【作者】 黄福波；

【导师】 强士中； 白继承；

【作者基本信息】 西南交通大学 ， 建筑与土木工程， 2003， 硕士

【摘要】 龙塘山3~#大桥位于新建内昆铁路DK286+042处，原设计为高路堤，路堤置于一巨型岩堆体上，岩堆体分布范围为DK285+490～DK286+760，全长1270m。由于在路堤填筑过程中发生了大范围的工程滑坡，经充分论证后设计变更为以桥通过，采用了抗滑墩设计方案。抗滑墩集抗滑桩与桥墩功能于一体，在地质差，地下水丰富且含有较多坚硬大孤石的滑坡体中开挖面积之大、掘进之深、工期之紧、施工难度之大的竖井，实为国内铁路工程建设史上之首例。在施工中我们针对不同深度的不同地质条件，及时改变开挖、支护方法，成功地穿越深浅两层滑动面，确保了本工程的工期、安全、质量。该方案是铁路工程建设中的大胆创新，工程的顺利完成，其设计和施工技术的成功经验，必将为今后铁路工程和公路工程在不良地质条件下的设计与施工提供了宝贵的范例与经验，具有重要的经济和社会效益。本文研究了新建内昆铁路龙塘山3~#大桥抗滑墩的设计变更、施工关键技术、大体积混凝土配合比试验及施工监测，作了如下方面的工作： (1) 在总结国内大型滑坡抗滑桩施工方法和经验的基础上，详细分析和叙述了内昆铁路龙塘山3~#大桥抗滑墩拟采用的施工方法及施工工艺情况。 (2) 抗滑墩施工过程中，开挖工艺、支护体系较为复杂，是抗滑墩施工的控制因素。本文在借鉴国内抗滑桩竖井开挖及支护方法的基础上，采用了微震动爆破开挖技术和信息化的支护手段，对微振动爆破进行了研究和监测，对支撑采用表面应变计和频率仪进行轴力监测，以指导施工。 (3) 针对大体积混凝土会产生大量水化热的特点，提出了低水化热混凝土的配合比应如何进行选择及其试配过程，指出了降低水化热的“双掺”技术措施及其他降温措施。 (4) 为了更深刻地了解DK286这一滑坡地段在施工过程中山体是否产生滑移、滑移速度以指导施工，及工程竣工后山体在雨季、列车动载情况下滑坡体抗滑墩的侧向受力情况，我们在2~#抗滑墩的主筋、墩身混凝土中均埋设了应力、应变计，实施了监测实验并对监测数据进行了分析。更多还原

【Abstract】 The Longtang Shan No.3 Bridge is situated at DK286+042 district of the newly built Neikun Railway. It was originally designed with 1270m length , which was located on a huge rock pile with a range of distribution of DK285+490-DK286+760. As a large-scale earth slide occurred during the embankment filling, the design was changed into transiting with a bridge after abundant demonstrations. The design adopted the scheme of skid resistance piers, which combined the functions of skid resistance piles and piers. Under the condition of tough geology, enriched groundwater and large lonestones in sliding mass, the largeness of the excavating area, the deepness of the excavation, the tightness of the term of works and the difficulties of the construction doubtlessly make the skid resistance piers the first pattern in the history of internal railway constructions. According to different geological conditions, we duly changed the methods of excavating and supporting, thus we successfully got through the deep and low sliding surfaces, and ensured the term of works, security and the quality of the project. The scheme is an audacious effort in the range of railroad engineering. As the project is successfully completed, the experiences of the designing and the construction techniques will provide precious paradigms for the prospective road and railroad constructions under poor geologies. The design and the execution are in possession of important theoretical and social significance. By the way of studying the changes of design, the key techniques, the testing of mixing ratio of large-sized concrete and the construction monitoring of the Longtang Shan No.3 Bridge, the thesis expounds following aspects:(1) Based on summarizing the construction methods and experiences of internal large scale skid resistance piles, the paper detailed states and analyzes the proposed execution methods and the execution techniques of the Longtang Shan No.3 Bridge of Neikun Railway.(2) The excavating technology and the supporting system are the governing factors since they are complicated during the construction of the skid resistance]piers. Based on drawing on the well shaft excavations and supporting systems of the internal skid resistance piles, the project adopted micro seismic activity blasting excavation technique and informatization supporting method, made investigation and monitoring to the micro seismic activity blasting, and inspected the supporting system with surface strain indicator and cymometer, in order to supervise the construction.(3) Considering that large size concrete will produce a mass of hydration heat, the thesis introduces how to select the mixture ratio of the concrete to reduce the hydration heat and its test-mixing procedures, points out the ’double intermixing’ technique of reducing hydration heat as well as other temperature dropping methods.(4) In order to comprehend profoundly about whether the massif slides and the speed of the sliding during the construction at DK286 district, as well as the lateral stressing complexion of the massif under the situations of rainy season and trains’ mobile loading after the project’s completion, we laid stress meter and straining meter in the main reinforcements and pier shaft concrete of the No.2 skid resistance pier, made monitoring test and analyzed the monitoring data.更多还原