基于反应加速度法的盾构隧道横向地震响应简化计算方法研究(任务书,开题报告,论文15000字)
摘要
随着地下空间的广泛运用，盾构隧道在现实生活中越来越扮演着无可替代的角色。然而地震作用下盾构隧道的破坏却相当严重，并且其破坏形式显著不同于地上结构。因此研究地震作用下的盾构隧道的反应规律及影响因素有重要意义。
本论文归纳了地震作用下常见的隧道破坏形式；总结了常用的地下结构抗震分析方法，并特别针对《城市轨道交通结构抗震设计规范》（GB50909-2014）中推荐使用的反应加速度法，详述了其基本原理，理清了其计算步骤；在此基础之上，计算了基于反应加速度法的实际工程中盾构隧道的内力与变形，并将其结果与动力时程分析法所得的结果进行了对比；同时，进一步通过设置单一变量，探究了包括盾构隧道所处的土质条件、隧道埋深、双孔并行盾构隧道净距等因素对其地震响应的影响。
研究结果表明：（1）一方面，反应加速度法只需施加加速度，计算较为简单；另一方面，反应加速度法无需计算土弹簧参数，且能考虑土与结构的相互作用，适用于不同规则地下结构的计算分析。因而，相比较于规范推荐的反应位移法而言，反应加速度法具有计算简单、操作方便、更接近于实际情况等优点；并且，反应加速度法与时程分析法采用相同的计算模型，计算结果相差不大；（2）土质条件对盾构隧道的内力与变形具有显著影响。在粉质粘土（可塑）、粉土（硬塑）、粉细砂、卵石这四类单一土层中，基于反应加速度法计算的单孔盾构隧道及双孔水平并行盾构隧道的内力与相对变形均逐渐增大；（3）盾构隧道埋深对结构的内力与变形也有一定影响。单一土层中埋深越大，基于反应计算速度法计算得到的内力与相对变形越大；（4）隧道间距对隧道结构地震响应影响较小。本论文对于在实际工程抗震设计计算分析中更进一步的认识、推广及应用反应加速度法具有重要意义。
关键词：盾构隧道；反应加速度法；地震响应；抗震分析方法
Abstract
The shield tunnel is playing a more and more irreplaceable role in our real life with the extensive use of the underground space. However, the damages of the shield tunnel under the earthquake is quite severe, the failure modes of which are distinguished from the structures above the ground.
The thesis summarizes the common failure modes of the tunnel under earthquake action; generalizes the seismic analysis methods of the underground structures, and specially describes the principles in detail and clarifies the calculation steps in the light of the response acceleration method recommended by the seismic design code for urban rail transit structure (GB50909-2014).Simultaneously,on the foundation of it, a practical shield tunnel calculation example based on the response acceleration method is included in this thesis, which results are compared with the internal forces and deformation obtained via the dynamic time history analysis method. Meanwhile, by setting a single variable, a probe on the factors, which may have an impact on the seismic response of the shield tunnel, such as the soil condition, buried depth, and the net distance of the two-hole shield tunnels, is carried out.
The results demonstrate as follows:
1) On the one hand, only the accelerations are required to apply through the response acceleration method, which makes the calculation easy; on the other hand, the soil spring parameters are not needed to calculate through this method and the interaction between the soil and the structures is taken into consideration, and this method can be applied to the irregular underground structures. Thus, compared with the response displacement methodrecommended by the code, the response acceleration methodhas the advantage of the easier calculation and more convenient operation, and approximates to the fact. In addition, the results of the response acceleration method are not quite different from those of the dynamic time history analysis method, the more accurate results.
2) The soil condition has a prominent impact on the internal forces and deformation of the shield tunnel, namely, internal forces and relative deformation based on the response acceleration method, obtained from calculating the single hole shield tunnel and the two-hole shield tunnels, are all gradually increased when the four kinds of the soils respectively are silty clay (plasticity), silt (hard plastic), fine sand and gravel.
3) The embedded depth also has certain influence on the internal forces and deformation of the shield tunnel. With the increase of the embedded depth, both the internal forces and relative deformation of the shield tunnels based on the response acceleration method are gradually increased.
4) The net distance has little effect on the internal forces and relative deformation of the two-hole shield tunnels.
The thesis is ofgreat significance to the further understanding, spreading and application of the response acceleration method in the seismic design and analysis of the actual engineering.
Key Words：Shield tunnel；the response acceleration method；seismic response；seismicanalysis method
目录
摘要 3
Abstract 4
第1章绪论 8
1.1研究目的和意义 8
1.2国内外研究现状 9
1.2.1国外研究现状 9
1.2.2国内研究现状 9
1.3研究内容 10
1.3.1 基本内容 10
1.3.2研究目标 11
1.3.3 拟采取的技术方案及措施 11
第2章地下结构抗震分析方法综述 12
2.1 地震作用下隧道的破坏形式及特点 12
2.2 常用的地下结构抗震分析方法 13
2.2.1 地震系数法 13
2.2.2 动力时程分析法 14
2.2.3 自由场变形法 14
2.2.4 土——结构相互作用系数法 15
2.2.5 有限元反应应力法 15
2.2.6 地下结构pushover法 16
2.2.7 强制反应位移法 16
2.2.8整体式反应位移法 17
2.2.9反应位移法 17
2.2.10反应加速度法 18
第3章基于反应加速度法的盾构隧道横向计算分析与讨论 20
3.1 反应加速度法计算步骤 20
3.2单孔隧道反应加速度法的横向计算分析 21
3.2.1计算模型 21
3.2.2计算荷载 23
3.2.3 计算结果 25
3.3动力时程分析法与反应加速度法结果比较 27
3.4单孔盾构隧道影响因素的讨论 30
3.4.1不同土质条件的影响 30
3.4.2盾构隧道埋置深度的影响 35
3.5水平并行双孔盾构隧道影响因素的讨论 40
3.5.1不同净距的影响 40
3.5.2不同土质条件的影响 41
第4章结论与展望 43
4.1 结论 43
4.2 展望 43
参考文献 45
致谢 47 |
