超大跨度悬索桥隧道锚承载特性的岩石力学综合研究  

ROCK MECHANICS COMPREHENSIVE STUDY OF BEARING CAPACITY CHARACTERISTICS OF TUNNEL ANCHORAGE FOR SUPER-LARGE SPAN SUSPENSION BRIDGE

作　　者：邬爱清[1] 彭元诚[2] 黄正加[1] 朱杰兵[1] 

机构地区：[1]长江科学院水利部岩土力学与工程重点实验室,湖北武汉430010 [2]中交第二公路勘察设计研究院有限公司,湖北武汉430056

出　　处：《岩石力学与工程学报》2010年第3期433-441,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金重点项目(50639090);西部交通建设科技项目(200431800024)

摘　　要：针对四渡河特大桥宜昌岸隧道锚承载特性问题,采用基于岩石力学的综合研究方法,从围岩地质与力学特性、隧道锚1∶12实体模型试验及隧道锚承载特性数值分析等方面,对隧道锚与围岩岩体变形机制、时效特征及超载安全性等方面开展系统研究。结果表明,通过岩石力学试验及基于实体模型试验获得的隧道锚围岩弹塑性及流变参数符合实际;在设计水平下,隧道锚锭围岩变形在mm级水平;隧道锚极限抗拉拔力≥7.6倍设计载荷,满足锚固安全系数>4.0的设计要求;实桥隧道锚碇的长期安全系数≥2.6。通过工程实际施工过程中的监测实施,对研究成果和结论的合理性进行验证。研究技术路线及成果可供山区类似桥梁建设借鉴。According to bearing capacity problem of a tunnel anchorage at Yichang side for Siduhe super-span suspension bridge, to study systematically the deformation and failure mechanism, the rheological characteristics and overloading capacities of the tunnel anchorage and its surrounding rock mass by a comprehensive rock mechanics research method are proposed. The approach included in the research consists of in-situ geological investigation, rock mechanical tests in laboratory and in the field, the 1 ： 12 anchorage physical model test with the same rock mass at site of the actual schemed tunnel anchorage, and the numerical simulations related to physical model test and the engineering analysis of bearing capacity evaluations of the actual tunnel anchorage. Several conclusions have been drawn. Firstly, the mechanical properties and the relevant parameters of the surrounding rock mass are obtained comprehensively by rock mechanical tests; and the physical model tests are quite reasonable compared to the actual monitoring results. Secondly, the total deformation of the actual tunnel anchorage is in the grade ofmm with the designing load which will be supplied by the suspension bridge. Thirdly, the design requirement for the safety factor of the tunnel anchorage, which is greater than 4.0, is evaluated to be satisfied by the 1 ： 12 in-situ physical model test where the maximum anti-pulling force is carried out in the physical test, and ultimate tensile bearing capacity is permanent safety factor of bridge anchorage is not less greater than 7.6 times of the design load. At last, the than 2.6 according to the rheological observations in the physical test. The rock mass deformation and some relevant results have been verified through monitoring in process of the bridge construction. In addition, the technological line is an example for bridge construction in some other similar mountain areas.

关 键 词：隧道工程 四渡河大桥 隧道锚 承载特性 实体模型试验 岩体试验 数值模拟 隧道锚监测 

分 类 号：U45[建筑科学—桥梁与隧道工程]