| 深中通道沉管临时锚拉系统承载性能足尺模型试验 |
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| 引用本文： | 闫磊,韩恒,贺拴海,徐国平,高亚斌.深中通道沉管临时锚拉系统承载性能足尺模型试验[J].中国公路学报,2022,35(10):47-54. |
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| 作者姓名： | 闫磊 韩恒 贺拴海 徐国平 高亚斌 |
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| 作者单位： | 1. 长安大学 旧桥检测与加固技术交通行业重点实验室, 陕西 西安 710064;2. 中交公路规划设计院有限公司, 北京 100088 |
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| 基金项目： | 国家重点研发计划项目(2021YFB1600300)；陕西省自然科学基础研究计划项目(2021JM-171)； 陕西省交通运输厅科研项目(21-63K) |
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| 摘 要： | 为了评估深中通道沉管水下对接时临时锚拉系统的承载安全性，利用模型试验的方法对锚拉系统的传力机理及安全冗余进行了研究。首先，利用数值方法对锚拉系统进行了仿真模拟，得到了目标荷载作用下各构件的响应并明确了加载分级标准；其次，制作了临时锚拉系统的1∶1足尺模型，利用自平衡加载的方式进行了变形及应力测试。为模拟施工现场偏差，对其设置横向及竖向各5 cm预偏量，采用千斤顶加载至结构屈服。试验结果表明：随着分级荷载的递增，锚板、肋板、拉杆应力及台座位移在结构屈服前均呈线性增长规律。当单根拉杆荷载递增至试验荷载1 000 kN时，试验台座相对位移量为5.6 mm，锚板及肋板的最大Mises应力分别达到183.1 MPa及187.5 MPa，距设计强度295 MPa和280 MPa有37.9%及33.0%的设计安全冗余；在1.4倍试验荷载下，试验台座相对位移量为7.7 mm，肋板最大Mises应力为285.3 MPa，已达到其设计强度，此时锚板最大Mises应力为258.5 MPa，设计安全冗余降为12.4%；在1.85倍试验荷载下，试验台座的相对位移量达到10.8 mm，肋板率先屈服，结构已经失效，此时锚板最大Mises应力为355.0 MPa，屈服安全冗余仅为9.0%，对应的拉杆应力为606.1 MPa，屈服安全冗余为27.4%。由此得出，该锚拉系统设计安全冗余较充足，建议将7.7 mm作为现场施工位移控制的参考值。研究成果可为同类沉管临时锚拉系统的设计及施工提供重要参考。
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| 关 键 词： | 隧道工程 沉管 足尺模型试验 承载性能 安全评估 锚拉系统 |
| 收稿时间： | 2022-08-15 |
Full-scale Model Test of Bearing Capacity of Temporary Anchorage System for Immersed Tube in Shenzhen-Zhongshan Link |
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| YAN Lei,HAN Heng,HE Shuan-hai,XU Guo-ping,GAO Ya-bin.Full-scale Model Test of Bearing Capacity of Temporary Anchorage System for Immersed Tube in Shenzhen-Zhongshan Link[J].China Journal of Highway and Transport,2022,35(10):47-54. |
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| Authors: | YAN Lei HAN Heng HE Shuan-hai XU Guo-ping GAO Ya-bin |
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| Affiliation: | 1. Key Laboratory for Old Bridge Detection and Reinforcement Technology of Ministry of Transportation, Chang'an University, Xi'an 710064, Shaanxi, China;2. CCCC Highway Consultants Co. Ltd., Beijing 100088, China |
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| Abstract: | In order to evaluate the bearing safety of the temporary anchorage system during the underwater interfacing of immersed tubes in Shenzhen-Zhongshan Link, the force transfer mechanism and safety redundancy of the anchorage system were studied by using the model test method. Firstly, the anchorage system was simulated by numerical method, and the response of each component under the target load was obtained and the loading classification standard was defined; Secondly, a 1∶1 full-scale model of the temporary anchorage system was made, and the deformation and stress were tested by self-balancing loading. In order to simulate the deviation of the construction site, the horizontal and vertical pre-deflection of 5 cm were set, and the jack was used to load the structure to yield. The results show that the stress of the anchor plate, rib plate, tension rod and the displacement of the pedestal increase linearly before the yield of the structure with the increase of the graded loading. As the load of a single tension rod increases to the test load of 1 000 kN, the relative displacement of the test pedestal is 5.6 mm, the maximum Mises stress of the anchor plate and the rib plate reaches 183.1 MPa and 187.5 MPa respectively, and there are 37.9% and 33.0% design safety redundancy from the design strength of 295 MPa and 280 MPa; Under 1.4 times of the test load, the relative displacement of the test pedestal is 7.7 mm, the maximum Mises stress of the rib plate is 285.3 MPa, which has reached its design strength. At this time, the maximum Mises stress of the anchor plate is 258.5 MPa, and the design safety redundancy is reduced to 12.4%. Under 1.85 times the test load, the relative displacement of the test pedestal reaches 10.8 mm, and the rib plate yields first. The structure has failed. At this time, the maximum Mises stress of the anchor plate is 355.0 MPa, and the yield safety redundancy is only 9.0%. The corresponding tension rod stress is 606.1 MPa, and the yield safety redundancy is 27.4%. It is concluded that the safety redundancy of the anchorage system is sufficient, and it is recommended to use 7.7 mm as the reference value for site construction displacement control. The research results of this paper can provide an important reference for the design and construction of similar temporary anchorage system for immersed tubes. |
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| Keywords: | tunnel engineering immersed tube full-scale model test bearing capacity safety assessment anchorage system |
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