特大悬索桥现场隧道锚塞体的自平衡法承载特性研究  

Study on Bearing Characteristics of Site Tunnel Anchor Plug Body of Grand Suspension Bridge by Self-balance Method

作　　者：戴自然[1] 廖万辉 周旭 吴福飞[1] 杨冬升[1] DAI Zi-ran;LIAO Wan-hui;ZHOU Xu;WU Fu-fei;YANG Dong-sheng(School of Materials and Architectural Engineering,Guizhou Normal University,Guiyang Guizhou 550025,China;Guizhou Highway Engineering Group Co.,Ltd.,Guiyang Guizhou 550001,China)

机构地区：[1]贵州师范大学材料与建筑工程学院,贵州贵阳550025 [2]贵州省公路工程集团有限公司,贵州贵阳550001

出　　处：《公路交通科技》2021年第8期93-100,共8页Journal of Highway and Transportation Research and Development

基　　金：贵州省交通运输厅科技计划项目(2020-123-015);贵州省科学技术基金项目(黔科合J字LKS[2013]41号,黔科合LH字[2014]7046号)。

摘　　要：为了检验超大吨位、边坡等复杂环境的特大悬索桥隧道锚塞体,自平衡测试方法被用于1∶10的现场2个模型隧道锚塞体试验。采用后推法测试技术对开州湖大桥进行试验测试,在模型锚塞体尾端位置安设千斤顶及位移杆(每个模型锚塞体下位移杆2个、上位移杆4个),沿着垂直作用方向加载,测试出模型锚塞体承载力和荷载-位移关系曲线表达式。结果表明:在加载过程中,模型锚塞体及周围岩体无破坏迹象,两个模型锚塞体洞口位置出现轻微裂缝开展,荷载位移曲线为缓变形。随加载时间的延长,锚塞体的位移呈增大的趋势,位移发生在15~45 min,且每级荷载值加载下,其位移最大不超过5 mm。右洞在各级荷载加载下其位移均高于左洞,部分高于5 mm。建议混凝土与岩体间的摩擦系数为0. 77和粘聚力为369 k Pa。两个模型锚塞体的安全系数分别为5. 3 (左洞)和5. 2 (右洞),满足最新《公路悬索桥设计规范》锚塞体抗拔安全系数和围岩稳定安全系数分别不应小于2. 0和4. 0的要求,为类似桥梁工程的长期安全性评价提供参考。In order to test the anchor plugs of tunnel connecting grand suspension bridge in complex environments such as super large tonnage and slopes,the self-balancing test method is used in the 1:10 field test of 2 tunnel anchor plug models.The Kaizhou Lake Bridge is tested by using the back-push method.Jacks and displacement rods(2 lower displacement rods and 4 upper displacement rods for each anchor plug model are installed at the end of the anchor plug model).The load is applied along the vertical direction,and the expressions of the bearing capacity and load-displacement relationship of the anchor plug model are obtained.The result shows that(1)there is no sign of failure of the anchor plug model and surrounding rock mass during the loading process,slight cracks developed at the openings of 2 anchor plug models,and the load-displacement curve shows slowly change;(2)with the extension of loading time,the displacement of the anchor plug body shows an increasing trend,the displacement occurs in 15-45 min,and the maximum displacement does not exceed 5 mm under each load;(3)the displacements of the right tunnel under different loads are higher than those of the left tunnel,partly higher than 5 mm.It is suggested that the friction coefficient between concrete and rock is 0.77 and the cohesion is 369 kPa.The safety factors of the 2 anchor plug models are 5.3(left tunnel)and 5.2(right tunnel)respectively.It meets the requirements that the anchor plug's pull-out safety factor and surrounding rock's stability safety factor should not be less than 2.0 and 4.0 respectively in the latest Specifications for Design of Highway Suspension Bridge,which provide a reference for the long-term safety evaluation of similar bridge projects.

关 键 词：桥梁工程 特大悬索桥 隧道锚塞体 现场模型 自平衡 承载 

分 类 号：U446.1[建筑科学—桥梁与隧道工程]