【作者】 刘晓纲；

【导师】 姚刚；

【作者基本信息】 重庆大学 ， 结构工程， 2005， 硕士

【摘要】 地下空间的开发和综合利用是本世纪城市建设的主题,随着城市旧城改造、和现代市政设施建设事业的迅猛发展,以及高层建筑的兴起,建筑基坑工程、地铁隧道工程等地下工程的设计和施工新理论新技术的研究成为当今工程界的热点和难点。由于土钉支护具有施工快速简便、经济可靠等许多优点,因此在地下工程中有着较多的应用,尤其是基坑支护工程中土钉支护技术的应用已占到了基坑工程总数的60-70%。但土钉应用的局限性限制了该项技术的推广,因此,自20世纪90年代开始,我国逐渐将复合土钉支护技术应用于基坑支护工程中,并取得了较好的经济效果。然而,在对复合土钉支护技术的理论研究上却相对落后,设计分析方法不完善,试验研究甚少,也因此发生了较多的基坑工程事故,造成了较大的经济损失和社会不良影响。因此,研究其工作机理、设计方法、以及施工技术,将使得该项技术更加完善,也有利于该项技术应用空间的扩展。本文以深圳假日广场深基坑支护工程(号称“深圳第一坑”,最深开挖21m)为背景,采用了理论指导、试验研究、模拟分析、工程应用和信息反馈相结合的方法,对预应力锚索复合土钉支护结构进行了全面深入的研究,对桩锚式复合土钉支护结构的变形进行了初步研究。一、从普通土钉到复合土钉的演变历程入手,介绍了土钉与复合土钉的研究与发展状况,指出了复合土钉支护技术在理论研究上存在的一些突出问题。二、简要介绍了在组合形式上灵活多变的各式各样的复合土钉支护结构及其施工技术要点。三、对预应力锚索复合土钉支护结构进行了大量全方位的现场原位测试试验。根据试验测试结果来研究分析预应力锚索复合土钉支护结构和桩锚式复合土钉支护结构的变形特征及规律。着重对预应力锚索复合土钉支护结构的作用机理进行了深入的研究;探索了土钉、锚索内力,面层土压力,孔隙水压力的变化规律;重点研究支护结构内力随基坑开挖,地下水、降雨、坡顶加荷卸荷、预应力锚索张拉、爆破震动等因素变化的分布和变化规律;阐明了钉-锚-土三者有机结合的相互作用关系;指出了支护结构以及二次高压劈裂注浆所引起的注浆效应对边坡土体物性参数的影响;分析了预应力锚索复合土钉支护结构和桩锚式复合土钉支护结构的破坏形式及其稳定性。四、结合FLAC 3D有限差分软件,建立了空间三维有限差分分析模型,对预应力锚索复合土钉支护结构施工进行了三维动态数值模拟。在模拟的过程中,引更多还原

【Abstract】 Exploitation and integrative application for underground space are the theme of city construction in this century. The study for design and new construction of underground engineering including foundation pit, metro, tunnel etc. has become pop and difficult problem with the rapid development of old city rebuilding and municipal works, as well as the increase of high-rise building.Soil nail supporting is broadly used in underground engineering, especially used in foundation pit because of its numerous advantages such as fast construction, economic security and so on. However, the generalization of soil nail is limited by itself applied conditions. Since 1990’s, composite soil nail supporting has been gradually used in retaining and protecting for foundation excavation in our country. Practice has showed its economic advantage. But compared with application of composite soil nail, theoretic study for composite soil nail is very laggard, so as to many engineering accidents, which brought biggish economic losses and harmful effect to society, happened because of incomplete design method, absent test study etc. Therefore, study for work mechanism, design method and construction technology of composite soil nail is useful of technically perfection, and also useful of broadly application of this technology.In this paper, author compare with Shenzhen Holiday Plaza Project (be known as firstly deepest foundation pit, deepest excavation depth is 21m), use combinative method for theory guidance, test study, simulation analysis, project application and information feedback, entirely and deeply study prestress anchor cable composite soil nail, and also make a pilot study for deformation of pile anchor composite soil nail.1. Author proceeds with the evolvement course from soil nail to composite soil nail, introduces actual study and development to soil nail and composite soil nail, points out some existent problems about composite soil nail in theoretic study.2. Brief introduces all kinds of composite soil nail supporting structure and their construction technique.3. Lots of entirely situ-test study for prestress anchor cable composite soil nail have been made. According to test results, author analyses deformation characters and its rules of prestress anchor cable composite soil nail supporting and pile anchor composite soil nail supporting, studies work mechanism of prestress anchor cable composite soil nail supporting structure, explores change regularity of inner force of soil更多还原