【作者】 Assim　Mohammed　Lateef（阿西姆）；

【导师】 张永兴；

【作者基本信息】 重庆大学 ， 桥梁与隧道工程， 2011， 博士

【摘要】 目前,中国已经成为隧道工程发展最多、最复杂和最快的国家之一。随着城市的发展,城市隧道数量不断增加。但是,根据许多相关研究结果表明,由于受地质条件、地形条件、运输气候条件、设计、施工、管理和周边建筑等其他方面的影响,城市隧道在使用期间出现了开裂、漏水、填土侵蚀等缺陷,这些缺陷严重影响和威胁到隧道的正常使用。在复杂的环境下,对服务中的城市隧道的安全评价是我们研究的主要焦点。特别是,该系统在本研究中尚处于初步阶段,因此迫切需要在这方面进行深入的研究。本论文基于中国重庆的八一隧道和向阳隧道的缺陷,对支护结构的安全性进行全面的评估。在此研究中,所做的工作及其得到的结果如下:①针对缺陷的类型,缺陷原因及影响做了相应的分析。通过分析,隧道支护结构的主要缺陷是:衬砌厚度减小,强度或衬砌厚度减少,衬砌后面存在孔洞,衬砌裂缝和渗水存在。对各种缺陷的特点,我们总结和分析了缺陷的检测方法。②利用有限元数值模拟,对衬砌厚度的减少,背后衬腔,安全系数强度折减所造成的影响进行了分析。然后分析了孔洞的位置和大小以及裂缝对隧道的稳定性的影响。此外,分析了现有裂缝的应力变化和塑性区的发展情况。因此,我们得出以下结论:当拱和边壁衬砌有效厚度小于2 / 3时,衬砌对安全性有很大影响;当局部衬砌强度减小时,安全系数就会降低,特别是在拱和侧墙顶部。当孔洞出现在衬砌背面时,安全系数会相应受到影响,但是当孔洞较小(小于0.5米)时,影响不大。当裂缝出现在衬砌拱部时,隧道拱部的拉应力会增加,在顶点处也会监测到最大压应力。③利用有限元数值模拟,对不同大小的拱顶空洞、拱侧孔洞和拱底孔洞以及修缮后的不同厚度的隧道衬砌进行了分析。我们得出如下结论:如果孔洞越大,空洞周围的岩石应力也越大;若孔洞注浆,传到拱顶的应力也越大,而且填充重量也会增加。随着填充体和岩体的交界面变大,从岩石传到灌浆材料到衬砌的压力也会增加。孔洞大小的变化对衬砌轴力的影响并不明显。弯矩和剪力在拱侧和拱底有相同的特征,然而弯矩和剪力值却有相反的特征。如果空洞变大,应力集中比较严重,应力扩散区域也较大。当衬砌薄时,就会承载较多的应力,衬砌的应力也会增加,相反,当衬砌厚时,应力分布较均匀。当衬砌较厚时,衬砌的重量就会很大,衬砌的应力就会变大。水平或垂直位移增量随着衬砌的厚度非线性变化。④根据该工程实例的缺陷特征,用全站仪、应变计、钢筋应力计、多点位移计对带缺陷的隧道进行了为期一年半的监测。对隧道裂缝、位移和应变的发展进行了系统的分析。更多还原

【Abstract】 At present China has become one of the countries with the largest, most complex and fastest growing tunnel projects. With the continuous development of urban construction, urban tunnels are constantly increasing. However, according to a lot of information obtained from related researches, it has been noted that due to the impact of geological conditions, terrain conditions, weather conditions and survey, design, construction, operations and other aspects of the surrounding buildings, the defects of lining such as cracking, leakage of water, back cavity and corrosion occur on the urban tunnel in-service. These defects and hazards have a huge impact and threat to tunnel in-service.The safety evaluation of urban tunnels in-service on a complex environment is the main focus of our study. In particular, the system being studied in this research is still in the preliminary stage, hence the need for urgency to carry out in depth study on this area. This thesis is thus based on the defects of a BAYI and XIANGYANG tunnels in Chongqing, China, with the objective of comprehensively evaluating the safety of the supporting structure. In this research, the work and results are as follows:①From the type of defects, the analyses of the causes and effects of the defects have been made. According to the analysis, the main defects of tunnel support structures are: lining thickness diminished, caves existing behind the lining, lining cracks and water seepage. Based on the characteristics of the various defects, we summarized and analyzed the detection method of the defects.②Using the finite element numerical simulation, analysis of the impact of the lining thickness reduction, cavity behind lining, the strength reduction of the safety factor was done. Then analyze of the impact of the cavities’location and size, and cracks to the stability of the tunnel. Furthermore, analyzes of the stress changes of the existing cracks and the development situation of the plastic zone. Thus, we draw the following conclusions that: When the effective thickness of the arch and the side wall lining is less than 2/3, lining has a greater impact on safety; When the strength of local lining reduces, the safety factor is reduced, especially the arch and the top of the side wall. When cavities appear at the back of the lining, the safety factor is been impacted, but when the cavity is small(less than 0.5m), the influence is little. When cracks appear at the arch of lining, tensile stress at the tunnel arch increases and the maximum compressive stress are observed in the crown.③Using the finite element numerical simulation, analyzes of the impact of the different sizes of vault cavity, arch side cavity, arch foot cavity and different thicknesses of the tunnel lining after repair was done .We draw up conclusions as follows: If the cavity is bigger, the stress in the rock mass around the cavity is larger; and if the cavity is grouted, the stress delivered to the vault is also bigger, and the weight of the fill is increased. As the interface between the fill and rock mass gets larger, the transmission force from the rock mass to the grouting material, then to the lining increase. The influence of the axial force of the lining is not obvious, as the sizes of the cavities changes. The moment and shearing have the same sign in arch side or arch foot, whereas moment and shearing in vault has opposite signs. If the cavity is bigger, the stress concentration is more serious and the area where the stress diffuses is larger. When the lining is thin, it will endure more stress and the stress in the lining grows up, conversely, when the lining is thick, the stress can be dispersed in the lining and is more homogeneous. If the lining is thicker, the weight of lining is greater and the stress of the lining grows higher. The horizontal or the vertical displacement increment is changed nonlinearly with the thickness of the lining.④According to the defects characteristics of this engineering example, the defected tunnel has been monitored with seam meter, strain gauge, anchor gauge and multipoint displacement instruments for a year and a half. The development of tunnel crack, displacement and strain has been analyzed systematically.更多还原