破碎围岩错缝拼装盾构隧道结构承载性能与变形控制指标

发布时间：2018-10-09 13:13

【摘要】：为确定破碎围岩错缝拼装盾构隧道结构变形控制指标,考虑顶部堆载、侧向卸载2种常见荷载工况,开展了错缝拼装盾构隧道承载性能演化规律研究。首先,基于接头刚度等效原则提出了不设传力衬垫的管片接头简化模拟方法,通过与相关文献实测数据对比螺栓轴力计算结果,验证了该方法具有一定合理性和适用性;其次,基于接头简化模拟和荷载结构法进行了隧道结构承载性能数值模拟,分析了管片承载状态随断面变形的发展规律;最后,根据管片承载状态临界点,提出盾构隧道结构安全等级划分方法和断面变形控制指标。研究结果表明:2种工况下管片承载构件屈服顺序存在差异,顶部堆载工况下屈服顺序为拱顶、拱底内侧钢筋,拱腰内侧混凝土,而侧向卸载工况下为拱顶、拱底纵缝螺栓,拱腰外侧钢筋,拱顶、拱底内侧钢筋,拱腰螺栓;考虑隧道耐久性、承载安全性以及结构加固时机,堆载工况下断面变形椭圆度控制值分别为0.712%、1.694%、2.156%,卸载工况下分别为0.876%、1.873%、2.757%。
[Abstract]:In order to determine the deformation control index of shield tunnel structure with broken wall rock, considering two common load conditions, top heaped load and lateral unloading, the evolution of load-bearing performance of staggered jointed shield tunnel is studied. Firstly, based on the principle of equivalent stiffness of joint, a simplified simulation method of segment joint without force transfer liner is proposed. The calculation results of bolt axial force are compared with the measured data of relevant literature, and the method is proved to be reasonable and applicable. Based on the simplified joint simulation and the load structure method, the numerical simulation of the bearing capacity of the tunnel structure is carried out, and the development law of the segment bearing state with the section deformation is analyzed, finally, according to the critical point of the segment bearing state, The method of safety grade classification and deformation control index of shield tunnel structure are put forward. The results show that there are differences in yield order of segment bearing members under two different working conditions. The yield order under top loading condition is arch top, arch bottom inner reinforcement, arch waist inner concrete, and lateral unloading condition is arch top, arch bottom longitudinal joint bolt. Considering the durability of tunnel, bearing safety and the opportunity of strengthening the structure, the control value of the ellipticity of the section deformation under the load loading condition is 0.712 / 1.694 and 2.156 respectively, and under the unloading condition it is 0.876 / 1.873 / 2.757, respectively, for the outside arch, the arch top, the inside of the arch bottom, and the bolt for the arch waist, considering the durability of the tunnel, the safety of bearing capacity and the opportunity of strengthening the structure.
【作者单位】：同济大学土木工程学院;同济大学土木信息技术教育部工程研究中心;厦门轨道交通集团有限公司;上海同岩土木工程科技股份有限公司;
【基金】：国家重点基础研究发展计划(“九七三”计划)项目(2015CB057806) 厦门市科技计划重大项目(3502Z20151006) 国家电网公司科技项目(SHJJGC160053)
【分类号】：U455.43

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