都向着全方位、多领域的方向发展。如平潭海峡、港珠澳海域、琼州海峡、浙江舟山大陆连岛工程、杭州湾、胶州湾、台湾海峡等都需要修建桥梁深水基础,最深可能达300m。跨越外海、海峡等的大跨、重载桥梁超深水下基础必将遇到:深水急流、风大浪高、地基软弱、勘测手段不足、地质条件复杂甚至未知等的恶劣环境。筑岛法和目前普遍采用的桩基础难以满足需求,将遇到超强水平荷载、深水施工平台、防浪消能设施陈旧的制约。这就是我国桥梁从业者今后所需面对的困难和挑战。这些纷杂多样的桥梁基础设计和施工的挑战和克服,必定使我国在桥梁行业迈大步,综合国力也得以体现,也为国外同行者提供了借鉴的经验。
[Abstract]:The rapid development of the country and city development, the construction of our country highway and high speed railway construction rapidly into the fast lane, shocked the world in the development scale and speed, become the industry leader and the forefront of the bridge. The bridge across the river, as an effective form of bad matter, even the Strait has been rapid the development of technology in China. The bridge has developed from the initial single form and backward technology, equipment development now has entered advanced ranks in the world. The lower reaches of the Yangtze River, China's river width, water depth, water rapids, the foundation of engineering geological condition is complex and changeable, the bridge construction in the complex natural and geographical conditions and site engineering geology under the condition of foundation construction has become more and more difficult. The foundation engineering is representative of the concealed works, assuming the existence of damage, not only found difficult, more difficult to restore the original state of the bridge foundation. As the load of the upper structure of the bridge is transferred to the special structure of rock and soil is the mainstay control of bridge structure safety. Based on safety and stability of bridge is mainly controlled by the engineering geological conditions of engineering geology. From this angle, the technical problems of large span bridge foundation type selection and in the construction of the engineering measures and solutions was studied. The main research results are as follows: 1, the current bridge technology development are systematically summarized, which can be summarized as the following four aspects: the breakthrough of super long span bridge; the new form and structure are constantly emerging; design concept and intention, construction technology ability and high performance materials, new technology innovation; the practicability of the bridge structure can reflect both colleagues aesthetic characteristics of.2, analyzes the main factors controlling system based selection of bridge needed to be considered for To ensure the stability of the bridge foundation, will have to consider the engineering field area hydrogeological conditions and engineering geological conditions, structural loads and coupling properties, structures and use of layout, the use cost of raw materials and the feasibility of implementation and the ratio of input and output factors such as control, combined with the use of safe and reliable, simple and feasible technology and economy reasonable and efficient principle, a detailed comparative analysis of different types of solution, optimized selection scheme based on the.3 bridge, Shanghai Tong Bridge foundation engineering geological analysis research, and make qualitative evaluation and quantitative, the selection of bearing stratum in the lower reaches of the Yangtze River area of new Nantong to Shanghai Railway (Shanghai Yangtze River bridge rail) in the engineering geological conditions in field area complex: the site characteristic field engineering (including meteorological conditions, geographical location, topography, etc.) in the area of geological field The conditions (including lithology, tectonic movement influence, geological conditions and main structure, fault activity, earthquake and rock and soil characteristics and parameters), field layer basic mechanical performance and the test results, the characteristics of hydrogeology and special properties of soil or rock and geological disaster risk assessment etc. in the aspect of engineering geology. Through the survey results and combined with the engineering geological evaluation and considering the characteristics of the existing foundation, mechanism and application of all kinds of the foundation bearing layer.4, deep water foundation selection optimization of deep foundation form and design intention analysis by collecting the integration of domestic and foreign hundreds of built and building bridges and carries on the comprehensive analysis, the selection of crossing the river, across the sea, deep water bridge foundation is effective, feasible, basic types of economy, building the tianshenggang special channel bridge Selection of foundation library deepwater foundation to be adopted. From the view of mechanics and engineering geology, economics, using AHP and fuzzy comprehensive evaluation method, selection optimization of bridge foundation, is a type of bridge deep water foundation. This paper combined with the Yangtze River Delta region a new cross river channel engineering example analysis. Analysis of formation from geological exploration and, this area is similar to bridge the related data and combined with the local hydrogeological conditions and climatic conditions, the navigation requirements, determine the bearing layer, can be used to form the basis of choice according to the requirements of the design intent and use, and through the AHP and fuzzy comprehensive evaluation method to select the most appropriate form of foundation and make the geotechnical engineering evaluation at the present stage of our country especially in the railway bridge (rail) the rapid development period of the bridge, the bridge has developed from the inland river, City Interchange, depth of gully, the Yellow River River, coastal medium and small span to now have to conquer the sea, Strait deepwater large span. Topographic and geological conditions of the complex and diverse functional requirements and other factors, promote our country bridge foundation and structure and construction are in full range, multi field direction. Such as the Pingtan Strait, Hong Kong Zhuhai Macao waters, Qiongzhou Strait, Zhejiang Zhoushan mainland link project, Hangzhou Bay, Jiaozhou Bay, the Taiwan Strait is to build bridge deep water foundation, the deepest may reach 300m. across the sea, Strait of long-span, heavy load bridge ultra deepwater foundation will meet: deepwater, high winds and waves, weak foundation survey lack of means, even unknown the bad environment with complex geological conditions. And the island method is now widely used in pile foundation is difficult to meet the demand, will encounter strong horizontal load, deep water construction platform, wave energy dissipation facilities this restriction. It is the difficulties and challenges that Chinese Bridge practitioners will face in the future. The challenges and overcome of these diverse bridge foundation design and construction will make our country take a big step in the bridge industry, and the comprehensive national strength is also reflected. It also provides reference for foreign travelers.

【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U443.1

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